坪井 直毅

BACKGROUND: Differences in chest HRCT findings between myeloperoxidase (MPO)- antineutrophil cytoplasmic antibody (ANCA) and proteinase 3 (PR3)-ANCA in Japanese patients with ANCA-associated vasculitis (AAV) remain unclear. METHODS: We reviewed chest HRCT findings at diagnosis in 195 patients with AAV enrolled in the Remission Induction Therapy in Japanese Patients with ANCA-associated Vasculitis and Rapidly Progressive Glomerulonephritis (RemIT-JAV-RPGN) observational cohort study (2011-2013). Findings were classified by ANCA subtype and compared. RESULTS: Abnormal chest HRCT findings were observed in 172 of 195 patients. Main findings included ground-glass opacity (n = 92, 47%), reticulation (n = 79, 41%), traction bronchiectasis (n = 67, 34%), and honeycombing (n = 4 9, 25%). Honeycombing (n = 46, 29%) and reticulation (n = 70, 43%) predominated in patients with positive MPO-ANCA, whereas nodules (n = 4, 44%) and cavities (n = 3, 33%) were more frequent in those with positive PR3-ANCA. Interstitial pneumonia (IP) was diagnosed in 89 patients, with HRCT patterns of definite usual interstitial pneumonia (UIP) in 31 (35%), possible UIP in 22 (25%), and inconsistent with UIP in 36 (40%). IP was more frequent in patients with positive MPO-ANCA than in those with positive PR3-ANCA (47% vs 11%, respectively; p = 0.003). Definite UIP was more common in MPO-ANCA positivity than in other subtypes (41% vs 0%, respectively; p = 0.023). CONCLUSIONS: In Japanese patients with AAV, IP with a definite UIP pattern was more frequent in patients with MPO-ANCA positivity while nodules and cavities were more frequent in patients with positive PR3-ANCA.

BACKGROUND: Cisplatin-induced nephrotoxicity (CIN) is a major dose-limiting adverse event that can lead to both acute and chronic kidney injury. The formation of thiol-cisplatin conjugates within renal tubular cells has been implicated as a key mechanism underlying CIN. Flopropione is an inhibitor of cysteine conjugate β-lyase 1, an enzyme that catalyzes the formation of the thiol-cisplatin conjugate, which might prevent CIN. OBJECTIVE: We designed a clinical trial to evaluate the safety of flopropione in patients receiving cisplatin-based chemotherapy and explore its efficacy in preventing CIN. METHODS: This is a phase 1 and 2a, single-center, randomized, open-label trial conducted in patients undergoing cisplatin therapy. Participants are randomized in a 5:2 ratio per cohort to receive either flopropione or no treatment. On the day of cisplatin administration, the flopropione group receives oral flopropione twice daily (80 mg in cohort 1, 160 mg in cohort 2, and 240 mg in cohort 3). On the following day, all cohorts receive 3 doses of 80 mg of oral flopropione. A step-up dose escalation design is adopted, progressing from cohort 1 to 3 after confirming safety at each level. The primary end point is the safety of flopropione use in combination with cisplatin; the secondary end points include changes in the levels of urinary biomarkers of nephrotoxicity such as neutrophil gelatinase-associated lipocalin, liver-type fatty acid-binding protein, and kidney injury molecule-1. Blood and urine samples are collected within 48 hours before cisplatin administration and at 24 hours, 48 hours, and 1 week after its initiation for safety and efficacy assessments. RESULTS: The first participant was registered in July 2024. As of January 2026, participant registration is ongoing. The final participant will complete the study by March 2026. Publication of results is expected by March 2027. CONCLUSIONS: This study is expected to contribute to advances in preventive strategies for CIN by providing evidence that inhibition of cysteine conjugate β-lyase 1 by flopropione may attenuate CIN. TRIAL REGISTRATION: Japan Registry of Clinical Trials jRCTs041220021; https://jrct.mhlw.go.jp/en-latest-detail/jRCTs041220021. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/87907.

UNLABELLED: Neutrophils are key effector cells in the pathogenesis of acute kidney injury (AKI), where neutrophil extracellular traps (NETs) play a critical role. Mac-1 (CD11b/CD18), a leukocyte surface integrin, is known to mediate inflammation. We hypothesized that Mac-1 regulates NETs formation and exacerbates ischemic AKI. The expression of Mac-1 and NETs was analyzed in peripheral blood and renal tissues from patients with kidney diseases. Mac-1 knockout (Mac-1⁻/⁻) mice were used to establish a bilateral renal ischemia-reperfusion injury (IRI) model and compared with wild-type (WT) controls. Primary neutrophils were isolated from bone marrow in vitro to investigate the mechanisms underlying NETs formation. CD11b and NETs were both implicated in patients with either AKI following cardiac surgery or interstitial nephritis. In a murine bilateral renal IRI model, NETs formation was detected in WT kidneys at 24 h, and DNase I treatment significantly alleviated renal injury. Compared to WT mice, Mac-1⁻/⁻ mice exhibited reduced dysfunction, inflammation, and NETs infiltration. In vitro, Mac-1⁻/⁻ neutrophils showed decreased PMA-induced NETs formation and reduced ERK phosphorylation. Furthermore, treatment with anti-Mac-1 antibody (M1/70) in the murine IRI model significantly attenuated kidney inflammation and injury. Mac-1 exacerbates kidney inflammation and dysfunction in ischemic AKI by mediating NETs formation through an ERK phosphorylation-dependent mechanism. Blockade of Mac-1 using the antibody M1/70 effectively ameliorates this injury, highlighting its potential as a therapeutic target. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10753-025-02327-z.

IgA nephropathy (IgAN) is characterized by glomerular deposits of IgA-containing immune complexes (IgA-ICs), which are suspected to originate from circulation. However, the composition of these ICs is not fully understood. To address this gap in knowledge, we performed label-free quantitative mass-spectrometry analyses of glomerular and circulatory IgA-ICs with a focus on complement proteins. Glomeruli of patients with IgAN compared to healthy glomeruli had greater amounts of several complement-system proteins associated with classical, alternative, and terminal pathways, including complement factor H-related (CFHR) proteins 1, 2, 3, and 5, C1q chains B and C, and properdin. Circulatory IgA-ICs of patients with IgAN vs. healthy controls had a greater abundance of complement proteins CFHR1, C1q chains A, B, and C, and properdin. Furthermore, levels of several complement proteins in circulatory IgA-ICs of IgAN patients were reduced after immunosuppressive therapy (i.e., tonsillectomy combined with pulse steroid therapy) but not in patients on comprehensive supportive therapy. CFHR1 exhibited the greatest decrease (Fold change = 48.16, P < 0.0001). These data together revealed the complexity of complement proteome in glomerular and circulatory IgA-ICs and suggested an association of complement regulatory proteins, such as CFHR1, with pathogenic IgA-ICs.

Artificial intelligence for rare pathological lesion detection faces dual challenges: expert annotation scarcity and domain shifts across institutions. Using multi-institutional kidney biopsies from 22 hospitals with 3 scanner types (NDPI, VSI, SVS), we demonstrate that model performance decreases dramatically across domains, with up to 70.3% reduction in detection precision for rare lesions such as crescents and segmental sclerosis (comprising only 2-3% of annotations). We present an approach integrating semi-supervised learning with residual CycleGAN-based domain adaptation, reducing mean Fréchet inception distance between institutions from 55.9 to 20.2 while preserving diagnostic morphology. We identified context-dependent optimal strategies: semi-supervised learning with 50% confidence threshold excelled in same-hospital scenarios (15.2-17.7% improvement for rare lesions), while our combined GAN-Semi-Supervised approach demonstrated superior performance in cross-scanner scenarios between NDPI and VSI formats (up to 63.4% improvement for crescents). This methodology enables robust performance across diverse healthcare settings with minimal expert annotation.

Tryptophan (TRP) metabolism through the kynurenine pathway generates multiple biologically active metabolites with diverse immunomodulatory effects, but their roles in glomerulonephritis (GN), particularly in innate immunity, remain poorly understood. Using a nephrotoxic serum-induced GN (NTS-GN) model, we first analyzed mice deficient in key TRP-metabolizing enzymes of the kynurenine pathway: Indoleamine 2,3-dioxygenase 1 and 2 (IDO1 and IDO2), and kynurenine 3-monooxygenase (KMO), and found that Ido1-deficient mice exhibited exacerbated kidney injury and glomerular neutrophil infiltration, whereas Ido2 deficiency had no significant impact. In contrast, Kmo-deficient mice showed reduced crescent formation. Unexpectedly, the concentration of kynurenic acid (KYNA), a downstream metabolite of IDO1, was elevated in the kidney cortex of Ido1-deficient mice. Exogenous KYNA administration improved survival, ameliorated renal injury, and reduced neutrophil infiltration in Ido1-deficient mice, indicating its protective effect against antibody-mediated injury. Moreover, KYNA suppressed immune complex-mediated neutrophil spreading, attenuated FcγR-dependent Syk phosphorylation, and reduced VEGF secretion in vitro. Our results position KYNA as a key modulator of neutrophil-driven inflammation in antibody-mediated GN. This study uncovers distinct roles for kynurenine pathway enzymes and highlights the TRP-KYNA pathway as a promising immunometabolic target for controlling innate immune responses in GN.

An 81-year-old man was treated with prednisolone, avacopan, and rituximab for microscopic polyangiitis and sulfamethoxazole/trimethoprim (SMX/TMP) and vonoprazan for prophylaxis. The liver enzyme levels were elevated 42 days after avacopan administration. Avacopan, SMX/TMP, and vonoprazan treatment were discontinued. A liver biopsy revealed vanishing bile duct syndrome. The patient was subsequently treated with ursodeoxycholic acid and glucocorticoid. Although vasculitis remained in remission, the patient ultimately died. Autopsy revealed persistent bile ductopenia and progressive liver cell injury confirmed by cytokeratin 7 positivity, severe cholestasis, and portal fibrosis. Further studies are required to elucidate associated mechanisms and risk factors.

BACKGROUND: Despite the widespread use of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in the management of chronic kidney disease, their role in autosomal dominant polycystic kidney disease (ADPKD) remains unclear. METHODS: This observational study evaluated the efficacy of the SGLT2i dapagliflozin in patients with ADPKD receiving tolvaptan. The primary outcome was the chronic estimated glomerular filtration rate (eGFR) slope, modeled using a multivariable linear mixed-effect model; a within-group analysis was also performed using an interrupted time series approach. RESULTS: A total of 48 patients receiving tolvaptan were analyzed (24 patients in the control group vs 24 patients in the dapagliflozin group). The mean follow-up duration was 649 ± 363 days across all patients. The chronic eGFR slope was -2.30 [95% confidence interval (CI) -3.47, -1.13] in the control group and -1.72 (95% CI -3.48, -0.03) mL/min/1.73 m2 per year in the dapagliflozin group (P = .595). In within-group analysis using an interrupted time series approach, the chronic eGFR slope changed from -2.34 (95% CI -3.39, -1.30) to -1.14 (95% CI -2.68, 0.40) mL/min/1.73 m2 per year following dapagliflozin initiation (P = .191). No serious adverse events were observed during the follow-up period. CONCLUSIONS: Although no statistically significant differences were observed, both between- and within-group analyses showed a numerically slower decline in eGFR with dapagliflozin. Importantly, no evidence of harm was observed. These findings may contribute to ongoing discussions regarding the potential role of SGLT2i in ADPKD.

OBJECTIVES: Sivelestat sodium hydrate (SSH) may be effective in the early stage of acute respiratory distress syndrome (ARDS) before the neutrophil extracellular trap scaffold structure is complete. Therefore, patients with suppression of fibrinolysis (SF) before the secondary fibrinolytic process might benefit from SSH administration. The primary aim of this study was to determine the effect of the SF state and combination therapy on the effect of SSH administration. METHODS: We retrospectively reviewed the data of patients diagnosed with ARDS at Fujita Health University Hospital between July 2005 and December 2016. Patients with ARDS were stratified into the SF and hyperfibrinolysis (HF) groups. Using the fibrin degradation product (FDP)/D-dimer ratio, cut-off values were set as follows: FDP/D-dimer >2 for the HF group and FDP/D-dimer ≤2 for the SF group. The 28-day mortality was the primary endpoint. RESULTS: In total, 168 patients (71 in the HF group and 97 in the SF group) were included in the analysis. The mortality within 28 days was not different based on SSH administration in either group (HF group: p=0.956, SF group: p=0.957). In the SF group, the mortality rate within 28 days in SSH-treated patients who received antithrombotic drugs was significantly higher than that in patients who received SSH only (p<0.05). However, this finding was not present in the HF group (p=0.786). CONCLUSIONS: Concomitant use of SSH and antithrombotic drugs might worsen the treatment outcome of patients with ADRS in the SF state.

BACKGROUND: IgA nephropathy (IgAN) is the most common type of primary glomerulonephritis. Elevation in the blood levels of aberrantly glycosylated IgA1 is a crucial initial step in IgAN pathogenesis. Here, we aimed to determine the longitudinal changes in the serum levels of IgA1 O- and N-glycoforms in patients with IgAN receiving different treatments. METHODS: We enrolled Japanese patients diagnosed with primary IgAN: 10 patients who underwent tonsillectomy and corticosteroid therapy (T-CST), 7 who received corticosteroid therapy (CST), 8 who received conservative therapy (CO), and 5 with other renal diseases who received corticosteroid therapy (ORD) as disease controls. IgA was purified from patient sera collected at diagnosis and post-treatment. After sample preparation, O-glycoforms of the hinge region (HR) and N-glycoforms of the fragment crystallizable region were analyzed using high-resolution mass spectrometry (MS). RESULTS: The MS analysis of O-glycoforms of IgA1 showed that the relative abundance of IgA1 with 3GalNAc3Gal, which we previously identified as a characteristic IgA1 O-glycoform in IgAN, decreased post-treatment only in the T-CST group (P = 0.0195). Regarding N-glycoforms, the relative abundance of fucosylated N-glycan at asparagine (Asn)340 increased in the IgAN group compared with that in the ORD group (P = 0.0189) and decreased post-treatment only in the T-CST group (P = 0.0195). CONCLUSION: The MS analysis of O- and N-glycoforms of IgA1 revealed substantial changes in their abundance in the T-CST group but not in the CST, CO, and ORD groups. Our study provides new insights into how specific treatments alter the IgA1 glycoform abundance.

BACKGROUND: As a joint project with the Ministry of Health, Labour and Welfare (MHLW), the Research Group on Intractable Renal Diseases is examining the feasibility of utilizing its personal clinical records database. We examine the validity of the initial-treatment data from the personal clinical records of patients with new-onset rapidly progressive glomerulonephritis (RPGN). METHODS: Personal clinical records for patients with either RPGN or anti-glomerular basement membrane (GBM) antibody nephritis were used. The data from 454 newly enrolled RPGN patients were compiled for analysis in 2 cohort studies (CS1 for all case analysis and CS2 for selective analysis of new-onset cases). RESULTS: In CS1, the serotypes of the 362 registered RPGN cases included 200 myeloperoxidase (MPO)-ANCA-positive, 98 anti-GBM-positive, and 9 proteinase-3 (PR3)-ANCA-positive cases, etc. CS2 included 96 of the MPO-ANCA-positive RPGN and 55 of the anti-GBM antibody-positive RPGN cases. For the initial treatment of MPO-ANCA-positive RPGN, the rates of glucocorticoid (GC) and GC pulse treatment were similar between the personal clinical records database and the nationwide questionnaire survey, but the rates of intravenous cyclophosphamide (CY) or rituximab were statistically significant lower in the personal clinical records database. For the initial treatment of anti-GBM antibody-positive RPGN, the rate of plasma exchange was similar between the two databases, but the rates of GC and per os CY tended to be lower in the personal clinical records database, although not statistically significant. CONCLUSION: Clear differences in initial treatment for new-onset RPGN patients were found between a personal clinical records database and another reported database.

BACKGROUND: This study is a continuation of the Japan Rapidly Progressive GlomeruloNephritis (RPGN) Working Group's chronological nationwide survey. METHODS: We analyzed 1,660 RPGN cases from 2016-2019 and compared them to 4,179 cases from five earlier periods (1989-1998, 1999-2001, 2002-2008, 2009-2011, 2012-2015). Data on causative diseases, clinical severity, 24-month life and renal survival, and treatment details were collected and compared. RESULTS: The most recent cohort showed an older median age at onset (median age 74 years), with improved serum creatinine levels (median 2.5 mg/dL). Cumulative survival at 24 months remained stable (periods 1989-1998, 1999-2001, 2002-2008, 2009-2011, 2012-2015, 2016-2019 were each 72.0%, 72.9%, 77.7%, 83.0%, 84.9%, 83.5%, p < 0.01), while renal survival showed a favorable trend in the most recent periods (there were each 68.7%, 75.4%, 76.7%, 73.4%, 78.2%, 78.4%, p < 0.01). Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV)-RPGN had similar outcomes to the overall cohort. Increased rituximab use was observed, with no significant differences in life and renal prognosis between rituximab (RIX) and cyclophosphamide (CY). In severe renal impairment (Cre ≥ 6), renal prognosis was better in the CY or RIX use group than in the non-use group (p = 0.035, 0.025). Anti-glomerular basement membrane disease had a poorer renal prognosis compared to other causes. CONCLUSIONS: Despite an increasingly older age of onset, both life and renal prognoses for new-onset AAV-RPGN from 2016 to 2019 remain comparable to the best in previous surveys, due to the impact of constant improvements in early diagnosis and changes in treatment.

BACKGROUND AND OBJECTIVES: Vitamin D receptor activators (VDRAs) are widely used in patients with osteoporosis; however, the frequency of acute kidney injury (AKI) due to VDRAs is unclear. This study aimed to investigate whether the incidence of AKI after VDRA initiation differed among patients with different renal functions. METHODS: The medical records of Japanese patients who were newly prescribed with VDRAs for osteoporosis at the Fujita Health University Hospital or Kyoto University Hospital between April 2012 and March 2022 were retrospectively reviewed in this study. The RIFLE (Risk, Injury, Failure, Loss of function, End-stage kidney disease) criteria were used to assess the incidence of AKI within 7 days after initiation of VDRA therapy. Additionally, the AKI algorithm was used to assess the incidence of AKI from 8 to 365 days after initiation of VDRA therapy. RESULTS: The incidence of AKI, as defined by the RIFLE criteria, was significantly higher in patients with normal renal function or end-stage renal failure than in those with mild renal decline (p < 0.05); the incidence of AKI, defined using the AKI algorithm, showed a similar trend. We found that the lack of serum calcium level monitoring before the initiation of VDRAs might be a risk factor for AKI defined by the RIFLE criteria (odds ratio = 2.004, p = 0.096). CONCLUSIONS: The incidence of AKI after the initiation of VDRA therapy was high, even if renal function was normal. Thus, our results suggest that monitoring serum calcium levels before the initiation of VDRA therapy is necessary, regardless of renal function.

INTRODUCTION: Clinical epidemiological data on monoclonal gammopathy of renal significance (MGRS) are lacking. In this retrospective observational study, MGRS was compared with B-cell or plasma cell malignancies (BCM/PCM) with renal involvement to clarify differences in their clinical features. METHODS: Among the 1408 renal biopsies performed at our hospital, 25 MGRS and 18 BCM/PCM patients were identified. We investigated baseline characteristics and hematologic parameters of MGRS in reference to BCM/PCM using multivariable analysis. Cox proportional hazards analysis was performed for end-stage kidney disease (ESKD) and all-cause mortality. RESULTS: Comparing the MGRS with the BCM/PCM, mean differences in creatinine level, estimated glomerular filtration rate, and clonal bone marrow plasma cell percentage were - 2.76 mg/dL, 27.72 mL/min/1.73 m2, and - 18.86%, respectively (all P < 0.001). MGRS group had a predominance of glomerular lesions such as immunoglobulin-associated amyloidosis, cryoglobulinemic GN, and MIDD, and a lower risk of acute kidney injury/acute renal disease compared to BCM/PCM. During a median observation period of 23.7 months, clone-directed therapy was performed in 32.0% of patients in the MGRS group, compared to 83.3% of patients in the BCM/PCM group. Compared with BCM/PCM, MGRS had a hazard ratio of 0.66 (95% confidence interval (CI) 0.23-1.92, P = 0.45) for ESKD and 0.33 (95% CI 0.11-1.03, P = 0.06) for death in multivariate logistic regression analysis. CONCLUSIONS: The clinical characteristics of MGRS and BCM/PCM with monoclonal immunoglobulin-associated renal disease are disparate. Understanding these differences is crucial for developing tailored clinical approaches and therapeutic strategies to improve patient outcome.

We compared different antineutrophil cytoplasmic antibody (ANCA) detection methods using a predominantly myeloperoxidase (MPO)-ANCA-associated vasculitis cohort. Stored sera from 147 patients with untreated ANCA-associated vasculitis (AAV), including microscopic polyangiitis and granulomatosis with polyangiitis (n = 115 and 32, respectively), and 124 disease controls were tested for P-ANCA and C-ANCA with immunofluorescence (IIF), and for MPO-ANCA and proteinase 3 (PR3)-ANCA with different antigen-specific immunoassays: direct enzyme-linked immunosorbent assay (ELISA), chemiluminescent enzyme immunoassay (CLEIA), third-generation fluorescent enzyme immunoassay (FEIA), and latex turbidimetrical immunoassay (LTIA). In addition, MPO-ANCA and PR3-ANCA titers were calibrated using certified reference materials (CRMs). The sensitivities and specificities for AAV diagnoses were 95% and 94% (IIF), 86% and 98% (ELISA), 93% and 94% (CLEIA), 92% and 96% (FEIA), and 68% and 88% (LTIA). Dual IIF/antigen-specific immunoassay testing reduced diagnostic accuracies from 94% to 93%. The quantitative agreement between ANCA levels measured using CLEIA and FEIA and calibrated using CRMs was not good. In conclusion, this study demonstrated the high performance of antigen-specific immunoassays for AAV diagnosis in a predominantly MPO-ANCA-associated vasculitis cohort and suggested that the benefit of dual IIF/antigen-specific immunoassay testing is limited. Standardizing ANCA measurements using different immunoassays was difficult, even when using CRMs.

BACKGROUND: The effect of worsening renal function and baseline chronic kidney disease (CKD) on outcomes in patients with chronic coronary syndrome in the setting of optimal medical therapy remains unknown. METHODS AND RESULTS: The REAL-CAD (Randomized Evaluation of Aggressive or Moderate Lipid Lowering Therapy With Pitavastatin in Coronary Artery Disease) study is a prospective, multicenter, randomized trial of high-dose (pitavastatin 4 mg/day) or low-dose (pitavastatin 1 mg/day) statin therapy in 12 118 patients with chronic coronary syndrome. The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, stroke, or unstable angina requiring hospitalization (major adverse cardiac and cerebral events [MACCE]). CKD was defined as an estimated glomerular filtration rate [eGFR] <60 mL/min per 1.73 m2. WRF was defined as a decrease in eGFR ≥20% in the initial year; borderline renal function was an annual decrease of 0%<eGFR<20%, and stable renal function was no decrease. Of 12 118 patients, 4340 had baseline CKD and 7778 did not. The rate of MACCE at 5 years was significantly lower in those without (5.5%) versus with CKD (9.5%) (P<0.0001). After excluding 1247 patients who had MACCE, were censored, or missing eGFR within 1 year, 10 871 patients were included. Of these, 3885 were baseline CKD and the remaining 6986 did not have baseline CKD. Of the 10 871 patients, 577 patients had WRF, 6014 patients showed borderline renal function, and the remaining 4280 patients maintained stable renal function. In patients with CKD, WRF was an independent predictor for MACCE at 4 years as compared with stable renal function (hazard ratio [HR]: 1.67; [95% CI, 1.03-2.73; P=0.039]). In patients without CKD, borderline renal function was a significant predictor for MACCE at 4 years compared with stable renal function (HR: 1.40 [95% CI, 1.03-1.91; P=0.032]). CONCLUSIONS: Baseline CKD was an independent predictor for MACCE in patients with CCS. WRF was a significant predictor for MACCE in patients with CKD. Because borderline renal function was an independent predictor for MACCE even in patients without CKD, mild-to-moderate annual declines of eGFR should be carefully monitored (NCT01042730). REGISTRATION: URL: https://www.clinicaltrials.gov; Unique Identifier: NCT01042730.

Background: Progression of chronic kidney disease (CKD) increases the risk of complications such as cardiovascular disease; however, knowledge regarding renal function in the general population is low. We aimed to determine factors necessitating CKD education in the general population. Methods: Participants for a health promotion seminar were recruited via the Sugiura Memorial Foundation website and Sugi Pharmacy stores. Those who agreed to participate in the seminar were included in the questionnaire survey after a health seminar. Results: Out of 1548 participants, 1050 answered all questionnaire items, resulting in a valid response rate of 67.83%. Multivariable analysis revealed that sex (OR = 0.611), pharmacy consultations (OR = 0.661), receiving a blood test within 1 year (OR = 0.268), awareness of blood pressure (OR = 0.038), and knowledge of blood glucose level (OR = 0.099) were factors for unawareness of renal function. Conclusions: This study suggests that female individuals unaware of their blood pressure or glucose levels, those who have not had a blood test within 1 year, and those who have not sought health consultations need education on renal function.

Severe acute kidney injury (AKI) is a risk factor for the future development of chronic kidney disease (CKD), and macrophages are an essential cell group implicated in injury, repair, and fibrosis during this progress. However, the underlying mechanism of how macrophages participate in the development of the disease is largely unclear. CD11b (Integrin αM) is highly expressed in monocytes/macrophages and has been verified to mediate broad functions. We found that CD11b-knockout mice were protected from the ischemia/reperfusion-induced AKI-to-CKD process. Additionally, renal macrophages from the kidneys of CD11b-deficient mice presented an M2-like, anti-inflammatory phenotype. We demonstrated both in vitro and in vivo that enhanced alternative activation in CD11b-knockout macrophages is regulated by the interleukin (IL)-4/signal transducer and activator of transcription (STAT) 6 axis, which is mediated by the inactivation of the Src-family kinase (SFK) member Lyn. Importantly, the therapeutical administration of CD11b-neutralizing antibody can effectively prevent AKI-to-CKD progress. Thus, our study verifies that CD11b plays a critical role in limiting the alternative activation of macrophages and may be a potential therapeutic target during the AKI-to-CKD process.

OBJECTIVES: In cell-free and concentrated ascites reinfusion therapy (CART), the protein recovery rate decreases when the filtration membrane gets clogged. Employing a device with a filtration membrane washing feature prevents clogging, but it leads to the loss of ascites within the filter, resulting in reduced protein recovery. This study employed a device with a membrane washing function to investigate the relationship between protein recovery rate and the quantity of washing solution used, depending on the selected washing method. METHODS: We analyzed cases of CART conducted at Fujita Health University Hospital between May 2021 and November 2022. The cases were divided and compared between two groups: one using flush and rinse as the washing method (flush+rinse group) and another using only flushing (flush group). RESULTS: We identified nine cases and 16 sessions. In the flush+rinse group, the median amount of washing solution used per membrane washing was 259 mL per cycle, whereas it was 54 mL per cycle in the flush group. This difference was statistically significant (p<0.0001). The median total protein recovery rate was 53.8% for the flush+rinse group and 78.8% for the flush group, with the latter showing a significantly higher value (p=0.0199). CONCLUSIONS: In CART using a membrane washing function, adopting a washing method that reduces the amount of washing solution leads to an increase in the total protein recovery rate.

OBJECTIVE: This study aimed to evaluate the Ministry of Health, Labour and Welfare (MHLW) diagnostic criteria for antineutrophil cytoplasmic antibody-associated vasculitis compared to the new American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 criteria. METHODS: Two nationwide cohort studies were used, and participants were categorised as having eosinophilic granulomatosis with polyangiitis, granulomatosis with polyangiitis (GPA), or microscopic polyangiitis (MPA) according to the American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 and MHLW criteria. RESULTS: Of the entire patient population, only 10 (2.1%) were unclassifiable according to the MHLW probable criteria, while a significant number of patients (71.3%) met at least two criteria. The MHLW probable criteria for MPA had some challenges in differentiating between MPA and eosinophilic granulomatosis with polyangiitis, and the same was true for MHLW probable criteria for GPA in differentiating MPA from GPA. Nevertheless, improved classification results were obtained when the MHLW probable criteria were applied in the order of eosinophilic granulomatosis with polyangiitis, MPA, and GPA. CONCLUSIONS: The application of MHLW criteria could categorise a substantial number of patients with antineutrophil cytoplasmic antibody-associated vasculitis into one of the three antineutrophil cytoplasmic antibody-associated vasculitis diseases. The classification was in accordance with the American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 criteria when considering the order of application.

Acute lung injury (ALI), which occurs in association with sepsis, trauma, and coronavirus disease 2019 (COVID-19), is a serious clinical condition with high mortality. Excessive platelet-leukocyte aggregate (PLA) formation promotes neutrophil extracellular trap (NET) release and thrombosis, which are involved in various diseases, including ALI. Macrophage-1 antigen (Mac-1, CD11b/CD18), which is expressed on the surface of leukocytes, is known to promote NET formation. This study aimed to elucidate the role of Mac-1 in extracellular histone-induced ALI. Exogenous histones were administered to Mac-1-deficient mice and wild-type (WT) mice with or without neutrophil or platelet depletion, and several parameters were investigated 1 h after histone injection. Depletion of neutrophils or platelets improved survival time and macroscopic and microscopic properties of lung tissues, and decreased platelet-leukocyte formation and plasma myeloperoxidase levels. These improvements were also observed in Mac-1-/- mice. NET formation in Mac-1-/- bone marrow neutrophils (BMNs) was significantly lower than that in WT BMNs. In conclusion, our findings suggest that Mac-1 is associated with exacerbation of histone-induced ALI and the promotion of NET formation in the presence of activated platelets.

INTRODUCTION: Coronary artery and heart valve calcification is a risk factor for cardiovascular death in haemodialysis patients, so calcification prevention should be started as early as possible. Treatment with concomitant calcimimetics and low-dose vitamin D receptor activators (VDRAs) is available, but not enough evidence has been obtained on the efficacy of this regimen, particularly in patients with short dialysis duration. Therefore, this study will evaluate the efficacy and safety of early intervention with upacicalcet, a calcimimetic used to prevent coronary artery calcification in this patient population. METHODS AND ANALYSIS: This multicentre, open-label, randomised, parallel-group controlled study will compare an early intervention group, which received upacicalcet and a low-dose VDRA, with a conventional therapy group, which received a VDRA. The primary endpoint is a change in log coronary artery calcium volume score from baseline to 52 weeks. The main inclusion criteria are as follows: (1) age 18 years or older; (2) dialysis is planned or dialysis duration is less than 60 months; (3) intact parathyroid hormone (PTH) >240 pg/mL or whole PTH level>140 pg/mL; (4) serum-corrected calcium≥8.4 mg/dL and (5) Agatston score >30. The main exclusion criteria are as follows: (1) history of parathyroid intervention or fracture in the past 12 weeks; (2) history of myocardial infarction, stroke or leg amputation in the past 12 weeks; (3) history of coronary angioplasty and (4) heart failure of New York Heart Association class III or worse. ETHICS AND DISSEMINATION: The study will comply with the Declaration of Helsinki and the Japanese Clinical Trials Act. The study protocol has been approved by the Fujita Health University Certified Review Board (file no. CR22-052). Written informed consent will be obtained from all participants. Study results will be presented in academic meetings and peer-reviewed academic journals. TRIAL REGISTRATION NUMBER: jRCTs041220126.

Objective The objective of this study was to estimate the humoral immune response evaluated by immunoglobulin G (IgG) against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike receptor-binding domain (RBD-IgG) following the third mRNA COVID-19 vaccination in patients with kidney disease who received immunosuppressive treatment. Methods The primary outcome was RBD-IgG levels after the third SARS-CoV-2 vaccination. The primary comparison was the RBD-IgG levels between patients with kidney disease who received immunosuppressive treatment (n=124) and those who did not (n=33). Results The RBD-IgG levels were significantly lower in the patients with kidney disease who received immunosuppressive treatment than in those who did not receive immunosuppressive treatment. The RBD-IgG levels were lower in patients treated with glucocorticoid monotherapy than in those who did not receive immunosuppressive treatment. Even in patients who received ≤ 5 mg prednisolone, the RBD-IgG levels were significantly lower. Nine of the 10 patients who received rituximab within one year before the first vaccination did not experience seroconversion after the third vaccination. Meanwhile, all nine patients who received rituximab only after the second vaccination experienced seroconversion, even if B cell recovery was insufficient. Patients treated with mycophenolate mofetil plus glucocorticoid plus belimumab had significantly lower RBD-IgG levels than those treated with mycophenolate mofetil plus glucocorticoid. Conclusions The RBD-IgG levels were lower in patients with kidney disease who received immunosuppressive treatment than in those who did not receive immunosuppressive treatment. Low-dose glucocorticoid monotherapy affected the humoral immune response following the third mRNA COVID-19 vaccination.

Extracellular histones induce endothelial damage, resulting in lung haemorrhage; however, the underlying mechanism remains unclear. Factor XIII, as a Ca2+-dependent cross-linking enzyme in blood, mediates fibrin deposition. As another isozyme, transglutaminase 2 (TG2) has a catalytic activity distributing in most tissues. Herein, we investigated whether TG2 promotes fibrin deposition and mediates the adhesion of platelets to ECs in histone-induced acute lung injury (ALI). We evaluated the lung histology and the adhesion of platelets to endothelial cells (ECs) after injecting histones to wild-type (WT) C57BL/6J and TG2 knockout (TG2-/-) mice, and administered a TG2 inhibitor (NC9) to WT mice. Pulmonary haemorrhage was more severe in TG2-/- mice than that in WT mice. The area of fibrin deposition and the proportion of CD41+CD31+ cells were lower in TG2-/- mice than in WT mice. Pre-treatment of NC9 decreased the area of fibrin deposition and the proportion of CD41+CD31+ cells in WT mice. These results suggest that TG2 prevents from pulmonary haemorrhage in ALI by promoting the adhesion of platelets to ECs and the fibrin deposition.

BACKGROUND: Sodium zirconium cyclosilicate, a non-absorbed non-polymer zirconium silicate, is a new potassium binder for hyperkalemia. A previous report showed that administering sodium zirconium cyclosilicate to patients with hyperkalemia allows a higher continuation rate of renin-angiotensin-aldosterone system inhibitors. However, no studies have compared sodium zirconium cyclosilicate with existing potassium binders for renin-angiotensin-aldosterone system inhibitor continuity. The purpose of this study was to evaluate the effect of sodium zirconium cyclosilicate on angiotensin-converting enzyme inhibitor /angiotensin receptor blocker continuation in patients with hyperkalemia compared to that of calcium polystyrene sulfonate. METHODS: Patients on angiotensin-converting enzyme inhibitors/angiotensin receptor blockers who were newly prescribed sodium zirconium cyclosilicate or calcium polystyrene sulfonate to treat hyperkalemia at a tertiary referral hospital between August 2020 and April 2022 were enrolled in this single-center, retrospective observational study. The primary outcome measure was angiotensin-converting enzyme inhibitor/angiotensin receptor blocker prescription three months after initiating potassium binders. RESULTS: In total, 174 patients on angiotensin-converting enzyme inhibitors/angiotensin receptor blockers who were newly administered sodium zirconium cyclosilicate (n = 62) or calcium polystyrene sulfonate (n = 112) were analyzed. The prescription rate of angiotensin-converting enzyme inhibitors /angiotensin receptor blockers at 3 months was significantly higher in the sodium zirconium cyclosilicate group than in the calcium polystyrene sulfonate group (89 vs. 72%). Multivariate logistic regression models showed that sodium zirconium cyclosilicate was independently associated with the primary outcome (odds ratio 2.66, 95% confidence interval 1.05-7.43). The propensity score-matched comparison also showed a significant association between sodium zirconium cyclosilicate and the primary outcome. CONCLUSIONS: Our study suggests that administering sodium zirconium cyclosilicate to patients with hyperkalemia allows for a higher continuation rate of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers than calcium polystyrene sulfonate. These findings suggest that sodium zirconium cyclosilicate has potential benefits for patients with chronic kidney disease receiving renin-angiotensin-aldosterone system inhibitors.

Abstract Introduction Indoxyl sulfate (IS) is a protein‐bound uremic toxin that causes uremic sarcopenia. IS has poor dialysis clearance; however, the addition of a binding competitor improves its removal efficiency. Methods Dialysis experiments were performed using N‐acetyl‐l‐tryptophan (L‐NAT) instead of l‐tryptophan (Trp) using pooled sera obtained from dialysis patients. The molecular structures of L‐NAT and Trp were similar to that of IS. Therefore, we examined whether Trp and L‐NAT were involved in muscle atrophy in the same manner as IS by performing culture experiments using a human myotube cell line. Results The removal efficiency of L‐NAT was the same as that of Trp. However, L‐NAT concentrations in the pooled sera increased at the end of the experiment. Trp (1 mM) decreased the area of human myocytes, similar to IS, whereas L‐NAT did not. Conclusion L‐NAT is a binding competitor with the ability to remove protein‐bound IS while preventing sarcopenia.

OBJECTIVES: Cardiovascular and renal diseases are closely related. Brain natriuretic peptide (BNP) and urinary albumin are established predictors for cardiac and renal morbidities, respectively. To date, no reports have investigated the combined predictive value of BNP and urinary albumin for long-term cardiovascular-renal events in patients with chronic kidney disease (CKD). The aim of this study was to investigate this theme. METHODS: Four hundred eighty-three patients with CKD were enrolled into this study and followed-up for 10 years. The endpoint was cardiovascular-renal events. RESULTS: During the median follow-up period of 109 months, 221 patients developed cardiovascular-renal events. Log-transformed BNP and urinary albumin were identified as independent predictors for cardiovascular-renal events, with a hazard ratio of 2.59 (95% confidence interval [CI], 1.81-3.72) and 2.27 (95% CI, 1.82-2.84) for BNP and urinary albumin, respectively. For the combined variables, the group with high BNP and urinary albumin had a markedly higher risk (12.41-times; 95% CI 5.23-29.42) of cardiovascular-renal events compared with that of the group with low BNP and urinary albumin. Adding both variables to a predictive model with basic risk factors improved the C-index (0.767, 0.728 to 0.814, p=0.009), net reclassification improvement (0.497, p<0.0001), and integrated discrimination improvement (0.071, p<0.0001) more than each of them alone. CONCLUSIONS: This is the first report to demonstrate that the combination of BNP and urinary albumin can stratify and improve the predictability of long-term cardiovascular-renal events in CKD patients.

OBJECTIVE: The objective of this study was to compare the ACR/EULAR 2022 criteria with the previous classification algorithm for anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). METHODS: We used data from two nationwide, prospective, inception cohort studies. The enrolled patients were classified as having eosinophilic granulomatosis with polyangiitis (EGPA), granulomatosis with polyangiitis (GPA), or microscopic polyangiitis (MPA) according to the new criteria; these criteria were compared with Watts' algorithm. RESULTS: Among 477 patients, 10.7%, 9.9%, and 75.6% were classified as having EGPA, GPA, and MPA, respectively; 6.1% were unclassifiable. Three patients met both the EGPA and MPA criteria and eight patients met both the GPA and MPA criteria. Of 78 patients with GPA classified using Watts' algorithm, 27 (34.6%) patients were reclassified as having MPA. Ear, nose, and throat involvement were significantly less frequent in patients reclassified as having MPA than in those reclassified as having GPA. Of 73 patients unclassifiable using Watts' algorithm, 62 were reclassified as having MPA. All patients reclassified as having MPA were MPO-ANCA positive, and 46 had ILD. CONCLUSION: Although the ACR/EULAR 2022 criteria cause overlapping multiple criteria fulfillments in some patients, those items contribute to classifying unclassifiable patients using Watts' algorithm into MPA.

Purpose: Coronavirus disease 2019 (COVID-19) mRNA vaccines are used worldwide to prevent severe symptoms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. IgA nephropathy (IgAN) is the most common form of glomerular injury after COVID-19 vaccination; however, because of the low frequency of such events, only a few reports have been published. A large pharmacovigilance database of real-world spontaneous adverse event (AE) reports is essential for evaluating the drug-associated safety signals regarding rare AEs. Herein, we aimed to investigate the frequency of IgAN after the COVID-19 vaccination, using the Japanese Adverse Drug Event Report (JADER) database. Methods: Data on drug-associated AEs reported between April 2004 and May 2022 were obtained from the JADER database on the Pharmaceuticals and Medical Devices Agency website. To evaluate the safety signals for the targeted AEs, reporting odds ratios (RORs), information components (ICs), and their 95% confidence intervals (CIs) were calculated using two-by-two contingency tables. Results: A total of 697,885 cases were included in the analysis. Safety signals were detected for IgAN (ROR: 6.49, 95% CI: 4.38-9.61; IC: 2.27, 95% CI: 1.70-2.83). Of 30 cases for IgAN associated with COVID-19 mRNA vaccines, 16 had information available on time to onset. Of the 16 cases, 11 occurred ≤2 days after vaccination, and two occurred >28 days after vaccination. Conclusion: These results suggest that, compared with other drugs, COVID-19 vaccination is associated with a higher frequency of IgAN. Monitoring of gross hematuria following COVID-19 vaccination should be needed.

BACKGROUND/AIM: Sepsis is a life-threatening biological condition that induces systemic tissue and organ dysfunction and confers a high mortality risk. Although the use of hydrocortisone in combination with ascorbic acid and thiamine (HAT therapy) significantly reduced mortality from sepsis or septic shock in a previous study, it did not improve mortality in subsequent randomized controlled trials (RCTs). Therefore, no definitive conclusion has been established on the benefits of HAT therapy for sepsis or septic shock. We performed a meta-analysis to assess the treatment outcomes of HAT therapy in patients with sepsis or septic shock. PATIENTS AND METHODS: We searched databases (PubMed/MEDLINE, Embase, Scopus and Cochrane Library) for RCTs using the terms "ascorbic acid", "thiamine", "sepsis", "septic shock", and "RCT". The primary outcome of this meta-analysis was the mortality rate, and the secondary outcomes were the incidence of new-onset acute renal injury (AKI), intensive care unit (ICU) length of stay (ICU-LOS), change in the Sequential Organ Failure Assessment (SOFA) score within 72 hours, and duration of vasopressor use. RESULTS: Nine RCTs were identified and included in the outcome evaluation. HAT therapy did not improve the 28-day and ICU mortality, new-onset AKI, ICU-LOS, or SOFA scores. However, HAT therapy significantly shortened the duration of vasopressor use. CONCLUSION: HAT therapy did not improve mortality, the SOFA score, renal injury, or ICU-LOS. Further studies are needed to confirm whether it shortens the duration of vasopressor use.

Abstract Perivascular mesenchymal cells (PMCs), which include pericytes, give rise to myofibroblasts that contribute to chronic kidney disease progression. Several PMC markers have been identified; however, PMC heterogeneity and functions are not fully understood. Here, we describe a novel subset of renal PMCs that express Meflin, a glycosylphosphatidylinositol-anchored protein that was recently identified as a marker of fibroblasts essential for cardiac tissue repair. Tracing the lineage of Meflin⁺ PMCs, which are found in perivascular and periglomerular areas and exhibit renin-producing potential, showed that they detach from the vasculature and proliferate under disease conditions. Although the contribution of Meflin⁺ PMCs to conventional α-SMA⁺ myofibroblasts is low, they give rise to fibroblasts with heterogeneous α-SMA expression patterns. Genetic ablation of Meflin⁺ PMCs in a renal fibrosis mouse model revealed their essential role in collagen production. Consistent with this, human biopsy samples showed that progressive renal diseases exhibit high Meflin expression. Furthermore, Meflin overexpression in kidney fibroblasts promoted bone morphogenetic protein 7 signals and suppressed myofibroblastic differentiation, implicating the roles of Meflin in suppressing tissue fibrosis. These findings demonstrate that Meflin marks a PMC subset that is functionally distinct from classic pericytes and myofibroblasts, highlighting the importance of elucidating PMC heterogeneity.

Galactose (Gal)-deficient IgA1 (Gd-IgA1) is involved in IgA nephropathy (IgAN) pathogenesis. To reflect racial differences in clinical characteristics, we assessed disease- and race-specific heterogeneity in the O-glycosylation of the IgA1 hinge region (HR). We determined serum Gd-IgA1 levels in Caucasians (healthy controls [HCs], n = 31; IgAN patients, n = 63) and Asians (HCs, n = 20; IgAN patients, n = 60) and analyzed profiles of serum IgA1 HR O-glycoforms. Elevated serum Gd-IgA1 levels and reduced number of Gal residues per HR were observed in Caucasians. Reduced number of N-acetylgalactosamine (GalNAc) residues per HR and elevated relative abundance of IgA1 with three HR O-glycans were common features in IgAN patients; these features were associated with elevated blood pressure and reduced renal function. We speculate that the mechanisms underlying the reduced GalNAc content in IgA1 HR may be relevant to IgAN pathogenesis.

Adipose-derived mesenchymal stem cells (ASCs) have shown therapeutic potentials against refractory diseases. However, the detailed therapeutic mechanisms remain unclear. Here, we report the therapeutic actions of human ASCs in nephritis, focusing on cellular dynamics and multi-organ networks. Intravenously-administered ASCs accumulated in spleen but not kidneys. Nevertheless, ASCs increased M2 macrophages and Tregs in kidneys and drove strong renoprotection. Splenectomy abolished these therapeutic effects. ASC-derived extracellular vesicles (EVs) were transferred to M2 macrophages, which entered the bloodstream from spleen. EVs induced the transcriptomic signatures of hyperpolarization and PGE2 stimulation in M2 macrophages and ameliorated glomerulonephritis. ASCs, ASC-derived EVs, and EV-transferred M2 macrophages enhanced Treg induction. These findings suggest that EV transfer from spleen-accumulated ASCs to M2 macrophages and subsequent modulation of renal immune-environment underlie the renoprotective effects of ASCs. Our results provide insights into the therapeutic actions of ASCs, focusing on EV-mediated modulation of macrophages and the spleen-kidney immune network.