Fervenza, Fernando C

ABSTRACT Background Membranous nephropathy (MN) associated with phospholipase A2 receptor (PLA2R) antibodies is the most common cause of nephrotic syndrome in non-diabetic adult patients. This study investigated the relationship between clinical phenotypes and renal outcomes in this population, emphasizing the potential for phenotype-based treatment stratification. Methods We conducted a retrospective, multi-center cohort study of PLA2R-positive MN. Unsupervised cluster analysis grouped patients based on clinicopathological characteristics. Primary outcomes included complete or partial remission within 2 years of biopsy and end-stage kidney disease (ESKD) or death during follow-up. Results Among 178 patients, three distinct clusters emerged (n = 89, 70, and 19). Within 2 years of biopsy, 102 patients (57%) achieved complete or partial remission. Cluster 1, characterized by the mildest disease markers, including the lowest body mass index, serum anti-PLA2R titer, serum creatinine, proteinuria, and triglycerides, had the highest remission rate of 72%, compared with 50% in cluster 2 and 54% in cluster 3. Cluster 2 had significantly lower remission compared to cluster 1 (HR 0.64, 95% CI 0.42–0.96, P = .03); results were similar in cluster 3, albeit not statistically significant (HR 0.50, 95% CI 0.23–1.09, P = .08). Elevated anti-PLA2R levels (>100 U/ml) and proteinuria (>8 g/24-hour) predicted reduced remission (HR 0.56, 95% CI 0.36–0.88, P = .01; HR 0.43, 95% CI 0.26–0.73, P = .002, respectively), while high high-density lipoprotein levels were protective (HR 1.01, 95% CI 1.00–1.02, P = .048). Overall, 21 patients (12%) developed ESKD or died. ESKD-free survival differed significantly across clusters (log-rank test P = .04). Conclusions Unsupervised clustering identified distinct clinical phenotypes in PLA2R-positive MN, each associated with different renal prognoses. Phenotype-based risk stratification could enhance treatment precision, improve patient outcomes, and potentially reduce treatment-related adverse effects.

Key Points Preexisting CKD, elevated serum creatinine, and severe interstitial fibrosis and tubular atrophy were linked to poor renal prognosis in renal sarcoidosis. Steroid therapy was strongly associated with renal recovery and improved long-term outcomes in renal sarcoidosis. Early detection and management of renal involvement in sarcoidosis are critical to preventing irreversible kidney damage. Background Renal sarcoidosis (RS) is a rare but potentially severe manifestation of sarcoidosis, primarily affecting the kidneys through granulomatous interstitial nephritis and calcium metabolic disturbances. This study evaluates the clinicopathologic features and renal outcomes of biopsy-proven RS, focusing on identifying predictors of renal recovery and disease progression. Methods This retrospective study included 43 biopsy-proven RS at Mayo Clinic (2012–2024). Demographic, clinical, laboratory, and histopathologic data were analyzed. Renal recovery within 6 months was classified as complete, partial, or no recovery based on serum creatinine (sCr) changes. Long-term adverse composite outcomes included the CKD onset, CKD progression, ESKD, dialysis initiation, or death. Logistic regression and Cox proportional hazards regression were used to assess predictors of renal outcomes. Results Among the cohort, 84% exhibited interstitial nephritis, with granulomatous interstitial nephritis in 33%. Calcium phosphate deposits were found in 58% of cases. Hypercalciuria (90%) was more common than hypercalcemia (74%). Within 6 months, 86% achieved recovery (74% complete, 12% partial), while 40% experienced long-term adverse composite outcomes. Higher sCr at biopsy (≥2.4 mg/dl) and moderate-to-severe interstitial fibrosis and tubular atrophy were associated with reduced complete recovery and worse long-term outcomes, while preexisting CKD significantly increased the risk of adverse long-term outcomes. Steroid therapy significantly increased the likelihood of complete recovery and reduced the risk of adverse long-term outcomes. Conclusions Preexisting CKD, elevated sCr at biopsy, interstitial fibrosis and tubular atrophy, and steroid therapy are key predictors of renal outcomes in RS. Early diagnosis and intervention are crucial to preventing irreversible kidney damage.

ABSTRACT Background Membranous nephropathy (MN) is a leading cause of nephrotic syndrome (NS). Since the identification of anti–phospholipase A2 receptor (anti-PLA2R) antibodies in 2009, the use of laser microdissection and tandem mass spectrometry (LMD/MS) has allowed the discovery of several target antigens in MN. Methods In this retrospective cohort study, adult patients evaluated at the Division of Nephrology at Brotzu Hospital (Cagliari, Italy) with biopsy-proven MN and a negative serological test for anti-PLA2R antibody underwent LMD/MS, performed at the Department of Laboratory Medicine and Pathology of Mayo Clinic (Rochester, MN, USA). Results Twenty-four cases of biopsy-proven MN were available for antigen detection by LMD/MS studies. High total spectral counts of PLA2R were detected in 12 out of 24 (50%) cases. In addition, high spectral counts of THSD7A and NELL1 were detected in two cases each, and EXT1/EXT2 and NCAM1 in one case each. Five putative antigens have been detected: SULF1, PGLYRP, HYAL1, THBS and SEZ6L2. Conclusions Our study highlights at least two interesting considerations. First, the determination of PLA2R on renal tissue in the diagnosis of PLA2R-associated MN is emphasized since 50% of our cases were falsely diagnosed with PLA2R-negative MN based on the serum anti-PLA2R antibodies determination. Second, our study shows six patients with MN likely associated with putative antigens, two of them showing new antigens never described before in literature (HYAL1 and THBS1). This high prevalence of putative antigens in our cohort is not easily explainable and paves the way for evaluating specific factors in the Sardinian population that could explain this evidence.

Key Points In phospholipase A2 receptor-membranous nephropathy, clinical variables and antibody levels over 3 or 6 months of treatment were predictors of remission at 1 year. Prediction models at 3 and 6 months had similar performance predicting remission, with the 3-month model allowing for earlier assessment of response. The 3-month and 6-month prediction models could be applied in those treated with supportive therapy, rituximab, calcineurin inhibitors, or cyclophosphamide. Background In patients with antiphospholipase A2 receptor antibody–associated membranous nephropathy, there is currently no accepted method to predict an individual's probability of remission after treatment with immunosuppression or supportive therapy using changes in antibody levels and clinical variables during the first 3–6 months of therapy. Methods Using a cohort of 187 patients from the Glomérulopathie extramembraneuse rituximab, Membranous Nephropathy Trial of Rituximab, and Sequential Treatment with Tacrolimus and Rituximab Versus Alternating Corticosteroids and Cyclophosphamide in primary Membranous Nephropathy clinical trials with antibody levels at baseline ≥14 RU/ml, we derived logistic regression models to predict proteinuria remission at 12 months that can be used at baseline or after 3 or 6 months of treatment. Treatment exposures in the trials included supportive therapy, rituximab, calcineurin inhibitors, and cyclophosphamide. Predictors in the models included male sex and baseline and changes in serum albumin, proteinuria, and antibody levels, with or without changes in eGFR. Results Proteinuria remission at 12 months was achieved in 107 patients. Compared with the model at baseline, the 3-month and 6-month models had better model fit with lower Akaike information criterion (186/158 versus 225) and higher R 2 (52.7%/62.4% versus 25.8%), better discrimination with higher C-statistic (0.87 and 0.91 versus 0.75, P < 0.001), and better calibration with lower integrated calibration index (0.89%/2.22% versus 2.51%). The 3-month and 6-month models had no consistent difference in prediction performance, and decision curve analysis demonstrated similar net benefit for treatment decisions based on either model up to a threshold probability of 31%. Prediction performance was similar after internal validation using optimism correction. Prediction performance was maintained within subgroups of different treatment regimens, including supportive therapy, rituximab, calcineurin inhibitors, and cyclophosphamide. Conclusions Either the 3-month or 6-month models can be used in patients with antiphospholipase A2 receptor antibody associated membranous nephropathy after 3 or 6 months of treatment with a variety of immunosuppression or supportive therapy to predict remission status at 12 months.

SLE is a chronic multisystem autoimmune disease that affects the kidneys in approximately 50% of patients, with the prevalence rising to as high as 70% in certain populations, such as African American and Asian people. Antimalarials—and particularly hydroxychloroquine (HCQ)—are currently considered a mainstay of therapy, together with immunosuppressants. Over the past decades, several studies have extensively investigated the mechanisms of action of antimalarial agents and their potential beneficial properties in patients with SLE in general. However, the evidence for the therapeutic benefit of HCQ in patients with lupus nephritis (LN) derives mainly from observational studies, conducted in an era before the refinement of induction and maintenance protocols for immunosuppressive therapy. Despite the paucity of high-quality evidence on its efficacy in LN, the nephrology community widely supports the universal use of HCQ in patients with LN, and recommendations for its use are firmly entrenched in various clinical practice guidelines. Nonetheless, the use of antimalarials may also carry inherent risks, underscoring the importance of personalized approaches in these patients. Herein, we comprehensively review the available literature on antimalarials in LN, aiming to update the current evidence, limitations, and future perspectives for the use of antimalarials in adults.

Abstract Objectives Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic (VEXAS) syndrome is an autoinflammatory disease caused by somatic mutation of UBA1 and affects multiple organ systems. Involvement of the kidneys is not well characterized. We aimed to investigate the incidence, risk factors and histopathologic features of acute kidney injury (AKI) in VEXAS syndrome. Methods Patients with genetically confirmed UBA1 mutation consistent with VEXAS were included. Charts were manually reviewed. Cox regression analysis was used to identify variables associated with time-to-first AKI event. For patients with a kidney biopsy, histopathologic findings were reviewed. Results Eighty-one patients were included, all white men, with a mean age of 66.3 ± 8.6 years. Median (IQR) follow up was 3.5 (2.1–5.2) years during which 20 (25%) developed AKI and 22% died. AKI relapsed in 90% of cases for a median of 6 times during the follow up period. Cumulative incidence estimates (95% CI) for AKI at 1, 3 and 5 years were 6.2% (0.80–11.3%), 16.7% (7.5–25.0%) and 27.9% (14.9–38.9%), respectively. Age and baseline C-reactive protein (CRP) were significantly associated with time-to-first AKI event. Six patients underwent a kidney biopsy. Findings included, plasma cell-rich interstitial nephritis (n = 3), neutrophilic-rich interstitial inflammation (n = 1), leukocytoclastic peritubular capillaritis (n = 1) and acute tubular injury (n = 1). AKI responded well to treatment with glucocorticoids but had relapse upon tapering. Conclusion AKI is an underrecognized feature of VEXAS occurring in 25% of patients in this cohort. Age at diagnosis and CRP were associated with time to first AKI event during follow up. Plasma cell-rich interstitial nephritis was the most common histopathologic finding.

Abstract Objective ANCA-negative granulomatosis with polyangiitis (GPA) remains a diagnosis of exclusion. Clinical differences between patients with ANCA-negative vs ANCA-positive GPA have not been analysed in sizable case-control studies, and the effects of ANCA-seroconversion from negative to positive are not well documented. Methods A single-centre, sex and age matched case-control study evaluated ANCA-negative vs ANCA-positive GPA from 1 January 1996 to 31 December 2015. Patients who experienced seroconversion were the subject of a case-crossover study. Clinical data and outcomes were retrieved from electronic medical records. Results ANCA-negative GPA was identified in 110 patients; 65% were female; median age was 55 (IQR 39–65) years at time of diagnosis. Disease severity was milder in ANCA-negative GPA (BVAS/WG = 2 vs 6, P &lt; 0.001). Mucous membranous/eye manifestations were more frequent in ANCA-negative GPA. General symptoms, pulmonary and renal involvement were more frequent in ANCA-positive GPA. Patients with ANCA-positive GPA relapsed more over 60 months (21.8% vs. 9.1%, P = 0.009) compared with ANCA-negative GPA and had shorter time to event (P = 0.043). Patients with general manifestations, BMI &gt; 30kg/m2 and necrotizing granulomatous inflammation were more likely to relapse. The 16 patients who seroconverted into ANCA-positive during follow-up had higher mean BVAS/WG at time of diagnosis (P &lt; 0.001) and increased incidence of relapses (P = 0.004) after seroconversion. Necrotizing granulomatous inflammation on biopsy in ANCA-negative GPA patients was identified as a risk factor for subsequent seroconversion to ANCA-positivity. Conclusion Patients with ANCA-negative GPA have milder disease and a lower frequency of relapse than those with ANCA-positive GPA. ANCA appearance portended higher disease severity and an increased frequency of relapses.