COVID vaccine-induced lupus nephritis: Case report and review of the literature.

Vaccines offer an effective strategy to prevent infectious diseases with minimal adverse effects. On rare occasions, vaccination can disrupt the immune response leading to induction of autoimmune diseases. We describe a case of new-onset lupus nephritis following COVID-19 vaccination with the first dose of the Pfizer vaccine. Her symptoms and lab values improved with steroids, hydroxychloroquine, and mycophenolate mofetil.

Kidney Failure in Pauci-immune Crescentic Glomerulonephritis: Rationale for Immunosuppression to Improve Kidney Outcome.

PURPOSE OF REVIEW: Pauci-immune crescentic glomerulonephritis is the hallmark finding in ANCA-associated vasculitis (AAV) when the kidneys are affected. The rationale for immunosuppression in AAV is based on the underlying autoimmune nature of the disease. Overall remission rates, kidney outcomes, and the burden of disease have greatly improved since the discovery of various immunosuppressive therapies, but relapses remain common, and a significant proportion of patients continue to progress to end-stage kidney disease. Here, we review the role of immunosuppressive therapies for the treatment of pauci-immune crescentic glomerulonephritis. RECENT FINDINGS: Besides the recognized role of B and T cells in the pathogenies of AAV, the focus on the contribution of inflammatory cytokines, neutrophil extracellular traps (NETs), and the complement system allowed the discovery of new therapies. Specifically, the C5a receptor blocker (avacopan) has been approved as a glucocorticoid-sparing agent. Additionally, based on observational data, more clinicians are now using combination therapies during the induction phase. There is also an evolving understanding of the role of plasma exchange in removing ANCA antibodies. Furthermore, the recent development of risk score systems provides physicians with valuable prognostic information that can influence decisions on immunosuppression, although future validation from larger cohorts is needed. The over-activation of various immune pathways plays a significant role in the pathogenesis of pauci-immune crescentic glomerulonephritis in AAV. Immunosuppression is, therefore, an important strategy to halt disease progression and improve overall outcomes. Relapse prevention while minimizing adverse events of immunosuppression is a major long-term goal in AAV management.

ANCA-Associated Vasculitis.

ANCA-associated vasculitis (AAV) is a necrotizing, small-to-medium vessel vasculitis associated with significant morbidity and mortality. AAV is a systemic autoimmune disease affecting kidneys, eyes, sinuses, peripheral nerves, skin, and upper and lower respiratory tracts. AAV tends to present in characteristic phenotypes categorized clinically as granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic GPA (EGPA). Kidney involvement is a common feature of AAV, and has important implications on disease prognosis and management. Existing therapies have been refined and improvements in our understanding of the pathophysiology of AAV has led to approval of novel therapies. In this review, we provide an overview of epidemiology, disease mechanisms, clinical presentation and review therapeutic strategies for induction and maintenance of remission.

Pneumocystis jirovecii Pneumonia Prophylaxis in Patients with ANCA Vasculitis on Rituximab Maintenance Therapy.

Introduction: Although an increased risk of Pneumocystis jirovecii pneumonia (PJP) has been reported in adults receiving rituximab for induction therapy, current evidence is lacking on the utility of PJP prophylaxis in ANCA-associated vasculitis (AAV) patients on maintenance rituximab therapy. The purpose of this study was to compare the incidence of PJP pneumonia and the outcomes of AAV patients with and without PJP prophylaxis. Methods: We performed an observational, single-center, retrospective study examining patients with AAV in clinical remission and on rituximab maintenance therapy. We divided the patients into two groups: those with and without PJP prophylaxis. We explored factors associated with PJP prophylaxis use. We additionally looked at several outcomes, including PJP infections, infections requiring hospitalizations, end-stage kidney disease (ESKD), and death. Data were analyzed using T test, Fisher's exact test, univariate, and multivariate logistic regression as appropriate. Results: A total of 129 patients with mean follow-up time of 7.2 (5.4) years were included: 44% received PJP prophylaxis and 56% of patients did not. There were no PJP infections in the entire cohort. Lung involvement was associated with increased odds of prescribing PJP prophylaxis (OR: 4.09 [95% CI: 1.8-9.82]). PJP prophylaxis did not decrease infection rates requiring hospitalizations, ESKD, or death. Glucocorticoid use, however, was associated with increased rates of infections requiring hospitalizations (OR: 5.54 [95% CI: 2.01-15.4]) and death (OR: 4.67 [95% CI: 1.36-15.71]) even after adjustment for age, gender, and use of PJP prophylaxis. Conclusion: Regardless of the use of PJP prophylaxis during the maintenance phase of AAV management, PJP pneumonia was not observed. AAV patients with lung involvement were more likely to be on PJP prophylaxis.

Clinical Presentation and Treatment Outcomes of Renal Medullary Angiitis in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: A Single-Center Case Series.

Introduction: Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) with renal involvement primarily affects the renal cortex and presents with key histopathologic findings of a pauci-immune necrotizing and crescentic glomerulonephritis. Infrequently reported and poorly characterized is renal medullary angiitis (RMA), a pathologic variant of AAV primarily involving the renal medulla. This study seeks to describe the presentation and treatment outcomes of RMA. Methods: In this single-center cohort, renal pathology samples classified as AAV with renal involvement underwent secondary review to determine if they met histopathologic criteria for RMA. Demographic, clinical, and laboratory data were obtained via electronic medical record review. Descriptive statistical analysis was performed on key variables. Results: Of the 136 kidney biopsy samples classified as AAV with renal involvement, histopathologic features of RMA were present in 13 cases. The mean (SD) age at the time of RMA diagnosis was 65 (19) years, and 54% were female. Most cases presented with extrarenal manifestations of disease. Initial median (IQR) estimated glomerular filtration rate and proteinuria on presentation were 16 (10-19) mL/min/1.73 m2 and 1,100 (687-2,437) mg, respectively. The primary histologic features were high degrees of interstitial inflammation comprised leukocytes, neutrophils, plasma cells, and eosinophils along with either interstitial hemorrhage or necrosis. All patients were treated with glucocorticoids in combination with either cyclophosphamide, rituximab, or mycophenolate. All patients achieved disease remission. During a median (IQR) follow-up of 42 (14-68) months, 1 patient reached ESKD and 1 patient died. Conclusions: In this single-center case series, we identified the presence of RMA in 9.5% of AAV samples that underwent secondary review. RMA presented with severe impairment in renal function and multisystem disease. Standard of care immunosuppression for AAV was effective for remission induction in RMA. It remains unclear whether standard prognostication tools are useful in this population.

Real-World Experience With Avacopan in Antineutrophil Cytoplasmic Autoantibody-Associated Vasculitis.

Introduction: Postmarketing data on outcomes of avacopan use in antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) are lacking. Methods: We performed a multicenter retrospective analysis of 92 patients with newly diagnosed or relapsing AAV who received therapy with avacopan. The coprimary outcome measures were clinical remission at 26 and 52 weeks. We use descriptive statistics and univariate logistic regression to assess outcomes and predictors of remission, respectively. Results: Of the 92 patients, 23% (n = 21) had a baseline estimated glomerular filtration rate (eGFR) < 15 ml/min per 1.73 m2 and 10% on kidney replacement therapy at baseline. Among those with kidney involvement, mean (SD) enrollment eGFR was 33 (27) ml/min per 1.73 m2 with a mean (SD) change of +12 (25) and +20 (23) ml/min per 1.73 m2 at weeks 26 and 52, respectively. In addition to avacopan, 47% of patients received combination therapy of rituximab and low-dose cyclophosphamide, and 14% of patients received plasma exchange (PLEX). After induction, the median (interquartile range [IQR]) time to start avacopan was 3.6 (2.1-7.7) weeks, and the median time to discontinue prednisone after starting avacopan was 5.6 (3.3-9.5) weeks. Clinical remission was achieved in 90% of patients at week 26 and 84% of patients at week 52. Of the patients, 20% stopped avacopan due to adverse events, with the most common being elevated serum aminotransferases (4.3%). Conclusion: A high rate of remission and an acceptable safety profile were observed with the use of avacopan in the treatment of AAV in this postmarketing analysis, including the populations excluded from the ADVOCATE trial.

Histologic and Clinical Factors Associated with Kidney Outcomes in IgA Vasculitis Nephritis.

BACKGROUND: Nephritis is a common manifestation of IgA vasculitis and is morphologically indistinguishable from IgA nephropathy. While MEST-C scores are predictive of kidney outcomes in IgA nephropathy, their value in IgA vasculitis nephritis has not been investigated in large multiethnic cohorts. METHODS: Biopsies from 262 children and 99 adults with IgA vasculitis nephritis ( N =361) from 23 centers in North America, Europe, and Asia were independently scored by three pathologists. MEST-C scores were assessed for correlation with eGFR/proteinuria at biopsy. Because most patients ( N =309, 86%) received immunosuppression, risk factors for outcomes were evaluated in this group using latent class mixed models to identify classes of eGFR trajectories over a median follow-up of 2.7 years (interquartile range, 1.2-5.1). Clinical and histologic parameters associated with each class were determined using logistic regression. RESULTS: M, E, T, and C scores were correlated with either eGFR or proteinuria at biopsy. Two classes were identified by latent class mixed model, one with initial improvement in eGFR followed by a late decline (class 1, N =91) and another with stable eGFR (class 2, N =218). Class 1 was associated with a higher risk of an established kidney outcome (time to ≥30% decline in eGFR or kidney failure; hazard ratio, 5.84; 95% confidence interval, 2.37 to 14.4). Among MEST-C scores, only E1 was associated with class 1 by multivariable analysis. Other factors associated with class 1 were age 18 years and younger, male sex, lower eGFR at biopsy, and extrarenal noncutaneous disease. Fibrous crescents without active changes were associated with class 2. CONCLUSIONS: Kidney outcome in patients with biopsied IgA vasculitis nephritis treated with immunosuppression was determined by clinical risk factors and endocapillary hypercellularity (E1) and fibrous crescents, which are features that are not part of the International Study of Diseases of Children classification.