Stimulation of the antitumor activity of the immune system using immune checkpoint inhibitors (ICIs) has proven efficacy in the treatment of multiple types of cancer, inducing the speedily expanding approval of therapeutic indications for ICIs. The literature regarding the immune-related toxicities and nephrotoxicity of ICIs is limited. Herein, we present a patient with lung cancer treated with atezolizumab, an IgG1 monoclonal antibody aimed at the programmed death ligand 1 (PD-L1), who presented with vasculitic skin rash and rapidly deteriorating renal function, new onset of significant glomerular hematuria and proteinuria. The renal biopsy revealed acute necrotizing pauci-immune vasculitis, with fibrinoid necrosis. The patient received a course of high-dose glucocorticoids with recovery of renal function and skin lesions. Further immunosuppressive therapy was withheld, due to active malignancy in the lung, while oncology consultation recommended the continuation of treatment with atezolizumab, as the patient had shown substantial response.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (ANCA-vasculitis) is an autoimmune disease characterized by inflammation and necrosis of small or medium vessels. In the past, the role of the complement in the pathogenesis of ANCA-vasculitis has been underestimated, due to the paucity of the complement at sites of injured glomeruli. Following evidence from animal models of the major role of the complement in pathogenesis of ANCA-vasculitis, the complement has again attracted interest. Immunohistology analysis of pauci-immune glomerulonephritis—ANCA glomerulonephritis (ANCA-GN)—reveals the presence of complement products and membrane attack complex, suggesting their involvement in the disease process. Researchers emphasize the complement classical or lectin pathway as a contributor to the development of ANCA-vasculitis. The era of targeted therapies to suspend the complement activation as a therapy for ANCA-vasculitis has arrived, and thus, the comprehension of its role is very important. This review summarizes recent insights on the important role of complement activation in the development of ANCA-vasculitis as well as the emerging therapeutic possibilities that target complement components for the treatment of this condition.

Objectives: Vaccination against SARS-CoV-2 has been vital in alleviating the spread of the recent pandemic. We aimed to estimate the frequency and type of adverse events related to SARS-CoV-2 vaccine in patients with lupus nephritis (LN), and assess its impact, if any, on the risk of subsequent reactivation of nephritis. Methods: This was a retrospective, multicenter study which included patients with biopsy-proven LN, who had received at least one vaccine dose. Patients who ended up with end-stage kidney disease (ESKD) prior to vaccination or were diagnosed with LN after vaccination were excluded. Adverse events, systemic or local, COVID-19 outcomes (full recovery, death, or long COVID-19), outcome of LN (remission, refractory disease, relapse, ESKD or death), demographics, laboratory measurements, and immunosuppressive regimens were recorded. Results: Sixty-seven patients were included. The median age was 33 (20–46) years. Induction therapy for LN was administered to 92.5% of patients and 74.6% received maintenance therapy. Of these, 94.02% were in remission at vaccination. The BNT162b2 mRNA vaccine was administered in 97.01% of cases, with mild systemic adverse symptoms in 28.35% (myalgias 17.91%, headache 13.43%, arthralgias 13.43%, and fever 10.44%) and local adverse effects in 35.82% (pain 25.37%, swelling 13.43%). Overall, among patients in remission upon vaccination, two (3.17%) experienced a LN relapse within 5.75 (±0.25) months, while 75% of those with active disease at vaccination achieved remission within 21 (±2) months. Conclusions: SARS-CoV-2 vaccination appears safe for LN patients without serious adverse events occurring, and there is no significant impact in the clinical course of the disease.

Background/Objectives: Acute interstitial nephritis (AIN) is a cause of acute kidney injury (AKI) during immune checkpoint inhibitor (ICI) therapy, but biopsy-confirmed data are limited. We estimated institutional proportions of biopsy-confirmed AIN clinically attributed to ICI exposure (ICI-AIN) and characterized its presentation, pathology, treatment, and renal outcomes. Methods: We retrospectively reviewed native renal biopsies performed at Attikon University Hospital from February 2021 through December 2025. Cases were included when ICI exposure preceded AKI and the treating nephrology team documented clinicopathologic attribution to ICI exposure. Results: AIN was identified in 15 of 339 native renal biopsies; 12 cases were attributed to ICI exposure, representing 3.5% of native renal biopsies and 0.8% of 1472 unique ICI-treated patients. Median serum creatinine increased from 1.05 mg/dL at baseline to 3.50 mg/dL at biopsy assessment. During the AKI episode, 10 patients (83.3%) met Kidney Disease: Improving Global Outcomes (KDIGO) criteria for stage 3 AKI. All patients had pyuria, negative urine cultures, and subnephrotic proteinuria. Hematuria and peripheral eosinophilia occurred in four and two patients, respectively. All patients received corticosteroids, and none required kidney replacement therapy. Complete, partial, and absent recovery occurred in eight, two, and two patients, respectively; under the stricter baseline-relative definition, the corresponding numbers were five, five, and two. Conclusions: Biopsy-confirmed ICI-AIN was infrequently detected. Severe AKI was common, urinary findings were nonspecific, and residual renal dysfunction frequently persisted after corticosteroid treatment.