Eculizumab in rapidly progressive glomerulonephritis: a case-series report

To describe the clinical outcomes and safety profile of eculizumab as adjunctive therapy in a case series of patients with rapidly progressive glomerulonephritis (RPGN) due to anti-glomerular basement membrane (GBM) disease and anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV).

We reported 7 patients with AAV and 5 patients with anti-GBM disease who presented to our center between March 2025 and January 2026. All patients received eculizumab (900 mg, 1-4 doses) in addition to standard immunosuppressive therapy. Serum creatinine (Scr), urinary red blood cell (uRBC) count, urine protein-to-creatinine ratio (UPCR), and dialysis dependence were assessed at baseline and at 3 months. Adverse events were monitored throughout follow-up.

In AAV patients, mean Scr decreased from 407.38 μmol/L to 231.27 μmol/L (p = 0.025), mean uRBC from 384.27/μL to 68.75/μL (p = 0.033), and mean UPCR from 2.20 g/g to 1.64 g/g (p = 0.179) at the 3rd month. In anti-GBM patients, mean Scr declined from 575.07 μmol/L to 263.80 μmol/L (p = 0.024), mean uRBC from 1648.60/μL to 461.92/μL (p = 0.132), and mean UPCR from 10.88 g/g to 3.75 g/g (p = 0.126). At baseline, 6 patients required renal replacement therapy, and after treatment, 4 became dialysis-independent. One AAV patient progressed to hemodialysis, and one anti-GBM patient remained dialysis-dependent. All anti-GBM antibodies and MPO-ANCA (except one patient) seroconverted to negative at month 3. During follow-up, only one case of COVID-19 infection and one oral ulcer were recorded; no severe infections occurred.

In this descriptive case series, we observed trends toward improved renal function and hematuria at 3 months in patients with severe RPGN who received eculizumab in addition to standard immunosuppression, with earlier initiation and milder baseline renal impairment appearing to correlate with more favorable outcomes. Nevertheless, the lack of a control group and the marked interpatient variability in baseline characteristics and concomitant therapies preclude any conclusion regarding a causal effect of eculizumab. Instead, these data serve as real-world observations that can generate hypotheses for future studies. Definitive evidence on the efficacy and safety of eculizumab in RPGN must await larger, prospective, controlled investigations.