Introduction:
According to the 2021 Kidney Disease: Improving Global Outcomes (KDIGO) guidelines, rituximab, calcineurin inhibitors (CNIs), and cyclical cyclophosphamide with corticosteroids (CYC/CS) are recommended as first-line therapies for managing anti-proteinuric-resistant primary membranous nephropathy (PMN). However, data on the medium- and long-term outcomes of patients treated with rituximab remain sparse. This study aims to elucidate the medium-term outcomes (3 years) of rituximab treatment in Indian patients with PMN.
Methods:
This study was conducted at the Postgraduate Institute of Medical Education and Research (PGIMER) in Chandigarh, India. It included biopsy-confirmed PMN patients (aged ≥ 16 years) who tested positive for anti-PLA2R antibodies, exhibited resistance to anti-proteinuric therapies, or suffered complications related to nephrotic syndrome and who were subsequently treated with rituximab. Patients with active viral replication and secondary causes of membranous nephropathy were excluded from the study. Serum anti-PLA2R autoantibodies were quantified using an enzyme-linked immunosorbent assay (ELISA) with commercially available kits (EUROIMMUN, Lubeck, Germany).
Results:
A total of 75 patients received rituximab therapy between September 2011 and February 2020. Of these, 52 met the inclusion criteria and none of the exclusion criteria. The mean age of the patients was 41.77 ± 14.46 years, with over 60% being male. The median baseline urine protein excretion was 6.93 g/day (interquartile range [IQR]: 4.73–10.72), and the median serum creatinine level was 0.90 mg/dL (IQR: 0.72–1.12). The mean serum albumin was 2.64 ± 0.67 g/dL, and the estimated glomerular filtration rate (eGFR) was 93.76 ± 31.79 ml/min/1.73 m² at baseline. The median baseline anti-PLA2R antibody titre was 113.49 RU/ml (IQR: 55.20–265.67). A substantial reduction in proteinuria was noted from baseline to 6 months (3.45 g), 12 months (1.50 g), 18 months (1.14 g), 24 months (0.96 g), 30 months (0.55 g), and 36 months (0.35 g). After excluding four patients lost to follow-up, 30 out of 48 patients (62.5%) achieved relapse-free remission at three years. Serological remission (anti-PLA2R antibodies) at six months was attained in 68.6% of patients. A total of 11 patients experienced a relapse after initially achieving partial or complete remission within three years; over 80% of these patients attained remission following retreatment with rituximab or cyclical cyclophosphamide/corticosteroids, or supportive care. Additionally, 15 patients (28.8%) experienced one or more adverse events, with upper respiratory tract infections being the most prevalent (15.38%).
Conclusions:
At three years, two-thirds of patients treated with rituximab achieved relapse-free remission while maintaining an acceptable safety profile.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.