Primary membranous nephropathy in Latin America: A multicentre study

Abstract

Introduction

Primary membranous nephropathy (PMN) poses a therapeutic challenge, necessitating effective treatment approaches. This study aims to assess the response of PMN patients to three treatment strategies: traditional Ponticelli scheme, monthly intravenous cyclophosphamide, and calcineurin inhibitors over a 6–12-month follow-up.

Objective

This study evaluates primary membranous nephropathy (PMN) patients diagnosed by renal biopsy, examining their response to three treatment schemes over a 6–12-month follow-up: traditional Ponticelli scheme, monthly intravenous cyclophosphamide, and calcineurin inhibitors.

Materials and methods

A multicentre retrospective analysis in three Latin American countries (Argentina, Colombia, Bolivia) encompassing 110 PMN patients diagnosed by renal biopsy over 5 years. Excluding 29 with incomplete records or a 12-month follow-up, patients were grouped by treatment: Ponticelli, intravenous cyclophosphamide, and calcineurin inhibitors. Clinical, histological, and laboratory features were compared for complete remission at one year according to KDIGO 2020 guidelines. Univariate and multivariate analyses were conducted. A comparative analysis of remission rates and adverse effects between the oral cyclophosphamide regimen versus calcineurin inhibitors was performed.

Results

Male sex showed the highest prevalence at 60.5%, with an average age of 50.3 ± 14, mainly in stage II (53.1%), and risk distribution (46.9% moderate, 53.1% high). CP IV showed higher haematuria, older age, and lower albuminaemia. While CP IV showed a trend toward higher complete remission (83%) at 12 months compared to CP PO (52%) and CNI (79%), statistical significance (p = .08) was not reached. Complications were significantly lower with CP IV (6.7%) and CNI (4.2%) than with CP PO (41%) with an OR 9.62 and a p-value of .006. These findings underscore the nuanced relationship between treatment modalities, remission rates, and complications in primary membranous nephropathy patients.

Conclusion

The traditional Ponticelli scheme did not significantly differ from intravenous cyclophosphamide and calcineurin inhibitors in achieving complete remission at 6 and 12 months. However, the Ponticelli group exhibited higher cumulative cyclophosphamide doses and more infectious complications compared to other subgroups.