Clinical characteristics and short term outcomes of childhood immune complex membranoproliferative glomerulonephritis and C3 glomerulopathy: a single centre retrospective study.

Abstract

Background: Membranoproliferative glomerulonephritis, with its immune complex variety and C3 glomerulopathy, is a rare glomerular disease in children. The objective of this study was to determine the clinical features and short-term outcomes in children.

Methods: This retrospective cohort study was conducted at the Department of Pediatric Nephrology, Sindh Institute of Urology and Transplantation, Karachi, from January 2020, to June 2022. All the children with membranoproliferative lesions identified via light microscopy and less than 18 years were included.

Results: A total of 35 children were diagnosed MPGN, 7 (20%) with C3 glomerulopathy and 28 (80%) idiopathic immune complex MPGN. In the IC-MPGN group, 14 patients (50%) had crescentic glomerulonephritis. Induction therapy consisted of cyclophosphamide and methylprednisolone followed by steroids, azathioprine was prescribed for maintenance phase. At the 18-month follow-up, 9 (64%) patients were in complete remission (CR), 3 (21%) were in partial remission (PR), and 2 (15%) progressed to chronic kidney disease. The remaining 14 (50%) had non-crescentic idiopathic IC-MPGN and were prescribed steroids only, cyclophosphamide with steroids and angiotensin converting enzyme inhibitors. The outcomes at 18 months were relatively poorer than those with the crescentic variety. Four (28%) patients achieved CR, 8 (56%) PR, and 2 (14%) did not respond. In the C3 glomerulopathy cohort, 3 (43%) had crescentic glomerulonephritis, one child was in CR, and two were in PR. The non-crescentic C3G were kept on ACEI 3 (43%) and Mycophenolate mofetil 1 (14%). One child treated with ACEIs achieved a PR, two were in CR, and one child treated with MMF did not respond.

Conclusions: The outcome of MPGN (immune complex and C3G) is quite variable, and aggressive therapy for crescentic glomerulonephritis may show a favourable response. Considering the similar clinical presentations and patient outcomes, C3G and IC-MPGN might represent two facets of the same disease.