Short-term renal and patient outcomes of primary immunoglobulin-associated mesangiocapillary glomerulonephritis: Insights from a developing country.

Background: Primary immunoglobulin (Ig)-associated mesangiocapillary glomerulonephritis (Ig-MCGN) is an immune complex glomerulonephritis of unknown etiology. It is a common cause of chronic kidney disease in developing countries. There is limited data available on renal and patient outcomes of this disease from developing countries.

Aim: To determine the short-term renal and patient outcomes of adults with a tissue-confirmed diagnosis of primary Ig-MCGN at a single center in Pakistan.

Methods: A retrospective cohort study of adult patients was conducted on biopsy-proven Ig-MCGN cases diagnosed between 1998 and 2019 at the Sindh Institute of Urology and Transplantation, Karachi, Pakistan. Secondary causes were excluded. The primary endpoint was renal survival without end-stage kidney disease (ESKD) or mortality. The secondary endpoint was the rate of remission during the 2-year follow-up period. Survival curves were made with the use of Kaplan-Meier estimates.

Results: A total of 163 patients were included in the study and their mean follow-up duration was 29.45 months ± 21.28 months. Among baseline characteristics, young age, lower estimated glomerular filtration rate, requirement of kidney replacement therapy, presence of crescents, and severity of interstitial fibrosis and tubular atrophy were found to have a significant association with renal outcomes. The renal outcomes were negatively correlated with the presence of hypertension, level of complements, and degree of proteinuria. In all, 63 (37.4%) patients were treated with steroids and 21 (13%) received combination therapy (cyclophosphamide with steroids). At 2 years, 124 (76.07%) patients were in complete remission or partial remission [56 (34.3%) and 68 (41.71%), respectively], while 32 (19.63%) patients progressed to ESKD and 7 (4.29%) patients died.

Conclusion: The outcomes of primary Ig-MCGN are guarded in Pakistan and require further prospective studies to improve our understanding of this relatively common disease so that more personalized treatment approaches can be developed.