Outcome of Patients with Primary Immune-Complex Type Mesangiocapillary Glomerulonephritis (MCGN) in Cape Town South Africa

BACKGROUND AND AIM: Mesangiocapillary glomerulonephritis (MCGN) is a common cause of chronic kidney disease in developing countries. Data on the renal outcome of patients with idiopathic MCGN is limited. The aim of this study is to investigate the outcome of patients with idiopathic MCGN presenting to the Groote Schuur Hospital (GSH) Renal Unit in Cape Town. MATERIALS AND METHODS: A retrospective study of patients with idiopathic MCGN followed up at our clinic. Seventy-nine patients with no identifiable cause of MCGN were included for analysis. A composite renal outcome of persistent doubling of serum creatinine or end stage renal disease (ESRD) was used. Kaplan Meier survival and Cox regression analysis were used to assess survival and identify factors predicting the outcome. RESULTS: The mean age at biopsy was 33.9±13.6 years and 41.8% were black. Mean duration of follow up was 13.5±18.8 months. Twenty-three patients (34.2%) reached the composite endpoint. Overall, median renal survival was 38.7±11.7 months (95% CI 15.7–61.8) with 2-year and 5-year renal survival of 61% and 40.3% respectively. No significant difference was found for renal survival between males and females, treatment or non-treatment with immunosuppression, presence or absence of crescents or histological type of MCGN (p>0.05). On univariate Cox-regression analysis, factors found to be associated with the outcome were the estimated glomerular filtration rate at biopsy (OR 0.97 [95%CI: 0.95–0.99], p<0.0001), black race (OR 3.03 [95%CI: 1.27–7.21], p = 0.012) and presence of interstitial fibrosis in the biopsy (OR 2.64 [95%CI: 1.07–6.48], p = 0.034). Age, systolic blood pressure and attaining complete or partial remission approached significant values with the endpoint. CONCLUSIONS: The outcome of idiopathic MCGN in Cape Town is poor and requires further prospective studies to improve our understanding of this common disease.