Z LI 1, J BULMAN 1, L BELL , R NANRA 1, B CHACKO 1,2
1John Hunter Hospital, Newcastle, Australia, 2Newcastle University, Newcastle, Australia
Introduction: Membranous nephropathy (MN) accounts for up to 20–40% of nephrotic syndrome in adults and is reported to be one of the most common forms of primary glomerulonephritis (GN) to result in ESRD. This retrospective cohort study aimed at characterising primary membranous nephropathy and identifying clinical predictors for ESRD (primary outcome) and progression (secondary outcome).
Method: We studied 221 consecutive patients (456 biopsies) with idiopathic membranous nephropathy over a 29-year period. Demographic, medical background, biopsy features, biochemical markers were recorded with follow up period of at least one year after biopsy diagnosis of MN. We stratified patients into two groups defined by >20% eGFR decline (progressors) and ≤20% eGFR decline (non-progressors). Variables are analysed using multiple logistic regression model to determine their association with renal progression. P values <0.05 were considered to indicate statistical significance.
Results: From the 112 patients (eligible to be included) followed up for a median of 6.4 years since diagnosis, only eight patients (7.14%) developed ESRD and 42 patients (37.5%) had > 20 % decline in GFR at last follow up. Statistical significance was not found in predictors of the primary outcome due to small number. In univariate analysis, lower eGFR (p=0.003) and nephrotic syndrome (p=0.037) at presentation predicted progression. Multiple logistic regression model identified age (OR=1.13, CI 1.03 to 1.23, P =0.009), MN biopsy stage (OR=2.51, 95% CI 1.02 to 6.20, p=0.045) and proteinuria (OR=1.25, CI 1.02 to 1.53, p=0.029) predicted progression.
Conclusions: Progression to ESRD is uncommon in MN, however many can have renal function decline long term. We found several predictors of renal progression consistent with previous studies.
Second year Advanced Trainee of Nephrology at John Hunter Hospital