Non-Diabetic Renal Diseases in Diabetic Patients with Emphasis on Infection-Related Glomerulonephritis

Abstract

ABSTRACT Background: Non -diabetic renal diseases (NDRDs) in diabetics are treatable and therefore have better prognosis. Infection-related glomerulonephritis (IRGN) is being frequently reported as NDRD. Objective: We attempt to study the clinicopathologic spectrum of diabetic patients with biopsy proven IRGN. Materials and Methods: This was a retrospective analysis of renal biopsies performed in diabetic patients from January 2014 to June 2021. Demographic data, clinical features, and other laboratory findings were collected. The renal biopsies were classified into diabetic nephropathy (DN) and NDRD. The patients with diagnosis of IRGN were studied in detail. Results: Of the 1972 renal biopsies done in diabetic patients, 537 were NDRD and 1233 were DN. The commonest NDRD was tubulo-interstitial nephritis (n = 173) followed by IRGN (n = 74). The IRGN cases were in the age range of 5-78 years (median-53.5) with M: F = 3.4:1. The median duration of diabetes was six years, with median HbA1c = 7.5. Proteinuria ranged from 0.041 to 13 g/day (median = 1.95) with median serum creatinine of 3.7 mg%. History of preceding infection was present in nine cases. These patients presented with rapidly progressive renal failure (RPRF, 17), nephritic syndrome (27), nephrotic syndrome (27), and asymptomatic proteinuria (3). Median C3-level was 47 mg/dl. The biopsies showed classic endocapillary hypercellularity with neutrophils in mesangium, 45 cases had associated DN. Immunofluorescence performed in 54 cases showed coarse granular deposits of C3C. Conclusions: IRGN should be kept in mind in diabetic patients presenting with RPRF or nephrotic proteinuria. The biopsy and immunofluorescence helps in accurate diagnosis.