Clinicopathological profile and outcome of adult infection-related glomerulonephritis: A prospective follow-up study

Background. Infection-related glomerulonephritis (IRGN) in adults is witnessing a dramatic shift in its epidemiology and outcome. Adult IRGN studies are all retrospective in nature, and Indian studies are scarce. Methods. We did this prospective study (September 2016–April 2018) on all patients with biopsy-proven IRGN and age ≥18 years satisfying three of five diagnostic criteria. Patients with persistent hypocomplementaemia (>3 months) were excluded. We did electron microscopy in those without a minimum of three diagnostic criteria and did an extensive search for any occult infection in every patient. Results. Forty-five patients were studied with a mean (SD) follow-up of 45.7 (20) weeks. Their mean age was 41.5 years (18–70 years), with a female preponderance (1:1.25). At presentation, the majority had oedema (100%), oliguria (84.4%), hypertension (80%) and haematuria (77.8%). Of them, 86.7% had renal insufficiency and 35.6% required dialysis. Only 53.3% of them had evidence of antecedent/ current infection, with skin/subcutaneous focus being the most common site. Hypocomplementaemia was present in 82.2% of patients. Salient pathological features were endocapillary proliferation (93.3%), neutrophilic infiltration (88.9%), presence of crescents (17.8%), interstitial infiltration (24.4%), moderate-to-severe interstitial fibrosis with tubular atrophy (IFTA; 15.5%) and underlying diabetic glomerulosclerosis (8.9%). Only 66.7% of patients made complete renal recovery. By logistic regression analysis, the predictors of poor outcome were a requirement for dialysis at presentation (p=0.04) and presence of IFTA (p = 0.03). Conclusion. A proportion of adult IRGN patients progress to chronic kidney disease.