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.