Clinicopathological study of infection-associated glomerulonephritis in adults

Infection-associated glomerulonephritis is uncommon in adults. In the present study, we have tried to determine the mode of presentation, the spectrum of morphology, and the prognostic factors for renal outcome in adult patients with infection-associated glomerulonephritis. Between July 2000 and June 2008, 20 adults (14 males, 6 females) with infection-associated glomerulonephritis were managed at a medical center in Taiwan. The patients' records were retrospectively reviewed with respect to clinical presentation, microbiology, serology, morphology of renal biopsy, and clinical course. All patients developed acute renal failure and the majority required dialysis support. The most frequently identified infectious agent was Staphylococcus (60%). Histological characteristics showed two distinct patterns of glomerulonephritis. One was diffuse endocapillary proliferative glomerulonephritis (65%) and the other was focal mesangial proliferative glomerulonephritis (35%). There were no significant differences in the clinical presentation and outcome between the two groups. However, glomerular neutrophil infiltration and subepithelial hump-shaped deposits were more commonly present in diffuse endocapillary proliferative pattern (P = 0.017, 0.004, respectively). Moreover, the percentage of patients with focal mesangial proliferative pattern significantly increased over time (P < 0.001). At the end of follow-up, 6 patients (30%) had died, 6 (30%) were in remission, 4 (20%) had renal insufficiency, and 4 (20%) were on chronic dialysis. The prognostic factors for renal outcome were peak serum creatinine, percentage of glomeruli affected by crescents, and interstitial infiltration (P = 0.02, 0.05, 0.01, respectively). Our data suggested that Staphylococcus had become the leading pathogen in adult infection-associated glomerulonephritis over the past 10 years. Furthermore, atypical histological feature with focal mesangial proliferative pattern was increasingly identified over time. The prognosis was still guarded, with a considerable mortality rate and risk for developing chronic renal failure.