Clinicopathologic Features of IgA-Dominant Infection-Associated Glomerulonephritis: A Pooled Analysis of 78 Cases

Abstract

Backgrounds: IgA-dominant infection-associated glomerulonephritis (IgA-dominant IAGN) is a unique form of glomerulonephritis. There are numerous case reports in the literature. However, the risk factors, treatment approach, and outcomes of the disease are not clearly characterized. Methods: We completed a pooled analysis based on published literature. Clinical features, laboratory findings, and histopathological changes were analyzed. A logistic regression model was employed to identify the determinants of disease outcome, for example, end-stage renal disease (ESRD) or death. Results: Seventy-eight patients with IgA-dominant IAGN from 28 reports were analyzed. All of these patients showed granular IgA deposits predominantly along the glomerular peripheral capillary walls using immunofluorescence and majority showed subepithelial ‘hump-shaped' electron-dense deposits using electron microscopy. The majority of patients had hematuria (76/78), proteinuria (75/78), acute kidney injury (AKI) (66/78) and hypocomplementemia (43/75) without a previous history of renal disease. All of the patients had clinical infections at the time of presentation. Skin infections (19/78) and visceral abscesses (15/78) were frequently encountered, and staphylococcus was the most common pathogen. After treatment with antibiotics and/or supportive therapy, the renal function of 42 patients (54.5%) improved, 9 patients (11.7%) had persistent renal dysfunction, 15 patients (19.5%) progressed to ESRD, and 11 patients (14.3%) died. A multivariate regression analysis revealed that age (odds ratio [OR], 30.71; 95% confidence interval [CI], 2.53-373.07; p = 0.007) and diabetes mellitus (DM) (OR, 16.65; 95% CI, 1.18-235.84; p = 0.038) were independent risk factors for ESRD or death. Conclusions: IgA-dominant IAGN has unique clinicopathological manifestations and treatment responses. Age and DM are independent risk factors associated with an unfavorable prognosis for IgA-dominant IAGN.