Acute Postinfectious Glomerulonephritis in the Modern Era

Acute postinfectious glomerulonephritis (APIGN) is uncommon in adults, and its incidence is progressively declining in developed countries. To our knowledge there are no modern North American series addressing epidemiology and outcome. Here we report the clinical and pathologic findings in 86 cases of adult APIGN diagnosed by renal biopsy in a large New York referral center between 1995 and 2005. The male:female ratio was 2:1, and mean age was 56 years, with 33.7% aged older than 64 years. Of the patients, 38.4% had an immunocompromised background, including diabetes (29.1%), malignancy (4.7%), alcoholism (2.3%), acquired immunodeficiency syndrome (AIDS) (2.3%), and intravenous drug use (1.2%). The most common sites of infection were upper respiratory tract (23.3%), skin (17.4%), lung (17.4%), and heart/endocarditis (11.6%). The 2 most frequently identified infectious agents were streptococcus (27.9%) and staphylococcus (24.4%). Hypocomplementemia was present in 73.9% of patients. The most common histologic patterns were diffuse (72.1%), focal (12.8%), and mesangial (8.1%) proliferative glomerulonephritis. Outcome analysis was performed on the 52 patients with a follow-up of >/=3 months (mean, 25 mo). Among the 41 patients without underlying diabetic glomerulosclerosis, 23 (56.1%) achieved complete remission, 11 (26.8%) had persistent renal dysfunction, and 7 (17.1%) progressed to end-stage renal disease (ESRD). Of the 11 patients with underlying diabetic glomerulosclerosis, 2 (18.2%) had persistent renal dysfunction, and the remaining 9 (81.8%) progressed to ESRD (p < 0.001). In patients without underlying diabetic glomerulosclerosis, correlates of complete remission were younger age, female sex, lower serum creatinine at biopsy, and absence of immunocompromised state. By multivariate analysis, age and serum creatinine at biopsy inversely correlated with complete remission, and serum creatinine at biopsy was the only correlate with ESRD. Outcome did not correlate with any pathologic feature (including crescents) or steroid treatment. Diabetes and aging have emerged as major risk factors for adult APIGN. Full recovery of renal function can be expected in just over half of patients, and prognosis is dismal in those with underlying diabetic glomerulosclerosis.