Postinfectious
glomerulonephritis (PIGN) is primarily a childhood disease that occurs after an
upper respiratory tract infection or
impetigo; its occurrence in older patients is not well characterized. Here, we report 109 cases of PIGN in patients ≥65 years old diagnosed by renal biopsy. The male to female ratio was 2.8:1. An immunocompromised background was present in 61%, most commonly diabetes or
malignancy. The most common site of
infection was skin, followed by
pneumonia and
urinary tract infection. The most common causative agent was staphylococcus (46%) followed by streptococcus (16%) and unusual gram-negative organisms. Hypocomplementemia was present in 72%. The mean peak serum
creatinine was 5.1 mg/dl, and 46% of patients required acute dialysis. The most common light microscopic patterns were diffuse (53%), focal (28%), and mesangial (13%) proliferative
glomerulonephritis.
IgA-dominant PIGN occurred in 17%. Of the 72 patients with ≥3 months of follow-up (mean, 29 months), 22% achieved complete recovery, 44% had persistent renal dysfunction, and 33% progressed to
ESRD. The presence of diabetes, higher
creatinine at biopsy, dialysis at presentation, the presence of
diabetic glomerulosclerosis, and greater tubular
atrophy and interstitial
fibrosis predicted
ESRD. In summary, the epidemiology of PIGN is shifting as the population ages. Older men and patients with diabetes or
malignancy are particularly at risk, and the sites of
infection and causative organisms differ from the typical childhood disease. Prognosis for these older patients is poor, with fewer than 25% recovering full renal function.