Post-infectious glomerulonephritis in pediatric patients over two decades: Severity-associated features

Background: The incidence of post-infectious glomerulonephritis (PIGN) has decreased over the last decades. As a result, recent epidemiological data from industrialized countries are scarce. Objectives: To evaluate patterns of PIGN in children and detect possible predictors of disease severity. Methods: We collected clinical and laboratory data of patients with PIGN admitted to Schneider Children’s Medical Center during 1994–2011. Diagnostic criteria included presence of hematuria with/without other features of nephritic syndrome along with hypocomplementemia and/or microbiological/ serological evidence of streptococcal infection. Patients with other diseases (systemic lupus erythematosus, vasculitis, etc.) were excluded from the study. Results: A total of 125 patients with a mean age of 5.8 ± 3.3 years (range 1.5–17.6), of whom 16% were < 3 years, matched the study criteria. Presenting features included hypertension in 103 (82.4%) patients, azotemia in 87 (70.2%), fever in 49 (40%), and elevated C-reactive protein in 75 (81.5%). Isolated macrohematuria was found in 21 (16%). Full-blown nephritic syndrome was diagnosed in 51 patients (41.1%) and 28 (22.9%) had nephritic syndrome with nephrotic-range proteinuria. Depressed C3 complement levels were associated with the presence of nephritic syndrome (OR 0.73, 95%CI 0.60–0.88, P = 0.001) as well as older age (OR1.24, CI 1.08–1.43, P = 0.001). At last follow-up (mean 42 months) all examined patients (100 of 125) had normal renal function, 6 had hypertension, and 1 had proteinuria. Conclusions: PIGN remains an important cause of glomerular disease in children and may affect very young patients. Nephrotic-range proteinuria with hypoalbuminemia seems to be more frequent than previously reported. Hypocomplementemia is associated with a more severe disease course, namely, azotemia and nephritic syndrome.