Objective: Postinfectious glomerulonephritis (PIGN) is one of most common causes of acute glomerular disease in children worldwide. Since its incidence has decreased over the last few decades recent epidemiological data from industrialized countries is scarce. Our study was designed to evaluate patterns of PIGN and detect possible predictors of disease severity.
Methods: Clinical and laboratory data was collected on patients with diagnosis of PIGN who were admitted to Schneider Children's Medical Center over a period of 17 years (1994-2011). Diagnostic criteria included: presence of hematuria and\or proteinuria with or without other features of nephritic syndrome along with hypocomplementemia and\or serological evidence of streptococcal infection.
Results: 125 patients were diagnosed with PIGN. Mean age at diagnosis was 5.75±3.27 years, 16% were younger than 3 years. Abnormal renal function was found in 87 (70.16%) patients, Fifty one (41.1%) suffered from nephritic syndrome and 116 (92.8%) had significant proteinuria, 40 (32.5%) had nephrotic syndrome, 20 (16.4%) children had features of both nephritic and nephrotic syndromes. Fever was present in 49 (40.02%) patients and C-reactive protein (CRP) was elevated in 74(80.4%).One patient needed short-term dialysis, in 7 patients kidney biopsy was performed because of unusual course of the disease and showed features compatible with PIGN. At the end of the follow-up (median duration 13 months) all 116 patients in whom data was available had normal renal function and only one had significant proteinuria. High blood pressure was found in (6%) patients. No change in clinical and laboratory patterns of the disease has occurred over the study period.
Significant association was found between nephritic syndrome and low serum C3 (OR:0.73, CI:0.60-0.88, p=0.001) and older age (OR:1.24, CI:1.08-1.43, p=0.001), AUC=0.76.
Nephrotic syndrome was significantly associated with low serum C3 (OR:1.19, CI:1.05-1.385, P=0.01), female gender(OR:2.65, CI:1.03-6.8, P=0.05), younger age (OR:0.84, CI:0.71-0.98, p=0.035) and anemia (OR:3.46, CI-1.01-11.8, p=0.032).(AUC)=0.73.
Conclusion: PIGN remains an important cause of glomerular disease in children and may affect very young patients. Nephrotic syndrome seems more common than previously appreciated. Fever and elevated CRP levels may be found during the acute phase. Depressed C3 serum levels might be a marker of more severe disease including presence of nephritic and nephritic syndromes. Long-term follow-up is needed to detect late consequences of the disease.
