Occurrence and Nature of Glomerular Lesions after Group A Streptococci Infections in Children

Abstract

A prospective study of renal involvement after group A streptococci infections was undertaken in 248 children who had weekly examinations for at least 6 weeks. Examination included urinalysis and measurement of serum complement (CH50) and antistreptolysin 0 titers. One hundred and ninety-four children remained normal. Fifty-four children showed either transient CH50depression (19 patients) or mild urinary abnormalities (15 patients), or both (20 patients), although they remained clinically asymptomatic. Renal biopsy specimens of all children with depressed complement activity and minor urinary abnormalities were examined by light and electron microscopy and by immunohistology. Lesions ranged from mild increase of mesangium and endothelial proliferation to the characteristic features of acute glomerulonephritis. The immune staining was granular. M and T typing of streptococci isolated showed various types that generally have been found in epidemics of acute glomerulonephritis. The incidence of glomerular injury after infection with group A streptococci seems much higher than previously thought. Only a few patients seem to become symptomatic; the others escape detection.