Asymptomatic acute poststreptococcal glomerulonephritis following upper respiratory tract infections caused by Group A streptococci.

During an observation period of 1-2 years in 2 different districts in Japan, 104 patients were found to have upper respiratory infections caused by group A streptococci. Fourty-nine of these patients were followed prospectively to determine if renal involvement would occur. Twelve patients developed transient serum complement (CH50) depression and urinary abnormality, and 2 of these developed mild hypertension.

Role of a streptococcal antigen in the pathogenesis of acute poststreptococcal glomerulonephritis. Characterization of the antigen and a proposed mechanism for the disease.

We studied the significance of a streptococcal protein (preabsorbing Ag) (PA-Ag) in the pathogenesis of acute poststreptococcal glomerulonephritis (APSGN). This protein was isolated from nephritogenic streptococci. Purification of PA-Ag was achieved by chromatography, followed by Sephadex IEF.

Hypercalcemia in childhood renal tumors.

Hypercalcemia is an uncommon complication of childhood renal tumors. It is exclusively seen in infants 6 months of age or younger with malignant rhabdoid tumor of the kidney (MRTK) or congenital mesoblastic nephroma (CMN). Secretion of parathormone or prostaglandin E2 by the tumor cells is responsible for the hypercalcemia in most of these patients.

Circulating immune complexes in patients with uncomplicated group A streptococcal pharyngitis and patients with acute poststreptococcal glomerulonephritis.

To investigate the role of circulating immune complexes (CIC) in the pathogenesis of acute poststreptococcal glomerulonephritis (AGN), sera were obtained serially from 13 patients with biopsy-proven AGN, 16 patients with group A streptococcal infection, and 20 age- and sex-matched controls. Samples were analysed for Clq-binding activity (Clq-BA), levels of IgG, IgA, IgM, C3 and C4, and antibody titres to streptococcal enzymes. Significant elevation of Clq-BA was observed in 11 patients (84.