Acute rheumatic fever and poststreptococcal acute glomerulonephritis caused by T serotype 12 Streptococcus.

We present a rare case of a 10 year old Japanese boy with acute rheumatic fever accompanied with poststreptococcal acute glomerulonephritis. We isolated group A Streptococcus serotype T 12, a strain that was thought to be nephritogenic but not rheumatogenic, from throat culture. Although rare, physicians should be aware that acute renal disease may accompany rheumatic fever.