Immunological abnormalities in children with acute rheumatic carditis and acute post-streptococcal glomerulonephritis.

Immunological functions were investigated in 10 children with acute rheumatic fever and 11 children with acute nephritis to try and elucidate the cause of heart damage in acute rheumatic fever. Children with acute rheumatic fever and carditis showed an increase in serum IgG, IgA and antistreptococcal antibodies during the acute stage. Lymphocyte transformation responses to phytohaemagglutinin and streptococcal antigens were reduced but this was due to a serum suppressor effect. After recovering from acute rheumatic fever a lymphocytosis and an increased lymphocyte blastogenic response to streptococcal antigen were found. T-cells, T-helper cells and T-suppressor cells showed some changes in acute rheumatic fever but these were not statistically significant in our study. None of the changes in immunological responses that were seen in acute rheumatic fever were found in acute nephritis. These results support the hypothesis that an abnormal immune response to streptococcal products is involved in the development of carditis and the other phenomena observed in acute rheumatic fever.