[Levels of total hemolytic complement, C3, C4 and antibodies against the myocardium in rheumatic fever].

The levels of the hemolytic complement (UH 50%), C3, C4 and the antibodies against myocardium and against the antigenic fractions of myocardium precipitated with ammonium sulphate were studied in 8 patients with active rehumatic fever (ARF), 28 with inactive rheumatic fever (IRF) and 26 people without cardiopaties (NI). The UH 50% was low in 2 out of 36 patients with rheumatic fever (RF). C3 was normal and C4 low in 12.5% of the ARF patients. C3 had subnormal values in 25% and C4 in 33% of IRF patients, this last value had a stadistic significant decrease with respect to the values of C4 in normal people. The 36 patients with RF had antibodies against the myocardium and also against the heart antigenic fractions precipitated with 10% ammonium sulphate. 11.5% of the normal group had anti-myocardial antibodies and none had antibodies against the fractions. The levels of anti-streptolysin-O and C-reactive protein were higher in the ARF group than in the patients with IRF or the normal people. The participation of the hemolytic complement, the anti-myocardium antibodies, the anti-streptococcus antibodies and the cytophilic activity in the etiopathogeny of rheumatic fever is discussed.