Rosette inhibition factor (s) in the sera of cardiopathic patients.

Sera from patients with active and inactive rheumatic fever, as well as with other cardiac or lung diseases, were examined for the presence of rosette inhibition factors. In addition, the levels of antistreptolysin-O and of C-reactive protein activity were also determined. Sera from patients and dog alveolar macrophages were used as the in vitro system for the formation of rosettes. Aggregated normal human gammaglobulin was used as control. Inhibitory activity was present in 50, 71, 90 and 93% of the sera tested from patients with active rheumatic fever, inactive rheumatic fever, other cardiopathies, or pulmonary diseases, respectively. Sera from healthy individuals showed only 3% inhibitory activity and this, only at a very low titre. No correlation was found between the titre of inhibitory activity and either the levels of antistreptolysin-O or the presence of C-reactive protein. It was concluded that the rosette inhibition effect seems to be a nonspecific manifestation of cardiac or pulmonary diseases and to be unrelated to either etiology or pathogenesis of the diseases.