Transformation of lymphocytes from patients with rheumatic fever by streptolysin S.

Lymphocytes from peripheral blood were tested for blast transformation reaction by streptolysin S (SLS), phytohaemagglutinin (PHA) and staphylococcal filtrate (SF). The subjects comprised twenty-eight patients with acute rheumatic fever, twenty-seven with other diseases and eight normal donors. The degree of transformation stimulated by SLS was markedly lower in most patients with acute rheumatic fever than in the other groups. On the other hand, all subjects reacted similarly to PHA and SF. The degree of blast formation induced by SLS was changed in many cases when the calf serum in the test medium was substituted by autologous plasma. The value of the reaction to SLS as a possible diagnostic test for acute rheumatic fever is limited as some patients with acute rheumatic fever react normally while some patients with other diseases show a diminished response.