[Procoagulant activity associated with mononuclear cells in active rheumatic fever]

Acute rheumatic fever (ARF) is associated with disseminated inflammation and tissue lesions with heavy fibrin deposition, specially in heart valves and myocardium. The immune pathogenesis of ARF has been suspected, but not satisfactorily proven. An active cellular immune reaction generates cell activators (lymphokines) from T cells, which are able to induce a procoagulant activity (PCA) in mononuclear cells. We studied PCA in peripheral blood mononuclear cells isolated form ARF patients as well as normal controls. The PCA from ARF was 1.5 to 15 times higher than the PCA from controls. This activity was associated with the presence of C-reactive protein and other acute phase markers. The PCA from mononuclear cells in ARF may be one of the mechanisms responsible for fibrin deposition.