Activation of the coagulation cascade in falciparum malaria

Abstract

The incidence and progression of coagulation abnormalities were studied in 52 patients with acute falciparum malaria. The patients were prospectively divided into 3 groups; severe (parasitaemia ≥5% or vital organ dysfunction), 12 patients; moderate (parasitaemia l%- < 5% without complications), 16 patients; and mild (parasitaemia < 1%), 24 patients. No case died or developed clinical evidence of disseminated intravascular coagulation. Conventional indices of coagulation (prothrombin time, partial thromboplastin time, fibrinogen, fibrin degradation products) were usuaily within the normal range but reduced plasma concentrations of antithrombin III (AT-III) levels were noted in all groups, and the incidence was significantly higher in patients with severe and moderate malaria (83% and 81%) compared with the mild group (37%; P < 0.005). Depletion of AT-III was associated with thrombocytopenia, decreased AT-III activity and elevated plasma concentrations of thrombin-antithrombin III complexes (P < 0.01), confirming activation of the coagulation cascade and increased clotting factor consumption. AT-III levels returned to normal coincident with clinical improvement. Activation of coagulation is a common and sensitive measure of disease activity in acute falciparum malaria. It is not a specific feature, nor is there evidence to suggest it has a primary pathological role in severe infections. © 1989 Oxford University Press.