Histamine changes in Plasmodium falciparum malaria.

Histamine, serum complement factor 3 (C'3) and platelets were studied in 33 Plasmodium falciparum patients. Elevation of histamine level in the blood was found during acute infection but was more marked in the group of patients with systemic complications. A correlation between histamine changes, clinical complications, reduction of C'3 and degree of thrombocytopenia was observed. The possible role of histamine in the development of complications in P. falciparum infection and the possible release of this substance through the activation of complement system and immune destruction of platelets were discussed.