The Role of Venom Haemorrhagin in Spontaneous Bleeding in Bothrops jararaca Envenoming

Abstract

Thirty-eight patients bitten by Bothrops jararaca were investigated. Twenty-six had signs of local or systemic haemorrhage. Twenty-two of these had incoagulable blood, and these patients were found to have low fibrinogen levels (mean 0.17 +/- 0.03 g/l), thrombocytopenia, very high thrombin-antithrombin III complex (850 +/- 184 micrograms/l) and D-dimer (170 +/- 44 micrograms/ml) antigen levels. Serum venom haemorrhagin levels were significantly higher in patients with clinical signs of haemorrhage (36.4 +/- 6.4 ng/ml) than those without (11.7 +/- 3.7 ng/ml; p less than 0.002). Twelve out of 13 patients with thrombocytopenia were bleeding. High levels of thrombomodulin (22.3 +/- 1.5 ng/ml) and haemorrhagin (35.7 +/- 7.7 ng/ml) were detected in these 12 patients, suggesting vascular endothelial damage. Haemorrhagin levels also correlated inversely with platelet count in these patients. It was concluded that thrombocytopenia is one of the main causes of bleeding in B. jararaca victims, possibly as a result of venom haemorrhagin activity.