Role of platelet aggregation in the pathogenesis of schistosomal cor pulmonale

ABSTRACT

Various mechanisms may contribute to the production of pulmonary hypertension which is the essential underlying hemodynamic factor in the production of schistosomal cor pulmonale. However, the pathophysiology of pulmonary hypertension is still, in many cases, unclear. This work was planned to study the role of platelets in the development of pulmonary hypertension in schistosomal patients. It was conducted on 15 hepatosplenic patients [10 with schistosomal cor pulmonale [group I] and 5 without [group II]]. Pulmonary arterial samples taken from group I and II showed increased platelet aggregates, decreased platelet count and fibrinogen levels, prolonged PPT and euglobulin clot lysis time in group I when compared with group II. Detection of circulating platelet aggregates in the first group was used as a simple screening test for the presence of intravascular coagulation in the pulmonary circulation of this group. Platelets release vasoconstrictor substances [5 hydroxytryptamine 5HT and thromboxane A2] during aggregation or activation and these substances may be a contributing vasospastic factor in pulmonary hypertension in the schistosomal patients