An investigation on thrombocyte function and thrombocyte kinetics in familial hypercholesterolaemia

Atherosclerosis and the accompaning complications of arterial thrombosis is the main cause for mortality in the economic active sector of the white South African population. The influence of hyperlipaemia on in vitro and in vivo thrombocyte function is studied. In vivo throbocyte function is evaluated by 1) the exemption of beta-thromboglobulin and the measuring of thrombocyte function in blood plasma, 2) by determining the circulating thrombocyte aggregate and 3) by measuring the kinetics of In111-labelled thrombocytes. The latter includes the measuring of the average thrombocyte lifetime and the in vivo-quantification of the distribution and seats of destruction of In111-labelled thrombocyte by means of scintillation and computer-aided imaging. Basal in vitro-thrombocyte aggregation has not differed from the normal. The most important thrombocyte function deviation was a disturbance in the balance between thomboxane and protaglandin synthesis. In familial hyperlipaemia was the balance in favour of thrombocyte aggregation and thrombosis. The In111-labelled thrombocytes in familial hyperlipaemia is destroyed in the reticulo-endothelial system at the end of their lifetime. This study shows that hyperlipaemia has an important influence on thrombocyte function. The high lipide-levels activate the thrombocytes in vivo, the thrombocyte function is then disturbed and that leads to raised thrombocyte output. This is an indication of the advanced atherosclerosis