Platelet aggregation abnormalities in arterial occlusive diseases (AOD).

Ex vivo and in vitro studies of blood platelets were performed on a total of 70 clinically healthy donors of different age and sex and compared with the results observed in 86 patients suffering from venous thrombotic or arterial occlusive diseases (AOD) of the lower limb using several techniques. Significant thrombocytic hyperfunction present was found both nephelometrically and with the Wu and Hoak method in AOD. The nephelometrical data could be substantiated with the platelet-count-ratio (PCR) technique. The present studies demonstrate that all techniques available have serious limitations. Both the Wu and Hoak and the Born methods are incapable to reveal latent and abortive platelet dysfunctions. Pilot studies suggest that the resolution power of the nephelometric device can be augmented when platelet reactivity is increased by a "physiological" maneuver, namely by maximal body exercise of the subject to be examined, immediately before the aggregation test. It is emphasized that adherence to constant experimental conditions is a "conditio sine qua non" for comparative studies on platelet function.