Determining the lifespan of platelets labelled with 111In oxinate--first results.

The paper presents the new method of platelet labelling, quality control of separation and labelling, as well as the investigation of the 111In oxinate labelled platelets lifespan. Among the 23 investigated persons, there were 4 hematologically healthy persons and 19 ITP patients. Homologous and autologous labellings were done in one and 22 persons, respectively. Determination of the platelet lifespan in healthy subjects enabled the estimation of "in vitro" procedures of separation and labelling, as well as "in vivo" behaviour of the labelled platelets. Our results show that 111In oxinate labelled platelets have normal lifespan (8.9 +/- 0.6 days), which means that the procedure of separation and labelling does not damage them. In the ITP patients the platelet lifespan is shortened (0.4-4.6 days), which confirms the mechanism of thrombocytopenia. In the subject where homologous labelling had been done, we found out the existence of sensibilisation toward the donor platelets, which lead to the correction of therapy.