The survival and sequestration of transfused donor platelets in cytostatic cytopenias

Aim. To study the survival and sequestration of transfused donor platelets labeled with 51Cr in patients with acute leukemia (AL). Subjects and methods. Seven donor volunteers and 39 patients with different forms with AL at various stages of polychemotherapy (PCT) were examined. Cytostatic therapy was accompanied by 51Cr-labeled platelet concentrate (PC) transfusions. The patients were on appropriate high-dose (HD) PCT. Results. The duration of donor platelet circulation was 8-10 days in healthy individuals. No platelet hypersequestration was recorded in both the spleen and the liver. Donor platelet survival was shorter in all patients with in a state of cytostatic cytopenia. There was an inverse correlation between the degree of circulation shortening and some clinical and hematological parameters (the bone marrow level of blastemia and blastosis, the XIIa-dependent fibrinolysis parameters). Four variants of radioactivity trends above the spleen and liver were identified. The findings suggest that there is platelet hypersequestration in the spleen, liver, and both organs. In some patients, the above both organs are uninvolved in the hypersequestration processes and the possible mechanism for increased consumption of transfused donor platelets, which is associated with recovery of the HD PCT-damaged vascular endothelium is considered. Conclusion. Shortening of transfused donor platelet circulation was found in relation to the level of blastosis. The described procedure may be used as one of the additional methods for evaluating the efficacy of donor PC transfusion and for specifying the pathogenesis of thrombocytopenias in AL patients on programmed HD PCT. A procedure is proposed to time the circulation of 51Cr-labeled platelets, by assessing deposit phenomena and estimating the level of their sequestration in the spleen and liver for the prediction of the efficiency of TC transfusions.