Obtención y uso de concentrados de plaquetasperspectiva actual

Abstract

Since the first direct transfusion through an anastomosis between recipient and donor blood vessels in 1914, advances in the world of transfusional medicine have been extensive and essential for the progress of medicine as we know it today. Throughout the following pages we will briefly review the production, storage and lesion of platelets concentrates, as well as the indication and adverse effects related to platelets transfusion. We will also describe our contribution to this field below. In our first study, we evaluated the in vitro quality of buffy coat leucodepleted platelet concentrates prepared by two automated OrbiSac or TACSI devices. Throughout a standard storage, differences in cell count, metabolic parameters, platelet function and activation, and proinflammatory molecules were analyzed on days 1, 5, and 7. Both platelet products met the standards in terms of platelet and leucocyte content. The in vitro evaluation of platelet metabolism, functionality, hypotonic shock response or platelet aggregation study, was similar between both products. However, the OrbiSac system induced a transient increase in platelet activation and a greater release of proinflammatory substances (sCD62P, RANTES and sCD40L) on the day of preparation of the platelet concentrates. In our second study we compared the transfusion efficacy of platelet concentrates prepared by the platelet-rich plasma method and those obtained by the buffy coat method, in a cohort of patients undergoing allogeneic haematopoietic stem cell transplantation. Transfusion of platelet concentrates produced by the buffy coat method was associated with a greater 24 hours post-transfusion corrected count increment, and resulted in less donor exposure in each single transfusion. As independent predictors of poor platelets transfusion response, we identified the diagnosis other than acute leukemia, splenomegaly, prophylaxis of graft-versus-host disease other than cyclosporin A and methotrexate, and transfusion of platelet concentrates produced by the platelet-rich plasma method. Despite the largest increase in platelet counts, the transfusion of buffy coat platelet concentrates provides no significant benefit regarding bleeding outcome. Finally, in our third study we have implemented a simple and effective protocol for the washing of buffy coat platelet concentrate with additive solution. Transfusion of washed platelet concentrates is indicated in specific patients, such as those suffering from severe transfusion reactions or immunoglobulin A or haptoglobin deficiency. Our procedure resulted in the loss of about 15% of total platelets. In vitro, a minimal increase in activation markers (P-selectin) or a decrease in platelet reactivity measured with the VerifyNow¿ test when using a weak agonist such as ADP was observed in these washed platelets. Platelet reactivity measured by light transmission agrregometry or using a powerful agonist such as TRAP in the VerifyNow¿ test was not affected. The in vivo efficacy of the washed platelets concentrates was investigated in a cohort of 11 onco-haematological patients who were expected to receive at least two platelet transfusion in a short period of time. The transfusion efficacy as determined by the increase in the one hour and 24 hour platelet increment showed, no statistically significant difference. Remarkably, the transfusion of these washed platelets concentrates was not associated with an increase in bleeding episodes.