Plasma Thrombopoietin Concentrations in Response to Platelet Transfusion Therapy

Abstract

Studies performed in rabbit and mouse models and in a limited number of human subjects, show that transfused platelets bind thrombopoietin (TPO) and decrease its concentration in the circulation. The aim of the present study was to further examine this relationship. The material comprised 12 patients receiving a total of 21 transfusions, as part of the routine clinical treatment. Blood samples were collected from the patients immediately before and 30 min after completion of the platelet transfusion, and the corrected platelet count increment (CCI) was calculated. A commercially available ELISA kit was used to determine plasma TPO concentrations. Statistically significant reductions in median TPO concentration were observed in response to the platelet transfusions. Patients who were refractory to platelet transfusions showed the slightest decrease in TPO concentration. As for the linear regression between change in TPO level and CCI, only borderline significance was observed. Thus, our findings support the concept that platelets can remove TPO from the circulation.

Analysis of the kinetics of TPOuptake during platelet transfusion

“…In the current study, it was shown, in accordance with previous findings, that, upon platelet transfusion, the plasma TPO concentration declines 16–18 . As in patients undergoing chemotherapy, who have fluctuating platelet counts, an inverse correlation was found between platelet count and TPO concentration.…”

“…Similar findings were reported in mouse models 4 . We 12 and others 17,18 showed that, in humans with thromb ocytopenia, the elevated plasma TPO concentration decreases upon platelet transfusion. In vitro studies, in which radiolabeled TPO was presented to human platelets, showed that platelets did indeed bind TPO.…”

Absolute immature platelet count may predict imminent platelet recovery in thrombocytopenic children following chemotherapy

“…Platelet transfusions may affect the endogenous production of platelets, because the primary stimulator of thrombopoiesis, thrombopoietin, is cleared from circulation by internalization and degradation via receptor‐mediated uptake in the platelets 20, 21. Platelet transfusions may therefore bias the results when studying changes in IPF in thrombocytopenia.…”

Platelet transfusion: future directions

“…Another benefit of low dose platelet therapy may be an earlier return of autologous platelet production in thrombocytopenic patients following chemotherapy or bone marrow transplantation. As platelets express the thrombopoietin receptor on their surface and transfused platelets have been documented to adsorb thrombopoietin [46,47], it is possible that lower dose platelet therapy may shorten the duration of thrombocytopenia. If thrombopoietin levels are not reduced by high‐dose platelet transfusions, more thrombopoietin would be available to stimulate autologous platelet production once megakaryocytopoiesis returns.…”