Platelet function in malignant hematological disorders

In this article, we summarize the current knowledge on new roles played by platelets and their interactions with blood components, and their possible implications in malignant hematological disorders.

Recent reports in the literature are revealing that platelets are important partners in different aspects of physiology and pathophysiology beyond hemostasis and thrombosis, including but not restricted to inflammation, cancer or host defense. Moreover, several studies suggest that platelet interactions with other blood cells could regulate functional and biochemical responses of each other. Finally, platelet alterations in number as well as in function have been observed in different hematological disorders related with the action of treatments.

Common complications of leukemia are bleeding and thrombosis, in which the number and activity of platelets undoubtedly play an important role. Probably related with their apparent structural simplicity compared with other hematological cells, the interest in platelets in malignant hematological disorders has been mainly restricted to the determination of the number of circulating platelets. However, different studies have demonstrated that numbers of platelets between 6 and 80 × 10(9) platelets/l are a poor indicator of the risk of bleeding, as this number does not give any information on the functional activity of these platelets.