Platelet immunobiology: platelets as prey and predator.

The immune response against platelets is a complex process involving many aspects of the innate and adaptive immune system. Immune destruction of platelets and megakaryocytes and the thrombocytopenia that ensues can cause different clinically significant haematological disorders such as foetal and neonatal alloimmune thrombocytopenia (FNAIT), transfusion‐induced platelet refractoriness or immune thrombocytopenia (ITP). These conditions are frequently difficult to manage so an understanding of the biological nature of these adverse conditions is critical for an understanding of how to potentially reduce them. Superimposed on these immune platelet attack mechanisms are the immune characteristics of the platelets themselves. This paper will give an overview of how the immune system recognizes platelet antigens and mounts efficient effector mechanism to mediate thrombocytopenia. It will also present evidence to suggest that platelets also play a role in stimulating these responses and suppressing them: a scenario where the ‘prey’ can become the ‘predator’. [ABSTRACT FROM AUTHOR]