Cellular immune mechanisms in autoimmune thrombocytopenic purpura: An update.

Autoimmune thrombocytopenic purpura (AITP) is a bleeding disorder in which autoantibodies are directed against an individual's own platelets, leading to enhanced clearance through Fc receptor (R)-mediated phagocytosis by macrophages residing in the reticuloendothelial system (RES), particularly in the spleen. The production of IgG autoantibodies is critically dependent on cellular immune mechanisms particularly relating to T cells. We review the recent literature of the cell-mediated immunology of AITP focusing on platelet phenotype, genetics, T-cell reactivities, and cytokine profiles in patients with AITP. Understanding the interaction between these cell-mediated mechanisms is vital for developing antigen specific immunotherapies to treat this autoimmune disease.