It is important to remember that alternate mechanisms, such as autoreactive CD8 + T cells, could be responsible for thrombocytopenia in patients lacking autoantibodies.[38] Although antiplatelet autoantibody testing is the fundamental method for determining the existence of ITP, the comparatively low sensitivity of these tests implies that ITP can be caused by more than just the presence of antiplatelet autoantibodies. The gene discussed is CD8A; the disease is autoimmune thrombocytopenic purpura.