thrombocytopenia purpura immune system disorder thrombotic microangiopathy thrombocytopenic purpura thrombopenic purpuras Purpura associated with a reduction in circulating blood platelets which can result from a variety of factors. purpura, thrombopenic NCIT:C26870 GARD:0025866 thrombopenic purpura MEDGEN:208992 purpuras, thrombocytopenic SCTID:302873008 MESH:D011696 UMLS:C0857305 purpuras, thrombopenic NANDO:2100188 thrombocytopenic purpura thrombocytopenic purpuras MONDO:0043768