Platelet Immunology Laboratory

Post Transfusion Purpura Workup

• Test Code: 3660-00
• CPT Codes: (86022, 86023)x2, 86021, 86807, 83890, 83912, (83892, 83898, 83894)x3, 83912

Post-transfusion Purpura (PTP) can occur in patients who have been previously sensitized to platelets by transfusion or through pregnancy. Transfusion of cellular blood products containing any platelets (e.g., platelets, granulocytes or red blood cell transfusions) induce a recall of a previously formed alloantibody against platelet specific antigen(s) between 5-10 days post-transfusion. In the process of recalling the alloantibody, the patient apparently also develops a transient autoantibody that leads to the destruction of the patient's own platelets often resulting in severe thrombocytopenia.

Strong positive antibody results against platelets from random donors and the absence of common platelet antigens in the patient are indicative of PTP.

• Tests Performed: Flow cytometry. Additionally flow test results may indicate the necessity of platelet antigen typing (DNA Testing), MAIPA or Pak-12G testing (Platelet Antibody Determination), HLA typing, and PRA testing.
• Test Types: Direct and Indirect
• Sample Required: Call the Platelet Immunology Laboratory at (206) 292-6543 for requirements.
• Analytic Time: 1 Day for Antibody Screen, 5 Days for additional testing.
• Send whole blood, room temperature
• Refer to Ordering Information page for submission and transporting requirements.