Platelet serology testing can aid in diagnosing antibodymediated thrombocytopenia and in investigating the cause of platelet refractoriness. Once the presence of HLA or platelet antibodies is confirmed, appropriate products can be chosen or platelet crossmatching can be performed to select platelets that may improve transfusion outcomes.Platelets express a lot of HLA antigens so a platelet transfusion causes exposure to foreign HLA. Pregnancy is a common way to make HLA antibodies. The baby has inherited its HLA type from each parent. The HLA antigens from the father are foreign to mother and HLA antibodies can be formed. Approx 40 of women make HLA antibodies during pregnancy. hla crossmatch platelets
Apr 10, 2013 Platelet crossmatching assays are a relatively lowcost and rapid alternative to the HLAmatched approach to the management of platelet refractoriness 3, 13, 14. Crossmatching assays have been used for the identification of candidate platelet donors and may be beneficial for patients in whom refractoriness is due to HPA alloimmunisation, so the HLAmatched platelet transfusion has no value
HLA Class I typed platelets should normally be provided for refractory patients with the aim of minimising exposure to mismatched Class I antigens. In the absence of a zero mismatched donor, a compatible donor can be selected on the basis of a lack of antigens or alleles corresponding to the antibody specificities identified in the patient. HLAmatched platelets are indicated for patients that have thrombocytopenia and have demonstrated CCI values consistent with immune refractory thrombocytopenia on at least two occasions. Although antibodies against HLA Class I antigens are the most common cause of alloimmune refractory thrombocytopenia, antibodies against ABO, or less commonly platelet specific antigens may be involved.hla crossmatch platelets Matched platelets are selected by crossmatching or donated by an HLAmatched blood donor. Testing for drugrelated immune thrombocytopenia can also be considered. Alloimmunized patients who do not respond to crossmatchcompatible platelets or HLAor HPAmatched platelets should be carefully reevaluated for the presence of nonimmune causes of refractoriness.
a need for HLAmatched platelet units. Most platelet crossmatching results fall somewhere in the middle of these two extremes, suggesting mild, moderate or significant degree of alloimmunization. Crossmatched platelets are only helpful for platelet refractoriness due to alloimmunization (either to HLA antigens, or rarely to platelet specific antigens). Crossmatched platelets do not prevent hla crossmatch platelets Detects antibodies to platelet antigens and HLA antigens found in patient sera. Up to 12 apheresis donor platelets are serologically tested with each patients serum to identify a compatible platelet product. Contraindications: Patients with adequate response to platelet transfusions. HLAMatching and Crossmatching in Platelet Transfusion. Abstract Repeated platelet transfusion often induces alloimmunization to HLAantigens resulting in a state of refractoriness of the thrombocytopenic patient. Such patients can be successfully treated with platelet concentrates from an HLA compatible sibling donor [1. How can the answer be improved? McFarland JG, Anderson AJ, Slichter SJ. Factors influencing the transfusion response to HLAselected apheresis donor platelets in patients refractory to random platelet concentrates. Br J Haematol 1989; 73: 380. Heal JM, Blumberg N, Masel D. An evaluation of crossmatching, HLA, and ABO matching for platelet transfusions to refractory patients.