Antoine Lewin1,2, Shadhiya Al Khan3, Lynnette Beaudin4, Lynne Meilleur4, Gwen Clarke4,5, Lucie Richard1,6. 1. Medical Affairs and Innovation, Héma-Québec, Saint-Laurent, QC, Canada. 2. Obstetrics and Gynecology, University of Sherbrooke, Sherbrooke, QC, Canada. 3. Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada. 4. Diagnostic Services, Canadian Blood Services, Edmonton, AB, Canada. 5. Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada. 6. Stem Cell and Reference Laboratories, Héma-Québec, Saint-Laurent, QC, Canada.
Abstract
BACKGROUND AND OBJECTIVES: The aims of the 19th International Society of Blood Transfusion Platelet Immunology Workshop were to compare the sensitivity and specificity of in-house and commercially available methods for the detection of alloantibodies against human platelet antigens. Survey regarding laboratory management of samples collected for the diagnosis of foetal neonatal alloimmune thrombocytopenia was also conducted. MATERIALS AND METHODS: Twenty-nine laboratories from 17 countries were invited to participate. Seven serum or plasma samples for antibody identification and eight DNA samples for genotyping were sent to participating laboratories. Additionally, samples, critical reagents, materials and instructions for three exercises, one using a commercial kit (Pak Lx), one on platelet preparation for the detection of anti-HPA-3 antibodies and one for testing four anti-CD109 monoclonal antibodies for anti-HPA-15 antibody detection, were provided. RESULTS: Anti-HPA-1a, anti-HPA-2b, anti-HPA-5b and anti-GPIV were detected by the majority of the 28 reporting laboratories using their respective in-house MAIPA assay and/or a commercially available assay. Conversely, very few laboratories correctly identified anti-HPA-3a and HPA-15b. DNA genotyping of HPA and HLA alleles was highly accurate, with just a few discrepancies relative to the expected results. The Pak Lx kit has proven reliable for detecting anti-HPA-1a, anti-HPA-5a and anti-HLA; however, it failed at identifying an anti-HPA-3a in a clinical sample. CONCLUSIONS: Some anti-platelet alloantibodies are reliably and consistently detected, yet others remain difficult to detect. Genotyping of HPA and HLA alleles has proven to be highly accurate and robust. Future work should focus on optimizing the detection of anti-HPA-3 and anti-HPA-15 antibodies.
BACKGROUND AND OBJECTIVES: The aims of the 19th International Society of Blood Transfusion Platelet Immunology Workshop were to compare the sensitivity and specificity of in-house and commercially available methods for the detection of alloantibodies against human platelet antigens. Survey regarding laboratory management of samples collected for the diagnosis of foetal neonatal alloimmune thrombocytopenia was also conducted. MATERIALS AND METHODS: Twenty-nine laboratories from 17 countries were invited to participate. Seven serum or plasma samples for antibody identification and eight DNA samples for genotyping were sent to participating laboratories. Additionally, samples, critical reagents, materials and instructions for three exercises, one using a commercial kit (Pak Lx), one on platelet preparation for the detection of anti-HPA-3 antibodies and one for testing four anti-CD109 monoclonal antibodies for anti-HPA-15 antibody detection, were provided. RESULTS: Anti-HPA-1a, anti-HPA-2b, anti-HPA-5b and anti-GPIV were detected by the majority of the 28 reporting laboratories using their respective in-house MAIPA assay and/or a commercially available assay. Conversely, very few laboratories correctly identified anti-HPA-3a and HPA-15b. DNA genotyping of HPA and HLA alleles was highly accurate, with just a few discrepancies relative to the expected results. The Pak Lx kit has proven reliable for detecting anti-HPA-1a, anti-HPA-5a and anti-HLA; however, it failed at identifying an anti-HPA-3a in a clinical sample. CONCLUSIONS: Some anti-platelet alloantibodies are reliably and consistently detected, yet others remain difficult to detect. Genotyping of HPA and HLA alleles has proven to be highly accurate and robust. Future work should focus on optimizing the detection of anti-HPA-3 and anti-HPA-15 antibodies.