ABSTRACT
INTRODUCTION: The HPA-15 antigen system is characterized by a low antigen expression on platelets. The antibodies against this antigen are implied in fetal/neonatal alloimmune thrombocytopenia (F/NAIT), post-transfusion purpura, and refractoriness to platelet transfusions. Detection of these antibodies appears to be related to the level of HPA-15 expression on the platelets used in the monoclonal antibody-specific immobilization of platelet antigen (MAIPA) assay. METHODS: We performed genotyping of 300 healthy blood donors for HPA-15 by TaqMan real-time PCR technology, and the HPA-15 antigen expression was investigated in 13 HPA-15aa and 19 HPA-15bb individuals. We also investigated the relevance of HPA-15 antigen expression on donor platelets used in MAIPA for antibody detection in 223 multitransfused hematological patients and 271 women with suspected F/NAIT. RESULTS: In Polish donors, the HPA-15a allele frequencies were lower than the HPA-15b (0.480 vs. 0.515). We identified three HPA-15 expression groups: high (36.7 ± 8.36 MFI - eight cases), medium (19.5 ± 6.2 MFI - 21 cases), and low (6.5 ± 5.9 MFI - three cases). The HPA-15 expression was stable over time. The HPA-15aa and HPA-15bb platelets with high antigen expression were used for anti-HPA-15 antibody detection; anti-HPA-15 antibodies were detected in 4/223 (1.8%) patients receiving multiple transfusions but in none of the 271 women with suspected F/NAIT. Further examination of the four sera by MAIPA with various platelets revealed the optical density in the assay to be closely related to the level of HPA-15 antigen expression. CONCLUSION: Anti-HPA-15 antibody detection should be based on carefully selected platelets with high HPA-15 expression level.
Subject(s)
Antigens, CD/genetics , Antigens, CD/immunology , Antigens, Human Platelet/genetics , Antigens, Human Platelet/immunology , Autoantibodies/blood , Immunoassay/methods , Neoplasm Proteins/genetics , Neoplasm Proteins/immunology , Adult , Alleles , Autoantibodies/immunology , Blood Platelets/immunology , Blood Platelets/metabolism , GPI-Linked Proteins/genetics , GPI-Linked Proteins/immunology , Gene Frequency , Genotype , Genotyping Techniques , Humans , Middle Aged , Young AdultSubject(s)
Hemolysis/immunology , Transfusion Reaction , Aged , Humans , Immunoenzyme Techniques , Isoantibodies/blood , MaleABSTRACT
The coagulation factor IX obtained at the Institute of Haematology and Transfusion in Warsaw was subjected to virological validation. Two lipide enveloped viruses were used: HSV-1 and Sindbis which may be a model for the viruses of B and C types in hepatitis. It was shown that heating of the freeze-drying preparations at 80 degrees C during 72 hrs leads to full inactivation of the added model viruses.
