These findings suggested a diagnosis of NAIT caused by anti-Nak(a).

Congenital haptoglobin deficiency caused by Hp(del) homozygosity is presumed to be present in Thailand as a risk factor for anaphylactic transfusion reactions with a frequency similar to that in Japan. The causative deleted allele of the haptoglobin gene, Hp(del), is distributed among Southeast Asian populations as well as among Northeast Asian populations.

The performance of currently available hepatitis B surface antigen (HBsAg) commercial kits was analyzed by using a panel of 212 well-characterized plasma donors all over the country and a panel of nine recombinant HBsAg mutants containing single point or combinations of mutations between amino acid residues 124 and 147 of the "a" determinant. HBsAg commercial kits in this study were machine-based immunoassays with a one-step sandwich ELISA method using either an automatic closed system or manual system. The sensitivity of all machine-based assays evaluated with 105 HBsAg plasma panels was 100% (95% CL = 95.6-99.9%), whereas the specificity with 107 HBsAg negative plasma ranged from 99.07% to 100% (95% CL = 94.2-99.9%). The relative performance of these kits to detect the hepatitis B virus (HBV) mutant panel members of the "a" determinant was found to differ. Interestingly, any commercial kits with monoclonal antibody capture and polyclonal antibody detection (mono/poly), but not mono/mono Ab capture and detection, could pick up the common HBsAg Gly145Arg mutant either solely or in combination with other mutations within the "a" determinant. New versions of HBsAg test kits should recognize multiple HBsAg epitopes in order to detect mutant HBsAg, together with providing good analytical sensitivity and specificity, because of the importance of these assays in HBV diagnosis and in protecting the safety of the blood supply.

Human platelet alloantigens (HPA) are important in neonatal alloimmune thrombocytopenia (NAIT), posttransfusion purpura (PTP), platelet transfusion refractoriness, passive alloimmune thrombocytopenia, and transplantation-associated alloimmune thrombocytopenia. Thus, HPA genotyping is essential in diagnosis and treatment. We analyzed HPA-1 to 6 and Gov alleles, using PCR with sequence specific primers (PCR-SSP) in 500 Thai blood donors who had been HLA class I antigen typed. HPA-4a was present in all samples. HPA-1b, -2b, -5b, and -6b were rare, and HPA-4b was not found. HPA-3a and -3b showed frequencies of 56.0 percent and 44.0 percent, respectively. Gov a and Gov b showed frequencies of 49.1 percent and 50.9 percent, respectively. The prevalence rates of HPA-1 to 6 gene frequencies (GFs) were consistent with those of other Asian populations rather than those of Caucasians. We also report on the GFs of Gov a and Gov b , which also are comparable to those of Asian populations. Our results could establish a useful HPA-and HLA-matched plateletpheresis donor file and provide an improvement of platelet alloantibody detection in alloimmune thrombocytopenic patients, and, therefore, a more effective platelet transfusion program.