Association of HLA class II Alleles and the Occurrence of Factor VIII Inhibitor in Thai Patients with Hemophilia A

OBJECTIVE: In this study HLA class II alleles were tested to investigate the association with the occurrence of FVIII inhibitor among Thai patients with hemophilia A.
METHODS: The distribution of HLA-DRB1 alleles and DQB1 alleles in 57 Thai patients with hemophilia A was determined using the PCR- sequence specific primer (PCR-SSP) method, and the association between the occurrence of factor VIII (FVIII) inhibitor and the presence of certain HLA class II alleles was investigated.
RESULTS: The frequency of HLA-DRB1* 15 was increased in hemophiliac patients both with and without FVIII inhibitors, whereas those of DRB1* 14, DRB1* 07 and DQB1* 02 were decreased in hemophiliac patients with FVIII inhibitors. Interestingly, only DRB1* 15 was significantly increased in patients with inhibitors compared with the controls (P = 0.021). Moreover, the frequency of DRB1* 15 in patients with inhibitor tended to be higher than patients with non inhibitor (P = 0.198).
CONCLUSION: Our data showed that the DRB1* 15 allele may contribute to the occurrence of inhibitor among Thai hemophilia A patients. However, a larger sample size and high-resolution DRB1 typing are warranted.