HLA-DRB1 allele in 35 patients with alveolar echinococcosis in Gansu Province of China

To investigate the association between histocompatibility leukocyte antigen (HLA)-DRB1 alleles and alveolar echinococcosis (AE). Thirty-five patients with AE in high prevalence areas in Gansu Province of China were tested for the HLA-DRB1 gene using the polymerase chain reaction with sequence-specific primer (PCR-SSP) technique. The results were compared with those of 104 healthy individuals. The frequency of the HLA-DRB1 * 040x gene was 26% in the patient group, which was significantly higher than that in the control group (9.62%) with a relative risk (RR) of 4.45 (chi(2) = 13.67, P < 0.01), and an etiological fraction (EF) of 0.20. The frequency of the HLA-DRB1 * 0701 allele was significantly lower in the patient group (2.86%) as compared to the control group (13.94%; chi(2) = 6.67, P < 0.05) with a preventable fraction (PF) of 0.30. The frequencies of other DRB1 alleles were not significantly different. Susceptibility to AE is significantly associated with the HLA-DRB1 * 040x. HLA-DRB1 * 0701 gene might confer protection against AE in humans.