HLA class II alleles: susceptibility or resistance to cystic echinococcosis in Yemeni patients.

This is the first study dealing with the association between HLA alleles and cystic echinococcosis (CE) in Yemeni patients. The present study aimed to detect the association of HLA-DRB(1) alleles and susceptibility or resistance to CE in Yemeni patients by HLA-DRB(1) typing; first by HLA-DRB(1) amplification using PCR then using the allele-specific probing technique based on the reverse hybridization principle. This case-control study was carried out on 66 unrelated patients with confirmed CE and 66 apparently healthy individuals. The association of class II HLA-DRB alleles was examined in the patients with CE and compared with control subjects. Frequency of HLA-DR16 allele was 18.2% among patients and was statistically significant (higher) than in the control group [3%; odds ratio (OR) = 6.5, chi (2) = 7.1, P = 0.011]. Frequencies of HLA-DR1, DR8, and DR52 alleles were decreased in the patient group (0.0%, 0.0%, and 56%, respectively) than in the control group (19.7%, 9.1%, and 74.2%, respectively) (OR = 0.0, 0.0, 0.443 and P < 0.0001, 0.04, 0.05, respectively). HLA-DR16 allele was found to be statistically positively associated with the occurrence of isolated hepatic CE, single cysts, and cysts >5 cm in size. In contrast, HLA-DR1 and DR52 alleles were found to be statistically negatively associated with the occurrence of isolated hepatic CE. This study demonstrates that susceptibility to CE in Yemeni patients is statistically significantly associated with the HLA-DR16 allele and resistance to CE is statistically significantly associated with HLA-DR1, DR8, and DR52 alleles. Thus, this study has identified that carriers of HLA-DR16 are at high risk for CE, so appropriate preventive measures and quick and careful treatment should be applied to those patients.