The association of HLA-DRB, DQA1, DQB1 alleles and haplotype frequency in Iranian patients with pulmonary tuberculosis.

OBJECTIVES: To investigate HLA-DRB1, DQA1 and DQB1 allelic polymorphism in Iranian patients with pulmonary tuberculosis (PTB).

METHODS: Forty patients with smear-positive PTB and 100 healthy individuals as a control group were studied for MHC class II allelic polymorphism by polymerase chain reaction with sequence-specific primers (PCR-SSP). The primer was supplied by biotest in the standard kit. DRB low resolution SSP and DQA, DQB intermediate resolution SSP was applied.

RESULTS: The comparison of the patients and the control group showed a significant increase in the frequency of the HLA-DRB1*07 and DQA1*0101 alleles (OR 2.7, 95%CI 1.19-6.13, P = 0.025 and OR 2.66, 95%CI 1.15-6.44, P = 0.04, respectively) in the patient group. The frequency of DQA1*0301 and DQA1*0501 was also significantly decreased (OR 0.254, 95%CI 0.075-0.865, P = 0.033 and OR 0.53, 95%CI 0.3-0.95, P = 0.045, respectively) in the PTB patients. Concerning haplotype frequency, DRB1*11501, QDQA1*0103 and DQB1*0601 were increased, but this difference was not statistically significant. In the DQB1 locus, DQB1*0501 was non-significantly over-represented.

CONCLUSIONS: HLA-DRB1*07 and HLA-DQA1*0101 appeared to be the predisposing alleles and HLA-DQA1*0301 and 0501 the protective alleles in our patients with TB.