Objective: To analyze the association between HLA-DR genes and pulmonary tuberculosis and to explore susceptible genes associated with pulmonary tuberculosis in a population of Han nationality from southern China.
Methods: Using case-control study, we detected by polymerase chain reaction-sequence specific primers (PCR-SSP) technique the 23 alleles of HLA-DR gene sites in 110 tuberculosis cases and 101 controls from Guangdong, Guangxi, Hunan, Hubei, Jiangxi and Fujian provinces. Gene frequency (GF) and odds ratio (OR) were calculated and compared.
Results: The frequency of DR16 allele in pulmonary tuberculosis cases was strikingly higher than that in the healthy controls (chi2=5.915, Pc< 0.05). Their GFs were 12.62% and 5.60% respectively, and the OR was 2.53. Significantly decreased frequency of DR1 and DR13.3 alleles in cases were found (chi2 values were 17.847 and 14.258 respectively, Pc < 0.01). Their ratios of GFs were 8.08% vs. 23.57% and 29.29% vs. 50.24%, and their ORs were 0.26 and 0.33 respectively.
Conclusions: The results suggest that DR16 allele is closely correlated to incidence of pulmonary tuberculosis in this population of Han nationality from southern China, or linked to susceptible genes which are functional. It is also suggested that expression of DR1 and DR13.3 alleles may be associated with an antagonist effect in the pathogenesis of pulmonary tuberculosis in this population.