Objective: To investigate the distribution of HLA-DRB alleles among the asthmatic children and find the alleles with a correlation with susceptibility or resistance to childhood asthma.
Methods: The sequence-specific polymerase chain reaction (SSP-PCR) was used to analyze the HLA-DRB genotype in 117 asthmatic children and 120 healthy children in Beijing. Then the frequency of each type, odds ratio (OR) and the 95% confidence interval (CI) of OR were calculated.
Results: The frequency of DR2 (15) in the asthmatic children was 12.0% (28/234) vs 5.4% (13/240) in the healthy children. The frequency was significantly higher than that of nonasthmatic children (OR = 2.590, 95% CI = 1.266-5.298, Chi(2) = 6.431, P < 0.05). Conversely, the frequencies of DR4, DR6 (1402), DR9 and DR53 in asthmatic children [9.4% (22/234), 0.9% (2/234),17.1% (40/234), 29.5% (69/234)] were significantly lower than that of the healthy children [16.3% (39/240), 5.0% (12/240), 31.3% (75/240), 44.2% (106/ 240)], P = 0.026, 0.008, 0.000, 0.001, OR = 0.481, 0.157, 0.312, 0.190. Multi-variate logistic regression demonstrated that the 95% CI of OR for each allele was 1.010-2.245, 0.757-1.116, 0.603-1.054, 0.855-1.014, 0.971-1.010, respectively.
Conclusion: The allele HLA-DR2 (15) is correlated with the susceptibility to childhood asthma whereas it is not related with the severity of asthma.