Background: Human leukocyte antigen (HLA) DR genes and the tumor necrosis factor (TNF) gene locus are associated with asthma and IgE production. TNFalpha-308G/A frequencies between Japanese and Caucasians in the UK have been found to be different. The roles of HLA-DRB1 and TNF genotypes are unknown in Taiwanese adolescents with IgE-mediated asthma (I-asthma).
Methods: From the population of a 1996 nation-wide survey, we recruited a random sample for a physical examination, determination of total serum IgE (sIgE), dust-mite-specific IgE, and HLA-DRB1, TNFalpha-308, and LTalphaNcoI polymorphisms by polymerase chain reaction.
Results: A total of 80 I-asthmatics and 69 non-asthmatics completed the study. We suggested that I-asthmatics had a higher frequency of the DR13 gene (OR = 8.6, 95% CI = [1.6-161]). The DR13 gene was associated with high sIgE and high dust-mite-specific IgE, especially Dermatophagoides farinae. No TNF haplotype or genotype was associated with I-asthma. The DR13 gene was linked to the LTalphaNcoI*1 allele. When sIgE was adjusted by multiple logistic regression, the risk of I-asthma was much higher for the DR13(+)/LTalphaNcoI*1 haplotype (OR = 25.6, 95% CI = [2.2-1378]) than for the others.
Conclusions: In Taiwanese children sensitized to Der f, the DR13(+)/LTalphaNcoI*1 haplotype was associated with a much higher risk of having clinical asthma than any other DR13/LTalphaNcoI haplotype.