Background Histo-blood groups, ABO, Lewis (Le) and secretor (Se) were found to be associated with lower lung function and wheezing in coal miners as well as in asthmatic children in some studies but not others, possibly reflecting the genetic heterogeneity among different ethnicities and local environmental exposure.
Objective The present study was conducted to determine the association between ABO, Lewis and secretor genetic complex with susceptibility of childhood asthma in Taiwan.
Methods We randomly selected 136 asthmatic children and 161 age-matched controls from a childhood asthma survey conducted in primary schools. ABO and Lewis blood groups were determined by red blood cell agglutination methods. Analysis of Se genotype was performed by PCR with sequence-specific primers.
Results There was a higher prevalence rate in secretor subjects (Se/Se) (odds ratio (OR)=1.7, confidence interval (CI)=1.022–2.938) in asthma as compared with controls. The combined effect of these three blood systems revealed that blood group O/secretor phenotype (Se/Se) (OR=2.7, CI=1.126–6.033), and blood group O/Le(a−b−) (OR=3.6, CI=1.080–11.963, P<0.03) individuals were significantly associated with asthma. The Lewis Le(a−b−) recessive genotype (OR=3.3, CI=1.267–8.482), or the joint blood group O/Le(a−b−) phenotype (OR=5.2, CI=1.259–21.429, P<0.02), was significantly associated with high serum IgE (>500 IU), respectively. There was no association of these three blood systems with the sensitivity of dust mite, Dermatophagoide pteronyssinus, in our study population.
Conclusions We concluded that blood group O/secretors (Se/Se) and O/Le(a−b−) were associated with childhood asthma, and may act as one of the predominant factors for environmental triggers of allergy for asthmatic children in Taiwan.