engleski

Extended TNFa/HLA-DR haplotypes in children with asthma in the croatian population sample

The region of human chromosome 6 containing the MHC has been identified as influencing asthma by several genome-wide searches. As a first step in dissecting MHC influences in childhood asthma in Croatia we have examined the HLA-DRB1 locus and TNFa microsatellite polymorphism in 131 healthy controls and 136 children with asthma. The distribution of HLA-DRB1 alleles and TNFa did not show any difference between patients and controls. For extended study, patients were divided into 2 groups according to differential phenotypic expression of symptoms: group A-asthma only (57 patients) and group B-asthma with rhinitis (79 patients). Comparison between group A and controls showed the increased frequency of DRB1*01 in patients (p=0.04). The analysis of TNFa revealed the significantly increased frequency of TNFa6 allele in DRB1*01 positive patients compared with DRB1*01 negative patients (p= 0.004), as well as in DRB1*01 positive controls (p=0.02). This suggests the possible role of the DRB1*01-TNFa6 extended haplotype in developing childhood asthma without rhinitis. Group B did not show any significant difference for the two analysed loci in comparison with controls. Analysis performed between two groups of patients showed the increased frequency of DRB1*16 allele in the group B (p=0.04). TNFa9 was significantly increased in DRB1*16 positive patients from group B when compared with DRB1*16 positive controls (p=0.005). The results indicate that TNF polymorphism may play an important role in asthma with rhinitis phenotype expression.

asthma; TNFa; HLA-DRB1

doi:10.1038/sj.gene.6363994