Background: Eosinophil peroxidase (EPO) gene codes a cationic protein released from the specific granules of activated eosinophils. Eosinophil granulocytes play a central role in the protection of organisms against parasites. They are also regarded as key effector cells in allergic inflammation. We attempted to determine the polymorphisms in the EPO gene typical for the Czech population and to analyze their associations with allergic rhinitis and its intermediary phenotypes.
Methods: We sequenced all 12 exons of the EPO gene, and selected variants were subsequently analyzed by polymerase chain reaction and restriction fragment length polymorphism methods in a case-control study comprising a total of 613 subjects (319 controls and 294 patients with rhinitis).
Results: In total, 5 polymorphisms (-1710T/C and -1710T/CTCC, 2649T/C, 3097A/G and 3979A/G) were found in the EPO gene. Polymorphisms 2649T/C and 3097A/G were in complete linkage disequilibrium (D' = 1 for both groups), and both of them were in a strong disequilibrium with the 3979A/G variant (D' = 0.801 for controls, D' = 0.848 for rhinitics). Consequently, these 3 polymorphisms were studied in association with the allergic phenotype. In a single locus analysis, only 3979A/G single nucleotide polymorphism was marginally significantly associated with rhinitis (p = 0.030, p(corr )> 0.05). This polymorphism also showed a marginal association with total serum IgE levels (log(e) IgE, mean +/- SD: genotypes GG = 2.60 +/- 1.20; GA = 2.47 +/- 1.88; AA = 2.38 +/- 1.49; p < 0.05). Furthermore, significant differences in haplotype frequencies between patients and healthy subjects were observed (p < 0.05).
Conclusions: Our study supports the hypothesis that genetic variability in the EPO gene may contribute to the susceptibility to allergic rhinitis (or related phenotypes) in the Czech population.
(c) 2009 S. Karger AG, Basel.