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Background Although many studies have implicated interleukin (IL)-4 promoter polymorphisms as potential determinants of disease susceptibility, there are no reports on the association between IL-4 promoter polymorphisms and nasal polyps. The aim of this study was to investigate the relationship between an IL-4 promoter polymorphism and nasal polyps.Methods The C-590T promoter polymorphism of the IL-4 gene was genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis in 106 Korean chronic rhinosinusitis patients with or without nasal polyps and 70 healthy Korean subjects.Results The frequency of the T allele at position -590 of the IL-4 gene in a Korean population was 0.85, which was significantly higher than those of other ethnic groups, and the T/T allele at position -590 of IL-4 was associated with protection against nasal polyps if compared with the C/C allele (relative risk, 0.529; 95% confidence interval, 0.307–0.912; p = 0.028).Conclusion T-590, which is dominant at position -590 of the IL-4 promoter, appears to be associated with a protective mechanism against nasal polyps in Korean populations.

Apical membrane antigen-1 is a candidate vaccine component for malaria. In the present study, we investigated the polymorphism of the Plasmodium vivaxapical membrane antigen-1 gene (PvAMA-1) in 30 Korean isolates. The polymorphic region of the PvAMA-1gene, corresponding to nucleotides 324–735 (aa 108–245), was amplified using polymerase chain reaction followed by cloning and sequencing. Two genotypes (SKAand SKG) were identified on the basis of amino acid substitution. These were identical to those of the Chinese isolates. The Korean isolates showed sequence variation at six positions on the basis of the sequence of the Sal1 strain. Of these, variation at position 189 (Glu/Lys) was found only in SKA. These two genotypes were related to the genotype of the circumsporozoite and Duffy binding protein of the Korean isolate. These findings suggest that two genotypes of P. vivaxcoexist in the endemic area and that the re-emerging parasite in Korea may be related to or have originated in East Asia.