Association between single nucleotide polymorphisms of surfactant protein D and allergic rhinitis in Chinese patients

The development of allergic rhinitis is considered to be determined by the interaction between genetic and environmental factors. Surfactant protein D (SP-D) has been proposed to offer protection against allergenic challenge at various levels in allergic responses. The present study aimed to investigate whether polymorphisms within the SFTPD gene (Met11Thr, Ala160Thr, and Ser270Thr) are associated with allergic rhinitis. Genotyping of SFTPD polymorphisms was performed using the pyrosequencing method. The study population comprised 216 patients with allergic rhinitis and 84 normal controls. The frequency of 11Thr/Thr genotype and Thr allele in the patient group was significantly higher than that in the control group after applying Bonferroni corrections (P = 0.007 and P = 0.006, respectively). Our subjects with the 11Thr/Thr genotype are more susceptible to allergic rhinitis. There were no significant differences between the patient group and the control group for frequencies of genotypes and alleles in either Ala160Thr or Ser270Thr single nucleotide polymorphisms (P > 0.05). No significant associations could be detected between any of these three SFTPD gene polymorphisms and the skin prick test response (P > 0.05). Meanwhile, there was a lack of association between the three loci and the levels of serum total immunoglobulin E (P > 0.05). In summary, our results suggest that the Met11Thr polymorphism in SP-D plays a major role in the genetic predisposition to allergic rhinitis in Chinese adult population, whereas the other two SP-D polymorphisms displayed no significant association with allergic rhinitis.