Relation of IL-33 and PSMA6 gene polymorphisms in asthma patients

Asthma is a chronic inflammatory airway disease with an increase in the prevalence worldwide. This is gene-by-environment disease, with multifactor pathogenesis, which has not been well established yet. IL-33 is a recently discovered cytokine with dual function. It can act as a traditional cytokine as well as an intracellular nuclear factor. Polymorphisms of genes encoding proteasomes could influence IL-33 effect in asthma. Aim: to evaluate serum IL-33 concentration in Lithuanian asthma patients with different PSMA6 gene polymorphisms. Methods: Patients with asthma (n=145; mean age 46.4±15.3yrs) and healthy subjects (n=150; mean age 41.0±14.4yrs) were involved in study. DNA from peripheral blood was extracted using Qiagen (Germany) DNA blood mini kit standardized protocol. SNPs of PSMA6 gene were evaluated using allele specific amplification and cleaved amplified polymorphic sequence methods: rs2277460 in promoter region (-110Cu003eA) and rs1048990 in 59UTR region (-8Cu003eG). IL-33 levels in serum were measured with Human IL-33 ELISA Kit according to the manufacturer9s protocol. Results: Analysis of all studied subjects showed that CA genotype is associated with higher concentration of IL-33 in comparison to CC genotype (1051.8 ± 298.3 pg/ml vs 573.4 ± 97.3 pg/ml, p G) and IL-33 level. Conclusions: Patients with PSMA6 gene CA genotype have higher levels of IL-33 than subjects with other genotypes. These results suggest that presence of this genotype is associated with more expressed inflammation.