Association of methylation and expression of IL-4 and IFN-γ in peripheral blood of asthmatic patients

This study aims to compare the expressions and methylation of interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) between Han and Uighur populations as well as their relationships with asthma. A total of 108 asthmatic patients (including 73 Han patients and 35 Uyghur patients) were included into this study, together with 150 healthy populations (including 120 Han patients and 30 Uyghur patients) as the control. The levels of IL-4 and IFN-gamma were measured by Polymerase Chain Reaction (PCR), their protein expressions were detected by Enzyme-Linked Immuno Sorbent Assay (ELISA), and their methylation degrees were detected by SNaPshot. Compared with the control group, the expressions of IL-4 and IFN-gamma genes and proteins were increased in the asthma group (P<0.05); the methylation degree of IL4-1SF locus was higher (P<0.05); the analysis toward the asthma group showed that the expressions of IL-4 and IFN-gamma genes in the Uyghur patients were slightly higher while their protein expressions were significantly decreased; however, there was no significant difference in the methylation level of IL-4 and IFN-gamma among different loci between the Han and Uyghur patients (P>0.05). IL-4 and IFN-gamma are overexpressed in asthmatic patients, especially in Han patients. The methylation degree of IL4-1SF locus in asthmatic patients is increased, but there is no difference between Han and Uyghur populations.