Study the relation of gene polymorphism of IL-4 and IL-5 with asthmatic patients in Iraqi population

In this study, the following biochemical parameters were determined: interleukin- 4 (IL-4) level and interleukin- 5 (IL-5) level. The present study also determined polymorphism in genes IL-4 (rs2243250), and IL-5 rs2069812 in the blood of asthmatic patients and control groups. In this case-control study, blood samples were collected from 50 asthmatic patients and 50 samples as the control group. The demographic characteristics of asthmatic patients for age, the age groups were (20 to 40 years), (41 to 60 years), and (61-80 years) (52, 40, 8%) respectively (P-value =0.000), whereas the percentage of male patients was higher (60%) than the percentage of female patients (40%)(P = 0.0174). Also, the percentage of non-smoking patients(70%) was higher than smoking patients (30%) (P-value =0.0318). The results of the present study showed significant differences (P˂0.05) between control and asthmatic groups in all biochemical markers. The mean Interleukin- 4 (IL-4) level in the control group was (399.25±251.78) pg/ml while its level in the case was significantly decreased to (266.61±175.11) pg/ml ( p-value=0.003). Furthermore, the level of Interleukin- 5 (IL-5) in the control group was 326.67±354.04 pg/ml, whereas, its level in the case group significantly decreased to 174.36±235.98 pg/ml ( p-value=0.003). The molecular investigations for the polymorphism of the IL-4 and IL-5 genes have been conducted through the PCR-RFLP technique for the SNPs rs2243250 and rs2069812. The results of IL-4 (rs2243250): The highest genotype in the case group was the CT heterozygote genotype (60%) followed by the homozygote genotype CC, TT (20%). The highest genotype in the control group was the TT homozygote genotype (76%) followed by the homozygote genotype CC (24 %). Analyses showed significant differences between cases and controls in the IL-4 (rs2243250) polymorphism (CC vs CT: OR=72.6190., 95% CI 3.9463 to 1336.3195, P= 0.0039). The analysis also showed significant differences between cases and controls in the IL-4 (rs2243250) polymorphism (CC vs TT: OR=0. 3158, 95% CI: 0.1061 to 0.9399, P=0. 0383), higher correlation between IL-4 level and IL-5 level with TT genotype (P = 0.001 and 0.000, respectively) also there is a significant correlation between age and CT genotype and age (p=0.009). The IL- 5 rs2069812 gene polymorphism revealed that The highest genotype in control group was TT homozygous genotype (66 %) followed by heterozygous genotype TC (34%) . In cases , the highest genotype was TC heterozygous genotype (64 %) followed by TT homozygous genotype (24%) and homozygous CC (12%).The genotypic frequency of heterozygous TC with homozygous TT (OR= 5.1765,95 % CI= 2.1372 to 12.5379, P= 0.0003). and the genotypic frequency of homozygous variant CC with the homozygous TT (OR=34.8, 95 percent CI=1.8255 to 664.9429, P= 0.0183).There were significant differences in C allele frequencies in patients as compared to the controls in the IL- 5 rs2069812 polymorphism (OR=3.3130, 95% CI = 1.7041 to 6.4408 , P=0.0004). A higher correlation between IL-4 level and IL-5 level with TT genotype (P = 0.017 and 0.004, respectively) also there are significant correlation between age and CC genotype and age (p=0.000).