Associations of IL-1β and IL-6 gene polymorphisms with Parkinson’s disease

OBJECTIVE The aim of this study was to explore the associations of interleukin-1β (IL-1β) and IL-6 gene polymorphisms with the pathogenesis of Parkinson's disease. PATIENTS AND METHODS A total of 200 patients with Parkinson's disease in our hospital were collected as the disease group. Meanwhile, 200 healthy subjects were taken as the control group. Peripheral blood samples were drawn from all research subjects. The polymorphic regions of IL-1β and IL-6 were amplified via polymerase chain reaction (PCR). Moreover, the polymorphisms were detected and analyzed, followed by further analysis based on the changes in gene expressions and Hoehn-Yahr grade of patients. RESULTS The allele distributions at IL-1β rs571556428 (p=0.015) and IL-6 rs543214973 (p=0.012) were statistically different between control group and disease group. In disease group, the G allele frequency at IL-1β rs571556428 and T allele frequency at IL-6 rs543214973 were significantly higher (p<0.05). Genotype distributions at IL-1β rs572292175 (p=0.017) and rs571556428 (p=0.000), and IL-6 rs543214973 (p=0.002) in disease group were also different from those in control group. In addition, the frequencies of CT genotype at IL-1β rs572292175, AA genotype at IL-1β rs571556428 and AA genotype at IL-6 rs543214973 in disease group were significantly lower (p<0.05). After modeling and analysis, it was found that the distribution of recessive model at IL-1β rs571556428 (p=0.012) and IL-6 rs543214973 (p=0.014) in disease group exhibited significant differences from those in control group. The frequencies of TA haplotype at IL-1β rs572292175 and rs571556428 (p=0.038) and GA haplotype at IL-6 rs1474348 and rs543214973 (p=0.047) in disease group were lower than those in control group (p<0.05). The polymorphisms at IL-1β rs571556428 and IL-6 rs1474348 were significantly associated with gene expression (p<0.05). Moreover, the expressions of IL-1β and IL-6 rose significantly in patients with GG genotype at rs571556428 and CG genotype at rs1474348, respectively (p<0.05). Furthermore, the polymorphism at IL-1β rs571556428 was significantly correlated with the grade of Parkinson's disease (p=0.000). Parkinson's disease was in a higher grade (grade 4-5) in patients with AA genotype, whereas in a lower grade (grade 1-2) in patients with GG and AG genotypes. CONCLUSIONS IL-1β and IL-6 gene polymorphisms are significantly associated with the pathogenesis of Parkinson's disease.