The Role of IL-2 and IL-8 Gene Polymorphisms in Parkinson's Disease Susceptibility

Abstract

Background: Parkinson’s disease (PD) is a progressive neurodegenerative disorder influenced by genetic and environmental factors. Objectives: This study investigates the association of interleukin-2 (IL-2) and interleukin-8 (IL-8) gene polymorphisms with PD risk using the tetra-primer amplification-refractory mutation system PCR (ARMS-PCR) technique. Methods: A case-control study was conducted involving 60 PD patients and 60 healthy controls. Blood samples were collected, and DNA was extracted using a standardized protocol. Genotyping was performed with the tetra-primer ARMS-PCR method, which allows for specific detection of single nucleotide polymorphisms (SNPs). Primers for IL-2 and IL-8 alleles were designed, and PCR conditions were optimized for accurate amplification. The PCR products were analyzed through agarose gel electrophoresis, and statistical tests, including chi-square analysis and odds ratio (OR) calculations, were applied to evaluate genotype distributions and associations. Results: The frequency of the IL-2 CC genotype was significantly higher in PD patients (30%) compared to controls (8.3%), indicating a 4.56-fold increased risk (P = 0.009). For the IL-8 gene, the TT genotype was observed in 48.3% of PD patients versus 33.3% of controls, corresponding to a 7.73-fold increased risk (P = 0.004). Combined genotype analysis showed that patients with both IL-2 CC and IL-8 TT genotypes had the highest susceptibility, with a cumulative risk increase of more than 10-fold. Gel electrophoresis results confirmed the specificity of the amplification, displaying distinct bands for each allele and validating the effectiveness of the tetra-primer ARMS-PCR technique. Conclusions: This study identifies IL-2 and IL-8 polymorphisms as significant genetic markers associated with an increased risk of PD. The use of tetra-primer ARMS-PCR proved to be a reliable and efficient method for detecting SNPs in cytokine genes. These findings underscore the potential of genetic screening in PD and suggest that targeting cytokine pathways could inform future therapeutic strategies.