Abstract
BACKGROUND AND OBJECTIVES: Certain genetic traits increase the likelihood of developing rheumatoid arthritis (RA); nevertheless, the association between RA and polymorphisms in the CD209 gene is ambiguous. This study sought to investigate the correlation between RA susceptibility and the CD209 single nucleotide polymorphisms rs4804803 (AG) and rs735239 (AG) within the Egyptian population. METHODS: This case-control study was conducted between January and October 2024 and included 108 participants. Of these, 54 patients were diagnosed with RA according to the 2010 classification criteria of the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR). Two CD209 promoter regions rs4804803 (-336A/G) and rs735239 (-871A/G) were genotyped for single nucleotide polymorphisms (SNPs) using multiplex polymerase chain reaction (PCR) and double amplification refractory system (dARMS). RESULTS: Patients with RA showed significantly higher frequencies of the CD209 rs4804803 SNP in the AG (P = 0.036) and GG (P = 0.006) genotypes compared to controls. Under the dominant paradigm, those with CD209 rs4804803 genotypes (AG+GG) had an elevated risk of RA (P = 0.003). In recessive inheritance model, RA patients had a greater frequency of the rs4804803 GG polymorphism than controls (P = 0.017). Additionally, relative to the A allele, the rs4804803 G allele raised the risk of RA (P = 0.001). No significant difference was observed between the two groups in the distribution of rs735239 genotypes. However, RA patients carrying the rs4804803 AG or GG genotypes exhibited significantly higher rates of morning stiffness (P = 0.001) and elevated CRP levels (P = 0.009). CONCLUSIONS: This work highlights the significant role of the CD209 rs4804803 polymorphism, particularly the G allele, in the elevated susceptibility to RA among Egyptians.