Study the association of Mycoplasma pneumoniae and (rs35445101) HLA-DRB1gene polymorphism with the immune susceptibility to rheumatoid arthritis

Background: Rheumatoid arthritis (RA) is an inflammatory immune disease that primarily affects the joints and has its root cause in immune system malfunction. It is unclear what causes RA, but research points to a combination of genetic predisposition, environmental exposures, and microbial infections. Objectives: This study aimed to illustrate the relationship between RA and Mycoplasma pneumoniae. Materials and Methods: The work was performed on 50 RA subjects of various ages, ranging from 25 to 75 years of age, who were treated at the rheumatology clinic in the city of Medical Marjan between February 2022 and October 2022. Blood samples were used for DNA extraction. VEGF-A.HLA-DRB1 and mycoplasma were detected by enzyme-linked immunosorbent assay. Results: The results show a significant increase in the serum concentration level of VEGF-A in RA patients infected with M. pneumoniae as compared to healthy individuals, but the results of RA patients with M. pneumoniae infections and RA patients without M. pneumoniae infections were nonsignificant (P > 0.05). The results showed a significant increase in the serum concentration level of HLA-DRB1 in the RA patients infected with M. pneumoniae as compared to the RA patients noninfected with M. pneumoniae and healthy individuals. Conclusions: In HLA-DRB1, the SNP rs35445101 shows that A allele behavior as recessive pathogenic allele in which the individual that carries AA genotype has a susceptibility to the disease 9.75 fold compared to an individual that carries GG and AG genotype (odds ratio 9.75 confidence interval 95% 1.19–79.78).