Impact of human leukocyte antigen-DPB1 rs9277535 and vascular endothelial growth factor receptor 1 rs9943922 on Rheumatoid arthritis susceptibility and activity in an Egyptian case-control study

Background/aim
Rheumatoid arthritis (RA) is one of the most common autoimmune systemic inflammatory diseases presenting with chronic articular and extra articular manifestations resulting in high incidences of deformities, disabilities, morbidities, and mortalities. Two polymorphisms, Rs9277535 of human leukocyte antigen (HLA)-DPB1 gene and rs9943922 of vascular endothelial growth factor receptor 1 (VEGFR1) gene, are suspected to have impact on the pathogenesis of RA. The current work aims to investigate the association of HLA-DPB1 gene rs9277535 and VEGFR1 gene rs9943922 with RA susceptibility in a sample of Egyptian patients.
Patients and methods
This case–control study involved 200 unrelated RA patients and 200 sex and age matched healthy volunteers acting as a control group. The patients were recruited from the Outpatient Clinics of the Rheumatology Department, National Research Centre, Centre of Medical Excellence, Cairo, Egypt. Patients were assessed clinically and laboratory for determination of disease activity. Genotyping of HLA-DPB1 (rs9277535) and VEGFR1 (rs9943922) was done using real-time PCR technique.
Results
The frequency of the G allele of HLA-DPB1 rs9277535 was found to be higher in RA group in comparison with the control group. Disease activity score28 and clinical disease activity index were significantly higher with GG genotype compared with AA after post hoc analysis (P=0.010, P=0.020, respectively). Moreover, this study found no significant differences regarding the distribution of VEGFR1 rs9943922 genotypes (P=0.120) or alleles frequencies (P=0.502) between healthy controls and studied patients.
Conclusion
Our study revealed an association between the G allele of HLA-DPB1 rs9277535 and RA susceptibility and disease activity while VEGFR1 rs9943922 single nucleotide polymorphism plays no role in predisposition to RA in a sample of the Egyptian population.