Autoimmunity

Aim: To identify the prevalence of HLA-DRB1 among Egyptian RA patients and to evaluate the association between HLADRB1 and rheumatoid factor (RF) isotypes (IgG, IgM, and IgA), anti-CCP antibodies.

 

Methods: Th e study included 150 RA patients and 150 controls. Quantitative Serum, RF IgM, IgG and IgA isotypes and anticyclic citrullinated peptide (anti-CCP) antibodies were measured using commercially available ELISA. HLA- DRB1 alleles {HLA-DRB1*01, HLA-DRB1*03 and HLA-DRB1*04}, were determined using the Dynal AllSetTM PCR-SSP low resolution typing kits -Dynal, UK). al, UK).

 

Results & Conclusion: HLA-DRB1*01 and *04 were associated with RA (OR: 6.1 95% CI: 3.5-10.7 and OR: 4.4 95% CI: 2.6-7.5 respectively). No association was found between HLA-DRB1*03 and RA (OR: 0.6 95% CI: 0.4-0.9). Th e association of HLADRB1* 01 and/or HLA-DRB1*04 alleles with positive anti-CCP is stronger than with negative anti-CCP (OR: 12.7 95% CI: 6.3- 25.7 and OR: 3.1 95% CI: 1.7-5.6 respectively) and also the association with positive RF isotypes is stronger than with negative RF isotypes compared to controls (OR:8.2, 95% CI:4.5-14.5 for positive RF IgG and OR: 2.55 95% CI: 1.2-5.5 for negative RF IgG; OR: 7.8 95% CI:4.3-14.1 for positive RF IgM and OR:4.0 95% CI: 2.1-7.8 for negative RF IgM; OR: 9.2 95% CI:4.8-17.8 for positive RF IgA and OR: 4.1 95% CI:2.2-7.4 for negative RF IgA). HLA-DRB1*01 and HLA-DRB1*04 are associated with Egyptian RA patients and carriers of HLA DRB1 *01 and/or *04 alleles are at higher risk of developing anti-CCP positive and RF positive RA than non-carriers.