The HLA-DRB1 gene plays an important role in the genetic predisposition to rheumatoid arthritis. The anti-citrullinated protein antibody (ACPA) is known to be associated with the susceptibility to rheumatoid arthritis (RA), as well as the severity of the disease. The aim of this study is to determine the HLA genes that are associated with the severity of the RA measured by seropositivity, functional status, radiological damage and the anti-modified citrullinated vimentin (MCV) levels.
Ninety-six patients diagnosed with rheumatoid arthritis and a control group consisting of 84 healthy individuals were enrolled in the study. The HLA-DRB1 type and subtypes were specified using the polymerase chain reaction with sequence-specific primers (PCR-SSP). The association of the HLA-DRB1 type and subtypes with seropositivity, anti-MCV levels, functional status and anatomical joint damage were explored using the modified Larsen scoring method.
The DRB1*01, DRB1*04, DRB1*07, DRB1*10, DRB1*11 and DRB1*15 alleles were found to be related with higher anti-MCV levels (p< 0.05). The DRB1*11 type and the DRB1*1001 subtype were observed to be associated with poor functional status (Stages 3-4). The DRB1*0801 subtype was associated with lower anti MCV levels (OR=8.35, p=0.02). DRB1*04 type and DRB1*0405 subtypes were related with radiological damage (OR=0.52 and 0.25; p=0.04 and 0.03, respectively). No significant relationship was observed between the RF seropositivity and the HLA-DRB1 alleles.
This study revealed the association between the HLA alleles and seropositivity, functional status, anti-MCV levels and radiological damage in patients in the Southeast Anatolian region of Turkey.