Prognostic importance of human leukocyte antigen DRβ1 gene and protein tyrosine phosphatase nonreceptor Type 22 gene polymorphism in rheumatoid arthritis

Abstract

Background: Major histocompatibility complex (MHC) or human leukocyte antigen (HLA) gene and some of the non-MHC genes are associated with genetic predisposition in rheumatoid arthritis (RA). The aim of the present study was to find the prevalence of HLA DRβ1 alleles and protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene single-nucleotide polymorphism (SNP) in RA patients and also assessed their correlation with laboratory and clinical parameters. Materials and Methods: One hundred and fifty cases of RA and 100 healthy controls were studied. relation to RA patients. HLA DRβ1 typing was done by low-resolution sequence-specific primer polymerase chain reaction and auto-antibodies (Abs) (rheumatoid factor [RF], anti-cyclic citrullinated peptide 2 (CCP2) Ab, anti-nuclear Ab, double-stranded deoxyribose nucleic acid, anticardiolipin Ab) were done by enzyme-linked immunosorbent assay. Results: In patients with RA, the most common HLA DRβ1 allele was DRβ1*04 (23.3%), followed by DRβ1*10 (20.7%), DRβ1*03 (9.3%), and DRβ1*01 (8.7%). Contrary to this, some alleles of DRβ1 were significantly less expressed in RA such as DRβ1*07 (P = 0.000) and DRβ1*14 (P = 0.010). DRβ1*04 positive patients had significantly more RF positivity while DRβ1*10 positive patients had increased RF and anti-CCP2 Ab. DRβ1*04 positive cases had positive correlation with disease activity score. DRβ1*10 positive patients had negative correlation with the age of the RA patients. These patients have shown early onset of disease. PTPN22 C1858T SNP was found in only 4% cases of RA. No correlation was established with PTPN22 SNP positivity and clinical parameters. Conclusion: In our study, RA patients have less DRβ1*04 positivity as compared to the Western literature. In our area, DRβ1*10 is more common than DRβ1*01. HLA DRβ1*07 and *14 are found to be protective for RA. PTPN22 SNP has not shown any diagnostic or prognostic significance while a follow-up study may be useful for prognostic importance of HLA DRβ1 typing in RA.