RESUMO
INTRODUCTION: Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory and multifactorial disease. Genetic predisposition seems to play an important role. The aim of this study is to explore the relationship between human leukocyte antigen (HLA)-DRB1 alleles and susceptibility, clinical and biological features of RA in an Algerian patient population. METHODS: Using polymerase chain reaction - sequence specific primers (SSP), 134 RA patients and 132 healthy controls were genotyped for HLA-DRB1 and HLA-DRB1*04 subtypes. RESULTS: HLA-DRB1*04 was found to have increased frequency in the RA group compared to controls (P < 0.001, OR = 3.14), and was associated with anti-citrullinated protein antibodies positivity (ACPA) (P = 0.01, OR = 2.35). In contrast, HLA-DRB1*07 was found to have a decreased frequency in patients compared to controls (P = 0.003, OR = 0.44) and significant decrease was observed in patients with the rheumatoid factor (RF) positivity subgroup (P = 0.009, OR = 0.29). HLA-DRB1*04:05 was associated with RA (P = 0.005, OR = 3.41), whereas, HLA-DRB1*04:02 showed a protective effect against RA (P = 0.003, OR = 0.20). CONCLUSIONS: HLA-DRB1*04 was associated with increased risk for RA and ACPA positivity, while HLA-DRB1*07 was associated with reduced risk for RA and RF synthesis in Algerian patients.