DR antigen distribution in Blacks with rheumatoid arthritis

Area of Science:

• Immunogenetics
• Rheumatology

Background:

• Rheumatoid arthritis (RA) is a chronic autoimmune disease.
• Genetic factors, including human leukocyte antigen (HLA) genes, play a role in RA susceptibility and severity.
• Previous studies have shown an association between HLA-DR4 and RA in various ethnic groups.

Purpose of the Study:

• To investigate the distribution of the DR antigen in Black patients with rheumatoid arthritis (RA).
• To determine if the DR4 antigen is associated with seropositive and seronegative RA in Black individuals.
• To explore the potential role of DR4 as a risk factor for aggressive RA in Black populations.

Main Methods:

• A case-control study was conducted involving 85 Black patients diagnosed with rheumatoid arthritis (RA).
• Patients were categorized into seropositive (n=63) and seronegative (n=22) groups based on latex fixation titer.
• DR antigen frequencies were compared between RA patients and a control Black population (n=162).

Main Results:

• The frequency of DR4 was significantly higher in both seropositive (22.22%) and seronegative (22.72%) RA patients compared to the Black control population (7.41%).
• A strong association was observed between DR4 and seropositive RA (Relative Risk [RR] = 3.57).
• A similar significant association was found between DR4 and seronegative RA (RR = 3.67).

Conclusions:

• The study confirms the association of DR4 with seropositive rheumatoid arthritis (RA) in Black individuals.
• The findings suggest a comparable association between DR4 and seronegative RA in this population.
• DR4 may represent a genetic risk factor for more aggressive rheumatoid arthritis (RA) in Black patients.