Background: Human leukocyte antigen HLA-DRB1 alleles encoding a common amino
acid sequence called shared epitope in the third hypervariable region of DRB1 molecule have been
identified as risk alleles for rheumatoid arthritis (RA).
Aim of the work: The aim was to study HLA-DRB1 01, 04 and 10 alleles in Egyptian RA
patients and determine their relation with anticyclic citrullinated peptide (anti-CCP) antibody level,
disease activity, clinical and radiological severity.
Patients and methods: The study involved 40 RA patients and 20 control. Simplified disease
activity index (SDAI) was calculated, clinical severity was assessed using the mechanical joint score
(MJS) and radiological severity evaluated using the simple erosion narrowing score (SENS). HLADRB1
genotyping and anti-CCP antibodies were detected.
Results: The mean patients’ age was 41.6 ± 12.7 years and disease duration 8.9 ±7.7 years. The
frequency of HLA DRB1 01, 04 and 10 in patients was 42.5%, 60% and 25% respectively. Of them
04 was significantly higher than in controls (p= 0.013) and was associated with anti-CCP positive
cases (p= 0.0008) while the absence of HLA-DRB1 alleles was significantly associated with negative
anti-CCP negative RA (p= 0.0008). There were significant associations between HLA-DRB1
01 and 04 with SDAI (p= 0.0002 and p= 0.005, respectively); between HLA-DRB1 04 and 10
with SENS (p= 0.002 and p= 0.001 respectively) and between HLA-DRB1 01, 04 and 10 with
MJS (p= 0.02, p= 0.03 and p= 0.02, respectively).