1Farha A. El-Chennawy, 1Shirin S.
Metwally, 2Waheed A. Sultan
1Immunology Unit, Clinical Pathology Department, 2Rheumatology and Rehabilitation Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
The aim
of this study is to analyse HLA-DR 4 alleles in Egyptian patients with
rheumatoid arthritis (RA) and to evaluate the effect of the responsible allele
on the severity of the disease and on the response to methotrexate (MTX)
therapy. The study group comprised 20 patients with RA (15 females and 5 males)
with age ranged between 31 – 50 years. Ten healthy subjects were considered as
controls. For HLA DRB1 typing, 121 healthy subjects, were considered as
controls. HLA DRB1 typing were performed
using reverse dot blot hybridization after amplification of the extracted DNA
using PCR, other parameters include CBC, ESR, CRP and Rheumatoid factor (RF)
estimation. Our results revealed that DRB1* 0402 allele is the most frequent
allele in patients with RA (40%) compared to controls (5.8 %), followed by
DRB1* 0403 which is found in (20%) of our patients compared to controls (4.1%),
DRB1* 1101 allele was found to be very frequent in normal Egyptian controls
(32.2%) while in RA patients it was 10% only. The frequency of erosion and deformity in DR4 positive patients were
91.7% and 66.7%, respectively, compared to DR4 negative patients, 37.5% and
12.5%, respectively. Significantly increased frequency of erosion and deformity
in patients with *0402 allele (100%) compared to patients lacking it (26.6%,)
and significant association between the presence of *0402 allele and the
unresponsiveness to MTX therapy were observed. We conclude that DRB1
*0402 and *0403 are the most frequent alleles in Egyptian RA patients, there is
a significant association between *0402 positive patients and disease severity
in the form of erosion and deformity. Lastly the presence of DRB1 *0402 allele
may be associated with resistance to MTX therapy.