Susceptibility epitope on HLA-DR beta chain for rheumatoid arthritis and the effect of the positivity on the clinical features.
A highly significant association of an amino acid sequence, '70Q71R72R73A74A' located on the DR beta-1 chain, with rheumatoid arthritis (RA) was confirmed in Japanese patients using polymerase chain reaction. The '70QRRA74A' is the most plausible candidate of susceptibility epitope in Japanese RA patients. The patients carrying the sequence showed slightly higher but not significant familial incidence. The positivity of the 'QRRAA' showed no effect on the positivity of the rheumatoid factor, rheumatoid nodules, and extra-articular signs. Also no significant differences in other clinical parameters (ESR, CRP, Hb, A/G) and age at onset were observed regarding the positivity. The risk that the 'QRRAA' positive subjects would suffer from RA was estimated to be about 1.3% which meant 7.2 times easier to get RA than those without 'QRRAA'.
Takeuchi
F
F
Department of Internal Medicine and Physical Therapy, Faculty of Medicine, University of Tokyo, Japan.
Matsuta
K
K
Watanabe
Y
Y
Tokunaga
K
K
Juji
T
T
Miyamoto
T
T
D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D001172:Arthritis, Rheumatoid / Q000235:genetics / Q000276:immunology*; D015343:DNA Probes, HLA; D000939:Epitopes / Q000235:genetics / Q000276:immunology; D005260:Female; D006684:HLA-DR Antigens / Q000235:genetics*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction
D015343:DNA Probes, HLA; D000939:Epitopes; D006684:HLA-DR Antigens