Linkage between rheumatoid arthritis susceptibility and the presence of HLA-DR4 and DR beta allelic third hypervariable region sequences in southern Chinese persons.
OBJECTIVE
To analyze HLA-DR and DQ associations with rheumatoid arthritis (RA) in patients from southern China.


METHODS
In 66 patients and 45 controls, restriction fragment length polymorphism studies were performed using DRB, DQA, and DQB probes, and DRB allele-specific typing of polymerase chain reaction-amplified DRB DNA:


RESULTS
The frequency of HLA-DR4 was significantly increased among RA patients (42.4% versus 17.8%). Increased frequencies of the DQA3 allele (77.8% versus 48.9%) and the DQB1*0302 allele (71.0% versus 46.3%), which are in linkage disequilibrium with DR4, were also found. Oligonucleotide typing showed that the amino acid sequence LLEQRRAA, spanning amino acid positions 67-74 of the DR beta molecule, was found in 19 of 49 patients and 5 of 32 controls. The main DR4 allelic subtypes found in the population were DRB1*0404 and DRB1*0405, both of which carried the sequence. There was no difference in subtype distribution between patients and controls.


CONCLUSIONS
Chinese RA patients have an increased frequency of HLA-DR4 alleles which possess the same DRB third allelic hypervariable sequence shown to be associated with susceptibility in Caucasian RA patients.
Seglias
J
J
Department of Medicine, Royal Postgraduate Medical School, London, United Kingdom.
Li
E K
EK
Cohen
M G
MG
Wong
R W
RW
Potter
P K
PK
So
A K
AK
D000483:Alleles; D000595:Amino Acid Sequence; D001172:Arthritis, Rheumatoid / Q000208:ethnology* / Q000235:genetics / Q000276:immunology*; D002681:China; D004198:Disease Susceptibility; D005784:Gene Amplification; D008040:Genetic Linkage; D006684:HLA-DR Antigens / Q000235:genetics*; D006801:Humans; D006824:Hybridization, Genetic; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length
D006684:HLA-DR Antigens