Influence of human leucocyte antigen-DRB1 on the susceptibility to rheumatoid arthritis and on the production of anti-cyclic citrullinated peptide antibodies in a Portuguese population.
OBJECTIVE
To clarify the influence of the HLA-DRB1 locus on the susceptibility to rheumatoid arthritis and the production of anti-cyclic citrullinated peptide antibodies (anti-CCP) in a Portuguese population.


METHODS
141 patients with rheumatoid arthritis fulfilling the American College of Rheumatology 1987 revised criteria for rheumatoid arthritis were compared with 150 healthy controls. Human leucocyte antigen (HLA)-DRB1 locus genotyping was assessed by polymerase chain reaction reverse probing assays and sequence-specific primers. Anti-CCP antibodies were quantified by ELISA in patients with rheumatoid arthritis. Frequencies between groups were compared by the two-sided Fisher's exact test and considered significant if p<0.05.


RESULTS
The HLA-DRB1*04 and HLA-DRB1*10 groups were highly associated with rheumatoid arthritis (p<0.001 and p = 0.031, respectively). High titres of anti-CCP antibodies were largely associated with the presence of HLA-DRB1*04/10.


CONCLUSIONS
The well-recognised susceptibility alleles to rheumatoid arthritis, HLA-DRB1*04, were associated with rheumatoid arthritis in Portuguese patients. The relatively rare DRB1*10 was also associated with rheumatoid arthritis, as was described previously in other southern European countries. Both groups were associated with high anti-CCP titres, reinforcing its relevance to disease onset.
Ligeiro
D
D
Centro de Histocompatibilidade do Sul, Lisboa, Portugal.
Fonseca
J E
JE
Abade
O
O
Abreu
I
I
Cruz
M
M
Nero
P
P
Cavaleiro
J
J
Teles
J
J
Trindade
H
H
Caetano
J M
JM
Branco
J
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000235:genetics / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology*; D016022:Case-Control Studies; D004198:Disease Susceptibility; D000939:Epitopes / Q000276:immunology*; D005260:Female; D005838:Genotype; D006684:HLA-DR Antigens / Q000276:immunology*; D059811:HLA-DRB1 Chains; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010456:Peptides, Cyclic / Q000276:immunology*; D011174:Portugal; D012306:Risk
D001323:Autoantibodies; D000939:Epitopes; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide