Only weak association between disease severity and HLA-DRB 1 genes in a Swiss population of rheumatoid arthritis patients.
This study analyses the prognostic value of HLA-DRB 1 genes for Swiss patients with rheumatoid arthritis (RA). HLA-DRB 1 genotyping was performed in 83 patients using the polymerase chain reaction and subsequent oligonucleotide hybridisation. They were categorised according to the presence of one or two putatively relevant genes (DRB 1*01 and/or DRB 1*04) and retrospectively evaluated for sex, age at disease onset, seropositivity, erosive disease and extraarticular manifestations. Sixty-one patients (73%) had disease-associated alleles. Twenty-four patients showed HLA-DRB 1*04 variants on both alleles or combined an HLA-DRB 1*04 variant with HLA-DRB 1*01, while 37 patients expressed only one relevant allele. Interestingly, 22 patients did not express any relevant allele. Some 52% of patients had nodular disease, 88% were seropositive. 96% had joint erosions and 11% expressed vasculitis and/or rheumatoid organ disease. A significant difference was observed only for the number of seropositive individuals, which was slightly higher in the group of patients expressing a double dose of disease-associated alleles than in patients who had no relevant alleles. Moreover, patients expressing homozygous DRB 1 alleles had a significantly earlier onset of disease than those who were heterozygous. We conclude from these findings that HLA-DRB 1 genotyping in a Swiss population of RA patients only weakly identifies clinical subsets with distinct profiles of disease manifestations and is not of strong prognostic value to determine disease severity in individual patients.
Seitz
M
M
Department of Rheumatology, University Hospital, Inselspital, Bern, Switzerland.
Perler
M
M
Pichler
W
W
D000483:Alleles; D001172:Arthritis, Rheumatoid / Q000235:genetics* / Q000503:physiopathology; D005260:Female; D005838:Genotype; D006684:HLA-DR Antigens / Q000032:analysis*; D059811:HLA-DRB1 Chains; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013557:Switzerland
D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains