RELATION BETWEEN HLA DRB1 ALLELES AND CORTICOSTEROID RESISTANCE IN GIANT-CELL ARTERITIS

Objective-To evaluate the clinical usefulness of genomic HLA typing du ring the first two years of established giant cell arteritis (GCA). Me thods-HLA typing was performed by PCR-SSO in 41 selected white patient s with GCA confirmed by biopsy. Patient data were compared with those of a control group of 384 bone marrow donors (relative risk, p value a nd chi(2) test for each allele). Clinical features at onset and respon se to treatment over a two year period were evaluated in relation to t he genetic pattern. Results-DRB104 was significantly increased in the GCA group (frequency of 48.78% compared with 19.79% in controls, p < 0.001). The distribution of the DRB104 subtypes in the GCA group was similar to that in controls. No clinical or biological differences wer e found in association with HLA at the time of diagnosis. Over the two year follow up, nine patients presented resistance to corticosteroid treatment and eight of these (88.88%) had DRB104 (p < 0.001) Conclusi ons-GCA seems to be associated with HLA DRB104 (regardless of the sub type) and this association appears to be accompanied by corticosteroid resistance, suggesting that genomic typing may be useful to identify patients eligible for early alternative treatment to corticosteroid dr ugs.