IS THERE AN INDICATION FOR HLA-DR TYPING FOR INDIVIDUAL PATIENTS WITHRHEUMATOID-ARTHRITIS

The clinical expression of rheumatoid arthritis (RA) varies considerab ly among individual patients. Genetic variations in human leucocyte an tigen (HLA) may influence susceptibility to RA and the severity of the disease. The literature concerning the association of HLA-DR with the susceptibility to and the clinical expression of RA is reviewed here, taking into account the different populations studied and different t yping techniques. An association between the 'shared epitope' and RA < (susceptibility)under bar> is present on a group level and may be of s ome pathophysiological interest. However HLA-DR typing is not useful a s a diagnostic test for individuals. The reported associations between HLA-DR and RA <(severity)under bar> are various, which might be due t o the different typing techniques used. Results from most studies usin g genomic techniques for HLA-DR typing show an association between HLA -DR4+, DR1+ and a more severe disease course in patient groups. Howeve r, this association is too weak to be relevant for individual patients . Therefore, with our current typing techniques, HLA-DR typing is nor a useful prognostic test for individual RA patients.