Association of DR4 related RFLP bands and RA in Greeks

Using the Taq1 restriction enzyme and DR beta, DQ alpha probes, the DNAs of Greek RA patients and controls were characterised for RFLP's associated with DR4. Three DR beta bands, 14.8kb, 6.1kb and 5.4kb were observed at significantly higher frequency in the patients compared with controls. By using a DQ alpha probe, the 2.6kb band (associated with DR1, DRw10, DRBR and DRw14 (Dw9)) was at a significantly raised frequency in the patients. The DQ alpha 5.3kb band associated with DR4, DR7 and DR9 was also raised in the RA patients although this increase did not reach statistical significance. In view of the previously documented lack of association between DR4 (and other DR antigens) and RA in Greeks, the results suggest that some degree of HLA class II association exists with RA in this population at the DNA level which may not be overtly reflected serologically.