HLA-DR6 (POSSIBLY DRB1-ASTERISK-1301) IS ASSOCIATED WITH SUSCEPTIBILITY TO TAKAYASU-ARTERITIS IN MEXICANS

Takayasu arteritis is characterized by a ''pulseless'' condition and o ccurs frequently in young females from Asian and South American countr ies. This disease has been found to be linked with major histocompatib ility complex (MHC) antigens in Japanese individuals. In the present s tudy we compared gene frequencies of class I, class II, and class III MHC genotypes in patients with Takayasu arteritis and ethnically match ed healthy controls. Serological typing was confirmed by molecular typ ing at the DNA level. We found significant increases in the frequencie s of human leucocyte antigen (HLA)-DR6 and HLA-B62 in patients compare d to the healthy controls (P corrected [C] = 0.0007, relative risk [RR ] = 5.08; PC = 0.05, RR = 3.13 respectively). However, since the numbe r of patients was considerably lower than the number of controls this can be considered as a tendency and not a true association. On the oth er hand, we found a significantly decreased frequency of HLA-DR4 in pa tients compared to healthy controls (PC = 0.04, RR = 0.34). At the DNA level, all DRG-positive individuals were HLA-DRB11301 whereas contro ls were HLA-DRB11301 (4.2%). Takayasu arteritis in Mexicans is probab ly associated with the HLA-DRG (DRB11301) gene.