Immunogenetics of peripheral arteriopathies

Takayasu's arteritis (TA) and thrombangiitis obliterans (Buerger's disease) are idiopathic, inflammatory arteriopathies with strong indications for th e involvement of autoimmunity and host genetic factors in their immunopatho genesis. The exact etiology of these arteriopathies still remains unknown e ven after almost nine decades of their description. A series of immunogenet ic studies conducted worldwide seeking to define genetic factors in governi ng immune response in these diseases have yielded conflicting results on th e involvement of HLA molecules. While an association of HLA-BS or its molec ular subtypes with Takayasu's arteriitis has been emphasized in patients fr om Japan, Korea and India, no such association has been reported in Mexican and North American patients. On the other hand, a limited data is availabl e on the association of HLA antigens with Buerger's disease. In this articl e, we provide an overview of the immunogenetics of Buerger's disease and Ta kayasu's arteriitis in the context of studies in North Indian patients and those in other ethnic groups. Our studies indicate a positive association o f Takayasu's arteriitis with the HLA-BS molecule with no preferential assoc iation with its two major subtypes. In Buerger's disease, we have observed a strong positive association with HLA-DRB1*1501 consistent with the findin gs in Japanese patients. These results suggest an important role of HLA lin ked factors in governing susceptibility to both arteriopathies.