Ulcerative Colitis, Takayasu Arteritis and HLA

Ulcerative Colitis, Takayasu Arteritis and HLA Takayasu arteritis is a chronic vasculitis involving mainly the aorta and its branches, the coronary and pulmonary arteries; this is well known due to its peculiar clinical symptomof pulselessness.The etiology of this morbid condition is, however, yet unknown.Recent studies on its pathogenesis have been focused in its autoimmunemechanisms (1).From this viewpoint, HLAanalyses have been widely studied and a haplotype of A24-B52-DR2has been focused as an expression of genetic factor of Takayasu arteritis.Both population and family studies have revealed a statistically significant high frequency of this haplotype, as compared with that in controls, suggesting the participation of a genetic factor, linked with this HLAhaplotype in the pathogenesis of this morbid condition (2, 3).This data is also thought to support "species difference" of Takayasu arteritis, because this disease is frequently encountered in Asian people and it is rare in Caucasian people; this haplotype is typical in Asian people.Onthe other hand, ulcerative colitis is an inflammatory bowel disease involving the colonic mucosa, which is, from its immunological findings, accepted as a type of autoimmune disorder (4).These morbid conditions have been reported to be complicated with various kinds of autoimmune diseases such as lupus erythematosus, chronic active hepatitis, autoimmune hemolytic anemia, etc.