Takayasu's arteritis and giant cell (temporal or cranial) arteritis.

Takayasu's arteritis (TA), of which the first case was described by Takayasu in 1905 (1), is a chronic inflammatory disease of unknown etiology that primarily involves the aorta, its major branches, and the pulmonary and coronary arteries. Synonymssuch as aortic arch syndrome, pulseless disease and aortitis syndrome reflect this anatomic localization. TAappears to be most commonin East Asia including Japan. According to a recent nationwide epidemiological survey, the total number of Japanese patients with TAin 1995 was estimated as 3,000 to 4,000, showing a predominantly high female prevalence (malerfemale ratio 1:9.2) (2). TA is known for characteristically affecting a young female population, although the mean age of Japanese patients with TAhas become older than previously described (2). In this issue of the Journal, a rare case of TA in a 69-year-old womanis reported (3). See also p 69. TA is also known for ethnic differences in the disease patterns and the associations of HLAantigens. For example, according to a newclassification of the angiographic findings for TA (4), types I and II in Japanese patients are statistically significantly more commoncompared to those in Indian patients (5). In contrast, Indian patients have a rather high frequency of type IV which involves only the abdominal aorta and its branches. Concerning HLAantigens, although Japa-nese patients with TAare knownto be associated with HLA-B52 and B39 (6), it has been suggested that HLA-B39 might be associated with the involvement of the abdominal aorta in TA (7). The case of TAassociated with HLA-B52and its hap-lotype reported in this issue (3) is thought to represent type V, which is characterized by the involvement of aortic arch, tho-racic aorta, abdominal aorta and their branches, according to the above angiographic classification. On the other hand, giant cell (temporal or cranial) arteritis (GCA), which was described by Hutchinson (8) in 1890 and by Horton et al (9) in 1932, has been recognized as a clinico-pathological entity characterized as granulomatous temporal arteritis of the elderly. The incidence is likely high in Northern European countries, but it is low in Japan. A nationwide epidemiological survey by the collaborative study of the Research Committeeon Intractable Vasculitis Syndromeand Epidemiology of Intractable Diseases sponsored by the Ministry of Health and Welfare of Japan was conducted for Japanese patients with GCAin 1998 (10). The total number of patients with GCAtreated in 1997 was estimated to be 690 (range 400-980), showing a weak predilection for women (male female …