Giant cell arteritis in Asians: a comparative study.

BACKGROUND Giant cell arteritis (GCA) is a common systemic vasculitis, with a presumed Caucasian predominance. The occurrence of GCA in Asians has rarely been addressed. This study aims to assess the incidence of giant cell arteritis in Asians. METHODS In this retrospective review, the self-reported ethnicities of patients with biopsy-proven GCA at the University of California-San Francisco (UCSF) were recorded. Ethnic distribution of the patient population served by UCSF was estimated from an age- and sex-matched control group. The odds ratio for each ethnicity (Asian and Caucasian) was determined and compared using Fisher's exact test and logistic regression analysis. RESULTS The ethnic distribution of the 38 patients with positive temporal artery biopsies were as follows: Caucasian n=31 (81.6%), Asian n=1 (2.6%) and other n=6 (15.8%). The ethnic distribution of the patient population served by UCSF was as follows: Caucasian 42%, Asian 28% and other 30%. The difference in the proportion of GCA in Asians and Caucasians was statistically significant (OR 0.049 (95% CI 0.0065 to 0.374), p=0.0036). CONCLUSIONS In our patient population, GCA was seen 20 times less frequently in Asian than Caucasian patients. Although this difference is significantly different (p=0.036), given the small sample size and wide CI this should be viewed as a rough estimate.