The epidemiology of giant cell arteritis : a 12-year retrospective study.

OBJECTIVE: To study the incidence of biopsy-proven giant cell arteritis (GCA) in a Hispanic population with clinical features suggestive of GCA.

DESIGN: Retrospective review.

PARTICIPANTS: Records of 121 consecutive patients who underwent temporal artery biopsy at the Doheny Eye Institute and the Los Angeles County/University of Southern California Hospital from January 1986 through April 1998 were reviewed.

MAIN OUTCOME MEASURES: The incidence of biopsy-proven GCA was determined, and the biopsy-positive group was compared with the biopsy-negative group. Study variables included age at diagnosis, gender, erythrocyte sedimentation rate (ESR), and ethnic background.

RESULTS: Among these 121 patients who underwent temporal artery biopsy, the mean age of those in the biopsy-positive group (75.2 +/- 5.0 years) was higher than that of those in the biopsy-negative group (69.1 +/- 9.2 years; P < 0.0001). There was no statistical correlation between biopsy-positive and biopsy-negative groups for gender or ESR level, but ESR was statistically significant for whites when we controlled for race. Nineteen of 66 white patients (29%) had positive biopsy results, whereas only 1 of the 9 Asian patients (11%) none of the 40 Hispanic patients (0%; P < 0.0001) and none of the 6 African American patients (0%) had positive biopsy results.

CONCLUSIONS: Giant cell arteritis occurs primarily in the white population. None of the Hispanic patients in our study was found to have positive biopsy results. Hispanic persons may have unknown factors that protect them from this disease. Further study is necessary to examine the genetic predisposition.