Similar Incidence of Giant Cell Arteritis Within Race

Rates of giant cell arteritis (GCA) are not affected by race between white and black patients, according to a retrospective cohort study by Nottingham University Hospitals National Health Service Trust in the United Kingdom.

Despite its clear association with advancing age, GCA’s exact link with different racial and ethnic groups is unknown, since most epidemiological data on GCA are derived from predominately white populations in Europe, according to the researchers. The purpose of the study was to examine the incidence of biopsy-proven GCA in a tertiary care center-based population with a sizeable proportion of black patients.

The researchers conducted a retrospective review to assess the medical records and histopathologic reports of all patients who underwent temporal artery biopsy (TAB) at John Hopkins Wilmer Eye Institute from 2007 to 2017. Biopsy results and demographic data, including age, sex, and self-reported race, were tabulated.

During the 10-year study period, TAB was performed in 586 individuals, including 382 white (65.2%), 167 black (28.5%), and 7 Asian (1.2%) patients. Eight of 586 patients (1.4%) identified themselves as being Hispanic, a separate category from self-identified race. The racial and ethnic background of 22 patients (3.8%) were unknown or other.

Of the 586 individuals, 93 had positive findings. The mean age was similar in white and black patients (75.4[9.1] vs. 74.1[9.2] years) with a mean difference of 1.3 years. Age was also found to be strongly associated with disease in patients undergoing biopsy, with a 4.4 % increase in likelihood of BP-GCA for each year older than 50 years.

The researchers also found that white patients had a higher pretest probability of disease, with 19.6% of those tested having BP-GCA compared with 8.4% of black patients, suggesting a greater need for surveillance of the black population or stronger link between symptoms and disease in the white population.

According to the study authors, the findings are notable in that they appear to contradict the commonly held belief that GCA is rare in black patients compared with white patients.

“Based on previous epidemiological data, many physicians may have a higher threshold for TAB in black patients, but our findings suggest this should not be the case,” the authors wrote.

Based on the study findings, the authors recommend that the same clinical thresholds for diagnosing and managing GCA be applied to black and white patients.

Reference

• Gruener AM, Poostchi A, Carey A, et al. Association of Giant Cell Arteritis With Race. JAMA Ophthalmol. doi:10.1001/jamaophthalmol.2019.2919. Published August 8, 2019. Accessed August 15, 2019.