Diagnosis of giant cell arteritis (GCA) may be predictable by a patient’s age and histopathological status of healed temporal arteritis (HTA), according to a study published in Clinical Neurology and Neurosurgery.
Patient records from the Robert Cizik Eye Clinic of the Ruiz Department of Ophthalmology and Visual Science at the McGovern Medical School at The University of Texas Health Science Center at Houston and Memorial Hermann — Texas Medical Center were retrospectively reviewed for this study. Patients (N=101) who underwent temporal artery biopsy between 2011 and 2019 were evaluated for predictors of a GCA diagnosis.
A total of 31 of the 101 patients were diagnosed with GCA. The GCA and no GCA cohorts were comprised of 87% and 66% women (P =.031), aged mean 74.4 and 68.9 years (P =.009), 45% and 16% had transient loss of vision (P =.005), and 10% and 0% had arteritic ischemic optic neuropathy (AAION; P =.028), respectively.
The GCA group was associated with abnormal C-reactive protein levels (97% vs 79%; P =.033), disrupted internal elastic lamina (74% vs 14%; P <.001), the presence of multinucleated giant cells (39% vs 0%; P <.001), transmural inflammation (55% vs 0%; P <.001), and CD68 differentiation clusters (73% vs 14%; P <.001) compared with the patients who did not have GCA, respectively.
At biopsy, 48% of the GCA group were positive and 16% were negative compared with 0% and 90% among the non-GCA cohort, respectively. In addition, 10% of the GCA and 3% of the non-GCA groups had HTA at biopsy and 26% and 7% had suggested HTA at biopsy, respectively.
Predictors for GCA included HTA (odds ratio [OR], 84.7; 95% CI, 3.9->999), suggested HTA (OR, 49.3; 95% CI, 5.1-472.1), age per 5-year increase (OR, 2.16; 95% CI, 1.03-1.32), and oral steroid dose per 1 mg per day increase (OR, 1.08; 95% CI, 1.01-1.16). These features had an area under the receiving operator characteristic curve (AUROC) of 92% for predicting GCA.
“The correlation between age and GCA has been recognized in previous studies, and age is known to be the single most important risk factor for a positive [temporal artery biopsy] and/or GCA diagnosis,” the researchers explain. “We found that older age was associated with GCA diagnosis, with an average age of 74.4 years in the GCA group compared to 68.9 years in the non-GCA group. The youngest patient in the GCA group was 59 years, compared to 44 years in the non-GCA group.”
“HTA and suggested HTA were prevalent biopsy findings and also appeared to have positive predictive value for determining GCA status. We found transient vision loss to be an important symptom in diagnosing GCA,” the study authors report. “Given the increasing use of CD68 staining and low sensitivity found in our study, further work is recommended to investigate the importance of the specific histopathologic finding of CD68 staining in the diagnosis of GCA. This is important especially in specimens that do not otherwise demonstrate signs of active or classic healed arteritis and for the resulting impact on patient management.”
This study was limited by the retrospective design and the fact that some patients had incomplete documentation of symptomatology.
Castro HMM, Bhattacharjee MB, Chaudhry IA, et al. Diagnosis of giant cell arteritis using clinical, laboratory, and histopathological findings in patients undergoing temporal artery biopsy. Clin Neurol Neurosurg. 2022;221:107377. doi:10.1016/j.clineuro.2022.107377