Distinct Clinical and Laboratory Profiles of Biopsy-Positive and Biopsy-Negative Giant Cell Arteritis: A Meta Analysis

Abstract

Objectives Although temporal artery biopsy (TAB) remains the diagnostic reference for giant cell arteritis (GCA) in resource-restricted settings that lack access to imaging, up to half of clinically diagnosed patients have negative biopsy results.[1,2] This study aimed to describe the characteristics of biopsy-negative (TAB − ) compared to biopsy-positive (TAB+) GCA. Methods We systematically searched Scopus, PubMed, Ovid MEDLINE, and the Cochrane Library to identify studies comparing demographic, clinical, and laboratory characteristics of TAB + and TAB − patients with GCA. Two independent reviewers screened a total of 4,452 records using predefined inclusion and exclusion criteria; 85 full-text articles were reviewed, and 11 met the criteria for inclusion. Extracted variables included study design, demographics, clinical features, laboratory investigations, and disease-related complications. A random-effects meta-analysis was performed, reporting mean differences (MDs) for continuous outcomes and odds ratios (ORs) for dichotomous outcomes, each with corresponding 95% confidence intervals (CIs). Heterogeneity across studies was evaluated using the I 2 statistic. Results A total of 11 studies (10 retrospective and 1 prospective) were included in the analysis, representing a broad geographic distribution. The majority originated from Europe (54.5%), followed by studies from Asia (27.2%) and North America (18.1%). The median sample size across studies was 114 patients, with a range from 42 to 715 patients. The mean follow-up duration is 13.45 ± SD 4.80 years [6-21 years]. TAB+ patients were slightly older than TAB− patients (MD = +4.36 years; 95% CI 1.62-7.09; I 2 = 68%). Inflammatory markers were significantly higher in the TAB+ group: erythrocyte sedimentation rate (MD = +14.06 mm/h; 95% CI 6.35-21.77; I 2 = 76%) and C-reactive protein levels (MD = +12.36 mg/L; 95% CI 0.44-24.29; I 2 = 63%). Jaw claudication was more frequent in TAB+ patients (OR = 3.07; 95% CI 1.79-5.26; p < 0.001; I 2 = 51%). Visual symptoms (OR = 1.62; 95% CI 0.66-3.96; I 2 = 65%), headache (OR = 1.22; 95% CI 0.70-2.14; I 2 = 61%) and polymyalgia rheumatica symptoms (OR = 1.06; 95% CI 0.69-1.61; I 2 = 7%) did not differ significantly between the 2 groups. Conclusion TAB+ GCA patients exhibit a distinct clinical and laboratory phenotype characterized by older age, higher acute phase reactants, and a greater likelihood of jaw calculation. These differences underscore the heterogeneity of GCA and highlight the importance of multi-modal diagnostic approaches. Recognizing these phenotypic patterns may also support more timely and effective management decisions. References [1.] Grossman C. Clin Exp Rheumatol 2019;37 Suppl 117:122-9. [2.] Agard C. Scand J Rheumatol 2019;48:474-81.