Sensitivity of Temporal Artery Biopsy in the Diagnosis of Giant Cell Arteritis

A Systematic Literature Review and Meta-Analysis

Emma Rubenstein; Carla Maldini; Solange Gonzalez-Chiappe; Sylvie Chevret; Alfred Mahr

Disclosures

Rheumatology. 2020;59(5):1011-1020. 

In This Article

Abstract and Introduction

Abstract

Objectives: Temporal artery biopsy (TAB) is a reference test for the diagnosis of GCA but reveals inflammatory changes only in a subset of patients. The lack of knowledge of TAB sensitivity hampers comparisons with non-invasive techniques such as temporal artery ultrasonography. We performed a systematic literature review and meta-analysis to estimate the sensitivity of TAB in GCA and to identify factors that may influence the estimate.

Methods: A systematic literature review involved searching electronic databases and cross-references. Eligibility criteria included publications reporting at least 30 GCA cases fulfilling the original or modified 1990 ACR classification criteria. The pooled proportion of TAB-positive GCA cases was calculated by using aggregated-data meta-analysis with a random-effects model and assessment of heterogeneity with the I 2 statistic. Subgroup analyses and meta-regression were used to examine the effect of patient and study characteristics on TAB positivity.

Results: Among 3820 publications screened, 32 studies (3092 patients) published during 1993–2017 were analysed. The pooled proportion of TAB-positive GCA cases was 77.3% (95% CI: 71.8, 81.9%), with high between-study heterogeneity (I 2 = 90%). The proportion of TAB-positive cases was slightly higher in publications before than in 2012 and after (P = 0.001).

Conclusion: The estimated sensitivity of 77% provides indirect evidence that TAB is not less sensitive than temporal artery imaging. The unexplained high between-study heterogeneity could result from differences in TAB sampling, processing or interpretation. The decrease in TAB-positive GCA cases over time could reflect an increasing propensity for clinicians to accept a GCA diagnosis without proof by TAB.

Introduction

GCA is an inflammatory vessel disease of the aorta and its branches, with a predilection for the branches of the carotid and vertebral arteries.[1,2] This disease occurs in people older than 50 years, predominantly women and people in northern European latitudes.[3,4] The diagnosis of GCA is based on a combination of suggestive cranial symptoms, such as new-onset headache or visual manifestations, elevated inflammatory marker levels and a favourable response to glucocorticoid therapy.[3] Temporal artery biopsy (TAB) is the most conventional test to ascertain a diagnosis of GCA,[4] although TAB reveals characteristic histopathological signs only in a subset of patients with a GCA diagnosis.[3,4] The potential explanations for GCA with a negative TAB are not clear and include false-negative results due to technical artefacts but also that GCA with a negative TAB might represent a true phenotypic variant.[3]

The proportion of patients with GCA for whom the diagnosis is documented by a positive TAB is not clear. Review articles generally place this proportion in a range of 40–90%,[3,4] but this figure has never been explored methodologically. The lack of knowledge of the sensitivity of TAB for GCA diagnosis hampers the comparison of TAB with other diagnostic tests, such as imaging of the temporal artery by ultrasonography (TA-US) or by MRI. In addition, precise knowledge of the proportion of patients with a GCA diagnosis who have no detectable TAB anomalies is also important for a better understanding of the general characteristics of GCA.

We performed a systematic literature review to comprehensively identify reports of GCA cohorts who underwent TAB and to estimate by meta-analysis the sensitivity of TAB for the diagnosis of GCA, based on a large sample size. The study also aimed at identifying cohort or study characteristics that may generate variations in the proportion of TAB-positive GCA cases.

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