Diagnosis of giant cell arteritis: when should we biopsy the temporal artery?

Temporal artery biopsy: A technical guide and review of its importance and indications

Temporal artery biopsy (TAB) is a surgical procedure that enables the histological diagnosis of giant cell arteritis (GCA). Performing a TAB requires expertise and a precise approach. Nevertheless, available data supports the value of tissue diagnosis in managing GCA. The current therapeutic recommendation for GCA is long-term glucocorticoid therapy, with an increasing emphasis on the addition of immunosuppressants/biotherapies. Though effective, immunosuppressants and other such biotherapies may put the patient at more risk. Optimizing the diagnosis through tissue evaluation is therefore important in weighing the risks and benefits of initiating therapeutic intervention. We evaluate the evidence supporting the importance of TAB and its indications. We also describe what technical approaches should be used to maximize sensitivity and to avoid possible complications during the procedure.

Clinical and technical determinants of positive temporal artery biopsy: a retrospective cohort study

Temporal artery biopsy (TAB) is one of the diagnostic tools to confirm the diagnosis of giant cell arteritis (GCA). We aim to evaluate the clinical and technical determinants of a positive biopsy. Demographics, clinical, technical, and laboratory data of all TAB's performed between 2007 and 2019 at a single academic medical center. 107 biopsies performed for 103 patients were included; 72.9% were female, and 27.1% were male. The mean age at the time of biopsy was 67.1 ± 9.3 years. One biopsy was excluded for lack of arterial tissue content. Of the remaining 106, 19.6% were positive. The length of the biopsy and the number of arterial cross-sections were not significantly associated with its result. A positive biopsy was seen more in patients with low albumin (p = 0.010) and hypothyroidism (p = 0.017) but less in those with prior glucocorticoids treatment (p = 0.028). Predictors of a positive biopsy included male gender [OR 4.029, 95% CI (1.330-12.209), p = 0.014]; elevated ESR [OR 3.998, 95% CI (1.908-6.787), p = 0.023]; polymyalgia rheumatica (PMR) symptoms [OR 5.121, 95% CI (2.094-9.872), p = 0.001]; and advancing in age (6.5% per every additional year), [OR 1.065, 95% CI (1.005-1.130), p = 0.033]. 53.7% of the patients were eventually diagnosed with GCA; 39.2% of them were based on positive biopsy. In conclusion, old age, male gender, elevated ESR, and PMR symptoms increase the odds of positive TAB. Technical factors, such as biopsy length and the number of cross-sections, did not influence eventual biopsy results, highlighting the pivotal role of the clinical presentation of the patients in selecting patients for TAB.

2021 American College of Rheumatology/Vasculitis Foundation Guideline for the Management of Giant Cell Arteritis and Takayasu Arteritis

OBJECTIVE

To provide evidence-based recommendations and expert guidance for the management of giant cell arteritis (GCA) and Takayasu arteritis (TAK) as exemplars of large vessel vasculitis.

METHODS

Clinical questions regarding diagnostic testing, treatment, and management were developed in the population, intervention, comparator, and outcome (PICO) format for GCA and TAK (27 for GCA, 27 for TAK). Systematic literature reviews were conducted for each PICO question. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of the evidence. Recommendations were developed by the Voting Panel, comprising adult and pediatric rheumatologists and patients. Each recommendation required ≥70% consensus among the Voting Panel.

RESULTS

We present 22 recommendations and 2 ungraded position statements for GCA, and 20 recommendations and 1 ungraded position statement for TAK. These recommendations and statements address clinical questions relating to the use of diagnostic testing, including imaging, treatments, and surgical interventions in GCA and TAK. Recommendations for GCA include support for the use of glucocorticoid-sparing immunosuppressive agents and the use of imaging to identify large vessel involvement. Recommendations for TAK include the use of nonglucocorticoid immunosuppressive agents with glucocorticoids as initial therapy. There were only 2 strong recommendations; the remaining recommendations were conditional due to the low quality of evidence available for most PICO questions.

CONCLUSION

These recommendations provide guidance regarding the evaluation and management of patients with GCA and TAK, including diagnostic strategies, use of pharmacologic agents, and surgical interventions.

2021 American College of Rheumatology/Vasculitis Foundation Guideline for the Management of Giant Cell Arteritis and Takayasu Arteritis

OBJECTIVE

To provide evidence-based recommendations and expert guidance for the management of giant cell arteritis (GCA) and Takayasu arteritis (TAK) as exemplars of large vessel vasculitis.

METHODS

Clinical questions regarding diagnostic testing, treatment, and management were developed in the population, intervention, comparator, and outcome (PICO) format for GCA and TAK (27 for GCA, 27 for TAK). Systematic literature reviews were conducted for each PICO question. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of the evidence. Recommendations were developed by the Voting Panel, comprising adult and pediatric rheumatologists and patients. Each recommendation required ≥70% consensus among the Voting Panel.

RESULTS

We present 22 recommendations and 2 ungraded position statements for GCA, and 20 recommendations and 1 ungraded position statement for TAK. These recommendations and statements address clinical questions relating to the use of diagnostic testing, including imaging, treatments, and surgical interventions in GCA and TAK. Recommendations for GCA include support for the use of glucocorticoid-sparing immunosuppressive agents and the use of imaging to identify large vessel involvement. Recommendations for TAK include the use of nonglucocorticoid immunosuppressive agents with glucocorticoids as initial therapy. There were only 2 strong recommendations; the remaining recommendations were conditional due to the low quality of evidence available for most PICO questions.

CONCLUSION

These recommendations provide guidance regarding the evaluation and management of patients with GCA and TAK, including diagnostic strategies, use of pharmacologic agents, and surgical interventions.

Clinical pathways for patients with giant cell arteritis during the COVID-19 pandemic: an international perspective

Giant cell arteritis, a common primary systemic vasculitis affecting older people, presents acutely as a medical emergency and requires rapid specialist assessment and treatment to prevent irreversible vision loss. Disruption of the health-care system caused by the COVID-19 pandemic exposed weak points in clinical pathways for diagnosis and treatment of giant cell arteritis, but has also permitted innovative solutions. The essential roles played by all professionals, including general practitioners and surgeons, in treating these patients have become evident. Patients must also be involved in the reshaping of clinical services. As an international group of authors involved in the care of patients with giant cell arteritis, we reflect in this Viewpoint on rapid service adaptations during the first peak of COVID-19, evaluate challenges, and consider implications for the future.

Multivariable prediction model for suspected giant cell arteritis: development and validation

Purpose

To develop and validate a diagnostic prediction model for patients with suspected giant cell arteritis (GCA).

Methods

A retrospective review of records of consecutive adult patients undergoing temporal artery biopsy (TABx) for suspected GCA was conducted at seven university centers. The pathologic diagnosis was considered the final diagnosis. The predictor variables were age, gender, new onset headache, clinical temporal artery abnormality, jaw claudication, ischemic vision loss (VL), diplopia, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and platelet level. Multiple imputation was performed for missing data. Logistic regression was used to compare our models with the non-histologic American College of Rheumatology (ACR) GCA classification criteria. Internal validation was performed with 10-fold cross validation and bootstrap techniques. External validation was performed by geographic site.

Results

There were 530 complete TABx records: 397 were negative and 133 positive for GCA. Age, jaw claudication, VL, platelets, and log CRP were statistically significant predictors of positive TABx, whereas ESR, gender, headache, and temporal artery abnormality were not. The parsimonious model had a cross-validated bootstrap area under the receiver operating characteristic curve (AUROC) of 0.810 (95% CI =0.766–0.854), geographic external validation AUROC’s in the range of 0.75–0.85, calibration p_H–L of 0.812, sensitivity of 43.6%, and specificity of 95.2%, which outperformed the ACR criteria.

Conclusion

Our prediction rule with calculator and nomogram aids in the triage of patients with suspected GCA and may decrease the need for TABx in select low-score at-risk subjects. However, misclassification remains a concern.