Does a temporal artery biopsy performed after 2 weeks of systemic steroid treatment provide diagnostic value?

Introduction

Temporal artery biopsy is considered the gold standard histological test in the diagnosis of giant cell arteritis (1). Ideally, a biopsy should be performed prior to commencing steroid treatment or within 2 weeks of initiating steroids. However, it may not always be feasible to perform a biopsy within this timeframe due to the urgent need for initiating steroids in these cases and delays in referral for biopsy or theatre constraints. Systemic steroid treatment is known to alter the classic histological features of a temporal artery biopsy, and there is debate regarding the benefit of performing a temporal artery biopsy after 2 weeks of initiating steroids (1).

This study seeks to evaluate the effect of high-dose corticosteroid treatment on temporal artery biopsy histology and its diagnostic value in patients who have received systemic prednisolone for more than 2 weeks.

Methods

In this observational study, a retrospective review of patients who underwent temporal artery biopsy between January 2018 and October 2023 at Royal Shrewsbury Hospital in the United Kingdom was performed, with scrutiny of the histology reports for features of giant cell arteritis, such as transmural inflammation with lymphocytes and/or macrophages, disruption of the elastic lamina and intimal hyperplasia.

Descriptive statistics were used for data analysis. Patients who were on systemic steroids for more than 2 weeks at the time of performing the temporal artery biopsy were studied. Histological evaluation of temporal artery biopsy specimens was performed by consultant histopathologists experienced in vasculitis diagnosis. The intensity of inflammatory cell infiltration was graded qualitatively based on standard morphological criteria—

• Mild:
  • Sparse and discontinuous infiltration of lymphocytes and/or macrophages;
  • Inflammatory cells confined to the adventitia or perivascular region without significant transmural involvement;
  • Minimal or no disruption of the internal elastic lamina (IEL);
  • No or minimal intimal hyperplasia.
• Moderate:
  • Dense but patchy infiltration of lymphocytes, histiocytes, and occasional multinucleated giant cells;
  • Transmural inflammation involving the media and adventitia;
  • Partial disruption or fragmentation of the IEL;
  • Presence of early intimal thickening.
• Severe:
  • Diffuse, dense transmural inflammation with granulomatous features and frequent multinucleated giant cells;
  • Widespread destruction of the IEL;
  • Prominent intimal hyperplasia and possible luminal narrowing;
  • May include fibrosis and scarring in chronic cases.

Ethical considerations

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patients for publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Results

A total of 60 patients were identified to have signs in keeping with or suggestive of giant cell arteritis on histological examination of temporal artery specimens. Informed consent was obtained from all patients, and all biopsies were performed under local anaesthesia.

There were 44 females and 16 males with a mean age of 73 years (range, 48–88 years). Mean length of temporal artery biopsy 2.3 cm (range, 1.1–4 cm). Mean duration of steroid treatment before performing the temporal artery biopsy was 2.7 weeks (range, 0 days to 13 weeks), details shown in Table 1. Nineteen (31%) patients had received more than 2 weeks of steroid treatment at the time of temporal biopsy. Nine patients were treated with intravenous methylprednisolone at presentation, and 50 patients were treated with an initial dose of 40–60 mg of oral prednisolone. One patient was on low-dose (15 mg) oral prednisolone for 6 months for polymyalgia rheumatica before undergoing a biopsy, which showed typical histological signs of temporal arteritis. One patient was on oral prednisolone and methotrexate for 2 months before a biopsy was performed, and typical histological signs of temporal arteritis were noted, as shown in Figures 1,2.

Figure 1 Histological sections showing a lymphocytic infiltrate within the tunica adventitia and media with occasional multinucleate giant cells, stained with HE. Original magnification: ×200 (A) and ×400 (B). At low power (A), the arterial wall is thickened with intimal hyperplasia and patchy disruption of the IEL (also see EVG image in Figure 2), resulting in luminal narrowing. At high power (B), a transmural granulomatous inflammation is seen, with lymphocytes, histiocytes, and multinucleated giant cells clustered near the fragmented elastic lamina. EVG, Elastic Van Gieson; HE, haematoxylin and eosin; IEL, internal elastic lamina.

Figure 2 Histological section showing intimal elastin fragmentation and duplication, stained with EVG. Original magnification: ×100. EVG, Elastic Van Gieson.

Discussion

Giant cell arteritis or temporal arteritis is an inflammatory vasculitis affecting the large and medium-sized arteries with a predilection for cranial arteries. Although laboratory tests and temporal artery ultrasound are performed while investigating a patient with suspected temporal arteritis, histological confirmation in temporal artery biopsy remains the gold standard for diagnosis (1).

Ideally a biopsy should be performed before the initiation of glucocorticoid therapy to increase the diagnostic yield. However, given the risk of permanent vision loss, clinicians often begin glucocorticoid therapy as soon as the diagnosis of giant cell arteritis (GCA) is suspected.

Classic histological findings in untreated temporal arteritis include a granulomatous inflammatory cell infiltrate with disruption of the IEL (1-3).

In our study, histological features in temporal artery biopsy specimens from patients who had received more than 2 weeks of steroid therapy showed similarities to pre-steroid classical features but with some differences, such as a milder and patchier inflammatory cell infiltrate, fewer histiocytes and residual scarring (2-4).

Our study findings are therefore similar to those reported previously in the literature, showing that histological features can persist in biopsy specimens despite steroid therapy (2-5). Limitations of our study were a retrospective observational design and a smaller cohort.

Maleszewski et al. (3) repeated temporal artery biopsy in patients who had undergone previous biopsy and were subsequently treated with systemic prednisolone. They found that the repeat temporal artery biopsy showed signs of continued active arteritis in 73% of patients in the first 6 months and in 44% of patients at 9–12 months.

Therefore, in patients posing a diagnostic dilemma due to equivocal clinical features, a temporal artery biopsy can still be considered, even if they have been on long-term steroids, if the treating clinicians feel that it will aid the diagnosis and management.

Conclusions

Histological signs indicative of giant cell arteritis were observed in 31% of patients who had been on systemic steroids for more than 2 weeks at the time of their temporal artery biopsy. Therefore, even if patients have been on long-term steroids, a temporal artery biopsy can still be considered if they present with equivocal clinical features and the treating clinician believes it will aid in the diagnosis.

Acknowledgments

None.

Footnote

Peer Review File: Available at https://aes.amegroups.com/article/view/10.21037/aes-25-9/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://aes.amegroups.com/article/view/10.21037/aes-25-9/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patients for publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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