Inflammation Often Remains Following Tocilizumab Use for GCA

TOPLINE:

Over one third of patients with giant cell arteritis exhibit vascular inflammation even after receiving treatment with tocilizumab and glucocorticoids for at least 6 months, which suggests the need for more effective anti-inflammatory strategies.

METHODOLOGY:

• Researchers conducted a retrospective cohort study to evaluate the effects of tocilizumab and glucocorticoid treatment on histopathologic changes in patients with giant cell arteritis.
• They included 13 patients (mean age at disease onset, 69.3 years; 53.8% women) with giant cell arteritis and an inflamed temporal artery biopsy (TAB) at diagnosis who were treated with tocilizumab and glucocorticoids for at least 6 months and followed from December 2017 to December 2023.
• All the patients underwent a second TAB, 18-fluorodeoxyglucose PET-CT, and color Doppler ultrasonography after receiving tocilizumab for a median duration of 2.4 years.
• Disease activity was evaluated through clinical manifestations, laboratory tests, and imaging findings, with active disease being defined by the presence of symptoms, an increase in inflammatory markers, or the need for an increased glucocorticoid dosage.

TAKEAWAY:

• The initial TAB showed transmural inflammation (TMI) in 11 of 13 patients and inflammation limited to adventitia and small vessel vasculitis in one patient each.
• At the second TAB, 5 out of 13 patients (38.5%) still presented inflammation. Of the 11 patients with TMI at the first TAB, 5 (45.4%) still showed inflammation at the second TAB: 4 had inflammation restricted to the adventitial/periadventitial tissue, and 1 had persistent TMI.
• Among nine patients with active vasculitis on PET-CT at baseline, three (33.3%) showed persistent activity at the follow-up, with a significant reduction in mean PET vascular activity score (mean difference, −6.5; P = .017).
• Color Doppler ultrasonography showed temporal artery inflammation in approximately one third of patients.

IN PRACTICE:

“Our findings suggest that persistent histological inflammatory alterations are predominantly limited to the adventitial vessels, while TMI [transmural inflammation] signs have regressed in most patients,” the authors wrote.

SOURCE:

This study was led by Caterina Ricordi, MD, Unit of Rheumatology, Azienda USL — IRCCS di Reggio Emilia, Reggio Emilia, Italy, and was published online on December 31, 2024, in RMD Open.

LIMITATIONS:

This study’s single-center and retrospective design may have introduced selection and referral biases. Most patients started tocilizumab at disease relapse, potentially selecting for more severe cases. The small sample size and lack of a comparator group of patients receiving only glucocorticoids limited the assessment of histologic changes without tocilizumab treatment. Moreover, the interpretation of persistent inflammation in temporal arteries varied based on different definitions of restricted inflammation as active inflammation.

DISCLOSURES:

This study did not report receiving any funding. The authors declared having no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.