Treatment of childhood-onset Takayasu arteritis: switching between anti-TNF and anti-IL-6 agents

Objectives Biologics are new treatment alternatives in Takayasu arteritis (TA), although data in childhood are limited. The aim of this study was to share our experience in seven childhood-onset TA patients who received a TNF-alpha inhibitor (adalimumab) or an IL-6 receptor inhibitor (tocilizumab) and the effect of switching therapy. Methods We retrospectively evaluated the medical treatment records of seven patients with TA, followed between August 2005 and January 2021 at the Pediatric Rheumatology Department of Hacettepe University Faculty of Medicine. Results The median age of patients was 14 (IQR 4) years, and six were female. All of the patients had severe disease and high acute-phase reactants. The patients initially received only steroids or steroids+CYC. Prednisone was decreased, and biologic agents were started once the acute phase reactants decreased, and the Indian Takayasu Activity Score (ITAS) returned to normal. Initially, four patients received tocilizumab (TCZ) [median 25.5 (IQR 41) months] and three patients received adalimumab (ADA) [median 13 (IQR 31) months]. However, due to the progression of MR angiography findings or persistent elevation in acute-phase reactants, the biologic agents were switched from TCZ to ADA in four patients and from ADA to TCZ in three patients. The patients' median follow-up time after changing was 50 (IQR 77) months, and median ITAS was evaluated as '0' after 2 (IQR 4) months. Conclusions In conclusion, both TNF-alpha and IL-6 inhibitors are effective alternatives in treating patients with childhood-onset TA. However, prospective randomized controlled trials are needed for the comparison of their effectiveness.