Use of tumour necrosis factor inhibitors (TNFi) has proved to be an important step forward in the treatment of axial spondyloarthritis (axSpA), but the duration of the therapy as well as the management in case of low disease activity (LDA) or remission are not clearly established. Currently, the identification of potential predictors associated with the treatment discontinuation is the basic purpose of many clinical studies. The aim of this study was to analyze the influence of the discontinuation of TNFi therapy on the disease activity in patients with low disease activity.
The study included 65 patients; 47 of patients (72%) were treated with etanercept, 16 (2%) with adalimumab and 2 (3%) with infliximab.
The mean age of the patients was 45 years, the mean BASDAI score was 6.8 and VAS for low back pain was 76 mm at baseline. 54 patients with axSpA (83%) achieved LDA after 9 months of anti-TNF therapy. During follow-up 40 patients (74% of patients with LDA) had an increase of the disease activity after mean 14 weeks and needed to restart the treatment with TNFi. After restart of the therapy LDA was regained in all patients after mean 7 weeks. 11 patients (17%) have never achieved LDA and 14 patients (22%) had LDA longer than 6 months without relapse. At baseline higher levels of CRP and ESR were observed in patients with relapse of the disease at the end of treatment and with LDA shorter than 6 months.
Changes in the values of disease activity indicators (CRP, ESR) correlated with more stable response to TNFi therapy. Over 50% of patients who were treated with TNFi needed to restart the therapy. Treatment resumption allowed to regain a good clinical effect among affected patients.