Intra-articular injection of etanercept into the sacroiliac joint of ankylosing spondylitis / 中华风湿病学杂志

ABSTRACT

Objective To evaluated intra-articular injection of TNF-α inhibitors into the sacroiliac joint as an effective and viable alternative. Methods Sixteen patients with documented ankylosing spondylitis (AS), without steroids or disease modifying anti-rheumatic drugs (DMARDs) were performed CT-guided intra-articular injections of etanercept (TNF-α antagonist) at week 0, 4 and 8 (25 mg per dose). Similarly, 20 patients with AS in the control group received systemic etanercept therapy at a dose of 50 mg per week for 8 weeks. All patients were followed up clinically and evaluated periodically. Pathological features of sacroiliitis were observed with light microscopy and immunohistochemistry. Expression of cytokines in joint biopsy samples was estimated by RT-PCR. Image changes of sacroiliitis were observed by SPECT/CT and MRI. Ttest, t'tesr and χ2 Fisher's test were selected. Results All the 16 patients who received intra-articular etanercept, the mean value of radiological nuclide decrease of the SIJ ROI (region of interest) in the SPECT improved significantly after 8 weeks treatment [(1.38±0.16 vs 1.45±0.14) P<0.05] . Bone marrow edema and fat deposition in MRI were relieved significantly after 8 weeks (P<0.05). In 8 patients the expression of TNF-α and TGF-β mRNA in joint tissue decreased significantly after 8 weeks [(0.89±0.06, 0.84±0.05) vs (l.08± 0.19, 1.13±0.33) (P<0.05)]. The occurrence of gynonitis, enthesitis, chondritis, subehondral bony plate destruction, bone marrow inflammation and inflammatory cell index also decreased significantly (P<0.05). Participants given intra-articular injection showed significant clinical improvement after 8 weeks and 12 weeks treatment(P<0.01 ) in BASDAI score [(32±13) mm]. Conclusion This study has shown that intra-articular injection of etanercept in SIJ can improve joint function and quality of life. It has a satisfactory safety profile and is cost effective. This mode of treatment is most beneficial in local arthropathy of recent onset and in those patients who do not tolerate systemic etanercept therapy.