MALT1 Positively Relates to Th17 Cells, Inflammation/activity Degree, and Its Decrement along with Treatment Reflects TNF Inhibitor Response in Ankylosing Spondylitis Patients

Background Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) facilitates CD4(+) T-cell differentiation, immune response, inflammation, and osteoclastogenesis. This study aimed to explore the relation between MALT1 and treatment efficacy to tumor necrosis factor inhibitor (TNFi) in ankylosing spondylitis (AS) patients. Methods This study recruited 73 AS patients underwent adalimumab treatment. Peripheral blood mononuclear cell (PBMC) was obtained at Week (W) 0, W4, W8, and W12 after treatment initiation; then, MALT1 was measured using RT-qPCR. Furthermore, PBMC and serum at W0 were proposed to flow cytometry and ELISA for Th1 cells, Th17 cells, IFN-gamma, and IL-17A levels measurement. Besides, 20 osteoarthritis patients and 20 healthy controls (HCs) were enrolled to detect MALT1. Results Mucosa-associated lymphoid tissue lymphoma translocation protein 1 expression was higher in AS patients compared with HCs (p < 0.001) and osteoarthritis patients (p < 0.001). Besides, MALT1 expression was positively linked with CRP (p = 0.002), BASDAI (p = 0.026), PGADA (p = 0.040), ASDAS(CRP) (p = 0.028), Th17 cells (p = 0.020), and IL-17A (p = 0.017) in AS patients, but did not relate to other clinical features, Th1 cells or IFN-gamma (all p>0.050). MALT1 was decreased along with treatment only in AS patients with ASAS40 response (p < 0.001), but not in those without ASAS40 response (p = 0.064). Notably, MALT1 expression was of no difference at W0 (p = 0.328), W4 (p = 0.280), and W8 (p = 0.080), but lower at W12 (p = 0.028) in AS patients with ASAS40 response compared with those without ASAS40 response. Conclusion Mucosa-associated lymphoid tissue lymphoma translocation protein 1 positively correlates with Th17 cells, inflammatory, and activity degree; meanwhile, its decrement along with treatment reflects the response to TNF inhibitor in AS patients.