Microfibrillar-associated protein 4 as a predictive biomarker of treatment response in patients with chronic inflammatory diseases initiating biologics: secondary analyses based on the prospective BELIEVE cohort study

Abstract

Background Currently, there are no reliable biomarkers for predicting treatment response in chronic inflammatory diseases (CIDs). Objective To determine whether serum microfibrillar-associated protein 4 (MFAP4) levels can predict the treatment response to biological therapy in patients with CIDs. Methods The BELIEVE study was originally designed as a prospective, multi-center cohort study of 233 patients with either rheumatoid arthritis, psoriatic arthritis, psoriasis, axial spondyloarthritis, Crohn’s disease, or ulcerative colitis, initiating treatment with a biologic agent (or switching to another). Clinical assessment and blood sample collection were performed at baseline and 14–16 weeks after treatment initiation. The primary analyses included participants with available blood samples at baseline; missing data were handled as non-responders. The patients were stratified into the upper tertile of serum MFAP4 (High MFAP4) versus a combined category of middle and lower tertiles (Other MFAP4). The primary outcome was the proportion of patients with clinical response to biologic therapy after 14–16 weeks. Results 211 patients were included in the primary analysis population. The mean age was 43.7 (SD: 14.8) years, and 120 (59%) were female. Positive treatment response was observed in 41 (59%) and 69 (49%) for High MFAP4 and Other MFAP4, respectively. When adjusting for pre-specified variables (CID, age, sex, smoking status, and BMI), the adjusted OR was 2.28 (95% CI: 1.07 to 4.85) for a positive treatment outcome in the High MFAP4 group. Conclusion A high MFAP4 status before initiating biological treatment is associated with a positive clinical response, when adjusting for confounding factors.