Oncostatin M as a key predictive factor for anti-TNF-α response in inflammatory bowel disease

Reliable biomarkers are needed to predict response to anti-TNF-α therapy in patients with inflammatory bowel disease.

The primary aim of this study was to evaluate the usefulness of serum oncostatin M (OSM) as a marker of response to anti-TNF-α therapy in patients with inflammatory bowel disease (IBD). A secondary endpoint was the identification of additional factors that may influence the response to anti-TNF-α treatment.

The study included 135 patients treated with infliximab or adalimumab. Serum OSM and faecal calprotectin levels were measured at baseline and after 14 weeks of therapy.

Baseline OSM levels were significantly lower in responders than in non-responders (MD = -348.07; 95% CI: -400.72 to -242.96; p < 0.001) and demonstrated high accuracy in predicting treatment outcomes (AUC = 0.908; 95% CI: 0.848-0.960; p < 0.001). Patients with baseline OSM concentrations below 216.82 pg/ml were more likely to respond to therapy, with a sensitivity of 92% and a specificity of 77%. Baseline faecal calprotectin levels showed low-to-moderate predictive value for treatment response (AUC = 0.690; 95% CI: 0.589-0.780; p = 0.005). A significant difference in treatment response was observed with respect to prior exposure to biologic therapy (23.9% vs. 69.8%; p < 0.001), with a moderate association strength as measured by Cramér's V (V = 0.44; 95% CI: 0.28-0.59).

Several factors - including age, disease location, concomitant IBD-associated spondyloarthropathy, calprotectin levels - may influence the response to anti-TNF-α therapy. However, only low serum OSM concentration was consistently associated with a better treatment response and may represent a promising biomarker and potential therapeutic target in IBD.