Elevated Serum OSM Expression a Promising IBD Biomarker

Serum oncostatin M (OSM) has shown promise as a surrogate biomarker to best assess disease activity in patients with inflammatory bowel disease (IBD).

A team, led by Ying Cao, Department of Laboratory Medicine, Zhejiang University School of Medicine Second Affiliated Hospital, examined the clinical value of serum oncostatin M as a surrogate biomarker.

Endoscopy

While endoscopy is still the top option for assessing disease activity and infliximab efficacy in patients with IBD, it is still invasive, costly, and time-consuming. In addition, infliximab is 1 of the top biological therapies for patients with IBD, but also elevates the risk of serious infections from immunosuppression. Also, up to 40% of IBD patients do not respond to anti-tumor necrosis factor treatments.

Oncostatin M is a cytokine of the IL-6 family which has shown promise as a diagnostic and therapeutic target for treating IBD. Recent research has found the overexpression of OSM can damage the integrity of the intestinal barrier function by downregulating the expression of tight junction and inducing epithelial-mesenchymal transition.

“However, the relationship between serum OSM and disease activity has not yet been explored in IBD patients,” the authors wrote.

New Biomarkers

The study included 189 patients with IBD, as well as 50 healthy controls and 34 patients without IBD. Of the patients with IBD, 122 were pre-infliximab treatment and 67 were in infliximab maintenance.

The investigators constructed a chemiluminescence immunoassay (CLIA) to quantify serum oncostatin M concentrations. They also used receiver operator characteristic (ROC) curve analysis to evaluate the performance of blood biomarkers to manage IBD.

There was a wide linear range of 31.25-25,000 pg/mL found from CLIA, with a low detection limit of 23.2 pg/mL. The precision and accuracy was also acceptable and applicable.

Both the IBD group (121.5; 95% CI, 43.3–249.4 pg/mL; P <0.001) and non-IBD patients (72.4; 95% CI, 51.4–129.6 pg/mL; P = 0.005) had higher serum OSM levels than the healthy control group (35.8; 95% CI, 23.2–56.4 pg/mL).

The investigators also analyzed clinical and endoscopic activity and found serum OSM levels were elevated in moderate and severe patients, compared to patients who were in remission.

Mucosal Healing

Another factor was mucosal healing.

Patients with IBD, but without mucosal healing had higher serum OSM levels compared to patients with IBD and mucosal healing (AUC, 0.843).

Serum OSM levels also increased in clinical non-responders (287.3; 95% CI, 127.9–438 pg/mL) compared to responders (24.1; 95% CI, 23.2–53.4 pg/mL; P <0.001). They also showed great recognition ability with an AUC of 0.898.

“The newly developed methodology of CLIA had great potential for use in the clinic,” the authors wrote. “Elevated serum OSM expression was a promising biomarker of severe disease and infliximab non-response in IBD patients.”

The study, “Serum oncostatin M is a potential biomarker of disease activity and infliximab response in inflammatory bowel disease measured by chemiluminescence immunoassay,” was published online in Clinical Biochemistry.