Serum PRO-C3 and C3M with CTE: Biomarkers for phenotyping and predicting progression in Crohn's disease

Objective : This research evaluated serum type III collagen formation (PRO-C3), degradation (C3M) biomarkers, and computed tomography enterography (CTE) scores for classifying Crohn's disease (CD) behavior, predicting primary nonresponse to infliximab, and assessing disease progression. A total of 112 CD patients admitted to Jinling Hospital from January 2021 to October 2023 were classified by Montreal behavior as B1 (n = 44), B2 (n = 46), and B3 (n = 22). Serum PRO-C3, C3M levels, and CTE scores were analyzed. Patients were followed until October 2024. Changes in serum biomarkers were monitored during infliximab therapy and in patients undergoing surgery. Significant differences in serum C3M, PRO-C3, and CTE scores were observed across the three Montreal behavior groups. The combination of PRO-C3 and CTE differentiated B1 from B2 disease (AUC = 0.76, 95 % CI: 0.66–0.86). C3M and CTE effectively distinguished B1 from B3 disease (combined AUC = 0.86, 95 % CI: 0.77–0.95), while C3M alone differentiated B2 from B3 disease (AUC = 0.80, 95 % CI: 0.69–0.91). At week 6 of infliximab treatment, C3M levels were elevated in non-responders ( P = 0.001). PRO-C3 levels, disease behavior, and smoking history were emerged as distinct predictive indicators for early surgical intervention. Serum C3M, PRO-C3, and CTE scores demonstrated strong performance in distinguishing CD behavior phenotypes. Elevated C3M levels at week 6 may predict infliximab nonresponse, while PRO-C3, disease behavior, and smoking history are correlated with an elevated risk of early surgery.