Serum calprotectin as a biomarker for postoperative complications in colorectal surgery: a pilot study defining...

Postoperative infections are the common cause of morbidity and mortality in colorectal surgery. Calprotectin, an S100 protein, may be a potential marker. The aim was to define the postoperative course (PC) of calprotectin in serum (CIS), compared to white blood cell (WBC), C-reactive protein (CRP), lactate and procalcitonin (PCT).

This prospective, single-center study measured all biomarkers preoperatively, on the first, third and fifth postoperative days (POD). The endpoint was the PC of CIS compared to the WBC, CRP, PCT, and lactate. CIS between benign and malignant disease and between patients with and without complications was compared. Also a correlation was carried out.

56 patients (14 rectum, 42 colon) were included. The postoperative CIS increased to preoperative values (p < 0.05). The preoperative CIS in malignant disease was higher (p < 0.05). CIS on the first and fifth POD was higher in the group with complications (p < 0.05). CIS and CRP, WBC and CRP on the third POD (p < 0.05) correlate in complications .

We present the normal course of CIS and its potential function as a marker for systemic inflammation. We showed that postoperative CIS were significantly higher in complications. Although our study has several limitations, - namely a small sample size and heterogeneous surgical procedures -, serum calprotectin may be an interesting biomarker for future larger studies, particularly due to its increased specificity for intestinal inflammation.

This study is prospectively registered in DRKS-ID (Deutsches Register Klinischer Studien, German WHO Register): DRKS00027142, data of registration 29.11.2021. This is a WHO-recognized primary registry that meets the requirements of the International Committee of Medical Journal Editors (ICMJE). We registered this study in the DKG (Deutsche Krebsgesellschaft) Sudybox ST-D512, data of registration 11.03.2022.