Monocytic HLA-DR Expression for Prediction of Anastomotic Leak after Colorectal Surgery

Earlier detection of anastomotic leakage (AL) after colorectal procedures could minimize the detrimental clinical impact of AL and thereby reduce morbidity and mortality.

We conducted a prospective study with assessment of the diagnostic accuracy of monocytic HLA-DR (mHLA-DR) expression compared with WBCs, C-reactive protein (CRP), and procalcitonin (PCT) in predicting AL in patients undergoing elective colorectal operation with anastomosis.

Comparison of the blood marker values on postoperative day (POD) 4 revealed significant differences for all markers, but the difference for mHLA-DR was highly significant (15% expression of monocytes in AL patients vs 34% in patients without AL; p = 0.001). Together with WBC (p = 0.026), mHLA-DR expression was the only test to show significance on day 3 (14% vs 31%; p < 0.001). Receiver operating characteristic analysis revealed that mHLA-DR expression had superior diagnostic accuracy compared with all other diagnostic markers both on POD 3 (mHLA-DR area under the curve [AUC] 0.928; WBC AUC 0.734; CRP AUC 0.707; PCT AUC 0.672) and POD 4 (mHLA-DR AUC 0.887; WBC AUC 0.738; CRP AUC 0.709; PCT AUC 0.696). Monocytic HLA-DR had a negative predictive value of at least 94% on PODs 3 and 4, as well as specificity and positive predictive values of 100% at a threshold of 23% on POD 3 and 24% on POD 4, respectively.

Expression of mHLA-DR appears to be a more accurate predictor for AL after colorectal operation compared with WBC, CRP, and PCT. It represents a promising test to precisely monitor the perioperative course of high-risk patients and contribute to safer discharge.