Prognostic value of preoperative neutrophil-to-lymphocyte ratio in Crohn's disease

The Neutrophil-to-lymphocyte-ratio has recently gained increased attention as a prognostic marker for malignant disease and short term outcomes. There is little data available in patients with Crohn's disease, thus the present study was conducted to correlate preoperative Neutrophil-to-lymphocyte-ratio values with disease phenotype and postoperative course. We comprised 373 patients, who underwent intestinal resection for symptomatic Crohn's disease at an academic tertiary referral centre between 2000 and 2014. Preoperative Neutrophil-to-lymphocyte-ratio values were calculated and analyzed in regard to disease phenotype and 30-day morbidity rate. All relevant data were obtained from the institutional database and individual chart review. Male patients had significantly higher preoperative Neutrophil-to-lymphocyte-ratio values compared to female patients (5 vs. 4; p = 0.0075). A higher Neutrophil-to-lymphocyte-ratio was also found in patients with an acute indication for surgery (6.15 vs. 4.3; p = 0.0374), presenting with abscesses (5.36 vs. 4.28; p = 0.0254), inflammatory masses (5.23 vs. 4.08; p = 0.0294) or malignancy in the resected specimen (9.06 vs. 4.35, p = 0.0231). Surprisingly, patients developing postsurgical complications showed significantly lower Neutrophil-to-lymphocyte-ratio values (3.77 vs. 4.67; p = 0.0461). Elevated preoperative Neutrophil-to-lymphocyte-ratio in symptomatic Crohn's disease is not predictive for complications. However, Neutrophil-to-lymphocyte-ratio showed a significant correlation with specific disease phenotypes. Most strikingly, Neutrophil-to-lymphocyte-ratio was highly elevated in patients with a colorectal cancer in the resected specimen, which needs to be addressed in future studies.