Neutrophil-lymphocyte ratio: a controversial marker in predicting Crohn's disease severity.

Peripheral blood-derived inflammation-based scores such as the neutrophil-lymphocyte ratio (NLR) have recently been proposed as prognostic markers in ulcerative colitis. In some previous serological markers are commonly used to detect the severity of the Crohn's disease (CD), but their sensitivity and specificity are relatively low. So we want to use simple indicators which are easy to obtain to predict disease severity. Now, we investigated and compared the capacity of NLR and other inflammatory markers in detecting CD activity and differentiating CD patients from healthy controls. These CD patients had not received corticosteroid or immunosuppressive drugs within a defined period of time. Data from our hospital between 2010 and 2012 was used. Neutrophil-lymphocyte ratio (NLR), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cells (WBC), platelet count and albumin were measured in 44 patients with active CD, 66 patients with inactive CD, and 55 healthy blood donors. Disease activity was assessed by the Crohn's Disease Activity Index. In the active CD group, NLR values were found to be elevated compared to inactive CD patients and controls (6.00±7.38, 5.53±6.18 and 1.84±0.85, respectively), but statistical difference was not found between active and inactive CD groups. The overall accuracy of NLR (cutoff: 2.13 fl), CRP (cutoff: 10.5 mg/dl), ESR (cutoff: 19.5 mm/hour) and WBC (cutoff: 9.2 × 10(9)/l) in differentiating CD patients from healthy controls was 80.9%, 67.3%, 71% and 60% respectively. NLR values were found to be correlated with WBC and CRP levels. NLR increased in CD patients compared with healthy subjects. NLR had the best accuracy in determination of CD patients and healthy controls. NLR did not show a discriminative value in disease activity.