Neutrophil-lymphocyte ratio as a predictor of adverse outcomes of acute pancreatitis.

Background: Most acute pancreatitis risk scoring systems use total white blood cell counts (WBC) as one of the risk factors. The value of the neutrophil-lymphocyte ratio (NLR) to predict the severity of acute pancreatitis has not been previously evaluated.

Methods: This observational study included 283 patients admitted to a tertiary center between 2004 and 2007. The patients were arranged into tertiles according to NLR and WBC values. The primary outcomes were intensive care unit (ICU) admission and length of stay (LOS) in the hospital.

Results: According to NLR tertiles, patients in the 3rd tertile (NLR ≥7.6) had significantly more ICU admissions (17 vs. 2.2%, p < 0.0001) and longer average LOS (6.2 vs. 4.2 days, p < 0.002) compared with those in the 1st tertile (NLR <3.6). According to WBC tertiles, patients in the 3rd tertile had more ICU admissions (12.6 vs. 6.2%, p = 0.12) and a longer average LOS (5.8 vs. 4.4 days, p = 0.059) compared to patients in the 1st WBC tertile, but this did not reach statistical significance. In the multivariate model including NLR, WBC and other predictors, only NLR tertiles (p < 0.0262) and modified early warning scores (p < 0.0025) were significant predictors of ICU admission. Likewise, in the multivariate model of LOS, only NLR and glucose level were significant predictors of longer LOS (p < 0.0161 and p < 0.0053, respectively).

Conclusion: NLR is superior to total WBC in predicting adverse outcomes of acute pancreatitis. According to our data, we suggest using the NLR cutoff value of >4.7 as a simple indicator of severity in patients presenting with acute pancreatitis. and IAP.