The relationship between neutrophil-lymphocyte ratio and clinal laboratory data in acute pancreatitis

Introduction: Neutrophil-lymphocyte ratio (NLR) is one of the laboratory biomarkers used in clinical practice to predict severity and mortality of acute pancreatitis (AP), however, there is currently insufficient information about the changes of NLR in the dynamics in relationship with other clinical and laboratory data. Aims: To assess the relationship between NLR values and other demographics, clinical and simple laboratory data in patients with acute pancreatitis. Methods: The data of two hundred twenty-nine patients with AP were analyzed. All patients were divided into two groups: the group with a positive outcome and the group with a fatal outcome. NLR was counted on the 1st, 3rd and 5th day after admission in each group. The dynamics of NLR index by groups and days, as well as its correlation with other 18 simple laboratory parameters were evaluated. Results: The level of NLR rate itself was significantly higher on the 1st, 3rd and 5th day in the group with the fatal result compared with the group with the positive result (p < 0.05). In patients with AP with the positive result of treatment, there was a gradual decrease in the rate between the 1st and the 3rd day (-21.8%) (p < 0.05). The overall dynamics of the indicator between the 1st and the 5th day was -21.5%. In contrast to the group of patients with the fatal outcome, despite the infusion therapy, there was an increase in NLR rate between the 1st and 3rd day of +15.7%. The overall dynamics between the 1st and 5th day was -34.0%. A significant negative relationship of the Spearman's rank correlation coefficient between NLR on the 1st and 3rd day with the fatal outcome was revealed. The highest reliability of this indicator was found on the 3rd day after admission (p < 0.0001). In the group of patients with a positive result, a correlation between NLR on the 1st day and stabs on the 1st day, segmental forms on the 1st day, serum amylase on the 1st day was found. A very high correlation was found with the level of lymphocytes on the 1st day (rs = -0.98, p < 0001). In the group of patients with the fatal outcome, a statistically significant correlation (p < 0.05) of moderate strength was found between the value of NLR and the following indicators: glucose level on the 1st day, total protein on the 5th day, prothrombin index on the 5th day. A high correlation was found with the level of segmental forms on the 1st day (rs = 0.7) and a very high correlation with the level of lymphocytes on the 1st day (rs = -0.99). Conclusions: There was a significant increase in NLR on the 1st, 3rd, and 5th day in the group of patients with AP with the fatal outcome compared with the group of patients with AP with the positive result. Elevated NLR levels on the 1st and 3rd day seem to be associated with hospital mortality in patients with AP. No correlation was found between NLR rate and clinical data in the group with fatal outcome. The main indicators among simple laboratory parameters for determining the predictors of lethal outcome in AP in different periods after hospitalization were: the level of blood glucose, lymphocytes, total protein, serum amylase, prothrombin index.