The Delta Neutrophil Index is an Early Predictive Marker of Acute Pyelonephritis in Patients with Ureteral Stone

Abstract

Objective: To determine the predictive value of the delta neutrophil index (DNI) for acute pyelonephritis (APN), which increases in conditions of infection and inflammation. Study Design: Observational, comparative cross-sectional study. Place and Duration of Study: Department of Urology, Kahramanmaraş Sütçü İmam University, Turkey, from December 2014 to November 2019. Methodology: The data of 205 patients, diagnosed with ureteral stone and urinary tract infection (UTI), were evaluated. For comparison, patients were categorised into two groups: those with lower UTI (LUTI) and those with APN. Together with demographic data of patients and ureteral stone, DNI, C-reactive protein (CRP), white blood cell (WBC) and other biochemical parameters were analysed. Results: There were 165 patients (80.5%) in the LUTI group and 40 patients (19.5%) in the APN group. In univariate analysis, age (p=0.023), creatinine (p=0.001), PT/INR (p=0.007), WBC (p <0.001), CRP (p=0.002) and DNI (p <0.001) were identified as predictors of APN. In multivariate analysis, CRP (p=0.019) and DNI (p=0.009) were significantly associated with the predictors of APN. Cut-off values were 11.75 mm3 for WBC, 22.2 mg/dL for CRP, and 1.3% for DNI. DNI value was positively correlated with WBC and CRP (r=0.369 vs. 0.740 and p <0.001, each). Conclusion: As an infection marker that can be monitored with a complete blood count and does not require additional costs, DNI can be used as an early predictor of APN. Patients with a DNI value of >1.3% should be considered for early intervention.