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

To determine the predictive value of the delta neutrophil index (DNI) for acute pyelonephritis (APN), which increases in conditions of infection and inflammation.

Observational, comparative cross-sectional study.

Department of Urology, Kahramanmaraş Sütçü İmam University, Turkey, from December 2014 to November 2019.

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.

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).

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. Key Words: Ureteral stone, Acute pyelonephritis, Delta neutrophil index, C-reactive protein, White blood cell.