The role of delta neutrophil index in early identification of severe acute pancreatitis in adult patients: a prospective diagnostic accuracy study

Objective: The primary outcome of this study is to evaluate the diagnostic performance of the initial delta neutrophil index (DNI) for early identification of severe acute pancreatitis (SAP). Material and Methods: All diagnoses and definitions were made according to the revised Atlanta classification. DNI (delta neutrophil index) was measured automatically using a hematology analyzer. The study included patients aged 18 years and older who were admitted with abdominal pain consistent with acute pancreatitis. The exclusion criteria encompassed patients with a known diagnosis of pancreatic malignancy, iatrogenic endoscopic pancreatitis, those presenting with abdominal trauma, and those experiencing exacerbation of chronic pancreatitis. Results: The median DNI for patients who developed SAP was 0.5 (0.29-1.1), while for non-severe patients, it was 0.2 (0.1-0.41). The difference between the two outcome groups was found to be statistically significant (p<0.001). The area under the curve (AUC) for DNI in predicting SAP was 0.727, with a 95% Confidence Interval (CI) of 0.628-0.825. At the optimal cut-off point, the sensitivity of DNI was determined to be 74.3%, with a 95% CI of 56.7%-87.5%. The specificity was calculated as 68.2% (95% CI=61.6%-74.3%). The positive likelihood ratio (LR+) was 2.34, with a 95% CI of 1.78-3.08, and the negative likelihood ratio (LR-) was 0.38, with a 95% CI of 0.21-0.67. Conclusion: Based on the results, the delta neutrophil index (DNI) shows promise as an essential inflammatory marker for the early diagnosis of SAP. While it may not demonstrate high performance as a standalone marker, our study indicates that DNI could serve as an independent predictor for this outcome. The significant difference observed in DNI values between patients who developed SAP and non-severe patients suggests its potential clinical significance in identifying severe acute pancreatitis cases at an early stage. Further investigations and validation studies are warranted to strengthen the reliability and generalizability of DNI as a diagnostic tool for SAP. Integrating DNI with other relevant clinical and laboratory parameters may enhance its diagnostic accuracy and contribute to more effective patient management strategies. With appropriate intervention and follow-up, the early identification of SAP using DNI may lead to improved patient outcomes and reduced complications, benefiting both the patients and the healthcare system.