CBC-Derived Inflammatory Indices in Acute Pancreatitis

Acute pancreatitis (AP) ranges from mild self-limiting disease to severe forms associated with persistent organ failure, infected necrosis, and substantial mortality. Early identification of patients at high risk of severe disease is essential for appropriate triage and management.

CBC-derived inflammatory indices such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) are inexpensive and widely available markers that have demonstrated prognostic value in critical illness. Their specific role in predicting severity and mortality in acute pancreatitis requires further evaluation.

This prospective observational study will assess admission and early serial CBC-derived indices as predictors of severe acute pancreatitis (defined by the revised Atlanta criteria) and 28-day all-cause mortality, and will compare their predictive performance with standard clinical severity scores including APACHE II and BISAP.

Inclusion criteria

• Age ≥ 18 years
• Diagnosis of acute pancreatitis based on at least two of the following: characteristic abdominal pain, serum amylase or lipase ≥ 3× upper limit of normal, or imaging consistent with acute pancreatitis
• Admission within 72 hours of symptom onset

Exclusion criteria

• Chronic pancreatitis without an acute episode
• Severe immunosuppression (neutropenia < 500/mm³ or high-dose immunosuppressive therapy after solid organ transplantation)
• Active non-pancreatic infection on admission requiring systemic antibiotics
• Refusal to provide informed consent