Pancreatic Laboratory Assessment

Diagnosis of Acute Pancreatitis

The American College of Gastroenterology recommends serum lipase as the preferred first-line test for acute pancreatitis diagnosis, with a diagnostic cutoff of ≥3 times the upper limit of normal, due to its superior performance characteristics 1
Serum amylase can be used as an alternative to lipase for acute pancreatitis diagnosis, but it has less specificity and a shorter diagnostic window, and should be used with the same cutoff of ≥3 times the upper limit of normal 1
For etiology determination and severity assessment in acute pancreatitis, additional labs such as liver function tests, serum triglycerides, and serum calcium should be obtained 1
C-reactive protein (CRP) at 48-72 hours, with a value of ≥150 mg/L, predicts severe disease in acute pancreatitis 1
Hematocrit, with a value of >44%, is an independent risk factor for pancreatic necrosis in acute pancreatitis 1
Blood urea nitrogen (BUN), with a value of >20 mg/dL, predicts mortality in acute pancreatitis 1
Procalcitonin is the most sensitive marker for detecting pancreatic infection in acute pancreatitis, and low values strongly exclude infected necrosis 1

The American Gastroenterological Association recommends against using serum enzyme testing (lipase, amylase, trypsin) for diagnosing chronic pancreatitis or pancreatic insufficiency, as it lacks sensitivity until disease is far advanced 2
Fecal tests, such as fecal elastase and fecal chymotrypsin, are the preferred non-invasive approach for chronic pancreatic insufficiency, with good discriminatory capacity for normal versus severely impaired function 2
Fecal chymotrypsin alone is sufficient for patients with clearly normal or severely impaired function, but those with intermediate values require confirmatory testing 2

Fecal elastase is the recommended first-line test for chronic pancreatic insufficiency due to its convenience and acceptable reliability, according to the European Society of Gastrointestinal Endoscopy 3
Fecal elastase offers the best balance of reliability and convenience without requiring prolonged urine collections, as stated by the American Gastroenterological Association 3
The Pancreolauryl test has ≥85% sensitivity for severe pancreatic insufficiency and is commercially available in the UK, as reported by the National Institute for Health and Care Excellence 3
The NBTP-PABA test has 64-83% sensitivity but pharmaceutical-grade reagents are not available in the UK, according to the European Society of Gastrointestinal Endoscopy 3

Do not use serum enzyme testing (lipase, amylase, trypsin) for diagnosing chronic pancreatitis or pancreatic insufficiency, as recommended by the American College of Gastroenterology 4