What lab workup is recommended for non-alcoholic pancreatitis?

From the Guidelines

The recommended lab workup for non-alcoholic pancreatitis includes serum amylase and lipase, with lipase being more specific and remaining elevated longer than amylase, as well as triglyceride levels, calcium levels, and liver chemistries, as stated in the 2007 AGA Institute medical position statement on acute pancreatitis 1.

Key Lab Tests

• Serum amylase and lipase: primary diagnostic markers, with lipase being more specific and remaining elevated longer than amylase, as supported by the 2019 WSES guidelines for the management of severe acute pancreatitis 1
• Triglyceride levels: essential to check for hypertriglyceridemia, which can cause pancreatitis when levels exceed 1000 mg/dL, as recommended by the 2019 WSES guidelines 1
• Calcium levels: should be checked since hypercalcemia is a potential cause, as stated in the 2007 AGA Institute medical position statement on acute pancreatitis 1
• Liver chemistries (bilirubin, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase): to evaluate liver function, as recommended by the 2007 AGA Institute medical position statement on acute pancreatitis 1

Additional Tests

• Complete blood count: to assess for leukocytosis and hemoconcentration
• Comprehensive metabolic panel: to evaluate electrolytes and renal function
• C-reactive protein and procalcitonin: to assess inflammation severity and predict complications, as recommended by the 2019 WSES guidelines 1
• Blood cultures: warranted if infection is suspected
• Arterial blood gases: to evaluate acid-base status in severe cases
• Serum IgG4 levels: when autoimmune pancreatitis is suspected

Imaging Studies

• Abdominal ultrasonography: to look for cholelithiasis or choledocholithiasis, as recommended by the 2007 AGA Institute medical position statement on acute pancreatitis 1
• CT or endoscopic ultrasonography (EUS): to evaluate for underlying pancreatic malignancy in patients over 40 years old, or to screen for occult common bile duct stones in patients with unknown etiology, as recommended by the 2019 WSES guidelines 1 and the 2022 AGA clinical practice update on the endoscopic approach to recurrent acute and chronic pancreatitis 1

From the Research

Lab Workup for Non-Alcoholic Pancreatitis

The lab workup for non-alcoholic pancreatitis typically involves the measurement of serum enzymes, including:

• Amylase: While amylase is often used as a first-line test, its specificity is low, and it can be elevated in various conditions other than pancreatitis 2.
• Lipase: Lipase has been shown to have a higher sensitivity than amylase in diagnosing acute pancreatitis and offers a larger diagnostic window 3.
• Isoamylase: Isoamylase can be used as an adjunct test, but its diagnostic value is similar to that of amylase and lipase 2.

Diagnostic Value of Enzyme Assays

The diagnostic value of enzyme assays in acute pancreatitis is as follows:

• Sensitivity: Lipase has been shown to have a higher sensitivity than amylase in diagnosing acute pancreatitis 3.
• Specificity: None of the enzyme assays are specific at the upper reference limit, but their diagnostic yields can be improved by raising cutoff levels to about three or four times the upper limit 2.
• Positive Predictive Value: The positive predictive value of amylase, isoamylase, and lipase can be improved by selecting an appropriate cutoff level 2.

Determining Severity and Etiology

It is essential to note that:

• No enzyme assay can determine the severity or etiology of acute pancreatitis 4, 3.
• Other laboratory tests, such as serum C-reactive protein and urinary trypsinogen activation peptides, may be useful in predicting the severity of acute pancreatitis 4.