What are the laboratory evaluations for pancreatitis (inflammation of the pancreas)?

From the Guidelines

For pancreatitis lab evaluation, start with serum lipase and amylase tests, with lipase being more specific and sensitive than amylase, and a lipase level more than three times the upper limit of normal is diagnostic for acute pancreatitis, as supported by 1 and 1. When evaluating a patient for pancreatitis, it is essential to consider the most recent and highest quality evidence to guide laboratory evaluations.

Initial Laboratory Tests

• Serum lipase and amylase tests should be ordered immediately upon suspicion of pancreatitis, with lipase being the preferred test due to its higher sensitivity and specificity, as noted in 1.
• A complete blood count (CBC), comprehensive metabolic panel (CMP), and C-reactive protein (CRP) should also be ordered to assess for inflammation, potential complications, and liver function, as recommended in 1 and 1.

Additional Tests

• For patients with suspected gallstone pancreatitis, liver function tests, including ALT, AST, and bilirubin, should be included to evaluate for biliary obstruction, as suggested in 1.
• In cases of suspected alcoholic pancreatitis, consider testing gamma-glutamyl transferase (GGT) and carbohydrate-deficient transferrin (CDT) as markers of alcohol use, as mentioned in 1.
• Serum triglyceride levels should be measured in patients without a clear etiology, as a level > 11.3 mmol/l (> 1000 mg/dl) may indicate hypertriglyceridemia as the cause, as stated in 1 and 1.

Monitoring and Severity Assessment

• Repeat lipase and CRP tests at 24-48 hour intervals to monitor disease progression and response to treatment, as recommended in 1 and 1.
• CRP levels ≥ 150 mg/l at the third day can be used as a prognostic factor for severe acute pancreatitis, as noted in 1.
• Procalcitonin is the most sensitive laboratory test for detecting pancreatic infection, and low serum values appear to be strong negative predictors of infected necrosis, as stated in 1.

Prioritization of Tests

• The most recent and highest quality study, 1, supports the use of lipase as the primary diagnostic test for acute pancreatitis, with a sensitivity and specificity of 79% and 89%, respectively.
• While other studies, such as 1 and 1, provide additional guidance on laboratory evaluations, the recommendations from 1 take precedence due to its recency and high quality.

From the Research

Laboratory Evaluations for Pancreatitis

The laboratory evaluations for pancreatitis include various tests to diagnose and assess the severity of the condition. The following are some of the key tests used:

• Serum amylase and lipase: These are the most commonly used tests for diagnosing acute pancreatitis 2, 3, 4, 5.
• Pancreatic isoamylase, immunoreactive trypsin, and elastase: These tests are more cumbersome and expensive, and have no clear role in the diagnosis of acute pancreatitis 2, 3.
• Serum C-reactive protein: This is the best available laboratory marker of severity at 48 hours 2.
• Urinary trypsinogen activation peptides: These can predict the severity of acute pancreatitis within 12-24 hours of onset, but are not widely available 2.
• Serum interleukins 6 and 8: These seem promising, but remain experimental 2.
• Phospholipase A2, cellular immunity markers, cytokines, activation peptides of trypsinogen and carboxypeptidase B, procalcitonine, pancreatitis associated protein, and serum amyloid A: These are newly introduced biochemical methods that may help in predicting the severity of acute pancreatitis 6.

Imaging Tests

Imaging tests such as ultrasonography and computed tomography (CT) can also be used to evaluate the biliary tract and pancreatic necrosis in acute pancreatitis 3, 6.

• Ultrasonography: This is useful for evaluating the biliary tract in acute pancreatitis 3.
• Computed tomography (CT): This is useful for estimating the presence and extent of pancreatic necrosis, and can help identify patients at high risk for systemic and local complications 3.

Limitations of Laboratory Tests

It is important to note that none of the laboratory tests available can accurately diagnose and assess the severity of acute pancreatitis on their own 2, 3, 6.

• Serum amylase and lipase have low specificity and can be elevated in other conditions 2, 3, 4.
• Other enzymes such as pancreatic isoamylase, immunoreactive trypsin, and elastase have no clear role in the diagnosis of acute pancreatitis 2, 3.
• The levels of these pancreatic enzymes do not correlate with the severity of the disease, and cannot accurately predict the subsequent clinical course of the patients 3.