From the Guidelines
The most reliable laboratory tests for diagnosing pancreatitis are serum lipase and amylase, with lipase being more sensitive and specific, and a lipase level three times the upper limit of normal strongly suggests pancreatitis. According to the 2019 WSES guidelines for the management of severe acute pancreatitis 1, the cut-off value of serum amylase and lipase is normally defined to be three times the upper limit. Additionally, other laboratory tests such as complete blood count (CBC), comprehensive metabolic panel, triglyceride levels, and calcium levels can be used to assess the severity of pancreatitis and its complications. C-reactive protein (CRP) can be used to evaluate inflammation severity, and procalcitonin is the most sensitive laboratory test for detection of pancreatic infection 1.
Some key laboratory findings that can be used to characterize an episode of severe acute pancreatitis include:
- Hematocrit > 44% which represents an independent risk factor of pancreatic necrosis 1
- Urea > 20 mg/dl which represents an independent predictor of mortality 1
- Serum triglyceride levels over 11.3 mmol/l (1000 mg/dl) which indicate hypertriglyceridemia as the etiology 1
- C-reactive Protein level ≥ 150 mg/l at third day which can be used as a prognostic factor for severe acute pancreatitis 1
It's also important to note that imaging studies like abdominal ultrasound, CT scan, or MRI can be used alongside these laboratory tests to confirm the diagnosis and assess for complications such as necrosis or pseudocysts. The 2019 WSES guidelines for the management of severe acute pancreatitis 1 and the UK guidelines for the management of acute pancreatitis 1 also support the use of lipase and other laboratory tests for the diagnosis of acute pancreatitis. The AGA institute medical position statement on acute pancreatitis 1 also recommends the use of lipase and other laboratory tests for the diagnosis of acute pancreatitis.
From the Research
Pancreatitis Test Labs
- The diagnosis of acute pancreatitis is usually based on the presence of abdominal pain and elevated levels of serum amylase and/or lipase 2, 3, 4.
- Serum lipase is now the preferred test due to its improved sensitivity, particularly in alcohol-induced pancreatitis, and its prolonged elevation creates a wider diagnostic window than amylase 2, 3, 4.
- Neither enzyme is useful in monitoring or predicting the severity of an episode of pancreatitis in adults 3, 4.
- New biomarkers including trypsinogen and elastase have no significant advantage over amylase or lipase 4.
- Serum amylase and lipase levels are not specific for pancreatitis and can be elevated in nonpancreatic conditions, leading to a large proportion of patients being falsely labeled as having acute pancreatitis 5.
- Radiological evidence and increased cut-off levels of enzyme elevation are necessary for a more accurate diagnosis of acute pancreatitis 5.
- Asymptomatic patients with chronic pancreatitis may have elevated concentrations of amylase, and macroamylasemia should be investigated before initiating any costly or complex procedures 6.
Comparison of Amylase and Lipase
- Serum lipase offers a higher sensitivity than serum amylase in diagnosing acute pancreatitis 2, 3.
- Lipase also offers a larger diagnostic window than amylase since it is elevated for a longer time, thus allowing it to be a useful diagnostic biomarker in early and late stages of acute pancreatitis 2, 3.
- The co-ordering of both tests has shown little to no increase in the diagnostic sensitivity and specificity, and unnecessary testing and laboratory expenditures can be reduced by testing lipase alone 2.