Rosh Internal Medicine Boost Practice Exam

If elevated, which laboratory value would be most sensitive and specific for a diagnosis of acute pancreatitis?

1. C-reactive protein level

2. Serum amylase level

3. Serum creatinine level

4. Serum lipase level

The correct answer is: Serum lipase level

The most sensitive and specific laboratory value for diagnosing acute pancreatitis is the serum lipase level. Serum lipase is an enzyme produced by the pancreas, and its levels typically rise within hours of the onset of pancreatitis and can remain elevated for several days. Compared to serum amylase, serum lipase is more specific to pancreatic injury and is not significantly affected by other conditions, making it a reliable marker for diagnosing acute pancreatitis. The specificity of serum lipase in relation to the pancreas itself reduces the likelihood of false positives that may occur with other conditions. This attribute makes it the preferred choice in clinical practice. It is also noteworthy that while C-reactive protein can indicate inflammation in the body, it is not specific to the pancreas, and serum creatinine reflects kidney function rather than pancreatic status. Serum amylase, though commonly used, lacks the specificity of serum lipase as it can also rise in conditions such as renal failure or salivary gland disorders. Thus, because of its superior sensitivity and specificity, elevated serum lipase levels are the most reliable laboratory value for diagnosing acute pancreatitis.