Lipase activity in serum measured with Ektachem is often increased in nonpancreatic disorders

For patients with symptoms of pancreatitis, measurement of amylase in serum reportedly is more sensitive than that of lipase in acute pancreatitis, whereas lipase reportedly is more specific. However, serum lipase activities exceeding the upper reference limit (URL) have been reported for many patients who did not have pancreatitis. I reviewed the serum lipase and amylase concentrations of 493 consecutive inpatients and emergency department patients for whom both tests were ordered. Serum lipase and amylase activities, determined with an Ektachem 700 analyzer, were less than or equal to URL for 390 patients (83%) and greater than URL for 103. Medical records of 101 of these 103 were reviewed; 18 had acute or chronic relapsing pancreatitis. In this latter group, serum lipase values greater than URL had 100% sensitivity and 84% specificity; those of serum amylase greater than URL had 72% sensitivity and 88% specificity. However, the test combination of serum lipase greater than URL and serum amylase less than or equal to URL also occurred in 84% of the patients in which review of the medical records revealed nonpancreatic gastrointestinal or hepatobiliary disorders as the primary problem (n = 55). Therefore, serum lipase activity measured with the Ektachem assay is also often increased in patients with intra-abdominal disorders that appear to be nonpancreatic.