Lipase/amylase ratio: not helpful in the early etiological differentiation of acute pancreatitis.

The value of the lipase/amylase ratio for early etiological differentiation of acute pancreatitis was tested in 103 consecutive patients with acute pancreatitis from an ongoing prospective study. On admission, amylase, but not lipase, was significantly lower in alcoholics than in nonalcoholics in general and especially in patients with biliary pancreatitis. Alcoholics as a group had significantly higher lipase/amylase ratios than non-alcoholics and patients with acute biliary pancreatitis. But although the mean values of the ratio were significant, sensitivity, specificity, positive and negative predictive values of lipase/amylase ratio were insufficient to separate alcoholics from nonalcoholics, patients with alcohol-induced pancreatitis from those with biliary etiology, and patients with biliary pancreatitis from those with pancreatitis of other etiologies in the individual case. Finally, there was no correlation between the ratio and the amount of pancreatic changes as judged from computed tomography. We concluded that the ratio does not allow for early routine clinical differentiation between etiologies of pancreatitis and evaluation of the severity of the disease.