Persistence of increased amylase and lipase concentrations in acute pancreatitis.

We question the variations in serum concentrations of lipase and amylase during acute pancreatitis reported by Loft and Lu (1). In the caption for their Figure 3, the authors stated that the graphs of the two enzymes in a patient with acute pancreatitis demonstrated “characteristic changes with time.” Serum concentrations of both enzymes peaked on the fourth day after onset and still had not decreased below the upper reference limit after 20 days. In addition, Loft and Lu mentioned in the text that these data were “typical for patients with pancreatitis.” As far as we know, these changes in the concentrations of the two enzymes in serum do not appear to be typical for acute pancreatitis. The values of these two enzymes in serum generally peak within two days after onset, and in most cases amylase values return to normal within one week of onset (2-7). Because the serum concentrations of amylase can return to normal shortly after onset and have poor specificity for diagnosing acute pancreatitis, monitoring the concentrations of pancreatic isoamylase and lipase in serum is preferred. A delay in the time for amylase and lipase to reach their peak values in serum was described for post-traumatic pancreatitis (8), whereas persistence of above-normal concentrations of both enzymes in serum was reported for this condition as well as for complications of acute pancreatitis, e.g., cysts (9). Could the behavior of serum amylase and lipase in the case presented by Loft and Lu be attributed to these conditions or perhaps to the method used to measure their activities (i.e., Kodak Ektachem)?