Comparison of urine trypsinogen-2 test strip with serum lipase in the diagnosis of acute pancreatitis.

Abstract

The accuracy of a new rapid urinary trypsinogen-2 test strip (actim Pancreatitis) was compared with that of serum lipase for detection of acute pancreatitis in patients with acute abdominal pain. A prospective study was conducted which consisted of 237 consecutive patients with acute abdominal pain admitted to the emergency unit at Helsinki University Central Hospital. The patients were tested on admission with the actim Pancreatitis test strip. Serum amylase, serum lipase, and urine trypsinogen-2 concentrations were also determined quantitatively. The actim Pancreatitis test strip result was positive in 27 out of 29 patients with acute pancreatitis (sensitivity 93%) and in 16 of 208 patients with non-pancreatic abdominal pain (specificity 92%). This was superior to that of serum lipase (sensitivity 79% and specificity 88%). With a cut-off > 3x the upper reference limit, the sensitivity of serum lipase was only 55% while the specificity was 99%. The high sensitivity for the actim Pancreatitis test strip resulted in a very high negative predictive value of 99%. All six patients with severe acute pancreatitis were detected by the dipstick. With a higher cut-off value (> 3x upper reference limit) for lipase, two patients with severe acute pancreatitis remained undetected. Combining the actim Pancreatitis dipstick with serum lipase a positive predictive value of 94% was obtained. Acute pancreatitis can be excluded with a higher probability with the actim Pancreatitis strip than with serum lipase determination, and therefore appears to be more suitable for screening of acute pancreatitis. With its high specificity with a cut-off > 3x the upper reference limit, serum lipase is suitable as a confirmatory test for pancreatitis when a positive dipstick result is obtained.