Evaluation of a new urinary amylase test strip in the diagnosis of acute pancreatitis.

We have developed a novel rapid test strip for detecting pancreatic amylase in urine and prospectively evaluated its accuracy in screening for acute pancreatitis (AP). The test strip is based on the immunochromatography principle and uses two monoclonal antibodies specific for pancreatic amylase. Urine samples were collected from 500 consecutive patients with acute abdominal disease (52 with AP) and prospectively tested with the strip. The accuracy of the test strip was compared with that of two quantitative urine amylase determinations and a urinary dipstick test for amylase (Rapignost). Sensitivity of the test was 69% and specificity was 97% in differentiating patients with AP from those with acute abdominal extrapancreatic disease at admission. The negative predictive value was 0.986. The test showed moderate agreement both with an assay measuring total amylase activity and with another measuring pancreatic amylase immunoreactivity. At similar high specificity (97%), quantitative determination of total amylase activity (cut-off 3960 U/L) and pancreatic amylase (cut-off 2180 micrograms/L) showed lower sensitivity (54% and 41%) than the test strip (69%). The test is specific and rapid to perform, and it rules out AP with high probability. It could therefore be useful in an emergency setting without laboratory facilities in the differential diagnosis of acute abdominal pain.