RAPID MEASUREMENT OF URINARY TRYPSINOGEN-2 AS A SCREENING-TEST FOR ACUTE-PANCREATITIS

Background Acute pancreatitis can be difficult to diagnose. We develop ed a rapid dipstick screening test for pancreatitis, based on the immu nochromatographic measurement of urinary trypsinogen-2. Methods We pro spectively compared the urinary trypsinogen-2 dipstick test with a qua ntitative urinary trypsinogen-2 assay, a urinary dipstick test for amy lase, and serum and urinary amylase assays in 500 consecutive patients with acute abdominal pain at two emergency departments. Acute pancrea titis was diagnosed according to standardized criteria. Results The ur inary trypsinogen-2 dipstick test was positive in 50 of the 53 patient s with acute pancreatitis (sensitivity, 94 percent), including all 7 w ith severe pancreatitis. Two patients with urinary trypsinogen-2 conce ntrations below the sensitivity threshold of the test (50 ng per milli liter) and one with a very high concentration had false negative resul ts. The test was also positive in 21 of the 447 patients without pancr eatitis (specificity, 95 percent), including 7 with abdominal cancers, 3 with cholangitis, and 2 with chronic pancreatitis. The sensitivity and specificity of the dipstick test were similar to those of the quan titative urinary trypsinogen-2 assay and higher than those of the urin ary amylase dipstick test. The serum amylase assay had a sensitivity o f 85 percent (with a cutoff value of 300 U per liter for the upper ref erence limit) and a specificity of 91 percent. The sensitivity and spe cificity of the urinary amylase assay (cutoff value, 2000 U per liter) were 83 and 88 percent, respectively. Conclusions In patients with ac ute abdominal pain seen in the emergency department, a negative dipsti ck test for urinary trypsinogen-2 rules out acute pancreatitis with a high degree of probability. A positive test usually identifies patient s in need of further evaluation. (C)1997, Massachusetts Medical Societ y.