Immunoreactive trypsin in acute pancreatitis: elevated levels do not correlate with hyperamylasaemia.

Immunoreactive trypsin (IRT) was measured in the serum of patients presenting with acute pancreatitis (AP) and compared to serum amylase levels. Both were elevated beyond the normal range at presentation (mean IRT 557 +/- 252 micrograms/l, range 181-1000 micrograms/l, mean control IRT 42 +/- 14 micrograms/l, range 15-82 micrograms/l; mean amylase 4500 +/- 3200 IU/l, range 600-10,500 IU/l, control amylase mean 175 +/- 43 IU/l, range 48-320 IU/l). There was minimal correlation between IRT and amylase elevation but both returned to normal at the same rate in patients who recovered. In 2 patients with persistently elevated IRT levels, one was found to have a pancreatic pseudocyst and the other subsequently died from alcoholic haemorrhagic pancreatitis. IRT is no better than amylase as a single diagnostic assay in AP but may be greatly elevated when amylase elevation is minimal. The combination of the two may improve diagnostic accuracy and persistent elevation of IRT may be of prognostic importance.