A NEW RAPID IMMUNOINHIBITION PANCREATIC AMYLASE ASSAY - DIAGNOSTIC-VALUE FOR PANCREATITIS

A new rapid immunoinhibition pancreatic amylase assay was compared to total amylase and lipase in an unbiased sample of 1005 emergency depar tment patients with suspicion of pancreatitis, of which 55 had a final diagnosis of pancreatitis. Imprecision of the assays for both amylase s (less than 2.5%) were better than for lipase (less than 6.1%). Corre lation (R(2)) of pancreatic amylase with total amylase was 0.991 but o nly 0.789 with lipase. Using Receiver Operator Characteristics analysi s, the best diagnostic cutoff point for all th ree enzymes was near th e upper limit of the reference interval. With pancreatic amylase, sens itivity, specificity, and predictive values for positive and negative results are, respectively, 85.5, 92.5, 39.8, and 99.1%; we found simil ar values for lipase but poorer values (78.2, 92.0, 36.1, and 98.7%) f or total amylase. Tests combination did not improve the diagnostic per formance significantly. In the diagnosis of pancreatitis, pancreatic a mylase (p = 0.037) and lipase (p = 0.049) had better diagnostic perfor mance than total amylase. The correct diagnosis of pancreatitis could be achieved in 47 instead of 43 patients with either pancreatic amylas e or lipase as opposed to total amylase among 1005 patients in this st udy. We conclude that pancreatic amylase and lipase are incrementally better diagnostic tools than total amylase for the diagnosis of pancre atitis.