[Diagnostic value of a diagnostic strip for determining urinary amylase]

Abstract

The semiquantitative determination of amylase in urine with a stick-method has produced controversial results as to its diagnostical significance. In our study we compared the result of the Rapignost-test with the simultaneously measures activity of enzymes (total amylase, pancreatic isoamylase in serum and urine and lipase) in 323 samples of serum and urine taken from 32 patients affected with acute pancreatitis. On the 1st day of hospitalization Rapignost was positive in only 17 out of 32 cases. Both sensitivity and specificity of the test depended of the values referred to. Near range limits and in cases with slight or average increase of the enzymes, the correspondence of Rapignost results were unsatisfactory. We found a good correspondence in cases with normal low and excessively high values of the enzymes. On the whole, Rapignost showed the best correspondence with the pancreas isoamylase in urine. The result of Rapignost was also positive in 5 out of 15 cases with extrapancreatic increased urinary amylase, which confirms its lack of organ specificity. From case to case, the -, and + + test results of Rapignost did not lead to any conclusions as to the absolute values of the enzymes in serum and urine. Our results show that Rapignost does not offer enough safety either to confirm or to exclude an acute pancreatitis, and especially it should not be used as a screening test in emergency diagnostics. The determination of the enzyme, in particular in serum, can not be eluded.