Amylase-Creatinine Clearance Ratio in Pancreatitis

To the Editor: We should like to comment on the recent paper of Johnson et al. (N Engl J Med 295:1214, 1976). The authors present evidence that in acute pancreatitis a renal mechanism (some “tubular-dysfunction factor”) is responsible for the enhancement of the amylase-to-creatinine clearance ratio (C_am/C_cr ratio) rather than an isoamylase abnormality. They state that there is no available information whether this “factor” functions in conditions other than acute pancreatitis. Earlier reports from several authors and recent findings of our groups have case doubt on the diagnostic value of the C_am/C_er ratio.