Amylase-Creatinine Clearance Ratio in Pancreatitis

To the Editor: Warshaw and Fuller (N Engl J Med 292:325–328, 1975) “confirm that the amylase/creatinine clearance ratio rises significantly and regularly in acute pancreatitis.” In another article in the same issue, Levine et al. found that this elevation in amylase/creatinine clearance ratios was not specific for acute pancreatitis. The methodology employed by both these groups of investigators displays an obvious distortion of the concept of creatinine clearance and thus may lead to inaccurate evaluation of the amylase/creatinine ratio. Creatinine clearance is defined as the ratio of urine creatinine concentration multiplied by urine volume divided by plasma creatinine concentration per….