Specificity of serum amylase and amylase creatinine clearance ratio in the diagnosis of acute and chronic pancreatitis.

In 31 patients with pancreatitis, the amylase to creatinine clearance ratio (CACR) was significantly greater than for controls (10.7 +/- 1.7 vs. 2.6 +/- 0.3, P less than .001). Sixteen pancreatitis patients with serum amylase (SAm) within the normal range had a mean CACR significantly greater than that of 19 hospital control patients with normal SAm (9.2 +/- 1.5 vs. 3.0 +/- 0.4, P less than .001). For control patients a highly significant inverse correlation between SAm and CACR was observed. No relationship was detected between these parameters for pancreatitis patients. The results suggest that the CACR may be of aid in establishing the diagnosis of pancreatitis even in patients without hyperamylasemia.