Specificity of Increased Renal Clearance of Amylase in Diagnosis of Acute Pancreatitis

Abstract

Renal clearance of amylase from the blood, expressed as a proportion of simultaneous creatinine clearance, is consistent within a narrow range (3.1 per cent ± 1.1 [S.D.]) in normal persons. In patients with acute pancreatitis the amylase/creatinine clearance ratio rises regularly and significantly (9.8 ± 3.5, p < 0.001). Only three of 42 patients with acute pancreatitis had a clearance ratio below 5.3 per cent. In contrast, the amylase/creatinine clearance ratio remained within the normal range in 44 patients with hyperamylasemia due to disease other than pancreatitis. This observation suggests that renal permeability to amylase is altered in acute pancreatitis, and provides a basis for using the amylase/creatinine clearance ratio in the differential diagnosis of hyperamylasemia. (N Engl J Med 292:325–328, 1975)