Fractional Urinary Clearance of Immunoreactive Lipase in Chronic Pancreatic Disease

Summary: Using an immunoenzymatic method, we studied lipase in the serum and urine of 23 controls, 22 chronic pan-creatitis patients in symptomatic remission, and in 9 patients with proven pancreatic cancer. Serum and urine lipase and its fractional urinary clearance were compared with those of am-ylase and immunoreactive trypsin. Lipase immunoreactivity was detectable in the urine of 81.5 % of the studied subjects (controls: 82%, chronic pancreatitis: 86%, pancreatic cancer: 66%); its output was higher than the upper limit of controls in 31.8 % of chronic pancreatitis and in only 1 of pancreatic cancer, and it was significantly correlated with the urinary output of trypsin (r = 0.487, P < 0.001), but not with that of amylase. A significant correlation was found between urinary output and serum levels for lipase, but not for trypsin or amylase. Frac-tional clearance of lipase was of the same magnitude as that of trypsin but only 0.1 % that of amylase. 19 % of chronic pan-creatitis and pancreatic cancer showed a fractional clearance of lipase above the upper limit of controls, compared with 45% for trypsin and 3.2 % for amylase. No difference in urinary clearance of the three enzymes was found between chronic pancreatitis and pancreatic cancer. In conclusion, although of no diagnostic relevance in pain-free patients with chronic pan-creatic disease, this measurement can provide information on the mechanisms of renal excretion of pancreatic enzymes