The ratio between amylase and creatinine in serum and urine. Also referred as fractional excreted of amylase. ALCR is calculated as:View OriginalView Original
Normal range:
Amylase urine: 1 " “17 U/hour
ALCR: 1 " “4%
Use
Differential diagnosis of pancreatitis
Diagnosis of pseudocyst of the pancreas, where the urine amylase may remain elevated for weeks after the serum amylase has returned to normal, after a bout of acute pancreatitis.
Interpretation
Increased In
Pancreatitis (>6%)
DKA
Renal insufficiency
Duodenal perforation
Large doses of corticosteroids
Pancreatic cancer
Myeloma and light chain disease
Decreased In
Macroamylasemia
Limitations
Macroamylasemia is characterized by high serum amylase but normal urine amylase. The ALCR remains useful for the diagnosis of macroamylasemia. In macroamylasemia, the clearance is very low.