Amylase-Creatinine Clearance Ratios and Serum Amylase Isoenzymes in Moderate Renal Insufficiency

Abdominal Pain in a Chronic Hemodialysis Patient

“…In healthy persons with a nor mal renal function this ratio is 3; with acute pancreatitis this ratio is greater than 9. The findings are not abso lutely specific for pancreatitis, however, as an increase in the ratio may be seen postoperatively in patients with diabetic ketoacidosis, massive burn injuries, and renal insufficiency [3,4], In the presence of renal insufficien cy, a patient with pancreatitis has an elevated serum amylase level, but the urinary amylase excretion is de creased. The isoenzyme of amylase constitutes 40% of total measurable amylase, and in most patients with renal insufficiency, its level in the serum is also elevated [5].…”

Interpretation of serum pancreatic enzymes in pancreatic and nonpancreatic conditions

“…Amylase excretion is hampered in renal failure leading to falsely raised serum amylase levels. This can also occur in conditions associated with reduced metabolic clearance of amylase, such as cirrhosis and acute hepatic dysfunction [66]. Macroamylasemia is a rare condition characterized by the formation of large complexes between amylase and immunoglobulins (usually IgA), which usually leads to a decrease in renal function and prolong the presence of amylase in serum and subsequently an abnormal increase in the level of serum amylase [15].…”

Uremic Exocrine Pancreopathy

“…While both forms are cleared by the kidneys, renal clearance of the pancreatic form predominates and this is reflected in the proportion of the two isoenzymes detected in normal urine [21][22][23]; it is thus expected that renal failure will have a differential effect on the levels of the two isoen zymes. Indeed, plasma levels of total amylase are in creased in patients with renal failure [10,II,19,[24][25][26] with a higher proportion of total amylase constituted by the pancreatic isoenzyme [20,[24][25][26][27], Salivary amylase is also increased in uremic subjects but to a lesser degree [24][25][26], These changes obviously complicate the diagno sis of pancreatitis in the setting of renal insufficiency. Lipase Several reports have described elevated circulating levels of the enzyme in uremic subjects [15,[28][29][30][31][32], This elevation has been correlated with the degree of reduc tion in GFR in predialysis subjects [32,33], As expected from the size of the enzyme, hemodialysis has no effect on circulating levels [32], The mechanism of the increase is unclear since the enzyme is not known to be cleared by the kidney [29,34],…”