Macrolipasemia
Macrolipasemia is the presence of serum lipase of a large molecular size, seen occasionally in otherwise healthy individuals, but more commonly in various diseases. Lipase is able to self-polymerize and/or form complexes with other blood proteins e.g. immunoglobulins.
Epidemiology
Epidemiological data on macrolipasemia is lacking however it is more common as healthy individuals age .
Pathology
Macroenzymes are not uncommon on laboratory assays of human blood. Many proteins self-polymerize or form complexes with other proteins, which are normal constituents of blood, e.g. immunoglobulins, carrier molecules, etc. .
Serum lipase has been found complexed to immunoglobulins and alpha 2-macroglobulin (α2-MG) . The latter is a common carrier protein found in normal blood.
Normal non-complexed lipase is freely filtered at the renal glomerulus. In macrolipasemia the molecule is too large to be filtered by the kidney resulting in a normal urinary lipase despite being elevated in the serum.
Interpretation
This condition can be confused with other causes of raised serum lipase (e.g. acute pancreatitis). Macrolipasemia is accompanied by normal serum lipase and urinary lipase levels. By contradistinction, in pancreatic disease the serum amylase will usually be elevated as well .
Causes of macrolipasemia
Macrolipasemia can be detected occasionally in well individuals, and is more common as age increases, although rarely seen in young people. More commonly it is detected in disease states:
History and etymology
"Macro lipase" was first described in 1987 by Stein and colleagues .
See also
