Macromolecular complex
Macromolecular complexes include both macrohormones and macroenzymes, which consist of hormones and enzymes respectively covalently bound to carrier molecules, e.g. immunoglobulins, or occasionally the molecule may self-polymerize. Their primary importance lies in their ability to produce an artifactually-high level of the particular hormone/enzyme in the blood as standard laboratory assays do not distinguish between the unbound and bound forms of the hormone/enzyme, e.g. in hyperamylasemia the serum amylase appears to be elevated but may actually be normal. This may lead to inappropriate investigations and therapy.
Macrohormones
- macro-thyroid stimulating hormone (macro-TSH)
- macroprolactin
Macroenzymes
Immunoglobulin-bound
- macro-alkaline phosphatase
- macroamylase
- macro-creatine kinase (macro-CK)
- macro-gamma-glutamyl transferase (macro-GGT)
- macro-lactate dehydrogenase (macro-LDH)
- macrolipase
Non-immunoglobulin-bound
- macroamylase: amylase may bind to hydroxyethyl starch
- macro-mitochondrial creatine kinase: mitochondrial CK self-polymerizes
- macrotrypsin: proteases may bind to alpha-2-macroglobulin
