Alternative name
MAG
Description
Antibodies to Myelin Associated Glycoproteins (MAG) may be found in demyelinating polyneuropathies associated with autoimmune mechanisms. The autoantibodies appear to be pathogenic and their levels correlate with disease activity. Anti-MAG antibodies are also found in some chronic sensory neuropathies and in Guillain Barre syndrome. The IgM anti-MAG can be polyclonal but in most (85%) cases is monoclonal, particularly IgMk paraproteins directed against the MAG of central and peripheral nerves. Reports suggest that 50% of IgM paraproteins may bind to MAG. Other IgMk paraproteins bind to sulphatides of perpiheral nerve axons associated with sensory or motor syndromes.
Indication
Seen in chronic sensorimotor neuropathies and occasionally Guillain-Barre syndrome. Should be assayed in all cases of neuropathy associated with an IgM paraprotein.
Interpretation
Present in >90% pateints with Immune mediated sensory motor polyneuropathy.
Sample
Serum Separator Tube (SST)
Assay details
ELISA
Restrictions
Referred test: only available to neurology staff.
Reference range
Positive/negative
Turnaround time
28 days
Analysing laboratory
Southern General Hospital Department of Neurology