GM1 Ganglioside Antibodies IgG/M

Label Mnemonic:	GM1
Epic code:	LAB3232
Downtime form:	Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

Commercial Mailout Laboratory
6240-8 RCP
356-8593

Specimen(s):

Serum

Collection Medium:

Red top tube 5 mL (Clot Activator)

Minimum:

Preferred Minimum: 0.3 mL serum
Absolute Minimum: 0.1 mL serum

If MAG Ab is ordered on the same patient, submit TWO 1 mL aliquots.

Rejection Criteria:

Room temperature specimens. Plasma, CSF, or other body fluids. Contaminated, heat-inactivated, hemolyzed , severely icteric, or lipemic specimens.

Delivery Instructions:

Deliver to laboratory immediately after collection. Critical frozen.

Turn Around Time:

1-4 days upon receipt at reference laboratory

Reference Range:

Asialo-GM1 Antibodies, IgG/IgM
  29 IV or less: Negative
  30-50 IV: Equivocal
  51-100 IV: Positive
  101 IV or greater: Strong Positive

GM1 Antibodies, IgG/IgM
  29 IV or less: Negative
  30-50 IV: Equivocal
  51-100 IV: Positive
  101 IV or greater: Strong Positive

GM2 Antibodies, IgG/IgM
  29 IV or less: Negative
  30-50 IV: Equivocal
  51-100 IV: Positive
  101 IV or greater: Strong Positive

GD1a Antibodies, IgG/IgM
  29 IV or less: Negative
  30-50 IV: Equivocal
  51-100 IV: Positive
  101 IV or greater: Strong Positive

GD1b Antibodies, IgG/IgM
  29 IV or less: Negative
  30-50 IV: Equivocal
  51-100 IV: Positive
  101 IV or greater: Strong Positive

GQ1b Antibodies, IgG/IgM
  29 IV or less: Negative
  30-50 IV: Equivocal
  51-100 IV: Positive
  101 IV or greater: Strong Positive

Interpretive Data:

Ganglioside antibodies are associated with diverse peripheral neuropathies. Elevated antibody levels to ganglioside-monosialic acid (GM1) and the neutral glycolipid, asialo-GM1 are associated with motor or sensorimotor neuropathies, particularly multifocal motor neuropathy. Anti-GM1 may occur as IgM (polyclonal or monoclonal) or IgG antibodies. These antibodies may also be found in patients with diverse connective tissue diseases as well as normal individuals. GD1a antibodies are associated with different variants of Guillain-Barre syndrome (GBS) particularly acute motor axonal neuropathy while GD1b antibodies are predominantly found in sensory ataxic neuropathy syndrome. Anti-GQ1b antibodies are seen in more than 80% of patients with Miller-Fisher syndrome and may be elevated in GBS patients with ophthalmoplegia. The role of isolated anti-GM2 antibodies is unknown. These tests by themselves are not diagnostic and should be used in conjunction with other clinical parameters to confirm disease.

Comments:

This test may be useful in the comprehensive evaluation of patients with autoimmune neuropathies. Test by itself is not diagnostic and should be used in conjunction with other clinical parameters to confirm disease.

Test Limitations:

Some antibodies may be associated with more than one disease and/or cancer.

Methodology:

Semi-Quantitative Enzyme-Linked Immunosorbent Assay

CPT Code:

83516 (x6)