Test ID: MGETH
Myasthenia Gravis (MG) Evaluation, Thymoma
Method Description
Describes how the test is performed and provides a method-specific reference
Muscle acetylcholine receptor (AChR) binding (IgG and IgM) are quantitated by immunoprecipitation assays. The high-affinity ligand (125)I-alpha-bungarotoxin is complexed with detergent-solubilized muscle AChR prepared from a mixture of innervated and denervated human muscle. AChR modulating antibody is detected in a bioassay: following 14-hour incubation with patient's serum, viable, noninnervated, monolayer cultures of human muscle cells are probed with (125)I-bungarotoxin to quantitate percent loss of surface AChR. Striational antibodies (IgG, IgM, and IgA) are detected by EIA using as antigen a mixture of sarcomeric proteins extracted from healthy adult rat skeletal muscle.(Griesmann GE, Kryzer TJ, Lennon, VA: Autoantibody profiles of myasthenia gravis and Lambert-Eaton myasthenic syndrome. In Manual of Clinical and Laboratory Immunology. Sixth edition. Edited by NR Rose, RG Hamilton, B Detrick, Washington, DC, ASM Press, 2002, pp 1005-1012)
CRMP-5-IgG is detected by Western blot assay using recombinant human collapsin response-mediator protein-5 as antigen.(Yu Z, Kryzer TJ, Griesmann GE, et al: CRMP-5 neuronal autoantibody: marker of lung cancer and thymoma-related autoimmunity. Ann Neurol 2001 February;49[2]:146-154)
Day(s) and Time(s) Test Performed
Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
ACh receptor (muscle) binding antibody: Monday through Thursday; 6 p.m., Saturday; 10 a.m.
ACh receptor (muscle) modulating antibodies: Monday through Thursday; 11 a.m.
Striational (striated muscle) antibodies: Monday through Thursday, Sunday; 10:30 p.m.
CRMP-5-IgG Western blot: Monday through Friday, 6 a.m.
AChR ganglionic neuronal antibody: Tuesday, Thursday, Sunday; 6 a.m.
Neuronal (V-G) K+ channel autoantibody: Tuesday, Thursday, Sunday; a.m.
GAD65 antibody assay: Monday through Thursday, Sunday; 8 a.m.


