Autoimmune Neuromuscular Junction Reflexive Panel

Content Review: July 2023 Last Update:

Autoimmune neuromuscular junction disorders are a broad range of rare, acquired conditions that affect the peripheral nervous system. Antibodies associated with these conditions can serve as useful markers of disease and help guide treatment. 

Disease Overview

Autoimmune neuromuscular junction disorders generally develop subacutely and can progress rapidly. They are characterized by fatigable weakness which may affect ocular, bulbar, axial, and respiratory muscles.  Antineural antibodies serve as useful markers of these diseases, and their detection may help establish a diagnosis, support treatment decisions, aid prognostication, serve as a prerequisite for enrollment in clinical trials, and guide the search for an associated malignancy.

For more information about laboratory testing for autoimmune neurologic diseases, including detailed information about panel test selection, refer to the ARUP Consult Autoimmune Neurologic Diseases - Antineural Antibody Testing topic. For more information about the testing strategy for myasthenia gravis, refer to the ARUP Consult Myasthenia Gravis - MG topic.

Test Description

ARUP’s Autoimmune Neuromuscular Junction Reflexive Panel can be used for the evaluation of suspected acquired autoimmune neuromuscular junction disorders.

This test is not recommended for the initial evaluation of myasthenia gravis. For more information on ARUP’s myasthenia gravis testing, refer to the Myasthenia Gravis Testing Test Fact Sheet.

Testing for individual autoantibodies is also available separately and can be used for long-term monitoring.

Antibodies Tested and Methodology

Autoimmune Neuromuscular Junction Reflexive Panel (3003017): Antibodies Tested and Methodology
Autoantibody Marker Method Individual Autoantibody Test Code

AChR Binding Ab, IgG

RIA

0080009

AChR Blocking Ab, IgG

Flow cytometry

0099580

AChR Modulating Ab, IgGa

Flow cytometry

0099521

CASPR2 Ab, IgGa

CBA-IFA, reflex titer

2009452

Ganglionic AChR Ab

RIA

3003020

LGI1 Ab, IgGa

CBA-IFA, reflex titer

2009456

N-type VGCC Ab, IgG

RIA

P/Q-type VGCC Ab, IgG

RIA

0092628

Striated Muscle Abs, IgG

IFA, reflex titer

0050746

Titin Ab, IgG

IFA

2005636

VGKC Ab, IgG

RIA

2004890

aPerformed via reflex only, depending on the results of other autoantibody tests; refer to Reflex Pattern diagram.

Ab, antibody; AChR, acetylcholine receptor; CASPR2, contactin-associated protein 2; CBA, cell-binding assay/cell-based assay; IFA, indirect immunofluorescence assay; Ig, immunoglobulin; LGI1, leucine-rich, glioma-inactivated protein 1; mGluR1, metabotropic glutamate receptor 1; MOG, myelin oligodendrocyte glycoprotein; NMDAR, N-methyl-D-aspartate receptor; PCCA, Purkinje cell cytoplasmic antibody; RIA, radioimmunoassay; VGCC, voltage-gated calcium channel; VGKC, voltage-gated potassium channel

Reflex Patterns

Autoimmune Neuromuscular Junction Reflexive Panel (3003017): Reflex Pattern

Reflex pattern for Autoimmune Neuromuscular Junction Reflexive Panel

Limitations

These tests do not include all known antineural antibodies:

  • Some antibodies are extremely rare or are of uncertain clinical significance.
  • As testing for newly described antibodies becomes available and their clinical relevance is established, these panels will evolve to reflect these discoveries.

Test Interpretation

Results

Results must be interpreted in the clinical context of the individual patient; test results (positive or negative) should not supersede clinical judgment.

Autoimmune Neuromuscular Junction Reflexive Panel (3003017): Results Interpretation
Result Interpretation

Positive for ≥1 autoantibodies

Autoantibody(ies) detected

May support a diagnosis of an autoimmune neuromuscular junction disorder

Negative

No autoantibodies detected

A diagnosis of an autoimmune neuromuscular junction disorder is not excluded