Paraneoplastic neurologic syndromes (PNSs) are diseases that occur due to the remote effects of tumors (usually malignant). Autoimmune neuropathies may present with a broad range of symptoms, including subacute progression, asymmetric or multifocal deficits, and selective involvement of motor, sensory, or autonomic nerves. Related conditions, such as autoimmune encephalitis, may exhibit similar symptoms. The overlap between these syndromes often makes diagnosis difficult.

Although antibody testing cannot be used as the sole diagnostic tool for PNS and related conditions, the detection of relevant antibodies in the appropriate clinical setting provides evidence for immune-mediated peripheral nerve disturbance and can help distinguish between similar disorders. For detailed disease and testing strategy information, visit the ARUP Consult Paraneoplastic Neurologic Syndromes and Associated Disorders and Autoimmune Neuropathies - Neuropathic Disease topics.

 

New Test Highlight: 3004359

Dipeptidyl Aminopeptidase-Like Protein 6 (DPPX) Antibody, IgG by IFA With Reflex to Titer, Serum

DPPX antibodies are uniquely present in some cases of PNS. ARUP offers DPPX testing in both our panels and as a standalone reflex test.

Test Information

When Should Testing Be Ordered?

Testing should be ordered whenever PNS or a related condition is suspected (e.g., in the case of a patient with suggestive symptoms and another autoimmune disease, as it is common for patients to have multiple autoimmune conditions). Testing may also be used to guide treatment. For more information about when testing may be appropriate, visit the ARUP Consult Paraneoplastic Neurologic Syndromes and Associated Disorders and Autoimmune Neuropathies - Neuropathic Disease topics.

Why Is Antibody Testing Important?

Antibody testing for PNS and related conditions may serve several important functions. For example, antibody testing is used to:

  • Aid in the diagnosis of PNS and/or related disorders
  • Direct a focused search for cancer
  • Differentiate autoimmune neuropathies from the neurotoxic effects of chemotherapy
  • Monitor the immune response of seropositive patients during cancer therapy
  • Detect early evidence of cancer recurrence in previously seropositive patients

Why Test With ARUP?

Testing options to meet your needs: ARUP offers multiple testing options for PNS and related conditions so that you can configure your testing strategy to the clinical situation. Options for antibody tests include:

  • Comprehensive panels for the evaluation of paraneoplastic autoimmune neuropathy, neuromuscular junction disorders, and/or encephalitis in the presence or absence of malignancy
  • Small, cost-effective, directed panels
  • Standalone tests that enable tracking of a single antibody over time

To assist you with test selection, ARUP provides visual overviews of PNS testing options:

Comprehensive clinical coverage: ARUP’s tests include antibodies with significant clinical impact that cover an estimated 95–99% of disease cases and minimize redundancy.

For an overview of the antibodies included in ARUP’s panels, see:

FAQs

How does ARUP select antibodies for its test menu?

ARUP selects antibodies for its test menu based on rigorous scientific evidence, with the goal of ensuring the detection of well-characterized antibodies with significant clinical impact. New antibodies are regularly evaluated, and testing is added to ARUP’s menu based on the latest recommendations and clinical relevance as demonstrated by emerging literature.

How do ARUP’s PNS testing options compare to panel tests offered by other laboratories?

ARUP offers a comprehensive assortment of standalone and panel tests for clinically significant antibodies that cover 95–99% of disease cases. These tests can be configured to meet your needs, minimize redundancy, and ensure cost-effectiveness. A significant number of these tests overlap with panel test offerings from our competitors.

Are there clinically relevant antibody tests that ARUP does not offer?

Although ARUP Laboratories offers tests that detect an estimated 95–99% of disease cases, some tests are not currently offered as standalone tests. For example:

  • A standalone test for N-type voltage-gated calcium channel (VGCC) antibody is not offered. This antibody overlaps with P/Q-type VGCC autoantibodies, and tests for these two antibodies are best ordered together for interpretation. These antibodies are part of ARUP’s Autoimmune Neurologic Disease Reflexive Panel (3003058) and Voltage-Gated Calcium Channel (VGCC) Antibody Panel (3002046) tests.
  • Antineuronal nuclear antibody type 3 and Purkinje cell cytoplasmic antibody type 2 likely represent <1% of disease cases; testing for these antibodies is not offered at ARUP Laboratories.
  • The clinical impacts of some antibodies, such as alpha internexin, GFAP, IgLon5, mGluR1, NIF heavy chain, and NIF light chain, are still being researched. Testing for these antibodies is not currently available at ARUP Laboratories.
Does ARUP have additional antibody tests in development?

Yes. ARUP Laboratories regularly adds offerings based on literature-demonstrated clinical impact. For example, cerebrospinal fluid (CSF) testing for the following antibodies is under development (serum testing is already available):

  • D dipeptidyl-peptidase–like protein 6 (DPPX) antibody
  • Purkinje cell cytoplasmic antibody type 3
  • Amphiphysin antibody

Panels Offered by ARUP:

Panel Test Code
Panel Name
3004070 Autoimmune Neurologic Disease Reflexive Panel, Seruma
3001431 Autoimmune Encephalitis Extended Panel, Seruma
3002929 Paraneoplastic Reflexive Panela
2007961 Paraneoplastic Antibodies (PCCA/ANNA) by IFA with Reflex to Titer and Immunoblot
3002787 Autoimmune Encephalitis Reflexive Panel, CSFb
3002887 Autoimmune Neurologic Disease Reflexive Panel, CSFb
2010841 Paraneoplastic Antibodies (PCCA/ANNA) by IFA with Reflex to Titer and Immunoblot, CSF
3001283 Autoimmune CNS Demyelinating Disease Reflexive Panel

aFor additional information about components, see the ARUP PNS and Related Disorders Panel Testing Serum Antibodies table.

bFor additional information about components, see the ARUP PNS Panel Testing CSF Antibodies table.

Additional Resources

In addition to comprehensive test offerings, ARUP offers a variety of free content to assist you in test selection: