Test ID: PAVAL
Paraneoplastic Autoantibody Evaluation, Serum

Serological evaluation of patients who present with a subacute neurological disorder of undetermined etiology, especially those with known risk factors for cancer

Directing a focused search for cancer

Investigating neurological symptoms that appear in the course of, or after, cancer therapy, and are not explainable by metastasis

Differentiating autoimmune neuropathies from neurotoxic effects of chemotherapy

Monitoring the immune response of seropositive patients in the course of cancer therapy

Detecting early evidence of cancer recurrence in previously seropositive patients

If IFA (ANN1S/83381, ANN2S/83382, ANN3S/83137, PCABP/83383, PCAB2/83138, PCATR/83076, AMPHS/83386, CRMS/83077, AGN1S/89080) patterns are indeterminate, paraneoplastic autoantibody Western blot is performed at an additional charge.

If client requests or if IFA patterns suggest CRMP-5-IgG, CRMP-5-IgG Western blot is performed at an additional charge.

If IFA pattern is suggestive of neuromyelitis optica (NMO), NMO-IgG is performed at an additional charge.

If IFA patterns suggest amphiphysin antibody, amphiphysin Western blot is performed at an additional charge.

If IFA patterns suggest GAD65 antibody, GAD65 antibody radioimmunoassay is performed at an additional charge.

If ACh receptor binding antibody is >0.02 or if striational antibodies are > or =1:60, ACh receptor modulating antibodies and CRMP-5-IgG Western blot are performed at an additional charge.

CRMP-5-IgG Western blot is also performed by specific request for more sensitive detection of CRMP-5-IgG. Testing should be requested in cases of subacute basal ganglionic disorders (chorea, Parkinsonism), cranial neuropathies (especially loss of vision, taste, or smell) and myelopathies.

See Paraneoplastic Evaluation Algorithm in Special Instructions.

• Paraneoplastic Evaluation Algorithm

ANN1S/83381, ANN2S/83382, ANN3S/83137, PCABP/83383, PCAB2/83138, PCATR/83076, AMPHS/83386, CRMS/83077, AGN1S/89080, NMOS/83185: Indirect Immunofluorescence Assay (IFA)

STR/8746: Enzyme Immunoassay (EIA)

CCPQ/81185, CCN/81184, GD65S/81596, ARBI/8338, ARMO/83378, GANG/84321, VGKC/89165: Radioimmunoassay (RIA)

WBN/83108, CRMWS/83107, ABLOT/89381: Western Blot

Container/Tube: 

Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 4 mL

Additional Information: Include relevant clinical information, name, phone number, mailing address, and e-mail address (if applicable) of ordering physician.

Forms: If not ordering electronically, submit a General Request Form (Supply T239) with the specimen.

Paraneoplastic autoimmune neurological disorders reflect a patient's humoral and cellular immune responses to cancer. The cancer may be new or recurrent, is usually limited in metastatic volume, and is often occult by standard imaging procedures. Autoantibodies specific for onconeural proteins found in the plasma membrane, cytoplasm, and nucleus of neurons, glia or muscle are generated in this immune response, and serve as serological markers of paraneoplastic autoimmunity. Cancers recognized in this context most commonly are small-cell lung carcinoma (SCLC), thymoma, ovarian (or related mullerian) carcinoma, breast carcinoma, and Hodgkin's lymphoma. Pertinent childhood neoplasms recognized thus far include neuroblastoma, thymoma, Hodgkin's lymphoma, and chondroblastoma. An individual patient's autoantibody profile can predict a specific neoplasm with 90% certainty, but not the neurological syndrome.

Four classes of autoantibodies are recognized in this evaluation:

-Neuronal nuclear (ANNA-1, ANNA-2, ANNA-3)

-Anti-glial/neuronal nuclear (AGNA-1; aka Sox1)

-Neuronal and muscle cytoplasmic (PCA-1, PCA-2, PCA-Tr, CRMP-5, amphiphysin, and striational)

-Plasma membrane cation channel, calcium channels, P/Q-type and N-type calcium channel, dendrotoxin-sensitive potassium channels and neuronal (ganglionic) and muscle nicotinic acetylcholine receptors (AChR). These autoantibodies are potential effectors of neurological dysfunction.

Seropositive patients usually present with subacute neurological symptoms and signs such as encephalopathy; cerebellar ataxia; myelopathy; radiculopathy; plexopathy; or sensory, sensorimotor, or autoimmune neuropathy, with or without a neuromuscular transmission disorder: Lambert-Eaton syndrome, myasthenia gravis, or neuromuscular hyper-excitability. Initial signs may be subtle, but a subacute multifocal and progressive syndrome usually evolves. Sensorimotor neuropathy and cerebellar ataxia are common presentations, but the clinical picture in some patients is dominated by striking gastrointestinal dysmotility, limbic encephalopathy, basal ganglionitis, or cranial neuropathy (especially loss of vision, hearing, smell, or taste).

Cancer risk factors include past or family history of cancer, history of smoking, or social or environmental exposure to carcinogens. Early diagnosis and treatment of the neoplasm favor less neurological morbidity and offer the best hope for survival.

See Paraneoplastic Evaluation Algorithm in Special Instructions.

NEURONAL NUCLEAR ANTIBODIES

Antineuronal Nuclear Antibody-Type 1 (ANNA-1)

<1:240  

Antineuronal Nuclear Antibody-Type 2 (ANNA-2)  

<1:240

Antineuronal Nuclear Antibody-Type 3 (ANNA-3)

<1:240

Anti-Glial/Neuronal Nuclear Antibody-Type 1 (AGNA-1)

<1:240

NEURONAL AND MUSCLE CYTOPLASMIC ANTIBODIES

Purkinje Cell Cytoplasmic Antibody, Type 1 (PCA-1)

<1:240

Purkinje Cell Cytoplasmic Antibody, Type 2 (PCA-2)

<1:240

Purkinje Cell Cytoplasmic Antibody, Type Tr  (PCA-Tr)

<1:240

Amphiphysin Antibody

<1:240

CRMP-5-IgG

<1:240

Note: Titers lower than 1:240 are detectable by recombinant CRMP-5 Western blot analysis. CRMP-5 Western blot analysis will be done on request on stored serum (held 4 weeks). This supplemental testing is recommended in cases of chorea, vision loss, cranial neuropathy, and myelopathy. Call the Neuroimmunology Laboratory at 800-533-1710 or 507-266-5700 to request CRMP-5 Western blot.

Striational (Striated Muscle) Antibodies

<1:60

CATION CHANNEL ANTIBODIES

N-Type Calcium Channel Antibody

< or =0.03 nmol/L

P/Q-Type Calcium Channel Antibody

< or =0.02 nmol/L

ACh Receptor (Muscle) Binding Antibody

< or =0.02 nmol/L

AChR Ganglionic Neuronal Antibody

< or =0.02 nmol/L

Neuronal VGKC Autoantibody

< or =0.02 nmol/L

Neuron-restricted patterns of IgG staining that do not fulfill criteria for amphiphysin, ANNA-1, ANNA-2, ANNA-3, AGNA-1, PCA-1, PCA-2, PCA-Tr, or CRMP-5-IgG may be reported as "unclassified antineuronal IgG." Complex patterns that include non-neuronal elements may be reported as "uninterpretable."

Antibodies directed at onconeural proteins shared by neurons, glia, muscle, and certain cancers are valuable serological markers of a patient's immune response to cancer. They are not found in healthy subjects, and are usually accompanied by subacute neurological symptoms and signs. Several autoantibodies have a syndromic association, but no autoantibody predicts a specific neurological syndrome. Conversely, a positive autoantibody profile has 80% to 90% predictive value for a specific cancer. It is not uncommon for more than 1 paraneoplastic autoantibody to be detected, each predictive of the same cancer.

Negative results do not exclude cancer.

The neuronal voltage-gated potassium channel antibody assay will not be performed for children (aged 18 years or younger) because normal values are not yet established for the pediatric population.

This evaluation does not include Ma2 autoantibody (alias: MaTa). Ma2 autoantibody has been described in patients with brainstem and limbic encephalitis in the context of testicular germ cell neoplasms. Scrotal ultrasound is advisable in men who present with unexplained subacute encephalitis. N-methyl-D-asparate receptor antibodies have been reported in women with paraneoplastic encephalitis related to ovarian teratoma.

This test should not be requested in patients who have recently received radioisotopes, therapeutically or diagnostically, because of potential assay interference. The specific waiting period before specimen collection will depend on the isotope administered, the dose given and the clearance rate in the individual patient. Specimens will be screened for radioactivity prior to analysis. Radioactive specimens received in the laboratory will be held one week and assayed if sufficiently decayed, or canceled if radioactivity remains.

1. Lennon VA: Calcium channel and related paraneoplastic disease autoantibodies. In Textbook of Autoantibodies. Edited by JB Peter, Y Schoenfeld. The Netherlands, Elsevier Science Publishers, B.V., 1996, pp 139-147

2. Voltz R, Gultekin SH, Rosenfeld MR, et al: A serologic marker of paraneoplastic limbic and brain-stem encephalitis in patients with testicular cancer. N Engl J Med 1999 June 10;340(23):1788-1795

3. Vernino S, Tuite P, Adler CH, et al: Paraneoplastic chorea associated with CRMP-5 neuronal antibody and lung carcinoma. Ann Neurol 2002 May;51(1):625-630

4. Pittock SJ, Kryzer TJ, Lennon VA: Paraneoplastic antibodies coexist and predict cancer, not neurological syndrome. Ann Neurol 2004;56(5):715-719

5. Sabater L, Saiz A, Titulaer MG, et al: Sox 1 antibodies are markers of paraneoplastic Lambert-Eaton myasthenic syndrome. Neurology 2007;68(Suppl 1):A290-A291

6. Dalmau J, Tuzun E, Wu H-Y, et al: Paraneoplastic anti-N-methyl-D-asparate receptor encephalitis associated with ovarian teratome. Ann Neurol 2007;61:25-36

7. Tan K. Lennon V, Pittock S: Voltage-gated potassium channel (VGKC) autoimmunity, Abstract, Annual Meeting of American Neurological Association, Washington DC, (October) 2007

8. Pittock SJ, Lucchinetti DF, Parisi JE, et al: Amphiphysin autoimmunity: paraneoplastic accompaniments. Ann Neurol 2005:58(1):96-107

Indirect Immunofluorescence Assay (IFA):

Before screening for neuronal nuclear and cytoplasmic autoantibodies, patient's serum is preabsorbed with liver tissue extract to remove nonorgan-specific autoantibodies. After application to a composite substrate of frozen mouse tissues (brain, kidney, and gut), washing, fluorescein-conjugated goat antihuman IgG is applied to detect the distribution and pattern of the patient's bound IgG.(Vernino S, Lennon VA: New Purkinje cell antibody [PCA 2]: marker of lung cancer related neurological autoimmunity. Ann Neurol 2000;47:297-305;Lennon VA: The case for a descriptive generic nomenclature: classification of immunostaining criteria for PCA-1, ANNA-1, and ANNA-2 autoantibodies. Neurology 1994;44:2412-2415; Chan KH, Vernino S, Lennon VA: ANNA-3 anti-neuronal nuclear antibody: marker of lung cancer-related autoimmunity. Ann Neurol 2001 September;50[3]:301-311; 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)

Radioimmunoassay (RIA):

Goat antihuman IgG and IgM is used as precipitant in all assays. Cation channel protein antigens are solubilized from neuronal or muscle membranes, in non-ionic detergent and complexed with a selective high-affinity ligand that is labeled with (125)I. (125)I recombinant human GAD65 is used as antigen to confirm GAD65 autoantibody (when suspected from immunofuorescent staining pattern).(Griesmann GE, Kryzer TJ, Lennon VA: Autoantibody profiles of myasthenia gravis and Lambert-Eaton myasthenic syndrome. In Manual of Clinical and Laboratory Immunology. 6th edition. Edited by NR Rose, RG Hamilton, et al. Washington, DC, ASM Press 2002, pp 1005-1012; Walikonis JE, Lennon VA: Radioimmunoassay for glutamic acid decarboxylase [GAD65] autoantibodies as a diagnostic aid for stiff-man syndrome and a correlate of susceptibility to type 1 diabetes mellitus. Mayo Clin Proc 1998 December;73[12]:1161-1166)

Acetylcholine receptor modulating antibodies (muscle AChR) are detected by incubating the patient's serum for 14 hours with viable, noninnervated, monolayer cultures of human muscle cells. Percent loss of surface AChR is then quantitated by probing with (125)I-alpha-bungarotoxin.(Howard FM Jr, Lennon VA, Finley J, et al: Clinical correlations of antibodies that bind, block, or modulate human acetylcholine receptors in myasthenia gravis. Ann NY Acad Sci 1987;505:526-538)

Enzyme Immunoassay (EIA):

A mixture of sarcomeric proteins extracted from innervated rat skeletal muscle is used as antigen to detect striational antibodies (IgG, IgM, and IgA).(Cikes N, Momoi MY, Williams CL, et al: Striational autoantibodies: quantitative detection by enzyme immunoassay in myasthenia gravis, thymoma, and recipients of D-penicillamine or allogeneic bone marrow. Mayo Clin Proc 1988;63:474-481)

Western Blot (WB):

WB is performed when IFA screening is not interpretable due to interfering autoantibodies. A mixture of neuronal antigens extracted aqueously from adult rat cerebellum is denatured, reduced, and separated by electrophoresis on 10% polyacrylamide gel (5% for PCA-2 and ANNA-3). Full-length recombinant human CRMP-5 antigen is used to confirm CRMP-5-IgG. Denatured full-length recombinant human amphiphysin protein is used to confirm Amphiphysin Antibody.(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]:145-154)

ANNA-1: Monday through Thursday, Sunday; 10:30 p.m.

ANNA-2: Monday through Thursday, Sunday; 10:30 p.m.

ANNA-3: Monday through Thursday, Sunday; 10:30 p.m.

AGNA-1: Monday through Thursday, Sunday; 10:30 p.m.

PCA-1: Monday through Thursday, Sunday; 10:30 p.m.

PCA-2: Monday through Thursday, Sunday; 10:30 p.m.

PCA-Tr: Monday through Thursday, Sunday; 10:30 p.m.

Amphiphysin: Monday through Thursday, Sunday; 10:30 p.m.

CRMP-5-IgG: Monday through Thursday, Sunday; 10:30 p.m.

Striational (striated muscle) antibodies: Monday through Thursday, Sunday; 10:30 p.m.

P/Q-type calcium channel antibody: Monday, Wednesday, Friday; 6 a.m.

N-type calcium channel antibody: Monday, Wednesday, Friday; 6 a.m..

ACh receptor (muscle) binding antibody: Monday through Thursday; 6 p.m., Saturday; 10 a.m.

AChR ganglionic neuronal antibody: Tuesday, Thursday, Sunday; 6:00 a.m

Neuronal (V-G) K+ channel autoantibody: Tuesday, Thursday, Sunday ; 6 a.m

Paraneoplastic autoantibody Western blot: Monday, Wednesday, Friday; 6 a.m.

CRMP-5-IgG Western blot: Monday through Friday; 6 a.m.

NMO-IgG: Monday through Friday; 9 a.m.

Amphiphysin Western blot: Tuesday, Thursday; 6 a.m.

GAD65 antibody assay: Monday through Thursday, Sunday; 8 a.m.

ACh receptor (muscle) modulating antibodies: Monday through Thursday; 11 a.m.

83519-59-ACh receptor (muscle) binding antibody

83519-59-AChR ganglionic neuronal antibody

83519-59-Neuronal VGKC autoantibody

83519-59-N-type calcium channel antibody

83519-59-P/Q-type calcium channel antibody

83520-Striational (striated muscle) antibodies

86256-AGNA-1

86256-Amphiphysin

86256-ANNA-1

86256-ANNA-2

86256-ANNA-3

86256-CRMP-5-IgG

86256-PCA-1

86256-PCA-2

86256-PCA-Tr

83519-59-ACh receptor (muscle) modulating antibodies (if appropriate)

84182-Amphiphysin Western blot (if appropriate)

84182-CRMP-5-IgG Western blot (if appropriate)

84182-Paraneoplastic autoantibody Western blot confirmation (if appropriate)

86255-NMO-IgG (if appropriate)

86341-GAD65 antibody assay (if appropriate)