TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: PVLE    
Paraneoplastic Vision Loss Evaluation, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

Evaluating patients with rapidly progressive vision loss where a paraneoplastic cause for vision loss (retinopathy or optic neuritis with other findings [eg, retinitis] is suspected)

 

Evaluating patients with small cell carcinoma who develop vision loss

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

If the indirect immunofluorescence assay (IFA) patterns suggest collapsin response-mediator protein-5 (CRMP-5) antibody, then CRMP-5 IFA titer and CRMP-5 Western blot are performed at an additional charge.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

There are 2 recognized forms of paraneoplastic vision loss: paraneoplastic autoimmune optic neuropathy with retinopathy accompanying collapsin response-mediator protein-5 (CRMP-5)-IgG, and cancer associated retinopathy (CAR) accompanying recoverin antibody. Both occur in the setting of occult small cell carcinoma of the lung or other body region.

 

Patients with CRMP-5-IgG associated optic neuropathy typically present with painless bilateral visual loss over weeks to months. At onset, there is typically bilateral optic disc edema without evidence of enhancement of the optic nerve on magnetic resonance imaging or elevated opening pressure on lumbar puncture. Visual acuity can range from 20/20 to hand motion. Patients typically have co-existing vitritis or retinitis. In addition, patients can have diplopia, typically from cerebellar involvement. The majority of patients with CRMP-5 associated optic neuropathy will have other neurologic deficits from CRMP-5 autoimmunity, such as asymmetric axonal polyradiculoneuropathy. CAR typically presents with subacute painless progressive bilateral (although asymmetry has been described) progressive vision loss over weeks to months, reflecting both rod and cone retinal dysfunction in most patients. Accordingly, symptoms often include nyctalopia (inability to see in dim light or at night), impaired dark adaptation, photopsia (flashes of light in the field of vision), photosensitivity, dyschromatopsia, and ultimately, severe visual acuity loss.

 

Patients with CRMP-5-IgG-related ophthalmitis may have improvements with intra-ocular or systemic corticosteroid treatment. Patients with recoverin-related retinopathy are unlikely to have vision improvement with treatment.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

COLLAPSIN RESPONSE-MEDIATOR PROTEIN-5 TITER

<1:240

 

RECOVERIN IMMUNOBLOT

Negative

 

COLLAPSIN RESPONSE-MEDIATOR PROTEIN-5 WESTERN BLOT

Negative

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 1-800-533-1710 to request CRMP-5 Western blot. Neuron-restricted patterns of IgG staining that do not fulfill criteria for CRMP-5-IgG may be reported as "unclassified antineuronal IgG." Complex patterns that include non-neuronal elements may be reported as "uninterpretable."

Interpretation Provides information to assist in interpretation of the test results

Recoverin IgG:

Seropositivity is consistent with a diagnosis of paraneoplastic retinopathy. Considerations include small cell carcinoma, pulmonary or extrapulmonary.

 

Collapsin response-mediator protein-5 IgG:

Seropositivity is consistent with a diagnosis of paraneoplastic retinitis or ophthalmitis. Considerations include small cell carcinoma, pulmonary or extrapulmonary.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Negative results do not exclude the diagnosis of paraneoplastic eye disease.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Cross SA, Salomao DR, Parisi JE, et al: Paraneoplastic autoimmune optic neuritis with retinitis defined by CRMP-5-IgG. Ann Neurol. 2003;54:38-50 doi: 10.1002/ana.10587.

2. Lopez A, McKeon A, Lachance D, et al: Recoverin antibody: Ophthalmologic and oncologic significance. Neurology. 2016 April 5;86(16 Supplement)P6.131