26607 Paraneoplastic Vision Loss Evaluation, Serum (PVLE)

​​​​​​CRMP-5; Anti-CV-2; Recoverin; Retinopathy; Ophthalmitis; Anti-CAR; CAR​

​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​

​Necessary Information: Relevant clinical information; Ordering provider name, phone number, mailing address, and e-mail address

Patient Preparation:

1. For optimal antibody detection, specimen collection is recommended prior to initiation of immunosuppressant medication.
   
2. ​This test should not be requested for patients who have recently received radioisotopes, therapeutically or diagnostically, because of potential assay interference. The specific waiting period before specimen collection will depend on 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 at Mayo labs will be held 1 week and assayed if sufficiently decayed or canceled if radioactivity remains.​
   

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

​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 commonly 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. In most cases, patients have coexisting vitritis or retinitis. In addition, patients can have diplopia, usually 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 presents with subacute painless progressive bilateral (although symmetry 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

​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. ​