Evaluating patients with suspected paraneoplastic encephalitides using serum specimens
Enzyme-Linked Immunosorbent Assay (ELISA)
Ta
PNMA2
Serum
Provide the following information:
1.Relevant clinical information
2.Ordering provider name, phone number, mailing address, and e-mail address
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 2 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.
1 mL
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 28 days | |
Frozen | 28 days | ||
Ambient | 72 hours |
Evaluating patients with suspected paraneoplastic encephalitides using serum specimens
Ma2 antibodies are IgG biomarkers found in patients with paraneoplastic encephalitis (limbic encephalitis or brainstem encephalitis) or cerebellar ataxia. Antibodies (Ab) to Ma antigens can be found directed at Ma2 alone, or both Ma1 and Ma2, but never Ma1 alone. The accompanying neurological disorders (encephalitis, dementia, brainstem encephalitis, cerebellar ataxia) are usually severe. The cancer associations are either testicular germinoma (Ma2 Ab positive only) or diverse (Ma1 and Ma2 Ab positive). Neurological improvement upon treatment of cancer or immunotherapy is more commonly encountered in those seropositive for Ma2 only than when compared to Ma1 and Ma2 together.
Negative
Seropositivity for Ma2 antibody is consistent with a diagnosis of an autoimmune central nervous system disorder (encephalopathy, dementia, seizure disorder, brainstem encephalitis or cerebellar ataxia). A paraneoplastic basis should be considered and include seminoma (testicular or extra-testicular).
A negative Ma2 antibody test result does not exclude autoimmune neurological disease or cancer.
1. 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 Jun 10;340(23):1788-1795. doi: 10.1056/NEJM199906103402303
2. Rosenfeld MR, Eichen JG, Wade DF, Posner JB, Dalmau J: Molecular and clinical diversity in paraneoplastic immunity to Ma proteins. Ann Neurol. 2001 Sep;50(3):339-348
3. Dalmau J, Graus F, Villarejo A, et al: Clinical analysis of anti-Ma2-associated encephalitis. Brain. 2004 Aug;127(Pt 8):1831-1844. doi: 10.1093/brain/awh203
4. Schuller M, Jenne D, Voltz R. The human PNMA family: novel neuronal proteins implicated in paraneoplastic neurological disease. J Neuroimmunol. 2005 Dec;169(1-2):172-176. doi: 10.1016/j.jneuroim.2005.08.019
5. Hoffmann LA, Jarius S, Pellkofer HL, et al: Anti-Ma and anti-Ta associated paraneoplastic neurological syndromes: 22 newly diagnosed patients and review of previous cases. J Neurol Neurosurg Psychiatry. 2008 Jul;79(7):767-773. doi: 10.1136/jnnp.2007.118588
6. Kunchok A, McKeon A: Opsoclonus in anti-Ma2 brain-stem encephalitis. N Engl J Med. 2020 Sep 24;383(13):e84. doi: 10.1056/NEJMicm1914516
7. Adams C, McKeon A, Silber MH, Kumar R: Narcolepsy, REM sleep behavior disorder, and supranuclear gaze palsy associated with Ma1 and Ma2 antibodies and tonsillar carcinoma. Arch Neurol. 2011 Apr;68(4):521-4. doi: 10.1001/archneurol.2011.56. Erratum in: Arch Neurol. 2011 Sep;68(9):1211
Ma2 antibodies are directed against their corresponding intracellular protein (PNMA2). The Ma2 autoantibody enzyme-linked immunosorbent assay (ELISA) is based on the principle of indirect ELISA that employs the ability of Ma2 autoantibodies to bind to antigenic protein (PNMA2) coated on the well surface of an ELISA plate. Detection of this bound antibody is accomplished using an anti-human secondary antibody that specifically recognizes the Fc region of the bound autoantibody. The secondary antibody is conjugated with alkaline phosphatase that enzymatically hydrolyzes a substrate molecule to produce an end product with a yellow color measurable at a wavelength of 405 nm. Controls and diluted samples are added in duplicate to coated plate wells and incubated for 2 hours, then washed extensively before adding the conjugated secondary antibody for an additional hour. After aspiration and washing, p-nitrophenyl phosphate substrate is added to each well and incubated for an additional hour before absorbance is measured at 405 nm.(Instruction manual: Capture ELISA Protocols. Abnova; R 1.1, 02/2011)
Tuesday, Friday
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
MA2ES | Ma2 Ab ELISA, S | 101868-8 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
605970 | Ma2 Ab ELISA, S | 101868-8 |