Ordering Recommendation

Aids in the diagnosis of autoimmune cerebellar ataxia and encephalitis. The presence of Ma2/Ta antibodies may be associated with cerebellar ataxia, encephalitis, dementia, and brainstem encephalitis. Ma2/Ta antibody disease may be paraneoplastic and is primarily associated with testicular cancer and adenocarcinoma. 

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Serum separator tube.

Specimen Preparation

Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP standard transport tube. (Min: 0.30 mL)

Storage/Transport Temperature


Unacceptable Conditions

Plasma. Contaminated, heat-inactivated, hemolyzed, or lipemic specimens.


After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 month


Qualitative Immunoblot


Mon, Thu, Sat


1-4 days

Reference Interval

Test Number
Reference Interval
  Ma2/Ta Antibody, IgG by Immunoblot, Ser Negative

Interpretive Data

IgG antibodies to Ma2/Ta are associated with paraneoplastic neurologic syndromes with phenotypes most often including a combination of limbic encephalitis, diencephalic encephalitis, and brainstem encephalitis. Patients with anti-Ma2/Ta paraneoplastic neurologic syndromes should be thoroughly evaluated for cancer, including testicular cancer and adenocarcinoma, as neurologic symptoms often precede cancer diagnosis. Use of immune checkpoint inhibitors has also been associated with an increased risk of anti-Ma2 paraneoplastic neurologic disease. Consider sending testing in CSF as well as serum to improve diagnostic yield. Results (positive or negative) should be interpreted in the context of the patient's complete clinical picture, as false positives may occur and a negative result does not exclude the diagnosis of paraneoplastic neurologic disease.

Compliance Category

Laboratory Developed Test (LDT)


Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
3017505 Ma2/Ta Antibody, IgG by Immunoblot, Ser 82423-5
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Ma
  • Ma2
  • PNMA2
  • Ta
Ma2/Ta Antibody, IgG by Immunoblot, Serum