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Test Code PCTTS Purkinje Cell Cytoplasmic Antibody Type Tr (PCA-Tr) Titer, Serum


Specimen Required


Only orderable as a reflex. For more information see:

-PAVAL / Paraneoplastic Autoantibody Evaluation, Serum

-DMS2 / Dementia, Autoimmune/Paraneoplastic Evaluation, Serum

-ENS2 / Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Serum

-EPS2 / Epilepsy, Autoimmune/Paraneoplastic Evaluation, Serum

-MDS2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Serum

-PCDES / Pediatric Autoimmune Encephalopathy/CNS Disorder Evaluation, Serum


Useful For

Serological testing for Purkinje cell cytoplasmic antibody-Tr for patients with acquired cerebellar ataxia of undetermined etiology, particularly if the patient has a history of Hodgkin lymphoma

 

Reporting an end titer result from serum specimens

Testing Algorithm

If the indirect immunofluorescence pattern suggests Purkinje cell cytoplasmic antibody type Tr (PCA-Tr), then this test will be performed at an additional charge.

Method Name

Only orderable as a reflex. For more information see:

-PAVAL / Paraneoplastic Autoantibody Evaluation, Serum

-DMS2 / Dementia, Autoimmune/Paraneoplastic Evaluation, Serum

-ENS2 / Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Serum

-EPS2 / Epilepsy, Autoimmune/Paraneoplastic Evaluation, Serum

-MDS2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Serum

-PCDES / Pediatric Autoimmune Encephalopathy/CNS Disorder Evaluation, Serum

 

Indirect Immunofluorescence Assay (IFA)

Reporting Name

PCA-Tr Titer, S

Specimen Type

Serum

Specimen Minimum Volume

0.6 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 28 days
  Frozen  28 days
  Ambient  72 hours

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus Reject

Clinical Information

Purkinje cell autoantibodies are among the antineuronal autoantibodies that are recognized clinically as markers of a patient's immune response to specific cancers (paraneoplastic autoantibodies).

 

The earliest description of a Purkinje cell cytoplasmic antibody (PCA) was reported by Trotter et al in 1976 as a serological accompaniment of paraneoplastic cerebellar ataxia in a patient with Hodgkin lymphoma.(1) IgG of that specificity was recently characterized more fully by Graus et al,(2) who confirmed the association with Hodgkin lymphoma and named the antibody "anti-Tr" in recognition of Dr. John L. Trotter's original report.

 

To accord with a generic classification of neuronal nuclear and cytoplasmic autoantibodies,(3) the name PCA-Tr was introduced to distinguish this Purkinje cell cytoplasmic antibody from PCA-1 (a marker of ovarian or breast carcinoma) and PCA-2 (a marker of small-cell lung carcinoma),(4) which are also found in patients presenting with paraneoplastic neurological autoimmunity.

Reference Values

Only orderable as a reflex. For more information see:

-PAVAL / Paraneoplastic Autoantibody Evaluation, Serum

-DMS2 / Dementia, Autoimmune/Paraneoplastic Evaluation, Serum

-ENS2 / Encephalopathy, Autoimmune/Paraneoplastic Evaluation, Serum

-EPS2 / Epilepsy, Autoimmune/Paraneoplastic Evaluation, Serum

-MDS2 / Movement Disorder, Autoimmune/Paraneoplastic Evaluation, Serum

-PCDES / Pediatric Autoimmune Encephalopathy/CNS Disorder Evaluation, Serum

 

<1:240

Neuron-restricted patterns of IgG staining that do not fulfill criteria for Purkinje cell cytoplasmic antibody type-Tr may be reported as "unclassified antineuronal IgG." Complex patterns that include nonneuronal elements may be reported as "uninterpretable."

Interpretation

A positive value (at 1:240 dilution or higher) is consistent with neurological autoimmunity and justifies a search for Hodgkin lymphoma. Purkinje cell cytoplasmic antibody type Tr has not yet been identified in any other context.

 

Seropositive patients usually have Hodgkin lymphoma and present with subacute cerebellar ataxia.(1-3)

Cautions

Interference from coexisting autoantibodies may preclude interpretation of the immunofluorescence pattern.

 

A negative result does not exclude neurological autoimmunity or Hodgkin lymphoma.

 

The Purkinje cell cytoplasmic antibody type Tr (PCA Tr) antigen, has not been defined immunochemically. It has been reported, but not yet confirmed that autoantibodies against glutamate receptors may occur in this context.(4)

 

No Western blot characteristics have been defined for the PCA Tr antigen.

Method Description

The patient's sample is tested by a standardized immunofluorescence assay that uses a composite frozen section of mouse cerebellum, kidney, and gut tissues. After incubation with sample and washing, fluorescein-conjugated goat-antihuman IgG is applied. Neuron-specific autoantibodies are identified by their characteristic fluorescence staining patterns. Samples that are scored positive for any neuronal nuclear or cytoplasmic autoantibody are titrated to an endpoint. Interference by coexisting non-neuron-specific autoantibodies can usually be eliminated by serologic absorption.(Honorat JA, Komorowski L, Josephs KA, et al: IgLON5 antibody: neurological accompaniments and outcomes in 20 patients. Neurol Neuroimmunol Neuroinflamm 2017 Jul 18;4(5):e385. doi: 10.1212/NXI.0000000000000385)

Day(s) Performed

Monday through Sunday

Report Available

6 to 8 days

Specimen Retention Time

28 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

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.

CPT Code Information

86256

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PCTTS PCA-Tr Titer, S 94352-2

 

Result ID Test Result Name Result LOINC Value
43439 PCA-Tr Titer, S 94352-2