Purkinje cell antibodies, Neuronal antibodies
A family of autoantibodies recognising antigens in the brain which are associated with a variety of neurological manifestations occurring as a result of malignancy, usually ovarian or small cell carcinoma of the lung. The autantibodies may also recognise the tumour. Patients present with paraneoplastic cerebellar degeneration usually triggering a search for a previously unsuspected malignancy.There are several groups of autantibodies:
- Anti-neuronal nuclear autoantibodies (ANNA) recognise neuronal nucleii (not including nucleoli) but not nucleii from other tissues.
- ANNA1 (Hu) are reactive with all neuronal nucleii especially purkinje cells but not glial cells.
- ANNA 2 (Ri) do not recognise nucleii of the peripheral nervous system.
- Purkinje cell cytoplasmic antibodies (PCCA or Yo antibodies recognise cerebellar tissue as a course granular staining of the Purkinje cell (no nuclear staining).
- Positive samples are confirmed by immunoblotting which detects anti-Hu,Yo and Ri but also MA1,MA2, CV2/CRMP5 and amphiphysin antibodies.
See also anti-GAD antibodies and antibodies to voltage gated calcium or potassium channels.
This is a rapidly expanding field with new autoantibodies recognised annually. However, the diagnostic significance of many of the hew autoantibodies is poorly defined.
Paraneoplastic cerebellar syndrome & neuropathies associated with ovarian and small cell carcinoma of the lung.
Hu antibodies associated with several neurological syndromes including subacute sensory neuropathy and encephelomyelits usually patients with small cell carcinoma. Ri antibodies associated with opsoclonus, ataxia, mystagmus and/or dysarthia usually patients with breast cancer. Yo antibodies associated with cerebellar symptoms; usually patients with ovarian cancer. An increasing number of paraneoplastic antibodies are being characterised.
Serum Separator Tube (SST)
Indirect immunfluorescence rabbit cerebellum and other tissues
Referred test: only available to Neurology staff.
Positive or negative
Churchill Hospital Department of Immunology