Amphiphysin antibody recognises 128 kDa protein and has a similar cerebellar distribution as GAD antibody.

Such autoimmunity (amphiphysin antibodies) to brain tissue can cause paraneoplastic stiff persons syndrome and can be associated with tumours of the breast and small cell lung carcinomas.

Amphiphysin antibody can be associated with Stiff-person’s syndrome and various other neurological conditions.

Image: Primate cerebellum showing staining of the granular layer with nuclei in red.