Absence of anti-P/Q calcium channel antibody in the sera of patients with anti-Yo antibody-positive paraneoplastic cerebellar degeneration

Subacute cerebellar ataxia in patients with cancer in whom metastasis to the cerebellum has not occurred and who exhibit neither infection, side effects of chemotherapy, nor nutritional deficiencies, is designated paraneoplastic cerebellar degeneration (PCD). A group of women with PCD and ovarian or uterine cancer harbor an anti-Yo antibody in their sera and CSF.1 Anti-Yo antibody binds to 52- to 62-kD and 34-kD proteins on Western blots of human Purkinje cell extracts and reacts with Purkinje and other neuronal cell cytoplasm on immunohistochemical analysis. This antibody may be produced against tumor antigens that also react with neuronal proteins. However, there is no evidence that anti-Yo antibody causes neuronal damage. We have failed in numerous attempts to produce animal models of PCD by injection of serum IgG from patients with PCD into rodent brains or by immunization of rodents with recombinant Yo protein; neuronal degeneration was not induced in any of these cases.2 However, the sera of PCD patients could contain minor antibodies …