Anti-neuronal autoantibodies and neurological paraneoplastic syndromes.

Remote effects of cancer on the nervous system or paraneoplastic syndromes are diseases of unknown cause that occur exclusively or with increased frequency in patients with cancer. Several hypotheses have been used to explain the pathogenesis of these disorders. One hypothesis is that the tumour and the nervous system share antigens, so that an autoimmune response generated against the tumour causes the neurological disorder. The best evidence for this hypothesis is found in the Lambert-Eaton myasthenic syndrome which can be transferred to animals by injecting them with IgG from patients. The identification of autoantibodies against Purkinje cell cytoplasmic protein antigens in patients with paraneoplastic cerebellar degeneration, autoantibodies against neuronal nuclear antigens in patients with paraneoplastic syndromes associated with small cell lung cancer and autoantibodies against retinal ganglion cells in patients with small cell lung cancer and retinal degeneration supports this hypothesis. The possible role of these autoantibodies in the pathogenesis of paraneoplastic neurological disease is discussed.