[Recent advances in paraneoplastic encephalomyeloneuronopathy]

Small cell lung carcinoma-associated paraneoplastic encephalomyeloneuronopathy involves the nervous system at various levels resulting in cerebellar degeneration, limbic encephalitis, myelopathy, sensory neuronopathy or brainstem encephalitis. Anti-neuronal nuclear antibody, which has been termed ANNA-1/anti-Hu/Type II a antibody, is observed in the serum or cerebrospinal fluid of the patients and is highly specific for the disorder. This antibody reacts with the nucleoproteins of most neurons in the nervous system and recognizes a group of nucleoproteins in neurons with a molecular weight of 34-42 kd, suggesting that the pathogenesis of this disorder may be autoimmune. Several cDNA clones encoding the antigens have been cloned; that is, HuD, PLE21/HuC and He1-N1. These antigens contain three highly similar RRMs as well as Drosophila ELAV and RBP9 proteins do. Several autoantigens 70K, A, B", and Ro contain RRM, and Ro antigen shares B cell epitopes with these antigens. Thus, RRMs may represent or encompass an autoimmune crossreactive determinant.