ANTIBODIES TO A SUBPOPULATION OF GLIAL-CELLS AND A 66 KDA DEVELOPMENTAL PROTEIN IN PATIENTS WITH PARANEOPLASTIC NEUROLOGICAL SYNDROMES

Background-Paraneoplastic neurological syndromes (PNS) are inflammator y disorders that probably depend on autoimmune processes. Several auto antibodies (anti-Hu, anti-Ri, and anti-Yo) have been characterised in PNS and proved to be helpful in the diagnosis. However, these do not a ccount for all the cases and the possibility that other types of antib odies could be detected was investigated. Methods and results-Of 45 pa tients with PNS whose serum was probed on paraformaldehyde fixed rat b rain sections, 11 patients were identified whose serum samples recogni sed a cytoplasmic antigen in a subpopulation of glial cells in the whi te matter of adult rat brainstem, cerebellum, and spinal cord that wer e double labelled with a monoclonal antibody specific for oligodendroc ytes. All serum samples reacted with a 66 kDa protein of newborn rat b rain on western blot analysis. These antibodies were designated as ant i-CV2 antibodies. Only one of the 11 patients had one of the well char acterised autoantibodies (anti-Hu). Five patients had cerebellar degen eration, three had Limbic encephalitis, two had encephalomyelitis, and one had Lambert-Eaton myasthenic syndrome. The tumours were small cel l lung cancer or undifferentiated mediastinal cancer in seven patients , uterine sarcoma in two, and malignant thymoma in two. Among 1061 con trol serum samples, only two patients had anti-CV2 antibodies. One had small cell lung cancer and the other malignant thymoma. Conclusions-T he detection of anti-CV2 antibodies in patients with neurological diso rders should be considered as an indication of the presence of an occu lt cancer.