Circulating antineuronal antibodies in small cell lung cancer.

Antibodies directed against neuronal cells were found in the serum of 10 out of 27 patients with small cell lung cancer (SCLC) by means of an indirect immunofluorescent test. Positive staining was found either in nuclei of neurons with sparing of nucleoli or in the cytoplasm only. Antibodies belonged to IgG or IgM. A comparison with a control group of 60 patients yielded a high specificity of the circulating antibodies for SCLC. Contrary to recent reports, we were not able to confirm an association between the existence of circulating antibodies against neurons and the incidence of neurologic paraneoplastic disorders.