Immunology of paraneoplastic syndromes: overview.

Cancers that cause disturbances of organs or tissues remote from the site of the tumor or its metastases are called paraneoplastic syndromes. The nervous system can be affected at virtually any site, including the neuromuscular junction (e.g., Lambert-Eaton myasthenic syndrome, myasthenia gravis). Paraneoplastic syndromes affecting the central nervous system are characterized by (1) high titers of antibodies that react with both the cancer and the affected portion of the nervous system, (2) specifically reacting T cells in the blood and cerebrospinal fluid, and (3) autopsy evidence of neuronal destruction, inflammatory infiltrates, and antibody penetration. Clinically, paraneoplastic syndromes affecting the central nervous system are usually subacute in onset, rapid in evolution, and cause severe damage, but generally stabilize after several months with or without treatment. Immune suppression does not appear to be particularly effective in treating these disorders. Treatment of the underlying cancer sometimes ameliorates symptoms.