Anti-Ri: an antibody associated with paraneoplastic opsoclonus and breast cancer

Ann Neurol. 1991 Mar;29(3):241-51. doi: 10.1002/ana.410290303.


The serum and cerebrospinal fluid (CSF) of 8 women with ataxia, 6 of whom also had eye movement abnormalities believed to be opsoclonus, were found to contain a highly specific antineuronal antibody we call anti-Ri. Seven of the 8 women also had or developed cancer: carcinoma of the breast in 5, adenocarcinoma in an axillary lymph node in 1, and carcinoma of the fallopian tube in 1. Four patients presented with the neurological disorder; the cancer was diagnosed first in the other 4. Immunohistochemical studies using serum or CSF from all 8 patients revealed a highly specific antibody interaction with central nervous system neuronal nuclei but not with glial or other cells; the titer ranged from 1:5,000 to 1:320,000 in serum and from 1:2,000 to 1:16,000 in CSF. Biotinylated IgG from the patients' serum reacted with the tumors of 3 of 4 patients with anti-Ri antibody but not with breast cancers from patients without anti-Ri antibody. Immunoblots against cerebral cortex neuronal extracts identified protein antigens of 55-kd and 80-kd relative molecular mass. Serum titers by immunoblot ranged from 1:500 to more than 1:40,000 and CSF titers, from 1:10 to 1:2,000. The relative amount of anti-Ri was always higher in CSF than in serum. The antibody was not present in sera from normal individuals; patients with breast cancer without opsoclonus; other patients with opsoclonus; or patients with other paraneoplastic syndromes related to breast, ovarian, or small-cell lung cancer. We conclude that the presence of anti-Ri antibody identifies a subset of patients with paraneoplastic ataxia and eye movement disorders (opsoclonus) who usually suffer from breast or other gynecological cancer; the antibody when present is a useful marker for an underlying malignancy.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Antibodies, Anti-Idiotypic / analysis*
  • Antibodies, Anti-Idiotypic / blood
  • Antibodies, Anti-Idiotypic / cerebrospinal fluid
  • Antibodies, Neoplasm / analysis*
  • Antibodies, Neoplasm / blood
  • Antibodies, Neoplasm / cerebrospinal fluid
  • Blotting, Western
  • Breast Neoplasms / diagnosis*
  • Cerebral Cortex / immunology
  • Eye Movements*
  • Female
  • Humans
  • Immunohistochemistry
  • Middle Aged
  • Neurons / immunology*
  • Paraneoplastic Syndromes / diagnosis*


  • Antibodies, Anti-Idiotypic
  • Antibodies, Neoplasm