Neurophysiological and clinical responses to rituximab in patients with anti-MAG polyneuropathy

Clin Neurophysiol. 2011 Dec;122(12):2518-22. doi: 10.1016/j.clinph.2011.05.015. Epub 2011 Jun 15.

Abstract

Objectives: Rituximab treatment has shown clinical improvement in anti-myelin associated glycoprotein (MAG) polyneuropathy. We analyzed scores of clinical scales and the most sensitive electrophysiological parameters before and after immunomodulating treatment with rituximab in a group of patients affected by anti-MAG demyelinating polyneuropathy.

Methods: Clinical scores, the percentage of CD20 B-lymphocytes, anti-MAG antibody titers and electrophysiological data in 7 patients with anti-MAG polyneuropathy were analyzed. The patients were examined before a cycle with rituximab, 6, 12 and 24 months after the end of the treatment. Two patients were treated with rituximab additional cycles and re-evaluated 48 months after the first treatment.

Results: There were no evident correlation between anti-MAG serum antibody titers or clinical scales and electrodiagnostic data. Significant decrease in the proportion of CD20 B-lymphocytes was observed. Significant anti-MAG antibodies titers reduction was detected after re-treatment. At follow-up, pinprik sensation and two point discrimination presented a significant improvement compared with the score before treatment.

Conclusions: In our patients, rituximab did not improve any electrophysiological data. No correlation with anti-MAG serum antibodies course was found. With rituximab only pin sensibility improved.

Significance: Rituximab re-treatment significantly reduces anti-MAG serum antibodies titers but improves only small fibers sensibility.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies, Monoclonal, Murine-Derived / therapeutic use*
  • Antigens, CD20 / immunology
  • B-Lymphocytes / drug effects
  • B-Lymphocytes / immunology
  • Humans
  • Immunoglobulin M / blood
  • Immunoglobulin M / immunology
  • Immunologic Factors / therapeutic use*
  • Lectins / immunology*
  • Male
  • Middle Aged
  • Myelin-Associated Glycoprotein / immunology*
  • Polyneuropathies / drug therapy*
  • Polyneuropathies / physiopathology
  • Rituximab
  • Treatment Outcome

Substances

  • Antibodies, Monoclonal, Murine-Derived
  • Antigens, CD20
  • Immunoglobulin M
  • Immunologic Factors
  • Lectins
  • MAG protein, human
  • Myelin-Associated Glycoprotein
  • Rituximab