Chronic sensorimotor polyradiculopathy with antibodies to P2: an electrophysiological and immunoproteomic analysis

Muscle Nerve. 2008 Jul;38(1):933-8. doi: 10.1002/mus.20999.


In this study we report a patient with chronic progressive sensory ataxia, proximal weakness, immunoglobulin M (IgM) monoclonal gammopathy, and elevated protein levels in the cerebrospinal fluid, who showed a good response to prednisone. Electrophysiological study disclosed abnormalities predominantly of late responses (F waves and H reflexes), with no evidence of demyelination in the peripheral nerves, suggesting motor and preganglionic sensory nerve roots as the site of the lesion. An immune-mediated pathogenesis was considered and, to identify possible target antigens, we performed bidimensional electrophoresis and a Western blot study. Based on the suspected lesion site, we used human anterior and posterior root extracts. We identified IgM reactivity against peripheral nerve myelin protein P2. Enzyme-linked immunosorbent assay confirmed IgM reactivity toward one synthetic peptide from P2. To our knowledge, reactivity against P2 has not been reported previously in a paraproteinemic neuropathy. Furthermore, we demonstrated that bidimensional electrophoresis and Western blot of the tissue involved, as determined by clinical and electrophysiological studies, may be useful to establish clinical-immunological correlations in paraproteinemic neuropathies.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Anti-Inflammatory Agents / therapeutic use
  • Blotting, Western
  • Chronic Disease
  • Electrophoresis, Gel, Two-Dimensional
  • Electrophysiology
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Male
  • Myelin P2 Protein / genetics
  • Myelin P2 Protein / immunology*
  • Nerve Tissue Proteins / biosynthesis
  • Nerve Tissue Proteins / genetics
  • Polyradiculopathy / genetics*
  • Polyradiculopathy / immunology*
  • Polyradiculopathy / physiopathology
  • Prednisone / therapeutic use
  • Proteomics*
  • Spinal Nerve Roots / pathology


  • Anti-Inflammatory Agents
  • Myelin P2 Protein
  • Nerve Tissue Proteins
  • Prednisone