--abnormal blood proteins, particularly monoclonal antibodies, can cause peripheral neuropathy through cross-reactivity with nerve structures.

Take a look at:

http://neuromuscular.wustl.edu/antibody/mprotein.htm

http://myeloma.org/ArticlePage.action?articleId=750

http://www.neuropathy.org/site/DocSe...pdf?docID=1061