Monoclonal gammopathy and neuropathy.

PURPOSE OF REVIEW: The management of peripheral neuropathy associated with monoclonal gammopathies has been advanced by recent clinical studies. We review the causal association between monoclonal gammopathy and neuropathy, and critically review the recent evidence on treatment.

RECENT FINDINGS: IgM monoclonal gammopathy of undetermined significance (MGUS) is the most commonly found monoclonal gammopathy associated with neuropathy. Neuropathies associated with specific lymphoproliferative disorders may not respond to treatments aimed at that disorder. Standard immunomodulatory agents including steroids, intravenous immunoglobulin, and plasmapheresis have shown limited efficacy in IgM monoclonal gammopathy of undetermined significance. Newer studies have shown promising results with rituximab, a monoclonal antibody which targets the B cell surface antigen CD20 and results in a rapid and sustained depletion of B cells.

SUMMARY: There is a clear association between peripheral neuropathy and IgM MGUS with characteristic clinical, electrophysiology and pathologic features that make the disorder distinct from chronic inflammatory demyelinating polyneuropathy. The IgG and IgA monoclonal gammopathies are rarely associated with specific neuropathies. Long-term studies looking at the association between specific immunologic markers and disease recurrence are needed to ultimately develop targeted therapies.