Peripheral neuropathy and anti-MAG antibodies.

Peripheral neuropathy has been associated with monoclonal gammopathy in patients with Waldenstrom's macroglobulinemia, myeloma, B-cell lymphoma, and nonmalignant plasma cell dyscrasia. The neuropathy in these patients is heterogeneous and may be demyelinating or axonal, and sensory-motor or pure motor. The cause of neuropathy in many patients is unknown, but there is increasing evidence that in some cases it may be caused by autoantibody activity of M-proteins that bind to peripheral nerve antigens. Significant advances have been made in characterizing the autoantibody activity of M-proteins and correlating antigenic specificity with the type of neuropathy present, in elucidating the effector mechanisms responsible for causing nerve injury, and in understanding the causes for the aberrant immune response. This article reviews the recent advances made in this field and discusses their implications for the clinical evaluation and management of patients with peripheral neuropathy and monoclonal gammopathy.