Anti Myelin-Associated-Glycoprotein Antibody Peripheral Neuropathy Response to Combination Chemoimmunotherapy With Bendamustine/Rituximab in a Patient With Biclonal IgM κ and IgM λ: Case Report and Review of the Literature

Polyneuropathy associated with antimyelin-associated glycoprotein (anti-MAG) antibody, is an immune-mediated demyelinating, slowly progressing, sensory or sensorimotor ataxic neuropathy that has been associated with conditions that have an immunoglobulin (Ig)M paraproteinemia. Rituximab is the standard of care for anti-MAG antibody-associated peripheral neuropathy (AMPN) with small suboptimal trials showing < 50% response rates. Combination immunochemotherapy is the preferred first-line therapy for the treatment of many indolent lymphomas, including for Waldenstrom macroglobulinemia (WM), which is the best studied and most common of the clonal IgM-mediated conditions requiring treatment. It is logical to extrapolate conclusions from WM when treating the more rare IgM disorders such as AMPN. In this article we describe a case of a patient with AMPN associated with lymphoplasmacytic lymphoma who had a suboptimal response to rituximab, with a progression-free survival (PFS) of < 6 months, but who had a subsequent excellent clinical and serologic response to the combination of bendamustinerituximab with a PFS of 1 year to 4 cycles, and an additional > 1 year (ongoing) to 2 additional cycles. Her IgM levels and her anti-MAG titers responded symmetrically. On the basis of our extensive review of the available (limited) evidence for the treatment of this condition, combination chemoimmunotherapy might provide better response for AMPN and should be considered for patients with suboptimal or transient response to standard rituximab monotherapy. (C) 2016 Elsevier Inc. All rights reserved.