Auto-SCT in severe paraproteinemic neuropathy

Abstract

Paraproteinemic neuropathies (PNs) encompass a heterogenous group of neurological disorders, which may not be clinically distinguishable from chronic inflammatory demyelinating neuropathy (CIDP). They are by definition associated with monoclonal gammopathy or plasma cell dyscrasia. The non-malignant forms have also been termed CIDP with monoclonal gammopathy of undetermined significance (MGUS-CIDP).1 In spite of some experimental evidence,2 a causative role of the paraprotein for the neuropathy has not yet been proven beyond doubt, and the exact pathophysiology in all these disorders has not yet been uncovered.3 Only in a defined subset of patients does a monoclonal IgM kappa paraprotein react specifically with myelin-associated glycoprotein (MAG), and this is likely to be of pathogenic significance.4 Standard treatment options include i.v. Igs, plasmapheresis or immunosuppressive treatment (for example, corticosteroids, azathioprine or CY) and—rarely—immunoselective treatment using monoclonal antibodies (anti-CD20, anti-TNF-alpha and anti-CD52).5 The response to treatment is variable, but most patients can be stabilized or even improved.5 Nevertheless, a group of patients remain refractory to these treatment modalities, including some of those with anti-MAG-associated neuropathy.5 For these cases intensive immunosuppression followed by auto-SCT could be an alternative therapy concept. However, until now only two case reports have been published describing successful ASCT after high-dose melphalan (HD-Mel) followed by amelioration of neurological symptoms.6, 7