Introduction: Monoclonal gammopathy (MG) is reported in 1% of subjects above 50 years of age and in 3% of those above the age of 70. Of all patients with MG, 3% present polyneuropathy (PNP). The abbreviation MGUS (monoclonal gammopathy of undetermined significance) is used to describe a benign proliferation of M component (monoclonal) according to Kyle's criteria, with a potential to be malignant that is indicated by clinical, biochemical and haematological parameters. Aims. The aim of this study was to evaluate the effect of the clinical exacerbation of MGUS associated neuropathy, by referring to the existing literature and to our own experience in order to set out a number of proposals for treatment based on the deterioration of the patient's quality of life.
Case reports: Case 1: a 53 year old female with predominantly sensory sensory motor demyelinating polyradiculoneuropathy, associated to IgG lambda MGUS. Case 2: a 65 year old female with demyelinating sensory motor polyradiculoneuropathy associated to IgM kappa MGUS. In both cases there was a rapidly progressing neurological deterioration and no other data exist to suggest malign lymphoproliferation.
Conclusions: In addition to the treatments established for MG linked PNP, which are based on the modulation of the immune response, it has also been proved that when malign proliferation of plasmacytes exists specific treatment of the gammopathy can significantly stabilise or improve the neuropathic symptoms. We propose gammopathy specific haematological treatment in patients who still meet Kyle's criteria for MGUS with a torpid neurological course and scarce response to therapy with immunomodulators, prior to an important deterioration in the quality of life. We also suggest establishing this rapidly progressing clinical course as a criterion that indicates the process of becoming malign as put forward by Eurelings et al.