Autoimmune manifestations in patients with multiple myeloma and monoclonal gammopathy of undetermined significance.

BACKGROUND: Multiple myeloma (MM) and its precursor, monoclonal gammopathy of undetermined significance (MGUS), have been linked with several autoimmune conditions in the medical literature. Yet, significance of these associations is not well understood.

METHODS: Herein, we provide a comprehensive literature review on autoimmune disorders identified in patients with MM and MGUS. Most relevant papers were identified via searching the PubMed/Medline and EMBASE databases for articles published from inception until May 1, 2016.

FINDINGS: Scientific literature on autoimmune conditions in patients with MM and MGUS consists of several case series and a multitude of case reports. Our analysis suggests an increased prevalence of autoimmune conditions in patients with MM and monoclonal gammopathy of undetermined significance (MGUS), including various autoimmune hematologic and rheumatologic conditions among other entities. Conversely, persons with various autoimmune conditions tend to have a higher prevalence of MGUS and MM than the general population.

CONCLUSIONS: Future research is required to explore further the link between MGUS/MM and autoimmune disorders. Inflammation in the setting of autoimmunity may serve as a trigger for MGUS and MM. In addition, a common genetic susceptibility for developing both an autoimmune disease and MM/MGUS might also exist. Autoimmune hematologic and rheumatologic diseases may pose important clinical problems for the MM patients. Therefore, a catalogue of these problems is important so that physicians are able to consider, identify and address them promptly.