Autoimmune disease not associated with monoclonal gammopathy

Autoimmune disease not associated with monoclonal gammopathy 

Previous studies may have been affected by ascertainment bias 

Abstract: https://www.acpjournals.org/doi/10.7326/M23-2867   

URL goes live when the embargo lifts      

A study of more than 75,000 persons screened for monoclonal gammopathy of undetermined significance (MGUS) found no association between the presence of autoimmune diseases and MGUS. According to the authors, these findings are clinically significant because they indicate that recommendations to routinely screen patients with autoimmune disease for MGUS may not be warranted. The findings are published in Annals of Internal Medicine. 

Researchers from the University of Iceland analyzed a cross-sectional study where 75,422 adults were screened for MGUS to see if they could find an association between MGUS and autoimmune diseases. Of those screened, 10,818 had an autoimmune disease, and 599 of the patients with autoimmune diseases had MGUS. There were no differences between organ-specific and systemic autoimmune diseases or between antibody-positive and antibody-negative disorders. The authors determined that the diagnosis of an autoimmune diseases was not associated with MGUS, but it was associated with a prior clinical diagnosis of MGUS. These findings suggest that previously observed associations between autoimmune conditions and MGUS may have been affected by ascertainment bias. The authors caution that studies based only on clinical MGUS cohorts that are very likely to have been identified through work-up of the same diseases with which an association is being sought has led to a false association. 

Media contacts: For an embargoed PDF, please contact Angela Collom at [email protected]. To speak with the corresponding author, Ingigerdur Sverrisdottir, MD, please contact [email protected].