• Ingigerdur Sverrisdottir, Sigrun Thorsteinsdottir, Sæmundur Rognvaldsson, Thor Aspelund, Brynjar Vidarsson, Pall Torfi Onundarson, Bjarni A Agnarsson, Margret Sigurdardottir, Ingunn Thorsteinsdóttir, Signy Vala Sveinsdottir, Robert Palmason, Isleifur Olafsson, Fridbjorn Sigurdsson, Asdis Rosa Thordardóttir, Elias Eythorsson, Asbjorn Jonsson, Runolfur Palsson, Olafur Skuli Indridason, Gauti Kjartan Gislason, Andri Olafsson, Jon Sigurdsson, Hlif Steingrímsdóttir, Einarsson LongThorirT0000-0003-2377-7886University of Iceland, Reykjavik, Iceland, and Skåne University Hospital, Lund, Sweden (T.E.L.)., Malin Hultcrantz, DurieBrian G MBGM0000-0002-9883-3769Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Outpatient Cancer Center, Los Angeles, California (B.G.M.D.)., Stephen Harding, Ola Landgren, Sigurdur Yngvi Kristinsson, and Thorvardur Jon Love.
• University of Iceland, Reykjavik, Iceland, and Sahlgrenska University Hospital, Gothenburg, Sweden (I.S.).
• Ann. Intern. Med. 2024 Jun 1; 177 (6): 711718711-718.

BackgroundMonoclonal gammopathy of undetermined significance (MGUS) is a precursor of multiple myeloma (MM) and related conditions. In previous registry-based, retrospective studies, autoimmune diseases have been associated with MGUS. However, these studies were not based on a screened population and are therefore prone to ascertainment bias.ObjectiveTo examine whether MGUS is associated with autoimmune diseases.DesignA cross-sectional study within iStopMM (Iceland Screens, Treats, or Prevents MM), a prospective, population-based screening study of MGUS.SettingIcelandic population of adults aged 40 years or older.Patients75 422 persons screened for MGUS.MeasurementsPoisson regression for prevalence ratios (PRs) of MGUS among persons with or without an autoimmune disease, adjusted for age and sex.ResultsA total of 10 818 participants had an autoimmune disorder, of whom 599 had MGUS (61 with a prior clinical diagnosis and 538 diagnosed at study screening or evaluation). A diagnosis of an autoimmune disease was not associated with MGUS (PR, 1.05 [95% CI, 0.97 to 1.15]). However, autoimmune disease diagnoses were associated with a prior clinical diagnosis of MGUS (PR, 2.11 [CI, 1.64 to 2.70]).LimitationRegistry data were used to gather information on autoimmune diseases, and the homogeneity of the Icelandic population may limit the generalizability of these results.ConclusionThe study did not find an association between autoimmune disease and MGUS in a systematically screened population. Previous studies not done in systematically screened populations have likely been subject to ascertainment bias. The findings indicate that recommendations to routinely screen patients with autoimmune disease for MGUS may not be warranted.Primary Funding SourceThe International Myeloma Foundation and the European Research Council.

29 keywords...

hide…