Increasing Prevalence of Antinuclear Antibodies in the United States. Dinse GE1, Parks CG2, Weinberg CR3, Co CA1, Wilkerson J1, Zeldin DC4, Chan EKL5, Miller FW6. Author information 1. Clinical and Public Health Sciences, Social & Scientific Systems, Durham, NC, U.S.A. 2. Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, U.S.A. 3. Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, U.S.A. 4. Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, U.S.A. 5. University of Florida Health Science Center, Gainesville, FL, U.S.A. 6. Clinical Research Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, U.S.A. Abstract OBJECTIVE: Growing evidence suggests increasing frequencies of autoimmunity and certain autoimmune diseases, but findings are limited by the lack of systematic data and evolving approaches and definitions. We investigated whether the prevalence of antinuclear antibodies (ANA), the most common biomarker of autoimmunity, changed over a recent 25-year span in the U.S. METHODS: Serum ANA were measured by standard indirect immunofluorescence assays on HEp-2 cells in 14,211 participants ≥12 years old from the U.S. National Health and Nutrition Examination Survey, with approximately one-third from each of three time periods: 1988-1991, 1999-2004, and 2011-2012. We used logistic regression adjusted for sex, age, race/ethnicity, and survey-design variables to estimate changes in ANA prevalence across the periods. RESULTS: The prevalence of ANA was 11.0% (CI=9.7-12.6%) in 1988-1991, 11.5% (CI=10.3-12.8%) in 1999-2004, and 15.9% (CI=14.3-17.6%) in 2011-2012 (trend P<0.0001), which corresponds to 22, 27, and 41 million affected individuals, respectively. Among adolescents (ages 12-19 years), ANA prevalence rose steeply, with odds ratios of 2.02 (CI=1.16-3.53) and 2.88 (CI=1.64-5.04) in the second and third time periods relative to the first (trend P<0.0001). ANA prevalence increased in both sexes (especially males), older adults (ages ≥50 years), and non-Hispanic whites. These increases were not explained by concurrent trends in obesity/overweight, smoking, or drinking. CONCLUSION: The prevalence of ANA in the U.S. has increased considerably in recent years. Additional studies to determine factors underlying these increases could elucidate causes of autoimmunity and enable development of preventative measures. © 2020, American College of Rheumatology. Link to paper here