Antinuclear Antibodies and Autoimmune Disease

The prevalence of autoimmune disease, which collectively includes more than 80 conditions, has risen dramatically over the years, affecting more than 24 million people in the US¹ and an estimated one in ten people worldwide.² Genetics, infections, and changes in environmental exposures may play a role in the increasing number of cases.^1,3 To add to the complexity of the issue, autoimmune diseases disproportionately afflict women, and racial disparities are evident for certain autoimmune conditions.^4,5 As an example, research indicates that Black and Hispanic populations may be at a higher risk than other races for systemic lupus erythematosus (SLE).^5,6

Antinuclear antibodies (ANAs) are common biomarkers of autoimmune disorders, and recent research indicates that a rise in ANA presence in the US population has mirrored the increase of autoimmune disease worldwide in the past 25 years.^7-9 The detection of ANAs may indicate the future development of an autoimmune disease and may even precede symptoms by years.^7,10 Is ANA testing an effective proactive tool in the prevention of some autoimmune conditions? 

A Rise in Antinuclear Antibodies

Antinuclear antibodies are a group of autoantibodies produced by the immune system that target and bind to contents of a cell’s nucleus. While minimal amounts of ANAs may be detected in some healthy people, larger amounts may indicate an existing or impending autoimmune disorder. A recent cross-sectional study investigated the prevalence of ANAs in the US over a 25-year span, from 1988 to 2012.⁷ Investigators used blood test results (serum ANA measured by standard indirect immunofluorescence (IIF) assays on human epithelial type 2 (HEp-2) cells) from 13,519 participants aged 12 years or greater who participated in the National Health and Nutrition Examination Surveys, with approximately one-third of the participants from each of three time periods: 1988-1991, 1999-2004, and 2011-2012.⁷ Results for each time period indicated the following ANA prevalence percentages and estimations of ANA-positive individuals:⁷ 

• 1988-1991: 11.0% (~22.3 million)
• 1999-2004: 11.4% (~26.6 million)
• 2011-2012: 16.1% (~41.5 million)

The ANA prevalence increase was greatest from the second to the third time period. Researchers also noted that the increases were not due to other concurrent trends in obesity, smoking exposure, or alcohol consumption.⁷ Additional results from this study indicated that ANA prevalence specifically increased for:⁷ 

• Both women and men, with men showing the greater increase.
• Adults who were 50 years or older, with the noted potential influence of increased age-related exposures, such as medications.
• Adolescents between 12 and 19 years of age, with positive ANA tests nearly doubling then tripling over the time periods (from 5% to 9% to 13%).
• Non-Hispanic whites. Relative to race, results indicated higher ANA-positivity odds specifically in non‐Hispanic African American and Mexican American populations in 1988-1991, but racial differences decreased in the second and third time periods. 

ANA Testing, Detection, and a Window of Opportunity

A positive ANA test means that autoantibodies have been detected within the system; however, this positive test may be present without any evidence of disease.^11,12 Therefore, classification criteria for some autoimmune conditions such as SLE include both a detection of ANAs found through testing in addition to relevant clinical presentations.¹³ A standard screening for ANA detection is the IIF assay on HEp-2 cells,^11,14,15and an expanded profile of autoantibody testing may be available for some autoimmune conditions.¹⁶ While ANAs may be present in the body without any other indication of disease, for many patients, ANA levels may rise years before any autoimmune symptoms, or a clinical diagnosis.¹⁷

Studies have indicated autoantibodies as a potential predictor of conditions such as SLE, inflammatory bowel disease, type 1 diabetes, systemic sclerosis, and rheumatoid arthritis (RA).^17-22 Can such a predictive window offer an opportunity for successful interventions to stop an autoimmune disease process before it emerges? Recent studies have suggested a need for more personalized data collection, such as genetics and combinations of biomarkers, and enhanced data analysis methods in research studies to increase the overall predictive power of ANAs and other autoantibodies.²¹ 

In a clinical setting, ANA testing may present an opportunity to expand personalized interventions that emphasize awareness and prevention of potential autoimmune disease through strategies that address factors common in the progression of autoimmune conditions such as chronic inflammation and impaired intestinal permeability.²³ These proactive opportunities may ultimately improve health outcomes and promote wellness among a wide range of patients. 

Learn more about autoantibodies, autoimmune conditions, clinical applications, and the latest research from functional medicine experts at IFM’s upcoming Immune Functional Medicine Advanced Practice Module® (APM).