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Health and Disease

The Increasing Prevalence of Autoimmune Diseases

An autoimmune disease is a condition arising from abnormal immune responses which attack body parts, resulting in tissue damage, and often inflammation. Common diagnoses include Multiple Sclerosis and Systemic Lupus Erythematosus.

By Swetha Babu

Published 11:16 PM EST, Mon August 16, 2021

Introduction

NIH (National Institutes of Health) have revealed that up to 23.5 million American citizens have an autoimmune disease and the prevalence is increasing. 80-100 various autoimmune diseases have been identified by scientists who also assume that at least 40 other diseases could potentially have an autoimmune basis.

Classifications of Autoimmune Diseases

No tissue or organ is exempt from autoimmune diseases: these diseases can affect various organs and organ systems, varying greatly among the individuals who have them, in terms of severity and responsiveness to therapy.

Autoimmune diseases can be either localized or systemic:

–       Systemic autoimmune diseases affect many organs and tissues simultaneously. Examples of systemic autoimmune diseases include scleroderma (affecting the skin, intestines, and less commonly lungs and kidneys) and Sjogren’s Syndrome (affecting salivary glands, tear glands, and joints.) 

–       Localised autoimmune diseases are organ-specific and remain in only a certain part of the body, but often can develop into systemic diseases. Examples of localized autoimmune diseases include Hashimoto’s disease (affecting the thyroid) and Discoid Lupus Erythematosus (affecting the skin). Discoid LE is an example of a localized disease that can progress into Systemic LE, affecting various organs such as the kidneys.

Increasing Prevalence

In the UK alone, the incidence of various autoimmune diseases is increasing at ranges between 3% and 9% year on year. This includes:

•       7.0% increase per year of rheumatic diseases such as rheumatoid arthritis

•       6.3% increase of endocrinological conditions such as type 1 diabetes

•       3.7% increase of neurological such as Multiple Sclerosis (MS)

•       4–9% increase per year of coeliac disease

In the United States of America, the prevalence of autoimmunity is also rising. According to researchers at the Allergy and Immunology section at Yale School of Medicine, in the last 25 years, there has been a 44% increase in ANA antibodies (antinuclear antibodies), which are antibodies that target themselves, with over 41 million people affected. These ANA antibodies presage autoimmune diseases such as lupus and autoimmune arthritis.

Image 1 –  ANA antibodies with fluorescent dye

Costs for hospitals to aid affected individuals continue to rise as the incidence of these diseases increases. Direct and indirect costs for just three autoimmune diseases alone (type 1 diabetes, rheumatoid arthritis, and multiple sclerosis) currently add up to more than £13 billion per year in the UK. The costs are significantly high due to the absence of treatments that cure autoimmune diseases and the likelihood for patients to develop major secondary diseases. Treatment of autoimmune disease focuses on controlling the autoimmune reaction with immunosuppressants: Corticosteroids are often used to control inflammation and suppress the immune response. Another medication such as pain medication is often prescribed to suppress symptoms of the disease.

Causes and Possible Reasons for Increasing Cases

The immune system is exceedingly complex, and research has revealed some potential triggers for excess immune responses.

Genetics, and Environmental Factors

The most simple theory is that as a result of a mutation, an individual inherited a faulty allele (a version of a gene, which codes for a specific protein). Hence, the protein does not form correctly and fails to function effectively. E.g., In Type I Diabetes mellitus, a mutation in particular protein results in the destruction of beta cells in the Islets of Langerhans, as the cells are wrongfully targeted and destroyed, which results in the inability to produce insulin.

Another genetic-related theory is that a certain genetic background makes an individual more likely to have a sensitive immune system, which, upon an encounter with a certain trigger (such as an infection or climate), sets off an autoimmune disease. Chilblain Lupus Erythematosus is an example of a disease that can be inherited but may only be expressed when an affected individual inhabits a colder climate.

Smoking and Drugs

Certain substances, particularly blood pressure medications or antibiotics, can trigger the onset of drug-induced lupus, which is a more benign form of the disease but can still greatly affect an individual’s daily activities. Statins can trigger the onset of statin-induced myopathy, which causes muscle weakness.

Weight and Obesity

Being overweight or obese raises the risk of developing autoimmune diseases such as rheumatoid arthritis or psoriatic arthritis. The greater fat content and greater weight put stress on the joints, particularly the knees, and intruding fat tissues encourage further inflammation. The increasing global epidemic of obesity can contribute to the rising incidence of autoimmune diseases.

Research Advances to Lower Number of Cases

Clinical Trials

Knowledge about various autoimmune diseases and new therapies can be gained from clinical research studies, conducted with volunteers who undergo various medical tests. Clinical trials for autoimmune diseases include studying “the Pathogenesis of Chronic Inflammatory Rheumatic Diseases’” and studying “Patients Undergoing Therapy for Immune-Mediated Inflammatory Skin Conditions.” The purpose of these clinical research trials can enable various worldwide healthcare professionals to assess the safety and effectiveness of current and future therapies and to study how the onset and severity of the diseases can be dependent on inherited or acquired traits.

Laboratory Research

Researchers in laboratories investigate the molecular mechanisms of the immune response to understand the disease progression further whilst uncovering new treatment approaches. This information can enable patients’ risk for certain diseases to be recognized earlier and to provide appropriate treatments.

Translational Research

This involves linking both laboratory and clinical research as materials and information are exchanged and shared between these two disciplines. For example, demographic data and medical data from clinical trials can be studied together with blood samples and tissue samples to understand the diseases’ pathogenesis and progression to better target treatments.

Swetha Babu, Youth Medical Journal 2021

Conclusion

The increasing prevalence of autoimmune diseases and immune-related diseases continues to exert pressure on hospitals and to increase the costs for hospital treatments, due to the chronic nature of the diseases and the regular requirement for medication.

The ultimate goal of early diagnosis and therapy is prevention – before autoimmune diseases become a clinical problem.

Swetha Babu, Youth Medical Journal 2021

References

Lovell, D., Huang, B., Chen, C., Angeles-Han, S., Simon, T., Brunner, H. (2021) Prevalence of autoimmune diseases and other associated conditions in children and young adults with juvenile idiopathic arthritis. National Centre for Biotechnology Information. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7978075/

British Society for Immunology. (2018, Nov. 26) Report reveals the rising rates of autoimmune conditions. https://www.immunology.org/news/report-reveals-the-rising-rates-autoimmune-conditions

Yale School Of Medicine. (2021, May. 20) Understanding Autoimmune Diseases. https://medicine.yale.edu/news-article/understanding-autoimmune-diseases/

Image 1 – http://blog.mblintl.com/antinuclear-antibodies-and-the-ifa-test

Johns Hopkins Medicine, Johns Hopkins Arthritis Center. https://www.hopkinsmedicine.org/health/wellness-and-prevention/what-are-common-symptoms-of-autoimmune-disease

Mayo Clinic, Clinical Trials: Autoimmune Diseases. (2021) https://www.mayo.edu/research/clinical-trials/diseases-conditions/autoimmune-diseases

Benaroya Research Institute at Virginia Mason, Autoimmune Diseases.

https://www.benaroyaresearch.org/what-is-bri/disease-information/autoimmune-diseases

By Swetha Babu

Swetha Babu is a student at Wycombe High School in Buckinghamshire, UK. She is an aspiring medic with particular interests in rheumatology and neurology.

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