Autoimmune diseases occur when the immune system mistakenly attacks the body's own tissues, leading to a wide range of chronic symptoms and requiring diverse treatment approaches to manage these complex conditions.

Autoimmune diseases represent a group of conditions where the body's immune system, which is designed to protect against foreign invaders like bacteria and viruses, mistakenly targets and attacks its own healthy cells and tissues [1], [2]. This happens due to a breakdown in what is called 'immunologic tolerance,' meaning the immune system loses its ability to distinguish between 'self' and 'non-self' [1], [2].

These conditions affect a significant portion of the population, with an increasing incidence rate. Approximately 3% of individuals in North America and Europe are affected, and more than 75% of those diagnosed are women [2], [8]. While the exact cause is often unknown, autoimmune diseases are strongly linked to a combination of genetic, infectious, and environmental factors [2], [8].

What Are Autoimmune Diseases?

When the immune system loses its tolerance, it generates an inflammatory response against specific self-antigens, leading to autoimmune inflammation [1]. This inflammation can manifest as either organ-specific disorders, affecting a single organ, or systemic disorders, impacting multiple organs and systems throughout the body [1], [2].

There are many different types of autoimmune diseases, each with its own unique characteristics. Examples include:

Systemic lupus erythematosus (SLE) [1], [2]
Rheumatoid arthritis (RA) [1], [2]
Sjögren's disease [1]
Systemic sclerosis (scleroderma) [1], [2]
Autoimmune hepatitis (AIH) [3], [5]
Type 1 diabetes mellitus [2], [7]
Multiple sclerosis [2], [7]
Thyroiditis [2]

Beyond these well-known conditions, autoimmune pathology is also implicated in other common health issues such as arteriosclerosis, inflammatory bowel disease, schizophrenia, and certain types of infertility [2].

Diverse Symptoms and Diagnosis

The symptoms of autoimmune diseases are incredibly varied, ranging from mild to severe, and can be organ-specific or systemic [2]. Some individuals may experience non-typical clinical presentations or even be asymptomatic, as seen in some cases of autoimmune hepatitis [3]. Because these are chronic disorders, symptoms often persist over time [1].

Common symptoms can include fatigue, joint pain and swelling, skin rashes, fever, and organ dysfunction, though the specific presentation depends on the disease and the organs affected. For example, autoimmune hepatitis involves inflammation of the liver, which if left untreated, can lead to liver cirrhosis and death [3].

Diagnosing an autoimmune disease typically involves a combination of factors, including a review of symptoms, physical examination, and laboratory tests. For conditions like autoimmune hepatitis, diagnosis relies on identifying specific autoantibodies, certain biochemical markers, and characteristic histopathological features from tissue samples [3].

Current Treatment Approaches

The primary goal of treating autoimmune diseases is to control the chronic inflammation and manage symptoms, as many patients do not respond fully to available therapies [1]. Conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) and targeted therapies are commonly used [1].

For autoimmune hepatitis, first-line treatments include medications like predniso(lo)ne and azathioprine or mycophenolate mofetil [5]. While these medications can be life-saving, they often come with significant side effects that can negatively impact a patient's quality of life and adherence to treatment [5]. Less than 70% of patients achieve a complete biochemical response within six months, and over 20% experience side effects severe enough to require discontinuation of the medication [5]. Additionally, relapse rates can be high after treatment is stopped [5]. In severe cases or when therapeutic response is minimal, liver transplantation may be considered for autoimmune hepatitis, though it carries its own risks, including rejection [3].

Beyond specific disease treatments, managing associated comorbidities is crucial for better outcomes [3]. For instance, many autoimmune diseases, including antiphospholipid syndrome, rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome, and inflammatory bowel disease, are associated with an increased risk of venous thromboembolism (VTE), or blood clots [6]. Anticoagulant treatment may be indicated for primary and secondary prevention of VTE in these cases [6].

Emerging Therapies and Future Directions

Despite the challenges with existing treatments, the field of autoimmune disease therapy is evolving rapidly. In recent years, several new medications have been approved and are now used in clinical practice [1]. Furthermore, many promising drug candidates are currently under investigation, offering hope for more effective and targeted treatment options in the future for conditions like systemic lupus erythematosus, rheumatoid arthritis, Sjögren's disease, systemic sclerosis, systemic vasculitis, and inflammatory myositis [1].

Researchers are also exploring non-pharmacological interventions. Intermittent fasting, a dietary approach involving alternating periods of eating and fasting, is being studied for its potential benefits in autoimmune diseases [7]. Early research suggests it may help reduce inflammatory markers, modulate the immune system, improve gut microbiota, and enhance cellular repair mechanisms in conditions such as type 1 diabetes, rheumatoid arthritis, and systemic lupus erythematosus [7]. However, more research is needed to fully understand its effects on other autoimmune diseases like multiple sclerosis [7].

Managing Complications and Lifestyle Factors

Living with an autoimmune disease often involves careful management of symptoms and potential complications. It's important for patients to work closely with their healthcare providers to develop a comprehensive management plan. This plan may include monitoring for specific risks, such as the increased risk of venous thromboembolism seen in various autoimmune conditions [6].

Clinicians must also be aware of potential immune-related adverse events (irAEs) that can arise from certain medical treatments, such as immunotherapies used for cancer. For example, adjuvant nivolumab treatment has been reported to induce autoimmune polyendocrine syndrome, a life-threatening irAE [4]. This highlights the complex interplay between the immune system and various medical interventions.

While the understanding of disease mechanisms is still limited and patient presentations can be heterogeneous, ongoing research and the development of new therapies offer hope for improved outcomes and better quality of life for individuals living with autoimmune diseases [1], [5].

Sources

This article summarises published research for a general audience. It is not medical advice — talk to a qualified clinician about your own situation. Need help finding one? Browse doctors.