The Autoimmune Prodrome: Before Symptoms Begin

Executive Summary

• The autoimmune prodrome refers to a preclinical period when immune changes occur before a diagnosed autoimmune disease develops.
• In many conditions, people may have no symptoms during this phase, even though autoantibodies or other signs of immune activation are present.
• Researchers have found that the prodromal period of disease can last years or even decades, depending on the condition and individual factors.
• Understanding the prodromal stage of disease is a growing area of research that could someday lead to earlier detection and prevention strategies.

Autoimmunity Can Begin Long Before Symptoms

Even though flares of autoimmune disease symptoms can strike suddenly, taking people by surprise, the underlying biological process—where the immune system may begin producing autoantibodies or showing other signs of immune dysregulation before clear symptoms appear—can take weeks, months, or even years to develop in some cases.

The preclinical phase of an autoimmune disease is known as the autoimmune prodrome. During the prodromal period of disease, the immune system has already begun to change, but a person may not yet have symptoms or meet the criteria for a formal diagnosis. Still, autoantibodies and other markers of immune activation may be present long before clinical disease becomes apparent.

Research regarding the prodromal stage of disease is still in its early stages. There is still a lot to learn about this period of asymptomatic autoimmunity, but furthering our understanding is a significant priority for the National Institutes of Health (NIH), as catching a disease this early presents a critical opportunity to intervene before full-blown symptoms manifest.

What Is Autoimmune Prodrome?

The preclinical, often asymptomatic phase that occurs before a full autoimmune disease is diagnosed is the best way to describe autoimmune prodrome. During this period, which can last months or even years until the individual meets the criteria for an official diagnosis, researchers may detect autoantibodies or other signs of immune activation even though the disease remains largely silent.

Are There Any Warning Signs?

Scientists have not identified a universal pattern that applies to every autoimmune disease or every person. However, during the prodromal period of an autoimmune disease, individuals may experience vague, non-specific health issues before irreversible organ or tissue damage occurs. 

These early warning signs typically fall into one of the four categories:

1. Neurological and psychiatric – Examples include migraines, unexplained headaches, depression, and anxiety.
2. Sleep and energy – This may manifest as severe, unexplainable fatigue or sleep disturbances, such as insomnia or recurring nightmares.
3. Musculoskeletal – Some people report widespread aches, fibromyalgia-like pain, and mild joint stiffness.
4. Gastrointestinal – Irritable bowel syndrome (IBS) symptoms, bloating, and digestive discomfort are also possible warning signs.

Keep in mind, the health complications mentioned above can occur for many reasons, and early warning signs associated with autoimmune prodrome vary widely from person to person—in fact, some people may be entirely asymptomatic.

Although someone may feel completely healthy during the prodromal period of disease, the immune system is already becoming dysregulated. In some diseases, tissue or organ damage may begin before obvious symptoms develop.

Autoimmune Prodrome Can Look Different Depending on the Disease

Scientists have discovered that immune system changes can precede disease diagnosis by years in many cases. Still, the prodromal phase looks different across various autoimmune diseases, as seen below.

Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) research from the New England Journal of Medicine showed that the mean interval between the earliest autoantibody detection and diagnosis ranged from 0.88 of a year for anti–nuclear ribonucleoprotein antibodies to 3.68 years for anti-Ro antibodies. The ability to detect antibodies like anti-Ro so early on in the development of SLE suggests that earlier risk assessment and future preventive strategies may one day be possible.

Multiple Sclerosis

There is a growing body of work that points toward the existence of a clinically symptomatic prodromal phase in multiple sclerosis (MS) that might span 5 to 10 years or more—check out this perspective article that summarizes the current state of knowledge of the MS prodrome. 

With this knowledge, some environmental factors previously thought to cause MS may actually reflect changes that occur during this early, preclinical phase of the autoimmune disease.

Type 1 Diabetes

Type 1 diabetes provides one of the clearest examples of preclinical autoimmunity, as research posted on the Journal of the American Medical Association reflects that children with persistent detection of two or more islet autoantibodies have a very high likelihood of eventually developing clinical type 1 diabetes. Nearly 70% of the children in this study with multiple islet autoantibodies developed diabetes within 10 years.

Thankfully, recent groundbreaking research has led to the FDA approval of a new therapy for delaying the progression of type 1 diabetes in high-risk individuals, which is especially promising when combined with the fact that islet autoantibodies can be used to predict the development of this particular autoimmune condition years in advance in some scenarios.

Why Researchers Are Paying Close Attention

The autoimmune prodrome represents a unique window of opportunity. If scientists can better understand who is at risk and how autoimmune diseases develop, it may become possible to intervene before irreversible damage occurs, delaying or preventing disease progression.

Six promising areas of research that tie into autoimmune prodrome are:

1. Autoantibodies and biomarkers
2. Genetics and environmental factors
3. Wearable technologies and sensors
4. Imaging and diagnostic tools
5. Predictive models using computational methods
6. New approaches to immunomodulatory therapies

These research efforts aim to identify people at higher risk and potentially delay or prevent disease progression.

What This Means for Patients

Unfortunately, most people do not know they are in an autoimmune prodrome, and routine screening for preclinical autoimmunity is not currently recommended for the general population. Nevertheless, researchers are focusing increasingly on prevention and early intervention.

Many questions remain unanswered regarding the prodromal period of disease, but researchers are hopeful that studying this early phase will lead to better ways to predict, delay, and ultimately prevent autoimmune disease.

The Autoimmune Association continues to support research, education, and advocacy aimed at improving the lives of people affected by autoimmune diseases and advancing understanding of the earliest stages of these conditions.

If you want to stay informed about future learnings regarding autoimmune prodrome and other important areas of research, subscribe to the Autoimmune Association’s Research Roundup newsletter.