Age, Ethnicity, and Unexpected Connections in Autoimmune Risk Factors

In the first two parts of this article series, we discussed factors that may lead to the development of autoimmune diseases or the occurrence of flare-ups of existing ones. We highlighted genetic susceptibility, gender and sex, lifestyle habits, medications, microbial imbalances, and stress, among other triggers.

Our review continues with three additional risk factor categories, including age, ethnicity, and diseases that are not related to autoimmune diseases.

1. Age

Autoimmune diseases may develop in childhood, adulthood, or later stages of life. Disease progression can vary depending on the age at which it first appears, a concept defined as age at onset (1). For example, early age at onset can affect the severity of diseases, such lupus and type 1 diabetes, but may not be as important for rheumatoid arthritis and multiple sclerosis (1).

Diseases that affect younger people include juvenile idiopathic arthritis, juvenile dermatomyositis, type 1 diabetes, and scleroderma (2, 3). Alopecia areata and lupus can also manifest in childhood (4, 5), while Raynaud’s syndrome is an example of an autoimmune disease that begins between 15 and 30 years old (6).  

Multiple sclerosis typically develops within the age range of 20 to 40 (7, 8), while various forms of autoimmune arthritis (such as rheumatoid and psoriatic) can manifest at any age but were reported to peak between 30 and 55 years old (1, 9).

Sjögren’s syndrome and Hashimoto’s disease are more commonly found in middle-aged people (10, 11), while atherosclerosis and bullous pemphigoid were reported to develop in older individuals, including those aged 90 and older (12, 13).

Despite the presence of autoantibodies that trigger autoimmunity, older people seem to be less susceptible to developing autoimmune diseases than children and middle-aged adults (1). This could be attributed to the presence of specialized immune cells (regulatory T cells) that play a role in preventing the development of disease signs and symptoms (14).

2. Race, ethnicity, and geographic location

Autoimmune diseases affect people from all races, ethnicities, and geographic regions. Although certain autoimmune diseases appear to be more prevalent in specific populations, their diverse nature poses challenges in conducting extensive studies (15, 16).

Over the years, lupus, as well as nephritis associated with lupus, sarcoidosis, and systemic sclerosis, have been reported to be prevalent in African Americans (17, 18, 19). In contrast, multiple sclerosis, rheumatoid arthritis, and celiac disease have been reported to be prevalent in people of Caucasian origin (20, 21). A study highlighted an increase in multiple sclerosis occurrence in African American populations (22). The same study highlighted that multiple sclerosis is less common in Hispanic and Asian populations than in Caucasians of European descent (22).

In another study, researchers examined the occurrence of autoimmune diseases in different populations according to sex, race, and geographical area. Researchers specifically observed that the rates of lupus, multiple sclerosis, and rheumatoid arthritis varied in African American communities living in different regions of the US (16).

Autoimmune hepatitis is known to affect people of all racial and ethnic backgrounds. However, a retrospective study reported it to be prevalent in Latino, Black, and Asian/Pacific Island communities living in underserved and vulnerable communities of San Francisco (23).

Systemic sclerosis has a high prevalence in Native Americans because of genetic predisposition caused by DNA variants. However, the development of the disease in these populations may also be connected to other genes and environmental factors (24).

Research has aimed to uncover how the connections between ethnic diversity, genetic susceptibility, and environmental factors influence autoimmunity in different populations. Despite the research advances, the underlying causes for the increased prevalence of autoimmune diseases in specific ethnic groups or geographic regions are still unknown. Scientists are actively engaged in investigating how social factors contribute to the severity and outcomes of diseases such as lupus (25). The goal is to investigate the factors contributing to racial disparities in autoimmune diseases and improve the well-being of patients and their families by enhancing the accuracy of diagnosis and improving treatment options.

3. Illnesses and conditions (other than autoimmune diseases)

Certain illnesses and conditions can increase the likelihood of developing an autoimmune disease. Examples of these conditions are high blood pressure, high cholesterol, and high CRP levels (CRP is an inflammation marker that has been associated with cardiovascular disease, heart attack, and stroke). These factors have been identified as possible risks for developing autoimmune diseases, such as arteriosclerosis and psoriasis (26, 27, 28).

Bullous pemphigoid has various triggers and risk factors, including neurologic diseases such as Parkinson’s disease, Alzheimer’s disease, epilepsy, and stroke. Nevertheless, the mechanisms behind these complex relationships are poorly understood and should be studied further (29).

Our understanding of cancer’s role as a risk factor for the development of autoimmune diseases is still poor. Specifically, the association of bullous pemphigoid and different cancer types (kidney, laryngeal, blood) has been controversial (29). Another example is the relationship between vitiligo and melanoma, which remains unclear (30, 31).

Reduce your risk

If you have an autoimmune disease, talk to your doctor about ways to minimize flare-ups, effectively manage existing diseases and conditions, maintain a balanced diet, and adopt a healthy lifestyle. Remember that autoimmunity is a multifaceted condition triggered by tightly connected factors. However, belonging to a specific group or ethnic background and having the mentioned illnesses or conditions does not imply the development of an autoimmune disease.

About the Author

Damiana Chiavolini, MS, PhD is a freelance writer who specializes in medical and life science topics. As a trained researcher, she authored journal articles in the areas of infection and immunity and wrote booklets and book chapters about different diseases. As a professional communicator, she writes feature articles for magazines and other publications and produces content for higher education platforms. Damiana is also an experienced academic editor, microbiology educator, writing coach, and fragrance blogger. She is a contributing member of the American Medical Writers Association and the immediate past-president of the association’s Southwest Chapter.

Carolyn Serraino

See Full Bio