Autoimmune diseases are a spectrum of diseases that occur due to dysfunction in the way the body regulates its defense system. To better understand what autoimmune diseases are, let’s briefly look at what the immune system does and how its defensive function can be dysregulated in autoimmune diseases.
So What’s The Immune System?
The immune system is the body system that works to protect us against falling sick. It comprises different kinds of white blood cells and other cells found in specialized body tissue such as blood, skin, and elsewhere that work to protect us against disease. Some of the cells in the immune system produce antibodies that attack infectious organisms in our bodies. The other cells may directly attack and kill disease-causing organisms or protect us from foreign bodies that cause us to fall ill. When disease occurs, our immune systems are critical in helping to fight it off and helping recovery. As a result, we must have a well-functioning immune system as it is often the difference between staying healthy most of the time and falling ill frequently.
That’s great. But what could go wrong?
Well, here’s the snag. A part of the way the immune system protects you from disease is to detect the presence of foreign bodies in your system and attack it. By this function, the immune system protects the body from the disease-causing effects of those foreign bodies. However, where this process can go wrong is where the immune system attacks the body’s cells and tissues. Fortunately, this is not very common due to a process called tolerance. Tolerance is the immune system’s non-responsiveness (that is, it will not attack) the body’s tissues. Tolerance is developed during the early phases of life, and the protective effect usually lasts for life. However, despite this, sometimes for a variety of reasons, the body’s immune system may become sensitized to and consequently attack the body’s normal cells and tissues, usually resulting in what is described as an autoimmune disease.
So How Does Autoimmunity Develop?
There are some possible ways by which autoimmune diseases develop. Below we will look at some examples of these:
Genetic
Some autoimmune diseases have a genetic basis. They are due to the presence of what are known as susceptibility genes. Some genes are associated with autoimmune disease, and the best example of this is the Human leukocyte antigen (HLA) genes. HLA-27, in particular, is known to be strongly associated with the condition known as Ankylosing spondylitis.
Defective Tolerance
As stated earlier, the body cells are protected from attack by the immune system in a process called tolerance. This tolerance process may be defective in some cases, and as such, the protection against attack the body cells enjoy becomes compromised. Consequently, autoimmune disease may develop.
Abnormal Display Of Self-Antigens
These antigens, which belong to the body cells but are usually not displayed, may attract the notice of the immune cells and consequent attack.
Inflammation
Inflammation can also play a role in the development of an autoimmune response.
Dysfunction Of Regulatory Mechanisms
The body regulatory mechanism on the immune cell actions can be compromised, resulting in autoimmune disease.
Sex
Females are also more predisposed to having autoimmune diseases than males are. What are examples of autoimmune disease? Usual examples of autoimmune diseases include the following:
- Type 1 Diabetes Mellitus
- Rheumatoid Arthritis
- Psoriasis
- Multiple Sclerosis
- Systemic Lupus Erythematosus
- Inflammatory Bowel disease
- Graves’ disease
- Sjogren’s Syndrome
- Hashimoto Thyroiditis
