When Your Immunity Turns On You: What Are Autoimmune Diseases?

A healthy body is genetically programmed to fight off infections. The system involved in this function is known as the immune system.

The detection of foreign pathogens like bacteria, viruses, fungi, parasites etc is most incredible in the human body.

This complex system works more often than one would think. In our day-to-day activities, there are various opportunities for pathogens to enter the body.

Infection is most commonly spread when your hands touch an infected surface and then your face. Although the immune system can easily fight off small infections, if it fails to do so, this same infection could multiply and advance to be very harmful.

When the immune system fails, the condition is known as autoimmune disease.

When this happens, the immune cells fail to recognize and differentiate between the cells that belong to the pathogen and the ones that belong to the human body.

As a result, the system “turns on you” as it starts to attack all the cells present at the site, including healthy body cells, and the body weakens.

Causes

Numerous factors contribute to this failure. Scientists believe that the autoimmune disease is highly linked to genetics.

It could also be caused by the combination of environmental factors and genetics.

For example, the body possesses a gene which can cause mutations and abnormalities in the immune system but the gene is still inactive.

Environmental factors like smoking, drugs, toxic agents, dietary supplements, etc. could trigger and activate this genetic mutation.

Smoking- one of the biggest environmental trigger of autoimmunity  Credits: unsplash

How The Immune System Destroys Body Cells

The end result of autoimmunity is the failure of the immune cells to differentiate. However, there is no one fixed mechanism for this occurrence.

⦁ Antigen is a substance which induces or stimulates the immune cells to produce antibodies, proteins that bind to the pathogens like bacteria and viruses and defend the body against this invasion.

Antigens are present on the surface of pathogens and human body cells (self antigens). They are known as markers because immune cells use it to identify and differentiate between the host cells and the foreign cells.

However, if one has autoimmune disease, the immune cells lose their mechanism to identify self antigens present on the surface of body cells and start attacking it instead.

This leads to diseases like rheumatoid arthritis (bone disease), multiple sclerosis (neurological disease) and psoriasis (skin disease).

⦁ Another cause for destruction of self antigens by the immune cell is the failure of the activation induced cells death (AICD). In this process, when immune cells like T cells become old and are unable to efficiently perform its function, it undergoes apoptosis (cell death).

This failure of AICD leads to the destruction of self antigens by worn-out dysfunctional immune cells and leads to autoimmunity.

In most cases, once the immune cells start attacking the body cells, it releases cytokines. This substance causes inflammation and pain in the body, especially in joints.

pain as a symptom of autoimmune disease  Credits: unsplash

Symptoms

The following symptoms are observed in most autoimmune diseases patients at the early stages: ⦁ Muscle ache ⦁ Fatigue ⦁ Swelling ⦁ Redness ⦁ Rashes ⦁ Numbness and tingling sensation

Most Common Autoimmune Diseases

They are the following:

⦁ Systemic lupus erythematosus (SLE)

It is the most common type of lupus. In this condition, the immune cells randomly attack any part of the body cells and is very unpredictable.

Outer myelin sheath covering of nerve cells  Credits : pixabay

⦁ Multiple sclerosis

The outer protective layer of nerve cells is known as myelin sheath. This condition occurs when the immune system attacks this protective lining and causes problems in the transmission of signals in the nervous system.

⦁ Type 1 diabetes

The immune cells attack the endocrine function of the pancreas. They are responsible for producing insulin, hormones that keep the sugar levels in the blood in check.

Thus, the condition leads to high blood sugar known as diabetes.

weight loss due to Addision’s disease  Credits: unsplash

⦁ Addison’s disease

In this condition, the cells of the adrenal glands are attacked. As a result, the hormones responsible for storing glucose and carbohydrates are not produced.

Moreover, it leads to the deficiency of sodium and excess of potassium, causing weight loss, tiredness, low blood sugar and fatigue.

⦁ Rheumatoid arthritis (RA)

The immune cells attack the joint: the tissue lining and synovial fluid, causing proliferation and inflammation in the joints. This leads to redness, stiffness and pain.

⦁ Celiac disease

Gluten is a type of protein found in rice, wheat and rye. In this condition, when gluten enters the small intestine, it serves as an environmental factor that triggers autoimmunity.

As a result, the immune cells attack the digestive tract and cause inflammation.

caption: ointment for psoriasis on hands  Credits: pexel

⦁ Psoriasis

In normal conditions, skin cells grow consistently over time and replace old skin cells that fall off. However, in psoriasis, the immune cells attack skin cells and as a result, they grow rapidly and inconsistently to make up for the loss.

The extra build in the skin is followed by inflammation and redness.

⦁ Inflammatory bowel disease

A disease where immune cells attack the cells of the tissue lining of the intestinal wall and cause inflammation.

Bottom Line

Most autoimmune diseases are specific, meaning they will most likely target an organ or function and there are numerous different mechanisms that lead to autoimmunity.