Immune System – Disorders, Genetics, Diagnosis, Treatment

The immune system is comprised of organs, cells, and specialized tissue. (1) In the human body, the immune system weighs about two pounds. It is considered a diffuse organ, meaning it is the body’s defense system.

Cells (lymphocytes) and antibodies (molecules) that monitor the identity of the body comprise the immune system.

When pathogens- bacteria and viruses, invade the body, the immune system’s defense system goes into action. It is programmed to recognize the “normal” in the body from the invaders.

The cells and molecules of the immune system reach most tissues through the bloodstream, entering the tissues by penetrating the walls of the capillaries.

They move about the body, patrolling it for foreign agents, and then return to the lymphatic system, a vascular system of their own. (2)


Daily, the body is exposed to dangerous organisms. These organisms threaten the body, risking its wellbeing. Mucous membranes like the skin, throat, and nose are the entry points for these organisms.

The immune system’s function is to assure that the body’s organs, tissues, and cells stay safe from these organisms.

The immune system is a host defense system. In other words, the immune system response is to “meet” and “kill” these hazardous organisms that enter the body. The immune system’s role is to eliminate toxic and allergenic substances that enter through mucosal surfaces.

The immune system recognizes and reacts to invading pathogens foreign to the body and fights the foreign agent.

Through an interactive network of lymphoid organs, cells, humoral factors, and cytokines, the immune system protects the body from infection and disease. (3)

Its host defense system works through pattern recognition. (4)

When its network recognizes an invader, it starts to attack the invader, eradicating pathogens and casual molecules.

If the network fails, it is programmed for a repeat attack. It is the immune system’s effector mechanisms that destroy a vast range of microbial cells and clear a broad range of toxic and allergenic substances. (5)

Immune system disease causes

When the immune system attacks the body, autoimmune disease results. There are over 80 different autoimmune disorders. Causes of autoimmune disease include:

  • Genetics (6)
  • Environmental factors (7)
  • Western Diet (8)
  • Possibly hygiene (9)

Some studies conclude that women are more susceptible to autoimmune diseases than men. The study claims that autoimmune diseases in women are about 2 to 1 compared to men. Research also shows that some autoimmune diseases like lupus are more common in certain ethnic groups. (10) (11)

Immune system disorders and genetics

Research has linked genetics and certain autoimmune diseases. Technical advances have advanced human genetics tremendously. High-risk genes are identified through entire genome scanning, a technology that is just a few years old. (12)

The ability to scan the entire genome has brought to light new information on the link between genetics and autoimmune disease. (13)

Research shows autoimmune disorders have a complex genetic basis; multiple genes contribute to disease risk, each with generally modest effects independently. (14)

Researchers conclude that common genes underlie multiple autoimmune disorders like multiple sclerosis and lupus. (15)

Immune system disorders and environmental factors

Viruses, bacteria, and infectious pathogens can trigger autoimmunity. In autoimmune pathology, multiple arms of the immune system may be involved. (16)

Chronic inflammation is an autoimmune reaction associated with autoimmune disease. When the anti-response system of the body is impaired, inflammation results. Inflammatory autoimmune diseases include rheumatoid arthritis and lupus. (17)

Inflammation is a common symptom of infectious diseases. Bystander activation’ describes an indirect or non-specific activation of autoimmune cells caused by the inflammatory environment present during infection. (18)

Immune system and diet

Nutrition is crucial for a healthy immune system. A balanced diet high in fruits and vegetables helps to supply the body with proper nutrition and boost the immune system. (19)

The following foods are said to keep the immune system strong; however, a balanced, healthy diet is crucial.

  • Citrus fruits
  • Broccoli
  • Red bell peppers
  • Yogurt
  • Spinach
  • Turmeric
  • Ginger
  • Papaya
  • Almonds
  • Green tea
  • Poultry
  • Shellfish
  • Kiwi
  • Sunflower seeds

Immune system disease and diet

Nutrition is a critical determinant of immune responses. (20)

Diet can help to ease symptoms and reverse the damage of many of the 80 autoimmune diseases. With immune system disorders and disease, diets high in fat, sugar, gluten, and sodium need to be restricted. Experts suggest a plant-based, whole food diet to keep the body balanced, relieve symptoms, and reverse the damage. (21) (22) (23) (24)

According to a 2001 study released in the journal Rheumatology, a vegan and gluten-free diet can significantly improve rheumatoid arthritis signs and symptoms. (25)

With an autoimmune disease, it is necessary to keep inflammation down, a common symptom of immune system diseases and disorders. Cytokines’ balance is essential to support autoimmune disease. (26)

Cytokines, small secreted proteins released by cells, have a specific effect on the interactions and communications between cells. (27)

Again, a plant-based diet helps to support healthy cytokines. Both omega-3 and omega-6 fats are precursors in the production of new cytokines. (28) (29) (30)

Most common immune system diseases & disorders

A healthy immune system fights infection and disease. When the immune system is unhealthy, illness and disease can result.

The primary parts of the immune system are white blood cells, antibodies, the complement system, the lymphatic system, the spleen, the thymus, and the bone marrow.

The immune system distinguishes between normal, healthy cells and unhealthy cells. Unhealthy cells are recognized by infection or cellular damage due to non-infectious agents like cancer or sunburn.

When cells are under attack or die in vivo, the immune system is alert. The host evolved mechanisms detect the death of cells and rapidly work to determine the nature of their demise.

If cells have died due to violence or disease, both defense and repair mechanisms are mobilized in the host. (31)

When the body suffers from immune system disorders, abnormally low activity or overactivity of the immune system results.

Overactivity and under-activity immune system disorders:

Allergic diseases

Allergic diseases are common and include allergies to foods, stinging insects, sinus disease, hay fever, anaphylaxis, medications, asthma, dermatitis, hives, and eczema. (32)

Autoimmune disease

Autoimmune disease can be classified from common to rare.

These include:

Immunodeficiency is a term used for under activity of the immune system.

Underactivity of the immune system can:

  • Be inherited (33)
  • Occur due to medical treatment such as the body weakening through chemotherapy or corticosteroids (34) (35)
  • A result of another existing disease like HIV/AIDS or cancer (36) (37)

Common immune system disorder symptoms

John Hopkins Medicine lists the following common autoimmune disease symptoms:

  • Fatigue
  • Skin problems
  • Joint pain and swelling
  • Abdominal pain or digestive issues
  • Swollen glands
  • Recurring fever

The following symptoms are symptoms of possible immune system problems:

  • Cold hands
  • Bathroom problems
  • Dry eyes
  • Fatigue
  • Mild fever
  • Headaches
  • Rash
  • Joints ache
  • Patchy hair loss
  • Repeated infections
  • Sensitive to sun
  • Numbness and tingling in the feet and hands
  • Trouble swallowing
  • Unexplained weight change
  • White patches
  • Yellowing of the skin or eyes

Immune system disease diagnosis

Immune system diseases can be difficult to diagnose. An immune system disease is an autoimmune disease.

Typically, an autoimmune disorder is diagnosed by: (38)

  • Blood tests
  • Patient medical history
  • Physical exam

Auto-antibody tests

Some blood tests distinguish auto-antibodies in the blood. The immune system produces auto-antibodies and attacks the body’s cells, tissues, and organs.

Inflammation and organ function tests

Tests may be performed on the organs to determine if the organs are functioning correctly.

Immune system disease treatment

Immune system disease, i.e., autoimmune disease treatments include:

  • Hormone replacement therapy
  • Enzyme replacement therapy
  • Corticosteroids

Immune disorders and exercise

Various studies find that exercise induces a physiological change in the immune system. It is thought that exercise can be employed as a model of temporary immunosuppression that occurs after physical stress. (39)

Fatigue is among the most common symptom of immune system disorders. According to ScienceDirect, moderate exercise enhances gene expressions for receptors detecting muscle metabolites of chronic fatigue syndrome patients, worsening symptoms after exercise. (40)

Immune system disorder patients need to consult with their doctors to discuss an exercise routine that is suitable for their specific disorder. Typically, gentle exercise, like walking, is recommended.

Immune system and cigarette smoking

Smoking weakens the immune system, leaving the body at a higher risk for illness and disease. (41)

Diseases associated with tobacco smoking include cancer, heart disease, lung cancer, and stroke. (42) (43)

Antibodies are damaged and destroyed with smoking, leaving smokers fewer antibodies to help ward off infections and sickness. Antioxidants like vitamin C are also destroyed by smoking. (44)

The immune system’s response to fighting off an infection is weaker, therefore, less effective. However, according to Nature Reviews, there is evidence that smokers have a lower incidence of some inflammatory and neurodegenerative diseases. (45)

While nicotine suppresses the immune system, it is said that it may have therapeutic potential as a neuroprotective and anti-inflammatory agent.


The immune system is a diffuse organ, meaning it is the body’s defense system. Its role is to respond to and fight, threatening organisms that enter the body through mucous membranes. Cells called lymphocytes, and antibodies, called molecules patrol the body to identify harmful pathogens, also called viruses and bacteria.

When the body is under attack, the cells and molecules fight the invaders. If a first attack fails, a repeat attack is programmed. When the immune host defense system fails, it can’t recognize functional cells and tissues, as well as organs from normal, or healthy.

When this occurs, the cells and antibodies can start to attack the body, resulting in autoimmune disease. Nutrition is a crucial factor for a healthy immune system. Research shows that food can ease the symptoms, as well as reverse the damage of some disorders.

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