Immune System & Autoimmunity
IMMUNE SYSTEM
- White blood cells (leukocytes) - responsible for protecting your body from infection. They circulate in blood and lymph.
- The spleen - a fist-sized organ in the upper left side of your abdomen, next to your stomach and behind your left ribs. Mainly act as blood filter.
- The bone marrow - The soft, spongy tissue that has many blood vessels and is found in the center of most bones. Makes nearly all the components of your blood (red blood cells, leukocytes and platelets).
- The lymphatic system - carries lymph instead of blood. Lymph carries immune-related cells.
- The thymus - pyramid-shaped lymphoid organ that is immediately beneath the breastbone at the level of the heart. Primary function to facilitate the maturation of T-cells.
- The tonsils, adenoids and appendix - these are gateways for pathogens to enter the body, so lymphoid tissue is also there.
WHAT IS LYMPHATIC SYSTEM?
Lymphatic system is a part of our immune system. It forms a network similar to the blood vessels. Immune-related cells circulate in this system through a liquid called lymph that carries them to areas that need them. Leukocytes are stored in lymphoid organs. These include the thymus, the spleen, the bone marrow, lymph nodes, and the tonsils, adenoids and appendix.
- Innate Immunity
People are born with some level of immunity that will attack invaders from day one. This innate immunity includes the first line of defense against pathogens such as the skin, mucous membranes, and some immune cells that consist of granulocytes (i.e., neutrophils, eosinophils, and basophils), mast cells, monocytes, macrophages and dendritic cells.
It responds in the same way to any type of unwanted substance, therefore its mechanism of action is referred as nonspecific. The word nonspecific might be confusing for some people, but it will make more sense when this immunity is compared to adaptive immunity.
- Adaptive Immunity
Adaptive immunity can also be viewed as immunity that a person acquires as he/she adapts through his/her life. This is measured by the range of antibodies to different pathogens that they develop. The development of antibodies can happen in two ways.
To begin with, it can occur naturally as in by the work of B lymphocytes after exposure to various diseases. One B lymphocyte can only make one specific antibody. To illustrate, one might make an antibody against the bacteria that cause pneumonia, and another might recognize the common cold virus. Keep in mind that antibodies lock on to the antigen but do not kill it. They only mark it for death. The killing is the job for other cells, such as phagocytes.
In addition, antibodies can also be developed through the utilization of vaccinations. Vaccines contain weakened or dead bacteria or viruses, or even just a few proteins or sugars from their surface. This is because those proteins or sugars are what antibodies will bind to.
- Passive Immunity
This is a temporary type of immunity that derives from another person. For instance, a new-born receives antibodies from the mother through the placenta before delivery and in breast milk following delivery. This passive immunity protects the infant from some infections during their early life.
HOW DOES IMMUNE RESPONSE WORKS?
Our immune system recognizes two types of danger signals with induction of an innate and then adaptive immune response. Those two signals are danger-associated molecular pattern (DAMPs) and pathogen-associated molecular pattern (PAMPs). DAMPs are cell-derived and released as endogenous danger signals that alert the innate immune system to unscheduled cell death, to microbial invasion and in response to stress. On the other hand, PAMPs are derived from microorganisms, which means they are present in diverse organisms but absent in our body. PAMPs provide exogenous danger signals that alert the immune system to the presence of pathogens, thereby promoting immunity.
Endogenous and exogenous here simply refer to their origin where 'endo' means inside while 'exo' means outside. Most DAMPs and PAMPs bind to specific receptors called pattern recognition receptors (PRRs) which are borne by some innate immune system cells as well as many epithelial cells. The activation of these PRRs promotes inflammatory cytokine expression and antimicrobial pathway that are required for microbial clearance. In case of persistent antigen invasion, further signals are transmitted to drive adaptive immunity.
4 VITAMINS AND SUPPLEMENTS TO STRENGTHEN IMMUNE SYSTEM
- Vitamin C
Vitamin C is a powerful antioxidant, anti-inflammatory and can strengthen our immune system. Plus, it speeds up wound-healing and is great for skin. However, human can't either manufacture or store it in the body. Furthermore, it gets rapidly used up during infection and when under tremendous stress. Therefore, a good dose to start taking vitamin C is 500mg two times daily for maximum absorption.
- Vitamin D
Vitamin D is able to enhance our innate immune system in killing bacteria and viruses. It does this by directly impacting the function of monocytes, macrophages, and dendritic cells, as well as the secretion of related cytokines. In addition, it can reduce the frequency of upper respiratory infections.
In contrast, low vitamin D has also been correlated with a higher incidence of autoimmune disease like multiple sclerosis. It is suggested to start with 1000 to 2000 international units per day, taken with a meal.
- Zinc
Zinc is needed in trace amount which, when taken, gives crucial effects on the effectiveness of the cells and cytokines of our innate and adaptive immune systems. Furthermore, it aids in fighting viruses and protects us from free radical damage to our cells.
It has also been shown to shorten the duration of a cold when given as a supplement. Zinc is recommended to be added in 15 to 30mg daily, especially at the first signs of cold or flu.
- Curcumin
Curcumin is traditionally known for its anti-inflammatory effects, and now, has been shown in the last two decades to be a potent immunomodulatory agent that can modulate the activation of T cells, B cells, macrophages, neutrophils, natural killer cells and dendritic cells.
Other than that, it also improves the health of our gut bacteria, which adds to our overall immune health. Curcumin best be taken 1000mg per day with food as it is not absorbed well in the body.
WHAT IS AUTOIMMUNITY?
If an immune response from a healthy immune system fundamentally targets antigens, or faulty or dead cells, then immune responses in autoimmunity attacks healthy cells, tissues and other normal body constituents instead. This may sound alarming, but autoimmunity is actually quite common. Problem will only arise if a disease is caused by this type of immune response, which is termed as an "autoimmune disease". However, how do we determine if one has autoimmunity or not?
Autoimmunity refers to the presence of antibodies and T cells that react with autoantigen, which is usually a normal protein or complex of proteins that is produced endogenously. Those antibodies and T cells are generally termed as autoantibodies and autoreactive T cells respectively. Autoimmunity is widely determined through Antinuclear Antibody (ANA) test, using autoantibodies as the biomarker. The result that will come up from the test will either be negative or positive.
Negative result means that antinuclear antibodies were not found in your blood, and you're less likely to have an autoimmune disorder. However, it does not definitely rule out that you won't have autoimmune disease. Conversely, positive result means that antinuclear antibodies were found in your blood. You will then be more likely to undergo more tests for further diagnosis. To make a note, it is called 'antinuclear' because it targets the nucleus of the cells.
The reason why autoantibodies is usually used as the biomarker is because using autoreactive T cells in clinical laboratory is much more complicated to test for.
WHAT ARE THE COMMON AUTOIMMUNE DISEASES?
- Type I Diabetes
Insulin is a type of hormone produced in our body to regulate blood sugar levels. It is produced by cells in the pancreas. However, in type I diabetes, the immune system attacks and destroys those cells, inhibiting the production of insulin.
The outcome of this disease is having high blood sugar levels, which can result to damage on the blood vessels and organs, including the heart, kidneys, eyes and nerves.
- Rheumatoid Arthritis
Joints are the ones being attacked in this disease. The symptoms include redness, warmth, soreness, and stiffness in the joints. Unlike osteoarthritis, which commonly affects people as they get older, rheumatoid arthritis can start as early as your 30s or sooner.
- Psoriasis / Psoriatic Arthritis
It is normal that your skin cells will grow and then shed when they're no longer needed. However, psoriasis causes skin cells to multiply too quickly. The extra cells build up and form inflamed, red patches, commonly with silver-white scales of plaque on lighter-toned skin. On darker skin, psoriasis can appear purplish or dark brown with gray scales.
Be noted that the complications don't stop there. Up to 30% of people with psoriasis also develop swelling, stiffness and pain in their joints. This is instead called psoriatic arthritis.
- Multiple Sclerosis
This disease will attack the protective coating of our neuron, namely myelin sheath. The damage to this coating will bring about the result of slow signal transmission speed between your brain and spinal cord, to and from the rest of your body. This leads to numbness, weakness, balance issues and trouble walking. According to a study in 2012, about 50% of people with multiple sclerosis need help walking within 15 years after the disease starts.
- Systemic Lupus Erythematosus
In the 1800s. lupus was first described as a skin disease because of the rash it commonly produces. However, there is a systemic form of this disease, which is most common, that actually affects many organs, including the joints, kidneys, brain and heart. The most common symptoms include joint pain, fatigue and rashes.
- Inflammatory Bowel Disease
Inflammatory bowel disease describes conditions that cause inflammation in the lining of the intestinal wall. Each type of inflammatory bowel disease affects a different part of the gastrointestinal tract. For example, Crohn's disease can inflame any part of the alimentary canal while ulcerative colitis affects only the lining of the colon and rectum.
- Addison's Disease
Adrenal glands are responsible for producing hormones cortisol, aldosterone and androgen. This disease will attack adrenal glands, thus affecting the production of said hormones.
Deficiency of aldosterone will lead to sodium loss and excess potassium in the bloodstream. Symptoms include weakness, fatigue, weight loss and low blood sugar.
- Grave's Disease
This disease attacks the thyroid gland in the neck, causing it to produce too much of thyroid hormones, which control the body's energy usage or familiarly known as metabolism. High level of these hormones revs up your body's activities, causing symptoms like nervousness, a fast heartbeat, heat intolerance and weight loss.
One potential symptom of this disease is bulging eyes, called exophthalmos. It can occur as a part of Grave's ophthalmopathy (which refers to any eye disease), which occurs in around 30% of those with Grave's disease, according to a 1993 study.
- Sjögren's Syndrome
This condition attacks salivary glands, the gland that provide lubrication to the eyes and mouth. The hallmark symptoms are dry eyes and dry mouth, but it may also affect the joints or skin.
- Hashimoto's Thyroiditis
Unlike Grave's disease, this disease slows down thyroid hormone production to a deficiency. Symptoms include weight gain, sensitivity to cold, fatigue, hair loss, and swelling of the thyroid, or in other words, goiter.
- Myasthenia Gravis
In this disease, the communication from nerves to muscles is impaired as nerve impulses that help the brain control the muscles are affected. Due to this, signals can't direct the muscles to contract. The most common symptom is muscle weakness, which worsens with activity and improves with rest. Muscles that control eye movements, eyelid opening, swallowing, and facial movements are often involved.
- Autoimmune Vasculitis
Autoimmune vasculitis happens when the immune system attacks blood vessels. The inflammation that results narrows the arteries and veins, allowing less blood to flow through them.
- Pernicious Anemia
The intrinsic factor, a protein made by stomach lining cells, needed for the small intestine to absorb vitamin B12 from food is caused to insufficient. Anemia will be developed and the body's ability for proper DNA synthesis will be altered with lack of mentioned vitamin. It is more common in older adults.
- Celiac Disease
People with celiac disease can't eat foods containing gluten, a protein found in wheat, rye and other grain products. This is because the immune system attacks the small intestine and causes inflammation when gluten is in the intestine. It affects about 1% of people in the US according to a 2015 study.
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