The immune system and how to strengthen it

Immune system is very vital for survival because without it, the body will be exposed to attacks from bacteria, parasites, viruses and so on. In this interview with GERALDINE AKUTU, Dr. Obiefuna Ajie, Chemical Pathologist/Lecturer at the College of Medicine, University of Lagos sheds light on the immune system, how it functions and ways to keep it healthy.

How does the immune system work?
The immune system works in a coordinated pattern to protect the human body from various attacks ranging from different infections to malignancies (cancer). This is achieved through secretion of chemicals that is able to kill or neutralize offending agents.
 
The immune system is composed of two types, the first is Non-specific type (innate) — this is generalized immune response and often is the first line of the body’s reaction to foreign body attack. This includes physical barriers like skin and mucous membranes with their secretions that may be able to stop foreign invaders. There are also cells like the natural killer cells that are readily protective and acts immediately when the body tissues are invaded by taking the agent in whole or by secretions, which can digest the foreign body.
 
The second is the Specific type (Acquired) – Fights specific infection or cancer cells after an initial sensitization. The lymphocytes present in the blood belong to this class. There are two types: the B lymphocytes, which essentially secrete antibodies to fight foreign bodies (humoral response) and then the T lymphocytes (cellular response), which act by secreting chemicals, engulfing foreign bodies and also increasing signals to other cells, which can help increase the capacity of the body to fight the foreign invaders. The lymphocytes are produced from the bone marrow. However, the T lymphocytes need to get primed in the thymus gland to carry out their functions.

What makes a person immune to diseases?
This can only be when the immune system of an individual is intact and is adequately primed to deal with the disease. There should be proper coordination among the different cells involved in the immune response and also have the capacity to generate the different chemicals or signals involved in eliciting the expected immune response.
 
Some disease conditions can easily be curtailed when low dose amount of the invading organisms enters the body. This can be seen in some bacterial infections. The human body can be stimulated to produce adequate protective mechanism before the organism is encountered. This is the technique used in vaccination against specific diseases like polio. In some situation, the immune system is unable to destroy invading organism.
 
The organism persists and could cause disease state such as seen in HIV infection. When the immune system fails to protect against disease conditions, then drug therapy to control the disease or protect the body against the effect of the disease state is carried out.

When and why does the immune system malfunction?
The immune system malfunctions due to the presence of particular disease condition (Either from birth or later acquired in life), human body unable to produce the cells involved in immune response, human body unable to produce the right or adequate signals to different cells involved in immune response and misinterpretation of generated signals to propel immune response. The above mentioned can be seen in extremes of age, malnutrition, poor lifestyles like smoking, excessive alcohol intake, poor sleep pattern, lack of exercise and excessive weight gain.

What natural foods boost immunity
These are essentially food, which you do not have to cook or require light cooking such as fruits and vegetables, like citrus fruits, spinach, tomatoes, pepper, ginger and almond. These contain vitamins such as vitamin C and E, which are vital for proper immune function. A balanced diet is a requirement for normal function of the human body.
 
However, our diet in this environment may be limited either out of ignorance or inability to get the right food combination. The use of supplement has helped to bridge this gap. These supplements often contain microelements and vitamins, which help the immune system function.
 
In some disease states, specific immune associated chemicals such as interferons can be genetically engineered and then administered to help in immune function such as in hepatitis B infection.

Loss of sleep depresses immunity because this causes increase in the level of stress hormones such as cortisol, which depresses production, maturation and function of cells involved in immune response. Also, good sleep period allows for the body to regenerate weak and dying cells.

What is auto-immune disorder?
This is a medical condition in which the immune system of an individual begins to attack the tissues of the body. The immune system views specific tissues of the body as foreign and so attacks and destroys those tissues. In normal situation, the immune system recognizes the tissues of the body through the mechanism of immune tolerance. However, this mechanism malfunctions due to genetic, disease or unknown reasons. Cells of the body that can be attacked include the thyroid gland (which can later cause hypothyroidism) or collagen of connective tissues, which can cause specific organ damage or generalized tissue damage involving various organs of the body. These conditions will require various investigations, which will be evaluated by professionals in that field.

What are the Medicare and lifestyle pattern to nurture the immune system?
A good and functional immune system requires Healthy living – Moderate food intake to maintain healthy weight, regular exercise, avoid smoking and excess alcohol, vaccination at the right time and go for periodic health checks to detect disease conditions early which may later affect the immune system function.