What Is Immunology?
Immunology deals with the study of the immune system and is an important area of medical and biological study. Through its various defense mechanisms, the immune system protects us from infection. When the immune system is malfunctioning, it can lead to diseases such as autoimmunity, allergies and cancer. Immune responses may also contribute to many common disorders not traditionally regarded as immunologic, such as metabolic, cardiovascular, and neurodegenerative conditions, such as Alzheimer’s disease.
What Are Immunologists?
Scientists and clinicians who specialize in immunology are called immunologists. Immunologists typically work in laboratories that focus on research, either in academia or in private industry (for example, in the pharmaceutical industry). Clinical immunologists, on the other hand, specialize in diagnosing and treating diseases of the immune system, such as autoimmune diseases and allergies.
The Immune System
A complex system of structures and processes, the immune system protects us from disease. It consists of both molecular and cellular components. These components have two functions: nonspecific mechanisms, those that are inherent to an organism, and responsive responses, which are adaptive to specific pathogens. The study of fundamental or classical immunology involves the components of innate and adaptive immunity.
A person’s innate immunity is the first line of defense and is nonspecific. That is, no matter how different each potential pathogen may be, the responses are the same. Physical barriers (e.g. skin, saliva, etc.) and cells (e.g. macrophages, neutrophils, basophils, mast cells) are all part of innate immunity. During the first few days of an infection, these components are ready to work and protect an organism. In some cases, this is sufficient to get rid of the pathogen, but in other cases, the first defense becomes overwhelmed and a second line of defense is triggered.
The second line of defense is adaptive immunity, which involves the immune system building up memories of infections encountered so that it can mount an enhanced response specific to the pathogen or foreign substance. Antibodies are involved in adaptive immunity, which generally target foreign pathogens roaming free in the body. In addition, T cells attack pathogens that have colonized cells and can kill them directly or modulate the immune system.
A person with an immune system disorder is incapable of mounting a proper defense because of a problem with their immune system. Thus these disorders are almost always associated with severe infections that persist, recur, and/or result in complications, making them severely debilitating and even fatal. There are two types of immunodeficiencies: primary immunodeficiencies are typically present at birth, are generally hereditary, and are relatively rare. One example is common variable immunodeficiency (CVID). Generally, secondary immunodeficiencies develop later in life and may result from an infection, as is the case with AIDS following HIV infection.
Autoimmune diseases occur when the immune system attacks the body it is supposed to protect. Autoimmune diseases are characterized by a defect that leaves patients unable to distinguish ‘secondary’ autoimmune diseases, which manifest later in life due to a variety of factors. Autoimmune diseases like rheumatoid arthritis and multiple sclerosis fall under this category. Similarly, autoimmune diseases can manifest locally, as in Crohn’s Disease affecting the GI tract, or systemically, as in systemic lupus erythematosus (SLE).
An asthma attack can be debilitating and even deadly. Normally, this occurs when the immune system reacts to particles inhaled from the air, and over time, it can lead to thickening of the airways. This is a common cause of illness, especially in children. The origin can be complex and poorly understood in some cases, although it often has an allergic component.
As a disease characterized by uncontrollable growth and proliferation of cells, cancer has a number of hallmarks, one of which is the ability for cancer cells to avoid being destroyed by the immune system. Scientists have begun to manipulate the immune system to defeat cancer (immunotherapy) after learning that evasion of the immune system contributes to the development of cancer. Cancer immunotherapy involves stimulating the body’s innate defenses against cancerous cells. It shows extraordinary promise as a new weapon in our arsenal against cancer. Another application of immunological knowledge against cancer involves monoclonal antibodies (proteins that find and directly bind to a specific target protein called an antigen. An example
is Herceptin, a monoclonal antibody used to treat breast and stomach cancer). In addition, a number of successful cancer vaccines have been developed, most notably the HPV vaccine.
Transplants involve the transfer of cells, tissues, or organs from one person to another. Immunity’s recognition of transplanted organs as foreign is the greatest barrier to transplants. It is essential to understand the mechanism and clinical features of rejection in order to determine a diagnosis, recommend treatment and develop new strategies and drugs to manage transplants.
Vaccines are agents that teach the body to recognize and fight infections caused by harmful pathogens, such as bacteria, viruses, and parasites. In the event of infection, vaccines act as a sneak preview of a specific pathogen, triggering the body’s immune system to prepare itself. A vaccine contains a harmless element of the infectious agent that stimulates the immune system to mount a response, starting with the production of antibodies. The immune system responds to the vaccine by making antibodies that are specific to the provoking agent as well as forming ‘memory cells’. Upon encountering an infectious agent a second time, these memory cells quickly produce enough antibodies to deal with the threat. The pathogens inside the body are eventually destroyed, preventing further infection. Thanks to the successful application of vaccines, several infectious diseases, including smallpox, measles, mumps, rubella, diphtheria, tetanus, whooping cough, tuberculosis, and polio, no longer pose a threat to Europe.
An antibody is a substance produced by your immune system. When you have allergies, your immune system makes antibodies that identify a harmless substance as harmful. Your immune system responds to an allergen by inflaming your skin, sinuses, airways, and digestive system. Food allergies can be prevented by avoiding certain foods. By experimenting with an elimination diet, you can determine what is causing your allergies. To avoid food allergies, read food labels carefully and ask questions when dining out.
Allergies can cause a variety of symptoms. The symptoms you experience depend on the type and severity of your allergy. Asthma, sneezing, itching, rashes, a runny nose, or sneezing can indicate allergies. Allergic reactions can be mild, moderate, or severe. Anaphylaxis, a severe allergic reaction, is life-threatening. Skin and blood tests are used to diagnose allergies. The treatments include allergy shots, medicines, and avoiding substances that cause reactions. Swelling, hives, nausea, fatigue, and more are all symptoms of food allergies. It can take some time for an individual to realize they’re allergic to foods. You should seek medical attention as soon as possible if you have a severe reaction after eating. The doctor can determine the cause of your reaction or refer you to a specialist if necessary.
Allergy symptoms can lead to many complications. Your doctor can determine whether you have a sensitivity or a full-blown allergy based on your symptoms. A doctor can not only help you manage your allergy symptoms, but also prevent the worst complications. Allergic reactions can range in severity from mild irritation to anaphylaxis, which can be life-threatening. Symptoms of most allergies cannot be cured, but there are treatments that can help you manage them. If you experience a severe allergic reaction (anaphylaxis), seek immediate medical attention. When epinephrine auto-injectors (Auvi-Q, EpiPen, etc.) are available, use them right away. Even if your symptoms improve after the injection, you should still go to the emergency room to make sure they do not return when the effects of the epinephrine wear off.
You should consult a doctor if over-the-counter allergy medications are not providing enough relief. If you experience symptoms after taking a new medication, contact your doctor immediately. You may have experienced an anaphylactic reaction or a severe allergic reaction in the past. Speak to your doctor if you have experienced any of these symptoms. Since anaphylaxis is a complicated condition, you should probably consult an allergist or immunologist. Often, allergy treatment involves prescribing an antihistamine to control symptoms. Both over-the-counter and prescription medications are available. Depending on the severity of your allergies, your doctor will tell you what is best for you.
As a branch of the medical and biological sciences, immunology focuses on the immune system and its function. The immune system defends us against infection through several lines of defense. Diseases, such as cancer and autoimmunity, can occur when the immune system is not functioning properly.
A physician specializing in allergies, asthma, and immunologic disorders, such as primary immunodeficiency disorders, is an immunologist (also known as an allergist).
You might be prescribed over-the-counter or prescription medications in the form of pills or liquid, nasal sprays, or eyedrops. Your doctor may suggest allergen immunotherapy if other treatments do not completely alleviate your allergies.
Immunodeficiency diseases and disorders occur when the immune system is not functioning normally. An immunodeficiency that arises from a genetic cause is called a primary immunodeficiency disease. Over 200 primary immunodeficiency disorders exist.
Asthma, familial Mediterranean fever, and Crohn’s disease (inflammatory bowel disease) are all caused by an overreaction of the immune system, while autoimmune polyglandular syndrome and some facets of diabetes are caused by the immune system attacking ‘self’ cells and molecules.