Lymphocytes are a kind of white blood cell. These essential cells circulate in blood and lymph fluid. They defend your body by attacking at the first sign of an invasion by harmful organisms. There are three main types of lymphocytes that work together to help identify and eliminate infections and other disease:.
Low levels of T cells or too few NK cells can lead to uncontrolled viral, fungal, and parasitic infections. B-cell lymphocytopenia can lead to an increase in harmful and different types of infections.
Lymphocytopenia may be a sign of an underlying illness, condition, or other factor. The majority of causes are acquired. This means that you develop rather than inherit them. T cells make up the greatest proportion of lymphocytes, and T-cell lymphocytopenia is the most common.
However, this condition can affect all three cell types. These can include:. Certain immunosuppressant medications that are used to treat autoimmune disorders may additionally cause lymphocytopenia. Viral, bacterial, parasitic, and fungal infections are a common cause of lymphocytopenia. Any type of serious infection may cause your lymphocyte count to fall.
For example:. Lymphocytopenia may be a sign of sepsis or acute bacteremia. The former is a severe infection that causes systemic inflammation, and the latter is a bacterial presence in the blood that could lead to sepsis. Both instances require urgent medical attention. Malnutrition or undernutrition is a common global cause of lymphocytopenia. This occurs because the body lacks protein and other nutrients that are necessary to produce lymphocytes.
An eating disorder, such as anorexia nervosa , may lead to reduced-production lymphocytopenia. These are generally referred to as protein-losing enteropathy and include:. According to research , a deficiency of the mineral zinc in your diet can weaken immune health by causing T-cell lymphocytopenia and other immune system dysfunction.
To defend the body adequately, a sufficient Many disorders can decrease the number of lymphocytes in the blood, but viral infections including AIDS and undernutrition are the most common. A blood sample is used to make the diagnosis of lymphocytopenia, but a sample of bone marrow or lymph node may be needed to determine the cause. Lymphocytes Lymphocytes One of the body's lines of defense immune system involves white blood cells leukocytes that travel through the bloodstream and into tissues, searching for and attacking microorganisms and The lymphocyte count is normally above 1, cells per microliter of blood 1.
A reduction in the number of lymphocytes may not cause a noticeable decrease in the total number of white blood cells.
All three types have important functions in the immune system Components of the Immune System The immune system is designed to defend the body against foreign or dangerous invaders. Such invaders include Microorganisms commonly called germs, such as bacteria, viruses, and fungi Parasites Too few B cells can lead to a decrease in the number of plasma cells, which produce antibodies.
Decreased antibody production can cause an increase in bacterial infections. People who have too few T cells or too few NK cells have problems controlling certain infections, especially viral, fungal, and parasitic infections. Severe lymphocyte deficiencies can result in uncontrolled infections that can be fatal. Various disorders and conditions, including infection with viruses such as human immunodeficiency virus Human Immunodeficiency Virus HIV Infection Human immunodeficiency virus HIV infection is a viral infection that progressively destroys certain white blood cells and can cause acquired immunodeficiency syndrome AIDS.
HIV is transmitted It causes a fever, runny nose, sore throat, cough, headache, muscle aches myalgias , and a general Lymphocytopenia can be. Certain viral infections such as influenza Influenza Flu Influenza flu is a viral infection of the lungs and airways with one of the influenza viruses.
In most people, the inflammation begins suddenly and lasts only a few weeks. Undernutrition Undernutrition Undernutrition is a deficiency of calories or of one or more essential nutrients. Undernutrition may develop because people cannot obtain or prepare food, have a disorder that makes eating or The risk for all-cause mortality with lymphopenia was more pronounced in participants aged 70 years or younger compared with those aged more than 70 years.
The absolute 2-year risk for all-cause mortality was highest in men and women who smoked, were aged at least 80 years, and had a lymphocyte count below 0. The study authors suggested that lymphopenia may be an indicator for frailty or lead to reduced immune surveillance. Read next. January 15, Receive an email when new articles are posted on. Please provide your email address to receive an email when new articles are posted on. You've successfully added to your alerts.
The innate immune system responds to pathogens in a generic way but does not have long-lasting protection. The adaptive immune system responds to pathogens by using memory from previous encounters of a pathogen [ 3 ].
One gene, LSP1 lymphocyte-specific gene 1 , is expressed in lymphocytes and other cells as well. LSP1 transduces signals between white blood cells [ 4 ]. Mature lymphocytes undergo programmed cell death. This helps preserve homeostasis and tolerance in the body [ 5 ].
T cells come from the bone marrow and mature in the thymus and sometimes the tonsils. Different types of T cells include killer, helper, regulatory, memory, and natural killer T cells. They destroy infected cells and help prevent autoimmune diseases. Inappropriate killer T cell activities can lead to the persistence of the pathogens or autoimmune disease [ 7 ].
They help with the activation of killer T cells, maturation of B cells, and secrete cytokines. They can only work when they are activated on the surface of antigen-presenting cells [ 8 ]. Helper T cells can be categorized into different groups based on their target pathogens, e. Th1, Th2, and Th Read this post to learn more about Th1 and Th2.
Regulatory T cells maintain tolerance, prevent autoimmune diseases, and limit inflammatory diseases. However, they also suppress immunity for certain pathogens and tumors [ 10 ]. Memory T cells live for a long time after an infection is over and help the immune system remember previous infections.
They rapidly multiply after re-exposure to previous infections. There are 3 types of memory B cells, including resident, central, and effector. Memory T cells are especially important for the development of vaccines [ 11 ]. Natural killer T cells help connect the adaptive with innate immune systems.
They can produce cytokines and regulate immune responses against autoantigens [ 12 ]. T cell deficiency can cause damage to the immune system.
Deficiency can cause hereditary conditions, severe fungal infections, cancer, and other chronic infections. T cell deficiencies are generally present in infants or toddlers [ 13 ]. B cells mostly function in the adaptive immune system.
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