A lymphocyte is a type of white blood cell which is usually found in the lymph, hence the name. It is the part of an immune system and includes 3 subtypes: B lymphocytes, T lymphocytes, and Natural Killer (NK) cells. They protect us from diseases and infections and serves as a barrier for all the foreign substances. B lymphocytes respond to pathogens with the production of antibodies. T lymphocytes have two types of cells: CD4+ or T helper cells which produce cytokines that lead to immune system activation, and CD8+ or cytotoxic T cells which respond creating enzymes in the form of granules that destroy the bacteria and viruses. NK cells are natural killer cells that act in a way where they distinguish the infected versus the normal cell through MHC (major histocompatibility complex) I on the cell membrane and kills the abnormal cell. Therefore, they do not need the activation of the other parts of the immune system, the lack of MHC I is sufficient.
The range between 15% to 40% of white blood cells belongs to lymphocytes. Lymphocytopenia or low lymphocytes count below 15% or 1000/μL. It can be a serious condition leading to severe infections due to reduced immune system and low antibodies and cytokines. Since they originate from bone marrow, a lot of processes that affect this tissue can result in low lymphocytes. There are numerous conditions, where we will list some of the most common ones.
Aplastic anemia is a disease which affects bone marrow. It represents in a deficiency of the three blood cells: white blood cells (leukopenia), red blood cells (anemia) and platelets (thrombocytopenia). When all three types of blood cells are missing, it is called by pancytopenia. It can be inherited and acquired type of aplastic anemia. The inherited one is also named as Fanconi anemia. With shutting down the production of the blood cells, it can result in various symptoms which reflect in every type of cell loss. For the white blood cells, the most frequent signs are fever and infections. Anemia represents in fatigue, weakness, pale skin, chest pain, headaches. Low count of platelets is associated with bleeding and bruising. Acquired type of aplastic anemia can be caused by radiation and chemotherapy, drugs, viral infections, toxins, autoimmune disorders and some unknown causes. It is more common in younger people in their early 20s or in elderly.
Treatment. It can be a life-threatening disease, so the therapy is considered very seriously. It usually involves blood transfusions including red blood cells and platelets. Other treatments include stem cell transplant, where if the donor can be found, first the recipient undergoes radiation and chemotherapy to get ready for receiving donor stem cells. After that, they migrate into the bone marrow and induce new cell production, resulting in normal cells. There are also treatments with immunosuppressants, antibiotics, and other drugs.
Some viral infections can cause low levels of lymphocytes such as AIDS, hepatitis or infections like tuberculosis. AIDS is the disease which is caused by HIV virus. It affects the immune system by destroying CD4+ T lymphocytes and reduces the function of the defense system. The name stands for human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS). The presence of pneumocystis pneumonia and other respiratory diseases accompanied with esophageal candidiasis and cachexia may indicate the presence of AIDS. It is associated with viral-induced cancers like Kaposi’s sarcoma, Burkitt’s lymphoma, and cervical cancer.
Treatment. The treatment depends on the cause. A doctor can administer drugs such as antibiotics, antiviral drugs, antifungal medications and other symptomatic therapy.
There are some autoimmune diseases which are linked to low lymphocytes count such as systemic lupus erythematosus, multiple sclerosis, rheumatoid arthritis and others. Multiple sclerosis attacks the myelin which insulates the nerves and enables the communication of the nervous system. Nerve damage progress over time and it results in weakness, tiredness, blurred vision, numbness, tingling sensations, cognitive problems, tremor. Lupus is an immune disorder which affects the tissue with swelling, inflammation and pain. It can express with fever, rash, pain, fatigue and other symptoms depending on the affected tissue. It happens due to an antibody-antigen complex concentration which activates the compliments and causes inflammation.
Treatment. Treatment for lupus depends on the damage of the tissue. They are aimed at improving the lives of the patient and reducing the onset of symptoms. They include anti-inflammatory drugs, corticosteroids, immunosuppressives, antimalarial drugs and some lifestyle changes. Multiple sclerosis has no cure. It can include drugs that can calm down the manifestation of the disease such as corticosteroids, muscle relaxants, physical therapy, plasma exchange, and some specific medications.
There are some cancers which can affect the bone marrow and result in lymphocytes reduction. Lymphoma, acute lymphoblastic leukemia, and chronic lymphocytic leukemia are the ones affecting lymphocytes. They can express in weakness, fatigue, frequent infections, weight loss, fever, enlarged lymph nodes. It is important to diagnose it early in order to treat it as soon as possible.
Treatment. The patients suffering from leukemia have to undergo radiation and chemotherapy. There are also bone marrow transplantation and stem cells transplants. The staging is very important at the start of the treatment.
Some drugs can cause lymphocytes drop. When taking some of these medications, it is important to count the number of the cells and to constantly track the range. It can be alarming if not treated early and if the condition progresses. It is important to have regular check-ups and appointments at your doctor’s office. If the treatment results in lymphocytes count drop, the doctor may exclude the drug choice and replace it with another one. Steroids are known to cause lymphocytes decline. There are also some side effects with the hormonal activity which stimulates the cortex of the adrenal gland, which can cause low lymphocytes levels as well.