Lymphocytopenia
Encyclopedia
Lymphocytopenia, or lymphopenia, is the condition of having an abnormally low level of lymphocytes in the blood. Lymphocytes are a white blood cell with important functions in the immune system. The opposite is lymphocytosis
, which refers to an excessive level of lymphocytes.
Lymphocytopenia may be present as part of a pancytopenia
, when the total numbers of all types of blood cells are reduced.
.
Lymphocytopenia, but not idiopathic CD4+ lymphocytopenia, is associated with corticosteroid
use, infections with HIV
and other viral
, bacterial, and fungal agents, malnutrition
, systemic lupus erythematosus
, severe stress
, intense or prolonged physical exercise
(due to cortisol
release), rheumatoid arthritis
, sarcoidosis
, and iatrogenic (caused by other medical treatments) conditions.
Lymphocytopenia is a frequent, temporary result from many types of chemotherapy
, such as with cytotoxic agents or immunosuppressive drugs. Some malignancies that have spread to involve the bone marrow
, such as leukemia
or advanced Hodgkin's disease, also cause lymphocytopenia.
Large doses of radiation
, such as those involved with nuclear accidents or medical whole body radiation, may cause lymphocytopenia.
. In adults, a lymphocyte level below 1,500 cells/microliter is diagnostic (proof of the condition), and in children, a lymphocyte level below 3,000 cells/microliter is diagnostic.
and Feline immunodeficiency virus
retroviral infections is treated with Lymphocyte T-Cell Immune Modulator
.
Lymphocytosis
Lymphocytosis is an increase in the number or proportion of lymphocytes in the blood, usually detected when a complete blood count is routinely obtained. Lymphocytes normally represent 20 to 40% of circulating white blood cells...
, which refers to an excessive level of lymphocytes.
Lymphocytopenia may be present as part of a pancytopenia
Pancytopenia
Pancytopenia is a medical condition in which there is a reduction in the number of red and white blood cells, as well as platelets.If only two parameters from the full blood count are low, the term bicytopenia can be used...
, when the total numbers of all types of blood cells are reduced.
Classification
In some cases, lymphocytopenia can be further classified according to which kind of lymphocytes are reduced. If all three kinds of lymphocytes are suppressed, then the term is used without further qualification.- In T lymphocytopenia, there are too few T lymphocytes, but normal numbers of other lymphocytes. It causes, and manifests as, a T cell deficiencyT cell deficiencyT cell deficiency is a deficiency of T cells, either caused by lymphocytopenia of T cells or by decreased function of individual T cells. It causes an immunodeficiency of cell-mediated immunity.-By complete versus partial deficiency:...
. This is usually caused by HIVHIVHuman immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
infection (resulting in AIDSAIDSAcquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
), but may be Idiopathic CD4+ lymphocytopenia (ICL), which is a very rare heterogeneous disorder defined by CD4+ T-cell counts below 300 cells/muL in the absence of any known immune deficiency condition, such as human immunodeficiency virus (HIV) infection or chemotherapy. - In B lymphocytopenia, there are too few B lymphocytes, but possibly normal numbers of other lymphocytes. It causes, and manifests as, a humoral immune deficiencyHumoral immune deficiencyHumoral immune deficiencies are conditions which cause impairment of humoral immunity, which can lead to immunodeficiency. It can be mediated by insufficient number or function of B cells, the plasma cells they differentiate into , or the antibody secreted by the plasma cells.They are associated...
. This is usually caused by medicationMedicationA pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
s that suppress the immune system. - In NK lymphocytopenia, there are too few natural killer cells, but normal numbers of other lymphocytes. This is very rare.
Causes
The most common cause of temporary lymphocytopenia is a recent infection, such as the common coldCommon cold
The common cold is a viral infectious disease of the upper respiratory system, caused primarily by rhinoviruses and coronaviruses. Common symptoms include a cough, sore throat, runny nose, and fever...
.
Lymphocytopenia, but not idiopathic CD4+ lymphocytopenia, is associated with corticosteroid
Corticosteroid
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...
use, infections with HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
and other viral
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
, bacterial, and fungal agents, malnutrition
Malnutrition
Malnutrition is the condition that results from taking an unbalanced diet in which certain nutrients are lacking, in excess , or in the wrong proportions....
, systemic lupus erythematosus
Systemic lupus erythematosus
Systemic lupus erythematosus , often abbreviated to SLE or lupus, is a systemic autoimmune disease that can affect any part of the body. As occurs in other autoimmune diseases, the immune system attacks the body's cells and tissue, resulting in inflammation and tissue damage...
, severe stress
Stress (medicine)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...
, intense or prolonged physical exercise
Physical exercise
Physical exercise is any bodily activity that enhances or maintains physical fitness and overall health and wellness. It is performed for various reasons including strengthening muscles and the cardiovascular system, honing athletic skills, weight loss or maintenance, as well as for the purpose of...
(due to cortisol
Cortisol
Cortisol is a steroid hormone, more specifically a glucocorticoid, produced by the adrenal gland. It is released in response to stress and a low level of blood glucocorticoids. Its primary functions are to increase blood sugar through gluconeogenesis; suppress the immune system; and aid in fat,...
release), rheumatoid arthritis
Rheumatoid arthritis
Rheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
, sarcoidosis
Sarcoidosis
Sarcoidosis , also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells form as nodules in multiple organs. The cause of sarcoidosis is unknown...
, and iatrogenic (caused by other medical treatments) conditions.
Lymphocytopenia is a frequent, temporary result from many types of chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
, such as with cytotoxic agents or immunosuppressive drugs. Some malignancies that have spread to involve the bone marrow
Bone marrow
Bone marrow is the flexible tissue found in the interior of bones. In humans, bone marrow in large bones produces new blood cells. On average, bone marrow constitutes 4% of the total body mass of humans; in adults weighing 65 kg , bone marrow accounts for approximately 2.6 kg...
, such as leukemia
Leukemia
Leukemia or leukaemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts". Leukemia is a broad term covering a spectrum of diseases...
or advanced Hodgkin's disease, also cause lymphocytopenia.
Large doses of radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
, such as those involved with nuclear accidents or medical whole body radiation, may cause lymphocytopenia.
Diagnosis
Lymphocytopenia is diagnosed from the results of a complete blood countComplete blood count
A complete blood count , also known as full blood count or full blood exam or blood panel, is a test panel requested by a doctor or other medical professional that gives information about the cells in a patient's blood...
. In adults, a lymphocyte level below 1,500 cells/microliter is diagnostic (proof of the condition), and in children, a lymphocyte level below 3,000 cells/microliter is diagnostic.
Prognosis
Lymphocytopenia that is caused by infections tends to resolve once the infection has cleared. Patients with idiopathic CD4+ lymphocytopenia may have either abnormally low but stable CD4+ cell counts, or abnormally low and progressively falling CD4+ cell counts; the latter condition is terminal.Veterinary treatment
Lymphocytopenia caused by Feline Leukemia VirusFeline leukemia virus
Feline leukemia virus is a retrovirus that infects cats. FeLV can be transmitted between infected cats when the transfer of saliva or nasal secretions is involved. If not defeated by the animal’s immune system, the virus can be lethal...
and Feline immunodeficiency virus
Feline immunodeficiency virus
Feline immunodeficiency virus is a lentivirus that affects domesticated housecats worldwide and is the causative agent of feline AIDS. From 2.5% up to 4.4% of cats worldwide are infected with FIV...
retroviral infections is treated with Lymphocyte T-Cell Immune Modulator
Lymphocyte T-Cell Immune Modulator
Lymphocyte T-Cell Immune Modulator is an immune regulating polypeptide manufactured by T-Cyte Therapeutics and distributed by . Lymphocyte T-Cell Immune Modulator is a potent regulator of CD-4 lymphocyte production and function. It has been shown to increase lymphocyte numbers and Interleukin-2 ...
.