Lymphocytopenia

Overview
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.

Differential diagnosis of causes of lymphocytopenia
Lymphocytopenia can be caused by various types of chemotherapy, such as with cytotoxic agents or immunosuppressive drugs. Some malignancies in the bone marrow also cause lymphocytopenia.

People exposed to large doses of radiation, such as those involved with Chernobyl, can have severe lymphocytopenia.

A decreased number of certain types of lymphocytes, notably T cells, is a characteristic of AIDS.

Idiopathic CD4+ lymphocytopenia is the condition of having an abnormally low level of CD4+ T-cells. It has no known cause and is not associated with AIDS or any known infectious agent such as HIV or HTLV. It is associated with higher risks of opportunistic infections and cancer.

Lymphocytopenia may be present as part of a pancytopenia, when the total numbers of all types of blood cells are reduced. This can occur in marrow failure.

Lymphocytopenia, but not idiopathic CD4+ lymphocytopenia, is associated with corticosteroid use, infections with HIV and other viral, bacterial, and fungal agents, Hodgkin's disease, leukemia, malnutrition, systemic lupus erythematosus, high stress levels, whole body radiation, rheumatoid arthritis, and iatrogenic conditions.

In alphabetical order.


 * After influenza
 * After snakebite
 * Anesthesia
 * Antibody deficiency syndrome
 * Aplastic Anemia
 * Banti's Syndrome
 * Burns
 * Congenital immune deficiency
 * Cushing's Disease
 * Dermatomyositis
 * Drugs, toxins
 * Exudative enteropathy
 * Felty's Syndrome
 * Heavy exercise
 * HIV
 * Hodgkin's Lymphoma
 * Inflammatory Bowel Disease
 * Lymphocyte tuberculosis
 * Measles
 * Paroxysmal nocturnal hemoglobinuria
 * Polycythemia
 * Postoperative
 * Pregnancy
 * Sarcoidosis
 * Scarlet Fever
 * Secondary hypersplenism
 * Single non-Hodgkin's lymphomas
 * Surgery
 * Systemic Lupus Erythematosus
 * Trauma
 * Tuberculosis
 * Uremia
 * Whipple's Disease
 * Zinc deficiency

Diagnosis

 * Lymphocytopenia is diagnosed from the results of a complete blood count.


 * In adults, a lymphocyte level below 1.500 cells/microliter is suspected and below 1000 cells/microliter is diagnostic.


 * 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.