Autoimmune Leukopenia

Gordon Starkebaum, M.D.
David C. Dale, M.D.

The terms "autoimmune leukopenia," "autoimmune granulocytopenia," and "autoimmune Neutropenia" are often used synonymously to describe conditions in which autoantibodies to mature neutrophils, or their precursors, lead to cell destruction and a reduced blood neutrophil count. Leukopenia is generally defined as a reduction in the total white blood cell count to less than 4,000 cells per deciliter; Neutropenia is defined as a neutrophil count of less than 1,800 cells per deciliter. Neutropenia has numerous causes and mechanisms; the most frequent cause is reduced cell production by the bone marrow. Neutropenia also occurs because of abnormalities in the distribution of cells between the circulating and marginated pools of cells in the blood and accelerated cell destruction. Autoimmune leukopenia can be caused by any of these mechanisms.

Although the term "leukopenia" often implies "Neutropenia", there are many pathologic conditions in which not only neutrophils but also lymphocytes, monocytes, eosinophils, and basophils are concomitantly or specifically reduced. Lymphocytopenia is a common feature of the stress response to many infections and acute inflammatory illnesses. It occurs in systemic lupus erythematosus (SLE) and other collagen vascular diseases. Lymphocytopenia, monocytoenia, and eosinopenia are regularly seen with corticosteroid therapy. Reductions in any of the white blood cell elements may reflect an important ongoing pathologic process.

Other Conditions Associated with Neutropenia

There are a number of other conditions that include neutropenia as part of the symptoms. Depending on the nature of the main condition the way neutropenia is managed may differ from the treatment of "pure" SCN.

The main conditions that may include neutropenia are:

  • Severe Aplastic anaemia
  • Viral illnesses
  • Post chemotherapy or radiotherapy
  • Other drug-induced situations
  • Fanconi Anemia

There may be some other very rare disorders, congenital or acquired, that may be associated with neutropenia, e.g. myelokathexis, Hyper IgM, or Combined Immunodeficiency. This list may be incomplete and more information about diseases associated with neutropenia is being discovered all the time.