Neutropenia.

http://en.wikipedia.org/wiki/White_blood_cell

Neutropenia can be acquired or intrinsic.A decrease in levels of neutrophils on lab tests is due to either decreased production of neutrophils or increased removal from the blood.The following list of causes is not complete.

• Medications - chemotherapy, sulfas or other antibiotics, phenothiazenes, benzodiazepines, antithyroids, anticonvulsants, quinine, quinidine, indomethacin, procainamide, thiazides
• Radiation
• Toxins - alcohol, benzenes
• Intrinsic disorders - Fanconi's, Kostmann's, cyclic neutropenia, Chediak-Higashi
• Immune dysfunction - disorders of collagen, AIDS, rheumatoid arthritis
• Blood cell dysfunction - megaloblastic anemia, myelodysplasia, marrow failure, marrow replacement, acute leukemia
• Any major infection
• Miscellaneous - starvation, hypersplenism

Symptoms of neutropenia are associated with the underlying cause of the decrease in neutrophils. For example, the most common cause of acquired neutropenia is drug-induced, so an individual may have symptoms of medication overdose or toxicity. Treatment is also aimed at the underlying cause of the neutropenia.One severe consequence of neutropenia is that it can increase the risk of infection.