What make you white blood cell walk low?

What make you white blood cell walk low?
There is primary leukopenia that may be idiopathic (meaning nobody knows the cause) specially surrounded by male sand sp surrounded by blacks.
The main problem near leukopenia (low white cells) is neutropenia, that is when the neutrophils ( one type of white cells) are intensely low.
This could be:
1. hereditary (rare)
2.decrease production, includes
a. drug induced: chemotherapy, antibiotics, antipsychotics, some pain meds, antithyroid drugs, etc.
b.aplastic anemia, cyclic neutropenia, myelofibrosis, tumor invasion of the bone marrow
c. vitamin B12 or folate deficinecy.
d. infections close to TB, mono, HIV, mlaria, typhoid and many others.
3. Peripheral destruction:problems next to spleen, some drugs, autoimmune disorder
I believe it can be related to allergies. Leukopenia is the word that describes a low white cell count.
What causes Leukopenia?
Primary cause of this disease include the extensive neutrophil use or the reduction surrounded by the number of neutrophils produced in the blood. In medical slang, the disease could be acute (lasting for a couple of days) to chronic (lasting months/years). Leukopenia has be scientifically proven to be related to heredity and some race have be known to be more susceptible to the disease than others.
Secondary cause of Leukopenia could be stimulated by drugs generating an allergic counterattack (immune, toxic or hypersensitivity) by the body. Certain variants of the disease are air-borne and can be passed on through the atmosphere. Due to the character of the secondary cause, practitioners generally agree that it go back to the idea of the individual body system and can vary amongst population.
Could also be autoimmune.. spleen trouble