White blood cells are a major component of the body's immune system. A low number of WBCs is called leukopenia. Low white blood cell count may include (but are not limited to):
* Bone marrow failure (for example, due to infection, tumor, or abnormal scarring)
* Collagen-vascular diseases (such as lupus erythematosus)
* Disease of the liver or spleen
* Radiation
You'll have to wait to see if the count returns to normal, or not. Then, the doctor can better diagnose any possible problems.