Leukopenia

This condition is caused by decreased production of white blood cells in the bone marrow, increased breakdown of these cells in the bloodstream, or their sequestration in the spleen. Common causes are chemotherapy, radiation therapy, aplastic anaemia, myelofibrosis, and invasion of the bone marrow by malignancies such as leukaemia or multiple myeloma. Leukopenia can also be caused by autoimmune diseases (such as systemic lupus erythematosus and rheumatoid arthritis), severe infections (such as HIV, TB, dengue, and sepsis), and nutritional deficiencies (such as vitamin B12, folate, and copper). Some drugs, particularly antibiotics or immunosuppressants, may cause drug-related leukopenia.
Clinical presentations

Patients usually have no symptoms until they develop an opportunistic illness. Symptoms are recurring fever, chills, sore throat, mouth ulcers, cough, dyspnoea, and localised indications of infection (e.g., painful urination and draining wounds).
Diagnosis and Treatment

A complete blood count (CBC) confirms the diagnosis by showing a decreased WBC count. Treatment is directed to the underlying cause, administration of haematopoietic growth factors (e.g., G-CSF), and prevention or treatment of infections with appropriate antimicrobials.