What causes a decrease in White Blood Cells (WBC)?

From the Guidelines

If you have a low WBC count, consult a healthcare provider promptly for proper evaluation and treatment, as a decrease in white blood cell count can compromise the body's ability to fight infections. A decrease in white blood cell (WBC) count, known as leukopenia, can occur due to various causes including viral infections, certain medications, autoimmune disorders, bone marrow problems, or cancer treatments 1. Treatment depends on the underlying cause and severity. For medication-induced leukopenia, your doctor may adjust or discontinue the offending drug, such as azathioprine or cyclophosphamide, if the WBC count decreases to < 4,000/mm3 and the platelet counts fall below 100,000/mm3 1.

Key Considerations

• For infection-related decreases, treating the underlying infection often helps restore counts.
• In severe cases, medications like filgrastim (Neupogen) may be prescribed to stimulate white blood cell production.
• Supportive measures include avoiding people with infections, practicing good hygiene, and eating a balanced diet rich in proteins and vitamins.
• Regular monitoring through complete blood counts is essential to track recovery, as recommended by the European LeukemiaNet 1.

Management of Leukopenia

• According to the American Thoracic Society, corticosteroid therapy may suppress the immune response to skin tests, and preventive therapy may be considered for persons with a positive tuberculin skin test or those at risk 1.
• The European LeukemiaNet recommends hydroxyurea as a therapy to lower WBC in cases of hyperleukocytosis, given at dosages up to 50 to 60 mg/kg per day, until WBCs are less than 10-20 109 /L 1.
• The American Journal of Respiratory and Critical Care Medicine suggests that patients with sarcoidosis should undergo a baseline complete blood cell count testing to screen for hematological abnormalities, including leukopenia 1.

Monitoring and Prevention

• Patients taking azathioprine should also undergo monthly measurements of hepatocellular injury, and the dose of the medication should be reduced or stopped if abnormalities greater than three times the normal level are found 1.
• Forced diuresis, > 8 glasses (8 oz. each) of water daily, and monthly monitoring of the urine for red blood cells or other abnormality is recommended in an attempt to prevent clinically significant hemorrhagic cystitis in patients treated with cyclophosphamide 1.

From the Research

White Blood Cell Decrease

• A decrease in white blood cells (WBC) can be caused by various factors, including bone marrow disorders, infections, and certain medications 2.
• Myelosuppression, a common side effect of chemotherapy, can lead to a reduction in WBC, platelets, and red blood cells, making patients more susceptible to infections and other complications 3.
• Filgrastim and pegfilgrastim are used to stimulate the production of WBC in patients with neutropenia, a condition characterized by low WBC counts, and can help reduce the risk of infections and improve patient outcomes 3.

Diagnosis and Treatment

• Conventional methods of leukocyte analysis can provide valuable information for medical specialists, but may be time-consuming and labor-intensive 4.
• New technologies, such as microfluidic devices and point-of-care testing, are being developed to provide faster and more efficient WBC counting and analysis 4.
• In patients undergoing bone marrow transplantation, the number of CD34+ cells infused can affect the time to hematopoietic recovery and the need for supportive measures, highlighting the importance of optimizing WBC counts in these patients 5, 6.

Clinical Implications

• A decrease in WBC can have significant clinical implications, including an increased risk of infections and other complications, and may require prompt medical attention and treatment 2, 3.
• The use of filgrastim and pegfilgrastim can help mitigate the effects of myelosuppression and reduce the risk of infections in patients with neutropenia 3.
• Further research is needed to fully understand the causes and consequences of WBC decrease and to develop effective strategies for prevention and treatment 4, 5, 6.