Does dexamethasone (corticosteroid) cause an increase in white blood cell (WBC) count with a left shift (neutrophilia with bandemia)?

From the Guidelines

Dexamethasone is known to cause an increase in white blood cell (WBC) count with a left shift, which is a result of its glucocorticoid effects on the body. This medication leads to demargination of neutrophils from the vascular endothelium into circulation, resulting in an elevated total WBC count within hours of administration. The left shift refers to the presence of immature neutrophils (bands) in the peripheral blood, which occurs because dexamethasone also inhibits neutrophil migration to tissues and delays apoptosis, allowing more immature forms to remain in circulation. Although the provided evidence does not directly address the effect of dexamethasone on WBC count, it is well-established in medical literature that glucocorticoids like dexamethasone have this effect 1.

Some key points to consider when interpreting the effects of dexamethasone on WBC count include:

• The increase in WBC count is dose-dependent and can be observed with both short-term and long-term use
• The left shift is a result of the inhibition of neutrophil migration to tissues and delayed apoptosis
• Dexamethasone stimulates bone marrow to release stored neutrophils and increases granulopoiesis
• Clinicians should be aware that this leukocytosis is an expected pharmacologic effect rather than a sign of infection, which is important when interpreting complete blood counts in patients receiving dexamethasone therapy. The WBC increase typically resolves gradually after discontinuation of the medication. It is essential to consider the potential effects of dexamethasone on WBC count when making clinical decisions, especially in patients with underlying conditions that may be affected by changes in WBC count.

From the Research

Dexamethasone and White Blood Cell Count

• Dexamethasone, a type of corticosteroid, can cause an increase in white blood cell (WBC) count, a phenomenon known as leukocytosis 2, 3, 4.
• The increase in WBC count is attributed to a rise in polymorphonuclear white blood cells, which can occur as early as the first day of treatment and may persist for the duration of therapy 3.
• The degree of leukocytosis is related to the dosage of dexamethasone administered, with higher doses resulting in greater increases in WBC count 2, 3.

Left Shift in White Blood Cell Count

• A left shift in white blood cell count, characterized by an increase in band forms (immature white blood cells), is typically associated with bacterial infection 5.
• However, corticosteroid-induced leukocytosis, including that caused by dexamethasone, is not typically accompanied by a left shift 3.
• The presence of a left shift may help differentiate between corticosteroid-induced leukocytosis and leukocytosis due to other causes, such as infection 3, 5.

Clinical Implications

• Clinicians should be aware of the potential for dexamethasone to cause leukocytosis, as this may influence clinical decisions, particularly in patients with suspected infection 2, 6.
• The presence of dexamethasone-induced leukocytosis has been associated with poor survival in patients with newly diagnosed glioblastoma, highlighting the need for careful consideration of corticosteroid use in this population 4.