From the Guidelines
Dexamethasone can cause a significant increase in white blood cell (WBC) count, with some studies suggesting an increase of up to 10,000 cells/μL above baseline levels, particularly in patients with acute promyelocytic leukemia (APL) who are at risk of differentiation syndrome 1.
Key Factors Influencing WBC Increase
- Dexamethasone dosage: Higher doses are associated with greater increases in WBC count
- Duration of treatment: Longer treatment duration can lead to more pronounced WBC elevation
- Individual patient factors: Patients with certain underlying conditions, such as APL, may be more susceptible to significant WBC increases
- Concurrent medications: Other medications, such as arsenic trioxide, may interact with dexamethasone to influence WBC counts
Mechanism of WBC Elevation
The increase in WBC count is primarily due to demargination of neutrophils from the vascular endothelium and delayed apoptosis, while lymphocytes may decrease due to redistribution to lymphoid tissues 1.
Clinical Implications
The WBC elevation is generally transient and resolves after discontinuation of dexamethasone, typically returning to baseline within 1-2 days. However, this phenomenon can confound the interpretation of WBC counts when evaluating for infection in patients receiving corticosteroid therapy, highlighting the importance of careful monitoring and consideration of individual patient factors 1.
From the Research
Increase in WBC Count after Dexamethasone Use
- The increase in WBC count after dexamethasone use can vary depending on the dose and individual patient factors 2.
- A study found that the mean increase in WBC count peaked at 48 hours after steroid administration, with a mean increase of 2.4 × 10^9/L WBCs 2.
- The increase in WBC count was found to be dose-dependent, with low-dose steroids resulting in a mean increase of 0.3 × 10^9/L WBCs, medium-dose steroids resulting in a mean increase of 1.7 × 10^9/L WBCs, and high-dose steroids resulting in a mean increase of 4.84 × 10^9/L WBCs 2.
- Another study found that dexamethasone-induced leukocytosis was associated with poor survival in newly diagnosed glioblastoma patients, with a decrease in overall survival and progression-free survival 3.
- The use of dexamethasone and tocilizumab in COVID-19 patients was found to reduce the value of C-reactive protein and procalcitonin in detecting secondary bacterial infections, making it more challenging to interpret WBC counts in these patients 4.
Factors Influencing WBC Count Increase
- Patient age was identified as a risk factor for the development of dexamethasone-induced leukocytosis in primary glioblastoma patients 3.
- The presence of dexamethasone-induced leukocytosis was found to decrease overall survival and progression-free survival in glioblastoma patients 3.
- The use of immunomodulatory therapy, such as dexamethasone and tocilizumab, can affect the interpretation of WBC counts and other biomarkers in COVID-19 patients 4.
Clinical Implications
- Clinicians should be aware of the potential increase in WBC count after dexamethasone use and consider this when interpreting laboratory results 2.
- The use of dexamethasone and other immunomodulatory therapies should be carefully considered in patients with certain conditions, such as glioblastoma, due to the potential association with poor survival 3.
- Alternative biomarkers or diagnostic approaches may be needed to detect secondary bacterial infections in COVID-19 patients treated with immunomodulatory therapy 4.