From the Guidelines
Steroids, particularly glucocorticoids, typically cause an increase in total white blood cell (WBC) count, primarily due to neutrophilia, and produce characteristic changes on a differential, including increased neutrophils, decreased lymphocytes, decreased eosinophils, and decreased monocytes. This pattern is often called a "stress leukogram" or "steroid-induced leukocytosis" 1. The mechanism involves multiple effects: steroids enhance neutrophil release from bone marrow, decrease neutrophil migration out of circulation, inhibit neutrophil adhesion to vessel walls, and cause redistribution of lymphocytes from circulation to lymphoid tissues. Some key points to consider when evaluating the effects of steroids on WBC and differential include:
- The magnitude of these changes often correlates with steroid dose, with higher doses producing more pronounced effects 1.
- These alterations in WBC parameters are generally reversible upon discontinuation of steroid therapy, though the timeline for normalization depends on treatment duration and individual patient factors.
- It is essential to consider the potential risks and benefits of steroid therapy, including the risk of osteoporosis, myopathy, and psychologic effects, particularly in elderly patients 1.
- Methods to reduce the risk of steroid-induced osteoporosis should be instituted, especially in postmenopausal women, since even short-term therapy may cause reductions in bone mass 1. The provided evidence from various studies, including those published in 2000 1, 2009 1, 2010 1, and 2000 1, supports the understanding of the effects of steroids on WBC and differential. However, the most recent and highest quality study, published in 2010 1, provides the most relevant guidance on this topic.
From the Research
Effects of Steroids on WBC and Differential
- Steroids, specifically corticosteroids, are known to cause leukocytosis, which is an increase in the white blood cell (WBC) count 2, 3.
- The degree of leukocytosis is related to the dosage of steroids administered, with higher doses resulting in greater increases in WBC count 2, 3.
- The WBC response to steroids typically peaks at 48 hours after administration, with a mean increase of 2.4 × 10^9/L WBCs 2.
- The differential count is also affected, with an increase in polymorphonuclear white blood cells, monocytosis, eosinopenia, and a variable degree of lymphopenia 3.
- Glucocorticoids can regulate the proliferation, differentiation, and apoptosis of white blood cells, leading to changes in peripheral blood white blood cell counts 4.
- The effects of steroids on leukocytes can be similar to the changes in peripheral blood caused by bacterial infections, making it challenging to diagnose infections in patients on steroid therapy 4.
Key Findings
- A study of 28,425 patients found that the mean WBC count increased by 0.3 × 10^9/L, 1.7 × 10^9/L, and 4.84 × 10^9/L in low, medium, and high dose steroid groups, respectively 2.
- Another study of 80 patients found that prednisone-induced leukocytosis was extremely variable, with the white blood cell count surpassing 20,000/mm^3 as early as the first day of treatment 3.
- A review of the effects of glucocorticoids on leukocytes found that they can regulate the activation and secretion of white blood cells, inhibit the secretion of pro-inflammatory cytokines, and promote the production of anti-inflammatory cytokines 4.