Do corticosteroids cause an increase in neutrophil count?

From the Guidelines

Corticosteroids can cause an increase in neutrophil count, which is a well-documented effect of glucocorticoid steroids such as prednisone, dexamethasone, and methylprednisolone. This phenomenon, called steroid-induced neutrophilia, occurs because steroids both increase the release of neutrophils from bone marrow into circulation and decrease their migration out of blood vessels into tissues. According to the most recent evidence available, specifically from the study published in 2006 1, corticosteroids can cause an increase in neutrophils, which is relevant in the context of postinfectious cough treatment. The study suggests that a brief course of corticosteroids, starting with 30 to 40 mg of prednisone (or equivalent) in the morning, tapering to zero over 2 to 3 weeks, may be tried in patients with protracted and persistently troublesome coughs.

Key Points to Consider

• The increase in neutrophil count is generally temporary and resolves when the steroid is discontinued 1.
• This effect is dose-dependent, with higher doses causing more significant increases.
• The neutrophil elevation reflects the medication effect rather than necessarily indicating an infection or inflammation.
• Steroids extend neutrophil survival by inhibiting their natural cell death process.
• The use of corticosteroids should be carefully considered, taking into account the potential benefits and risks, including the increase in neutrophil count, as well as other potential side effects such as osteoporosis, myopathy, and psychologic effects, as noted in the study published in 2000 1.

Clinical Implications

• When interpreting complete blood count results in patients on steroid therapy, it is essential to consider the potential effect of steroids on neutrophil count.
• The increase in neutrophil count should not be misinterpreted as an indication of infection or inflammation, but rather as a medication effect.
• Clinicians should be aware of the potential risks and benefits of corticosteroid therapy and carefully weigh these factors when making treatment decisions.

From the Research

Corticosteroids and Neutrophil Count

• Corticosteroids have been shown to increase neutrophil count in several studies 2, 3, 4, 5.
• A study published in The Journal of Clinical Investigation found that administration of hydrocortisone and prednisone resulted in a significant increase in blood neutrophil count, with the upper three doses of both steroids increasing the count by approximately 4,000 cells/mm3 2.
• Another study published in the Scandinavian Journal of Haematology found that a single dose of prednisone resulted in a mean rise in neutrophil counts to 2.3 times the baseline value 3.
• A retrospective cohort study published in the Journal of Hospital Medicine found that corticosteroid administration resulted in a mean increase in white blood cell count of 2.4 x 10^9/L, with the increase peaking at 48 hours after steroid administration 4.
• A study published in the Journal for Immunotherapy of Cancer found that corticosteroid administration resulted in a significant increase in absolute neutrophil counts (ANCs) and a decrease in absolute lymphocyte counts (ALCs) 5.

Mechanism of Action

• The exact mechanism of how corticosteroids increase neutrophil count is not fully understood, but it is thought to be related to the reduction of neutrophil egress to the tissues and a decrease in neutrophil turnover rate 3.
• Corticosteroids may also affect the bone marrow neutrophil reserve response, leading to an increase in neutrophil count 2.

Clinical Significance

• The increase in neutrophil count caused by corticosteroids can make it difficult to diagnose infections or other conditions that may cause an increase in white blood cell count 4.
• The use of corticosteroids may have implications for the management of COVID-19, as the increase in neutrophil count and decrease in lymphocyte count may affect the immune response to the virus 5.