Prednisone, a glucocorticoid, increases white blood cell (WBC) count primarily by altering the distribution and production of these cells. It mobilizes neutrophils and lymphocytes from the bone marrow and other storage pools into the bloodstream, resulting in a higher circulating WBC count. This effect is not limited to one type of WBC; lymphocytes, particularly, show a marked increase. However, the effect on monocytes and eosinophils is more complex and can vary.
The mechanism involves the interaction of prednisone with intracellular receptors. Binding to these receptors influences gene expression, leading to changes in cytokine production. Reduced production of certain cytokines that normally inhibit WBC release from storage contributes to the observed elevation. Conversely, prednisone can enhance the production of others that stimulate WBC production in the bone marrow.
This increase in WBC count is often temporary and resolves once prednisone treatment ends. However, the magnitude of the increase and duration depend on dosage and duration of prednisone use, as well as individual patient factors. Close monitoring of blood counts is therefore necessary during prednisone therapy to detect and manage potential complications.
It’s vital to remember that while a rising WBC count is a common side effect, it doesn’t necessarily indicate an infection. Other factors need to be considered in the clinical context. A comprehensive blood count and differential, along with a careful medical history, are critical in interpreting this finding.
