Does prednisone (corticosteroid) increase eosinophil counts?

Prednisone Decreases Eosinophil Counts

Prednisone consistently reduces eosinophil counts in both blood and tissues, with studies showing a two- to sevenfold reduction in sputum eosinophil counts after corticosteroid therapy. 1

Mechanism and Evidence

Corticosteroids like prednisone have a well-documented suppressive effect on eosinophilia through several mechanisms:

• In asthma patients, sputum eosinophil counts are consistently reduced (two- to sevenfold) by corticosteroid therapy 1
• Peripheral eosinophilia decreases after successful topical corticosteroid therapy in eosinophilic esophagitis (EoE) 1
• Oral prednisone (0.5 mg/kg daily) significantly decreases sputum eosinophil percentages and inflammatory cytokines (IL-5 and IL-8) in patients with severe refractory asthma 2
• In patients with sputum eosinophilia, prednisone (30 mg/day) produces a significant decline in median sputum eosinophil percentage from 9.7% to 0.5% 3

Clinical Applications

Asthma Management

• Prednisone is particularly effective in reducing eosinophil counts in patients with eosinophilic asthma
• Monitoring sputum eosinophil counts can help guide prednisone dosing in prednisone-dependent asthma 4
• The effect is most pronounced in patients with baseline sputum eosinophilia 2

Eosinophilic Esophagitis

• Systemic glucocorticosteroids (prednisone 1 mg/kg twice daily) effectively reduce eosinophil counts in EoE 1
• However, topical glucocorticosteroids are generally preferred over oral prednisone due to similar effectiveness with fewer systemic side effects 1

Time Course and Magnitude of Effect

• The effect of prednisone on eosinophil counts can be seen relatively quickly
• In asthma, the effect of inhaled corticosteroids may be seen as early as 6 hours after administration 1
• A short-term course of oral prednisone (0.5 mg/kg daily for 2 weeks) significantly reduces sputum eosinophil percentages 2

Important Considerations

• The eosinopenic effect of prednisone appears to be more pronounced in patients with baseline eosinophilia compared to normal subjects 5
• Patients with peripheral blood eosinophilia may be more susceptible to the eosinopenic effects of glucocorticoids than normal subjects 5
• The reduction in eosinophil activity follows improvement in clinical condition 6

Monitoring Recommendations

• Sputum eosinophil counts can be used to monitor response to prednisone therapy in asthma
• A halving or doubling of the sputum differential eosinophil count is considered clinically significant 1
• In prednisone-dependent asthma, monitoring with the aim of keeping sputum eosinophils below 3% can help maintain symptom control and preserve lung function 4

In summary, prednisone consistently and significantly decreases eosinophil counts in both blood and tissues, making it an effective treatment for eosinophilic conditions. The effect is most pronounced in patients with baseline eosinophilia and can be observed relatively quickly after initiating therapy.