Can prednisone (corticosteroid) affect Immunoglobulin E (IgE) serum results?

Effect of Prednisone on Serum IgE Results

Yes, prednisone can significantly affect serum IgE levels, with studies showing both increases and decreases in IgE depending on treatment duration and timing of measurement. 1

Mechanism and Evidence

Short-term Effects

• Short-term prednisone administration (1-2 weeks) can cause a rise in serum IgE levels
• In a study of asthmatic patients given 20mg prednisone twice daily for 7 days, all patients demonstrated an increase in serum IgE levels (p=0.005) 1
• This rise appears to be polyclonal, affecting IgE antibodies to both pollen and perennial allergens 1

Long-term Effects

• With continued corticosteroid treatment, IgE levels may eventually decrease
• In asthmatic patients, IgE levels were found to be significantly decreased (p<0.01) approximately 22 days after discontinuation of prednisone therapy 2

Mechanism of Action

• Prednisone appears to modulate T-lymphocyte function, specifically:
  • Decreasing interferon-gamma synthesis (p=0.005)
  • Not significantly affecting interleukin-4 production (p=0.6) 1
• This immunomodulatory effect on T cells likely explains the changes in IgE production

Clinical Implications

Diagnostic Considerations

• IgE testing should ideally be performed before starting prednisone therapy when possible
• If a patient is already on prednisone:
  • For short-term therapy (1-2 weeks): IgE levels may be falsely elevated
  • For longer-term therapy: IgE levels may eventually decrease
• Consider noting prednisone use when interpreting IgE results

Specific Clinical Scenarios

• Allergic Bronchopulmonary Aspergillosis (ABPA):

  • Diagnostic criteria include elevated serum IgE and IgG to Aspergillus 3
  • Prednisone is the mainstay of treatment, typically starting at 0.5 mg/kg/day 3
  • Total serum IgE is used to monitor treatment response 3
  • Be aware that the treatment itself may affect the monitoring parameter

• Eosinophilic Granulomatosis with Polyangiitis (EGPA):

  • Immunological tests including IgE are part of the diagnostic workup 3
  • Prednisone is a primary treatment, which may affect subsequent IgE measurements

Dose-Dependent Effects

• The effect of corticosteroids on immunoglobulins appears to be dose-dependent:
  • Higher doses (40mg prednisolone/day) significantly decrease IgG1, IgG2, and IgG3
  • Lower doses (10mg prednisolone/day) only significantly affect IgG3
  • Inhaled budesonide (3.2mg/day) showed no significant changes in immunoglobulin levels 4

Practical Recommendations

1. Document timing: When ordering IgE tests, document whether the patient is currently on prednisone and for how long
2. Baseline measurements: When possible, obtain baseline IgE levels before starting prednisone therapy
3. Interpretation context: Interpret IgE results in the context of prednisone use - elevated levels may be even more significant if the patient is on long-term prednisone (which would typically lower IgE)
4. Follow-up testing: Consider repeat testing after discontinuation of prednisone when the clinical situation allows

In summary, prednisone has a biphasic effect on IgE levels - initially causing an increase followed by a decrease with continued use. This effect should be considered when interpreting IgE results for diagnosis and monitoring of allergic and immunologic conditions.