Can prednisone (corticosteroid) cause an increase in C-Reactive Protein (CRP) or Erythrocyte Sedimentation Rate (ESR) levels?

Prednisone Does Not Cause Increases in CRP or ESR—It Suppresses Them

Prednisone and other corticosteroids consistently decrease CRP and ESR levels, not increase them. This is a fundamental anti-inflammatory effect of glucocorticoids that clinicians must understand when interpreting these inflammatory markers in patients on steroid therapy.

Mechanism of Effect on Inflammatory Markers

CRP Suppression

• Prednisone causes rapid and substantial reductions in CRP levels, with the most dramatic decreases occurring within the first 28 days of treatment 1, 2.
• In community-acquired pneumonia patients, prednisone 50 mg daily resulted in 46% lower CRP levels compared to placebo at days 3,5, and 7 (p < 0.001 for all time points) 1.
• In rheumatoid arthritis patients, prednisone caused abrupt falls in CRP by 28 days, with the largest proportional effect observed at 140 days compared to other disease-modifying agents 2.
• The correlation between CRP and SAA can be significantly influenced by prednisone use, making CRP a less reliable marker of inflammation in steroid-treated patients 3.

ESR Suppression

• ESR similarly decreases with prednisone treatment, following a pattern comparable to CRP reduction 2.
• In rheumatoid arthritis, prednisone caused ESR to fall abruptly by 28 days and remain suppressed thereafter 2.
• The magnitude of ESR suppression with prednisone was greater than with gold or dapsone therapy at 140 days 2.

Divergent Effects on Other Markers

• Prednisone has minimal effect on haptoglobin levels despite causing large reductions in CRP and ESR, suggesting differential effects on various acute phase reactants 2.
• Procalcitonin (PCT) levels are NOT suppressed by prednisone, making PCT a more reliable marker for monitoring infection resolution in glucocorticoid-treated patients 1.
• Leukocyte and neutrophil counts paradoxically increase with prednisone (mean difference of 27% for leukocytes and 33% for neutrophils, p < 0.001), despite the anti-inflammatory effects 1.

Clinical Implications

Monitoring Disease Activity

• When evaluating inflammatory conditions in patients on prednisone, CRP and ESR will be artificially suppressed and may not accurately reflect true disease activity 4.
• Guidelines for immune-related adverse events recommend monitoring ESR and CRP, but clinicians must recognize these values will be lower in patients already receiving corticosteroids 4.

Diagnostic Pitfalls

• A "normal" CRP or ESR in a steroid-treated patient does not exclude active inflammation or infection 1, 2.
• In prosthetic joint infection evaluation, CRP cutoffs (typically 13.5 mg/L for knee arthroplasty) may be unreliable in patients on chronic corticosteroids 4.
• Consider using PCT instead of CRP when monitoring infection in glucocorticoid-treated patients, as PCT is not suppressed by steroids 1.

Dose-Response Relationship

• The suppressive effect on inflammatory markers is dose-dependent and rapid, with moderate doses (10-20 mg prednisone daily) sufficient to significantly reduce CRP and ESR 4.
• Even low-dose prednisone (7.5 mg daily) can influence inflammatory marker interpretation 5.

Key Clinical Caveat

If CRP or ESR are elevated in a patient taking prednisone, this suggests either inadequate steroid dosing for the underlying inflammatory condition OR a concurrent acute process that is overwhelming the anti-inflammatory effects of the corticosteroid. This warrants immediate clinical evaluation rather than assuming the prednisone is causing the elevation 4.