No, Skyrizi (risankizumab) does not cause elevated WBC or neutrophil counts
Skyrizi is not associated with leukocytosis or neutrophilia. In fact, the FDA drug label and clinical trial data for Skyrizi show no evidence that this medication causes elevations in white blood cell count or absolute neutrophil count 1.
What the Evidence Shows
The FDA-approved prescribing information for Skyrizi lists comprehensive adverse reactions from multiple large clinical trials in Crohn's disease, ulcerative colitis, and psoriasis. Notably absent from these adverse reaction profiles is any mention of leukocytosis, elevated WBC count, or neutrophilia 1.
Actual Hematologic Effects of Skyrizi
The only hematologic adverse reaction documented in Skyrizi trials was:
- Anemia (4.5-4.9% in maintenance studies) - not leukocytosis 1
The clinical trials monitored thousands of patients:
- Crohn's disease induction: 620 patients on Skyrizi vs 432 on placebo
- Crohn's disease maintenance: 297 patients followed for 52 weeks
- Ulcerative colitis: 712 patients in induction studies, 347 in maintenance
- No elevation in WBC or neutrophil counts was reported as an adverse event 1
Alternative Explanations for Your Lab Values
Your WBC of 14.21 × 10⁹/L and absolute neutrophil count of 9.51 × 10⁹/L require investigation for other causes:
Common Causes to Consider:
Corticosteroid use - The most common medication-related cause of leukocytosis. Steroids can increase WBC by up to 4.84 × 10⁹/L within 48 hours of high-dose administration 2. Even medium doses cause mean increases of 1.7 × 10⁹/L 2.
Active inflammation - Your underlying inflammatory bowel disease or psoriasis activity itself can cause reactive leukocytosis
Infection - Must be ruled out, especially with neutrophil predominance
Stress response - Physical or physiological stress from illness
Other medications - Review all current medications
Important Caveat About Duffy Null Variant
If you are of African, Middle Eastern, or certain other ancestries, you may carry the Duffy null variant, which lowers baseline neutrophil counts by approximately 1,000-1,500 cells/µL 3. This is relevant because standard reference ranges may not apply, but this would cause lower counts, not the elevation you're experiencing.
Clinical Recommendation
Do not attribute these elevated counts to Skyrizi. Instead:
- Review for recent corticosteroid use (within 48 hours)
- Assess for signs/symptoms of infection
- Evaluate disease activity of your underlying condition
- Review complete medication list
- Consider repeating labs if clinically stable to assess trend
- If counts remain elevated or increase further, pursue standard workup for leukocytosis
The mechanism of action of risankizumab (IL-23 p19 subunit inhibition) has no known effect on bone marrow production of white blood cells 4, 5, 6.