Required Laboratory Tests Before Starting Ocrevus (Ocrelizumab)
Before initiating Ocrevus treatment, patients must undergo hepatitis B virus screening, quantitative serum immunoglobulins testing, and infection assessment to ensure safe administration and minimize risks. 1
Essential Pre-Treatment Laboratory Tests
Mandatory Tests
- Hepatitis B virus (HBV) screening: Complete HBsAg and anti-HBV tests as Ocrevus is contraindicated in patients with active HBV 1
- Quantitative serum immunoglobulins: Required to assess baseline immune status; patients with low immunoglobulins should be evaluated by immunology experts before treatment 1
- Complete blood count with differential: To establish baseline hematological parameters 2
- Liver function tests: Including ALT, AST, bilirubin, and alkaline phosphatase to assess liver health 2
- Renal function tests: Including creatinine and estimated GFR to evaluate kidney function 2
Additional Recommended Tests
- Screening for tuberculosis: Using either tuberculin skin test or IGRA (Interferon-Gamma Release Assay) 2
- Varicella zoster virus (VZV) antibody testing: Particularly in patients without clear history of chickenpox or shingles 2, 3
- HIV screening: To assess overall immune status before immunosuppressive therapy 2
- Pregnancy test: For women of childbearing potential 2
Pre-Infusion Assessment
- Active infection assessment: Must be performed prior to each dose; delay administration if active infection is present 1
- Vital signs: Baseline measurements before infusion to monitor for infusion reactions 4
Common Pitfalls and Considerations
- Vaccination timing: Complete all required vaccinations at least 4 weeks prior to treatment for live vaccines and 2 weeks prior for non-live vaccines, as vaccination response may be impaired after treatment 1
- Risk of infusion reactions: Ocrelizumab commonly causes infusion-related reactions (34-40% of patients), particularly with the first infusion 4
- Potential loss of immunity: Patients may lose previously acquired immunity to certain viruses (like varicella zoster) after treatment 3
- Monitoring for infections: B-cell depletion increases risk of infections; careful monitoring is required 5, 6
Follow-Up Monitoring
- Regular CBC and liver function tests: Recommended at follow-up visits to monitor for adverse effects 2, 6
- Immunoglobulin levels: Consider periodic monitoring during treatment 1
- MRI monitoring: To assess treatment response in MS patients 5, 6
Remember that proper pre-treatment laboratory assessment is crucial for patient safety and optimizing treatment outcomes with Ocrevus.