Laboratory Testing for Ocrevus (Ocrelizumab)
Before initiating Ocrevus, you must perform hepatitis B virus screening, complete blood count with differential, liver function tests, renal function tests, quantitative serum immunoglobulins, and pregnancy testing in women of childbearing potential. 1, 2
Pre-Treatment Laboratory Requirements
Mandatory Screening Tests
Hepatitis B virus (HBV) screening is required before starting Ocrevus, including both HBsAg and HBcAb testing, as the drug is contraindicated in patients with active HBV 2
- For HBsAg-negative but HBcAb-positive patients, or HBV carriers, consult liver disease experts before initiating treatment 2
Complete blood count (CBC) with differential establishes baseline hematological parameters and is essential before treatment initiation 1
Liver function tests including ALT, AST, bilirubin, and alkaline phosphatase must be performed to assess baseline hepatic function 1
Renal function tests including creatinine and estimated GFR are necessary to evaluate kidney function prior to starting therapy 1
Quantitative serum immunoglobulins must be measured before initiating Ocrevus 2
- Patients with low serum immunoglobulins require consultation with immunology experts before starting treatment 2
Pregnancy test is mandatory for all women of childbearing potential before initiating Ocrevus 1
Additional Recommended Pre-Treatment Tests
Tuberculosis screening using either tuberculin skin test or interferon-gamma release assay (IGRA) should be performed 1
Varicella zoster virus (VZV) antibody testing is advised, particularly in patients without clear history of chickenpox or shingles 1
HIV screening is recommended to assess overall immune status before starting immunosuppressive therapy 1
Vaccination Requirements Before Treatment
All live or live-attenuated vaccines must be administered at least 4 weeks prior to initiating Ocrevus 2
Non-live vaccines should be given at least 2 weeks prior to starting treatment whenever possible 2
Live vaccines are contraindicated during treatment and after discontinuation until B-cell repletion occurs 3, 2
Monitoring During Treatment
Before Each Infusion
- Active infection assessment is required before every dose; delay administration if active infection is present until it resolves 2
Ongoing Monitoring Schedule
Regular CBC and liver function tests should be performed at follow-up visits to monitor for adverse effects 1
While the FDA label does not specify exact monitoring intervals, clinical practice suggests monitoring every 3-6 months based on individual patient risk factors and clinical status 1
Critical Safety Considerations
Progressive multifocal leukoencephalopathy (PML) risk: Although extremely rare with Ocrevus (one case reported in MS after 4 years of treatment), maintain vigilance for neurological symptoms 4. No cases have been reported in ulcerative colitis patients treated with similar anti-CD20 therapies 4.
Infusion reactions: The most common adverse events are infusion-related reactions, nasopharyngitis, and urinary/upper respiratory tract infections 5. Premedication with corticosteroids and antihistamines is required before each dose 2.
Immunoglobulin monitoring: Patients who develop hypogammaglobulinemia during treatment require ongoing monitoring, as low immunoglobulin levels at baseline predict future occurrence 6.