Participants With Relapsing Multiple Sclerosis (Rapid-Start and Delayed-Start Cohorts)
Inclusion Criteria:
- Age 18 years or older.
- Diagnosis of relapsing-remitting multiple sclerosis according to the 2017 McDonald criteria.
- At least one gadolinium-enhancing lesion on an MRI of the brain, cervical spine, or thoracic spine within 4 weeks of relapse or hospitalization.
Exclusion Criteria:
- Diagnosis of primary progressive multiple sclerosis.
- Active hepatitis B.
- Current pregnancy.
- Allergy to gadolinium contrast or known allergy to ocrelizumab.
- Unable to complete an MRI.
- Contraindication to or intolerance of oral or intravenous corticosteroids.
- Another known neurological disorder, including a history of progressive multifocal leukoencephalopathy.
- Active bacterial, viral, fungal, or mycobacterial infection, or a history of recurrent aspiration pneumonia requiring antibiotic treatment.
- A condition that may require chronic systemic corticosteroids or immunosuppressants during the study.
- Treatment with an anti-CD20 or other B-cell-depleting therapy within 6 months before enrollment.
- Active cancer or malignancy.
- Prisoner status.
- Limited English-speaking capacity.
- Unable to provide informed consent.
Healthy Control Participants
Inclusion Criteria:
- Age 18 years or older.
- Able and willing to provide written informed consent and undergo study blood draws.
- No diagnosis or history of multiple sclerosis, clinically isolated syndrome, or another inflammatory or demyelinating disorder of the central nervous system.
- In generally good health, as determined by medical history and investigator review.
Exclusion Criteria:
- Multiple sclerosis, clinically isolated syndrome, myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), neuromyelitis optica spectrum disorder (NMOSD), or another neurological disorder that may affect study results.
- An autoimmune, inflammatory, hematologic, or immunodeficiency disorder that may affect B- or T-cell measurements.
- Active bacterial, viral, fungal, or mycobacterial infection at enrollment or blood collection.
- Current use of a disease-modifying therapy, B-cell-depleting therapy, systemic immunosuppressant, immunomodulatory therapy, or chronic systemic corticosteroids.
- Active cancer or malignancy, except adequately treated localized skin cancer if permitted by the investigator.
- Current pregnancy.
- A medical condition that, in the investigator's judgment, could increase risk, interfere with participation, or affect interpretation of immune cell or biomarker results.
- Unable or unwilling to undergo blood collection.
- Prisoner status.
- Limited English-speaking capacity.
- Unable to provide informed consent.