Immune-reconstitution Inflammatory Syndrome in Multiple Sclerosis Patients Treated With Natalizumab: A Series of 4 Cases

These cases demonstrate the need to consider and manage therapeutic strategies relative to the individual patient's risk for PML or IRIS. NTZ cessation to avoid PML risk can lead to severe IRIS without PML. On the other hand, if PML develops and is detected early, plasmapheresis may not be considered necessary and IRIS may be limited, with a favorable outcome. These 2 scenarios should be considered when managing NTZ MS patients.