Table 2.
| Direct effects | Indirect effects | Consequences (therapeutic and side effects) |
|---|---|---|
| Inhibition of migration of immune cells into CNS | Stabilization of BBB | Probably most important early therapeutic MoA Decreased CNS immunosurveillance |
| Inhibition of APC turnover in the CNS | Decreased antigen presentation in the CNS | Possibly MoA that underlies prolonged efficacy, but also further limits CNS immunosurveillance |
| Mobilization of lymphoid (especially pre-B) and lymphoid/myeloid (CD34+) precursors from the BM | Likely contributes to risk of PML |
CNS, central nervous system; BBB, blood-brain barrier; MoA, mechanism of action, APC, antigen-presenting cell; PML, progressive multifocal leukoencephalopathy; BM, bone marrow