Neuroimaging of Natalizumab Complications in Multiple Sclerosis: PML and Other Associated Entities

Figure 8

Pathophysiology of PML-IRIS: (a) natalizumab blocks the integrin, preventing lymphocyte tracking into the CNS. (b) To treat PML natalizumab must be rapidly cleared from the blood, often through PLEX. (c) With natalizumab effectively cleared from integrin receptors the lymphocytes reenter the CNS to attack the PML virus. The response is often overwhelming, possibly exacerbating IRIS and leading to further destruction of brain tissue.

(a)

(b)

(c)