Total Plasma Exchange in a Patient with Progressive Multifocal Leukoencephalopathy (PML) Associated with Natalizumab Therapy

Patient selection: multiple sclerosis with progressive multifocal leukoencephalopathy (PML)

Natalizumab inhibits transmigration of lymphocytes into the central nervous system. It blocks the binding of the alpha-4-subunit on the surface of lymphocytes with vascular cell adhesion protein.

Risk factors for PML:

(1) serum positive for antibodies against polyoma JC virus

(2) prior immunosuppressive therapy

(3) duration of natalizumab therapy, especially more than 2 years

Management:

(1) natalizumab therapy is discontinued

(2) total plasma exchange is performed with 1.0 to 1.5 total plasma volume exchanged every other day for a total of 5 exchanges

Replacement fluid: albumin

Within 2 to 6 weeks of completing plasma exchange the patient may experience the immune reconstitution inflammatory syndrome (IRIS) with clinical deterioration. The acute phase is treated with high-dose corticosteroids.