Good news regarding Tysabri, woo hoo!

This is wonderful news Re: those who are concerned about developing PML with the use of Tysabri..., let me briefly explain what my neurologist told me about PML: PML occurs when the immune system has been compromised (or becomes so low that it cannot fight off the JC virus which causes PML to occur)... Plasma Exchange or Plasmapheresis helps to rapidly remove Tysabri from the body, thereby reconstituting (or making strong again) the immune system..., I hope that the following information helps calm the fears of those who are afraid of Tysabri(a.k.a. Natalizumab)....,

Here is the article:

Plasma Exchange Accelerates Natalizumab Clearance
http://www.neura.net/channels/1.asp?id=907

Robert Fox, MD, Cleveland Clinic Foundation, Cleveland, Ohio, reported results of studies that showed that plasma exchange (PLEX) accelerates the clearance of natalizumab, an anti-alpha 4-integrin monoclonal antibody, and restores leukocyte migration into the central nervous system, thereby potentially improving the clinical outcome of patients who have suspected or confirmed cases of progressive multifocal leukoencephalopathy (PML).

The risk of PML, an opportunistic viral infection of the brain, is increased with natalizumab treatment, and, Dr. Fox noted, immune reconstitution is currently the only effective intervention for improving outcomes in patients with PML. In one study, 12 patients with MS who had received at least 3 monthly infusions with natalizumab 300 mg received three 1.5-volume exchanges, over 5 or 8 days, performed 10 to 14 days following their last natalizumab infusion. Mean serum natalizumab concentrations, monitored throughout the PLEX course, were reduced >95% from baseline immediately following PLEX, Dr. Fox reported, and natalizumab clearance was accelerated by 75 days compared with natural decline.

In a second study, performed in a subset of 6 of 12 patients, peripheral blood mononuclear cells (PBMCs) were assessed for chemokine CCL2-induced migration using an in vitro blood-brain barrier (ivBBB) model during natalizumab treatment and following PLEX. PBMC migration across the ivBBB was shown to increase by 2.2 fold after PLEX.

Based on the results of these studies, Dr. Fox noted that PLEX offers potential for immune reconstitution in potential PML cases associated with natalizumab treatment.

((((hugs))))

Love, Lauren :)