Israeli researchers have just published an article exploring the possible connection between PML and Tysabri. They hypothesize that the combination of Tysabri, which inhibits T-cell migration into the brain, along with other immunomodulators such as Avonex or azathioprine which further reduce T-cells in the central nervous system, leaves the brain vulnerable to attack by the PML-causing JC virus (JCV). While no new information is uncovered, this article is an interesting and easy read that covers all the major chemical players in the Tysabri-PML issue.
"This is the first time in the medical literature that PML is described in patients with MS or Crohn's disease. Taking into consideration that both MS and Crohn are autoimmune diseases but not immune compromised states, it is of major interest to understand why JCV infected, or was reactivated, in these patients. An intriguing speculation is that the occurrence of PML in the above reported patients was associated with the concomitant tratment of natalizumab (Tysabri) with either IFNb-1a (Avonex) or azathioprine...
We therefore suggest that treatment with natalizumab and another immunomodulating drug led to a "chronic" inhibition of T cell function. This rendered the brain "immune compromised" and therefore vulnerable to PML-- a process similar to what occurs in AIDS patients."
Click "read more" for a link to the full research article.
Link to Full Article
(Acrobat Reader required)
Click here
