JC Virus Detectable in Natalizumab-Treated MS Patients
Elliot M. Frohman, MD, PhD, from the University of Texas Southwestern Medical Center in Dallas, and colleagues enrolled 49 patients with MS and healthy volunteers to examine whether mononuclear cells in circulation from natalizumab-treated MS patients harbor JCV DNA. At baseline and at about three-month intervals up to 10 months into natalizumab treatment, 120mL blood samples were drawn from 26 MS patients. Twenty-three MS patients receiving natalizumab for >24 months and 18 healthy volunteers had one blood sample drawn.
The researchers identified detectable viral DNA in at least one cell compartment at one or more time points in 50% of the 26 patients with baseline and follow-up samples. Detectable viral DNA was seen in one or more cell compartments in 44%t of MS patients receiving treatment for >24 months and in 17% of healthy volunteers. Thirty-one and 24% of MS patients were confirmed to harbor JCV in CD34+ and CD19+ cells, respectively. One and zero healthy volunteers were viremic in CD34+ and CD19+ cells, respectively.
"JC virus DNA was detectable within cell compartments of natalizumab-treated MS patients after treatment inception and longer," the authors write. "These data link the mechanism of natalizumab treatment with progressive multifocal leukoencephalopathy."
Several authors disclosed financial ties to the pharmaceutical and biotechnology industries.