RT Journal Article SR Electronic T1 Application of the CSF JCV antibody index to early natalizumab-associated progressive multifocal leukoencephalopathy JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 1092 OP 1094 DO 10.1136/jnnp-2016-315298 VO 88 IS 12 A1 Clemens Warnke A1 Martijn T Wijburg A1 Hans-Peter Hartung A1 Joep Killestein A1 Ortwin Adams A1 Mike P Wattjes YR 2017 UL http://jnnp.bmj.com/content/88/12/1092.abstract AB