title: Progressive multifocal leukoencephalopathy in transplant recipients.
abstract: OBJECTIVE
  Transplant recipients are at risk of developing progressive multifocal leukoencephalopathy (PML), a rare demyelinating disorder caused by oligodendrocyte destruction by JC virus.
  
  
  METHODS
  Reports of PML following transplantation were found using PubMed Entrez (1958-July 2010). A multicenter, retrospective cohort study also identified all cases of PML among transplant recipients diagnosed at Mayo Clinic, Johns Hopkins University, Washington University, and Amsterdam Academic Medical Center. At 1 institution, the incidence of posttransplantation PML was calculated.
  
  
  RESULTS
  A total of 69 cases (44 solid organ, 25 bone marrow) of posttransplantation PML were found including 15 from the 4 medical centers and another 54 from the literature. The median time to development of first symptoms of PML following transplantation was longer in solid organ vs bone marrow recipients (27 vs 11 months, p = 0.0005, range of <1 to >240). Median survival following symptom onset was 6.4 months in solid organ vs 19.5 months in bone marrow recipients (p = 0.068). Case fatality was 84% (95% confidence interval [CI], 70.3-92.4%) and survival beyond 1 year was 55.7% (95% CI, 41.2-67.2%). The incidence of PML among heart and/or lung transplant recipients at 1 institution was 1.24 per 1,000 posttransplantation person-years (95% CI, 0.25-3.61). No clear association was found with any 1 immunosuppressant agent. No treatment provided demonstrable therapeutic benefit.
  
  
  CONCLUSIONS
  The risk of PML exists throughout the posttransplantation period. Bone marrow recipients survive longer than solid organ recipients but may have a lower median time to first symptoms of PML. Posttransplantation PML has a higher case fatality and may have a higher incidence than reported in human immunodeficiency virus (HIV) patients on highly-active antiretroviral therapy (HAART) or multiple sclerosis patients treated with natalizumab.
authors.affiliation: Department of Neurology, School of Medicine, The Johns Hopkins University, Baltimore, MD 21205, USA. fmateen@jhsph.edu
authors.forename: Farrah J
authors.initials: FJ
authors.lastname: Mateen
authors.forename: RajaNandini
authors.initials: R
authors.lastname: Muralidharan
authors.forename: Marco
authors.initials: M
authors.lastname: Carone
authors.forename: Diederik
authors.initials: D
authors.lastname: van de Beek
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Harrison
authors.forename: Allen J
authors.initials: AJ
authors.lastname: Aksamit
authors.forename: Mary S
authors.initials: MS
authors.lastname: Gould
authors.forename: David B
authors.initials: DB
authors.lastname: Clifford
authors.forename: Avindra
authors.initials: A
authors.lastname: Nath
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007577:JC Virus; D007968:Leukoencephalopathy, Progressive Multifocal / Q000175:diagnosis / Q000209:etiology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D039781:PubMed; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D019737:Transplants / Q000009:adverse effects*; D055815:Young Adult