title: JCV GCN in a natalizumab-treated MS patient is associated with mutations of the VP1 capsid gene.
abstract: OBJECTIVE
  To describe the clinical, neuroimaging, immunologic, and virologic characteristics of JC virus-associated granule cell neuronopathy (JCV GCN) in a natalizumab-treated patient with multiple sclerosis (MS) who developed immune reconstitution inflammatory syndrome (IRIS) after natalizumab withdrawal.
  
  
  METHODS
  We obtained longitudinal clinical data as well as MRI and proton magnetic resonance spectroscopy from this patient with MS. We measured JCV-specific cellular immune response in his peripheral blood by intracellular cytokine staining and sequenced a fragment of JCV VP1 capsid gene detected in his CSF. We contrast our findings with the first recently reported case.
  
  
  RESULTS
  This patient presented with worsening cerebellar symptoms and progressive cerebellar atrophy without new MS lesions on MRI after 63 months of natalizumab monotherapy. JCV DNA was detected in his CSF by PCR and harbored novel GCN-type mutations in the VP1 gene. He developed IRIS upon discontinuation of natalizumab and plasma exchange, which manifested itself by a worsening of clinical symptoms and contrast enhancement in the cerebellum on MRI. Treatment with corticosteroids resulted in resolution of IRIS, as demonstrated by proton magnetic resonance spectroscopy. The patient had a strong JCV-specific T-cell response in his peripheral blood and remains alive after 15 months from onset of symptoms, although with significant disability. He did not have MS relapse on glatiramer acetate.
  
  
  CONCLUSIONS
  JCV GCN should be considered in patients on natalizumab presenting with progressive cerebellar symptoms and cerebellar atrophy, and is associated with mutations in the JCV VP1 gene. Natalizumab withdrawal may be complicated by JCV GCN IRIS, and require treatment with corticosteroids.
authors.affiliation: From the Division of Neurovirology, Department of Neurology (S.P.A., X.D., E.B., S.B., I.J.K.), Center for Virology and Vaccine Research (S.P.A., X.D., E.B., S.B., I.J.K.), and Department of Medicine (I.J.K.), Beth Israel Deaconess Medical Center, Boston, MA; Department of Neurology (J.L.C., T.D.F.), University of Arizona College of Medicine, Tucson; and Barrow Neurological Institute (T.D.F.), Phoenix, AZ.
authors.forename: Shruti P
authors.initials: SP
authors.lastname: Agnihotri
authors.affiliation: From the Division of Neurovirology, Department of Neurology (S.P.A., X.D., E.B., S.B., I.J.K.), Center for Virology and Vaccine Research (S.P.A., X.D., E.B., S.B., I.J.K.), and Department of Medicine (I.J.K.), Beth Israel Deaconess Medical Center, Boston, MA; Department of Neurology (J.L.C., T.D.F.), University of Arizona College of Medicine, Tucson; and Barrow Neurological Institute (T.D.F.), Phoenix, AZ.
authors.forename: Xin
authors.initials: X
authors.lastname: Dang
authors.affiliation: From the Division of Neurovirology, Department of Neurology (S.P.A., X.D., E.B., S.B., I.J.K.), Center for Virology and Vaccine Research (S.P.A., X.D., E.B., S.B., I.J.K.), and Department of Medicine (I.J.K.), Beth Israel Deaconess Medical Center, Boston, MA; Department of Neurology (J.L.C., T.D.F.), University of Arizona College of Medicine, Tucson; and Barrow Neurological Institute (T.D.F.), Phoenix, AZ.
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Carter
authors.affiliation: From the Division of Neurovirology, Department of Neurology (S.P.A., X.D., E.B., S.B., I.J.K.), Center for Virology and Vaccine Research (S.P.A., X.D., E.B., S.B., I.J.K.), and Department of Medicine (I.J.K.), Beth Israel Deaconess Medical Center, Boston, MA; Department of Neurology (J.L.C., T.D.F.), University of Arizona College of Medicine, Tucson; and Barrow Neurological Institute (T.D.F.), Phoenix, AZ.
authors.forename: Terry D
authors.initials: TD
authors.lastname: Fife
authors.affiliation: From the Division of Neurovirology, Department of Neurology (S.P.A., X.D., E.B., S.B., I.J.K.), Center for Virology and Vaccine Research (S.P.A., X.D., E.B., S.B., I.J.K.), and Department of Medicine (I.J.K.), Beth Israel Deaconess Medical Center, Boston, MA; Department of Neurology (J.L.C., T.D.F.), University of Arizona College of Medicine, Tucson; and Barrow Neurological Institute (T.D.F.), Phoenix, AZ.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Bord
authors.affiliation: From the Division of Neurovirology, Department of Neurology (S.P.A., X.D., E.B., S.B., I.J.K.), Center for Virology and Vaccine Research (S.P.A., X.D., E.B., S.B., I.J.K.), and Department of Medicine (I.J.K.), Beth Israel Deaconess Medical Center, Boston, MA; Department of Neurology (J.L.C., T.D.F.), University of Arizona College of Medicine, Tucson; and Barrow Neurological Institute (T.D.F.), Phoenix, AZ.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Batson
authors.affiliation: From the Division of Neurovirology, Department of Neurology (S.P.A., X.D., E.B., S.B., I.J.K.), Center for Virology and Vaccine Research (S.P.A., X.D., E.B., S.B., I.J.K.), and Department of Medicine (I.J.K.), Beth Israel Deaconess Medical Center, Boston, MA; Department of Neurology (J.L.C., T.D.F.), University of Arizona College of Medicine, Tucson; and Barrow Neurological Institute (T.D.F.), Phoenix, AZ. ikoralni@bidmc.harvard.edu.
authors.forename: Igor J
authors.initials: IJ
authors.lastname: Koralnik
mesh_terms: D000328:Adult; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D002213:Capsid / Q000187:drug effects*; D006801:Humans; D054019:Immune Reconstitution Inflammatory Syndrome / Q000139:chemically induced / Q000235:genetics; D007577:JC Virus / Q000187:drug effects* / Q000276:immunology; D007968:Leukoencephalopathy, Progressive Multifocal / Q000188:drug therapy*; D008297:Male; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000188:drug therapy*; D009154:Mutation / Q000235:genetics; D000069442:Natalizumab
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000069442:Natalizumab