title: Patients with MS under daclizumab therapy mount normal immune responses to influenza vaccination.
abstract: OBJECTIVE
  The purpose of this study was to assess the potential immunosuppressive role of daclizumab, a humanized monoclonal antibody against the α chain of the interleukin 2 receptor, in vivo, by comparing immune responses to the 2013 seasonal influenza vaccination between patients with multiple sclerosis (MS) on long-term daclizumab therapy and controls.
  
  
  METHODS
  Previously defined subpopulations of adaptive immune cells known to correlate with the immune response to the influenza vaccination were evaluated by 12-color flow cytometry in 23 daclizumab-treated patients with MS and 14 MS or healthy controls before (D0) and 1 day (D1) and 7 days (D7) after administration of the 2013 Afluria vaccine. Neutralizing antibody titers and CD4(+), CD8(+) T cell, B cell, and natural killer cell proliferation to 3 strains of virus contained in the Afluria vaccine were assessed at D0, D7, and 180 days postvaccination.
  
  
  RESULTS
  Daclizumab-treated patients and controls demonstrated comparable, statistically significant expansions of previously defined subpopulations of activated CD8(+) T cells and B cells that characterize the development of effective immune responses to the influenza vaccine, while proliferation of T cells to influenza and control antigens was diminished in the daclizumab cohort. All participants fulfilled FDA criteria for seroconversion or seroprotection in antibody assays.
  
  
  CONCLUSIONS
  Despite the mild immunosuppressive effects of daclizumab in vivo demonstrated by an increased incidence of infectious complications in clinical trials, patients with MS under daclizumab therapy mount normal antibody responses to influenza vaccinations.
authors: Neuroimmunological Diseases Unit, Neuroimmunology Branch (Y.C.L., P.W., A.B., E.R., B.B.) and Clinical Neuroscience Program (T.W.), National Institute of Neurological Diseases and Stroke, NIH, Bethesda, MD; FDA (J.M., L.R.K., H.G.), CBER; and NIH Center for Human Immunology (B.B.), NIH, Bethesda, MD.
authors: Yen Chih
authors: YC
authors: Lin
authors: Neuroimmunological Diseases Unit, Neuroimmunology Branch (Y.C.L., P.W., A.B., E.R., B.B.) and Clinical Neuroscience Program (T.W.), National Institute of Neurological Diseases and Stroke, NIH, Bethesda, MD; FDA (J.M., L.R.K., H.G.), CBER; and NIH Center for Human Immunology (B.B.), NIH, Bethesda, MD.
authors: Paige
authors: P
authors: Winokur
authors: Neuroimmunological Diseases Unit, Neuroimmunology Branch (Y.C.L., P.W., A.B., E.R., B.B.) and Clinical Neuroscience Program (T.W.), National Institute of Neurological Diseases and Stroke, NIH, Bethesda, MD; FDA (J.M., L.R.K., H.G.), CBER; and NIH Center for Human Immunology (B.B.), NIH, Bethesda, MD.
authors: Andrew
authors: A
authors: Blake
authors: Neuroimmunological Diseases Unit, Neuroimmunology Branch (Y.C.L., P.W., A.B., E.R., B.B.) and Clinical Neuroscience Program (T.W.), National Institute of Neurological Diseases and Stroke, NIH, Bethesda, MD; FDA (J.M., L.R.K., H.G.), CBER; and NIH Center for Human Immunology (B.B.), NIH, Bethesda, MD.
authors: Tianxia
authors: T
authors: Wu
authors: Neuroimmunological Diseases Unit, Neuroimmunology Branch (Y.C.L., P.W., A.B., E.R., B.B.) and Clinical Neuroscience Program (T.W.), National Institute of Neurological Diseases and Stroke, NIH, Bethesda, MD; FDA (J.M., L.R.K., H.G.), CBER; and NIH Center for Human Immunology (B.B.), NIH, Bethesda, MD.
authors: Jody
authors: J
authors: Manischewitz
authors: Neuroimmunological Diseases Unit, Neuroimmunology Branch (Y.C.L., P.W., A.B., E.R., B.B.) and Clinical Neuroscience Program (T.W.), National Institute of Neurological Diseases and Stroke, NIH, Bethesda, MD; FDA (J.M., L.R.K., H.G.), CBER; and NIH Center for Human Immunology (B.B.), NIH, Bethesda, MD.
authors: Lisa R
authors: LR
authors: King
authors: Neuroimmunological Diseases Unit, Neuroimmunology Branch (Y.C.L., P.W., A.B., E.R., B.B.) and Clinical Neuroscience Program (T.W.), National Institute of Neurological Diseases and Stroke, NIH, Bethesda, MD; FDA (J.M., L.R.K., H.G.), CBER; and NIH Center for Human Immunology (B.B.), NIH, Bethesda, MD.
authors: Elena
authors: E
authors: Romm
authors: Neuroimmunological Diseases Unit, Neuroimmunology Branch (Y.C.L., P.W., A.B., E.R., B.B.) and Clinical Neuroscience Program (T.W.), National Institute of Neurological Diseases and Stroke, NIH, Bethesda, MD; FDA (J.M., L.R.K., H.G.), CBER; and NIH Center for Human Immunology (B.B.), NIH, Bethesda, MD.
authors: Hana
authors: H
authors: Golding
authors: Neuroimmunological Diseases Unit, Neuroimmunology Branch (Y.C.L., P.W., A.B., E.R., B.B.) and Clinical Neuroscience Program (T.W.), National Institute of Neurological Diseases and Stroke, NIH, Bethesda, MD; FDA (J.M., L.R.K., H.G.), CBER; and NIH Center for Human Immunology (B.B.), NIH, Bethesda, MD.
authors: Bibiana
authors: B
authors: Bielekova