title: Multiple sclerosis and risk of young-adult-onset Hodgkin lymphoma.
abstract: OBJECTIVE
  To determine whether there is an association between multiple sclerosis (MS) and young-adult-onset Hodgkin lymphoma (YAHL) as this will signal etiologic similarities relevant both to inherited characteristics and environmental exposures in childhood.
  
  
  METHODS
  Swedish general population registers identified a cohort of 29,617 with an MS diagnosis between 1968 and 2012, matched with a cohort of 296,164 without MS. Cox regression was used to assess the association of MS with subsequent YAHL (defined as onset between ages 15 and 39 years; n = 20), with adjustment, for age/period, sex, county of residence, and level of education.
  
  
  RESULTS
  The adjusted hazard ratio (and 95% confidence interval) for the association of MS with YAHL is 3.30 (1.01-10.73), resulting from 4 and 16 events in the MS and non-MS cohorts, respectively. All 4 of the YAHL diagnoses in MS occurred in women, and the association of MS with YAHL has a hazard ratio of 4.04 (1.17-13.94) among women. There was no notable association of MS with older-onset Hodgkin lymphoma.
  
  
  CONCLUSIONS
  There may be common risks for YAHL and MS, consistent with an etiologic role in MS for early-life exposures, such as to infectious agents.
authors.affiliation: Clinical Epidemiology and Biostatistics (S.M.), School of Medical Sciences, Örebro University, Sweden; Department of Epidemiology and Public Health (S.M.), University College London, UK; Clinical Epidemiology Unit (S.M., M.H.H., S. Burkill, S. Bahmanyar) and Centre for Pharmacoepidemiology (S. Bahmanyar), Department of Medicine, Solna, Karolinska Institutet; Department of Neurology (J.H., T.O.), Karolinska University Hospital Huddinge, Stockholm; Neuroimmunology Unit (J.H.), Department of Clinical Neuroscience and Centre for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital, Solna, Sweden; and Faculty of Medicine (S. Bahmanyar), Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Scott
authors.initials: S
authors.lastname: Montgomery
authors.affiliation: Clinical Epidemiology and Biostatistics (S.M.), School of Medical Sciences, Örebro University, Sweden; Department of Epidemiology and Public Health (S.M.), University College London, UK; Clinical Epidemiology Unit (S.M., M.H.H., S. Burkill, S. Bahmanyar) and Centre for Pharmacoepidemiology (S. Bahmanyar), Department of Medicine, Solna, Karolinska Institutet; Department of Neurology (J.H., T.O.), Karolinska University Hospital Huddinge, Stockholm; Neuroimmunology Unit (J.H.), Department of Clinical Neuroscience and Centre for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital, Solna, Sweden; and Faculty of Medicine (S. Bahmanyar), Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Mohammadhossein
authors.initials: M
authors.lastname: Hajiebrahimi
authors.affiliation: Clinical Epidemiology and Biostatistics (S.M.), School of Medical Sciences, Örebro University, Sweden; Department of Epidemiology and Public Health (S.M.), University College London, UK; Clinical Epidemiology Unit (S.M., M.H.H., S. Burkill, S. Bahmanyar) and Centre for Pharmacoepidemiology (S. Bahmanyar), Department of Medicine, Solna, Karolinska Institutet; Department of Neurology (J.H., T.O.), Karolinska University Hospital Huddinge, Stockholm; Neuroimmunology Unit (J.H.), Department of Clinical Neuroscience and Centre for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital, Solna, Sweden; and Faculty of Medicine (S. Bahmanyar), Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Sarah
authors.initials: S
authors.lastname: Burkill
authors.affiliation: Clinical Epidemiology and Biostatistics (S.M.), School of Medical Sciences, Örebro University, Sweden; Department of Epidemiology and Public Health (S.M.), University College London, UK; Clinical Epidemiology Unit (S.M., M.H.H., S. Burkill, S. Bahmanyar) and Centre for Pharmacoepidemiology (S. Bahmanyar), Department of Medicine, Solna, Karolinska Institutet; Department of Neurology (J.H., T.O.), Karolinska University Hospital Huddinge, Stockholm; Neuroimmunology Unit (J.H.), Department of Clinical Neuroscience and Centre for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital, Solna, Sweden; and Faculty of Medicine (S. Bahmanyar), Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Jan
authors.initials: J
authors.lastname: Hillert
authors.affiliation: Clinical Epidemiology and Biostatistics (S.M.), School of Medical Sciences, Örebro University, Sweden; Department of Epidemiology and Public Health (S.M.), University College London, UK; Clinical Epidemiology Unit (S.M., M.H.H., S. Burkill, S. Bahmanyar) and Centre for Pharmacoepidemiology (S. Bahmanyar), Department of Medicine, Solna, Karolinska Institutet; Department of Neurology (J.H., T.O.), Karolinska University Hospital Huddinge, Stockholm; Neuroimmunology Unit (J.H.), Department of Clinical Neuroscience and Centre for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital, Solna, Sweden; and Faculty of Medicine (S. Bahmanyar), Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Tomas
authors.initials: T
authors.lastname: Olsson
authors.affiliation: Clinical Epidemiology and Biostatistics (S.M.), School of Medical Sciences, Örebro University, Sweden; Department of Epidemiology and Public Health (S.M.), University College London, UK; Clinical Epidemiology Unit (S.M., M.H.H., S. Burkill, S. Bahmanyar) and Centre for Pharmacoepidemiology (S. Bahmanyar), Department of Medicine, Solna, Karolinska Institutet; Department of Neurology (J.H., T.O.), Karolinska University Hospital Huddinge, Stockholm; Neuroimmunology Unit (J.H.), Department of Clinical Neuroscience and Centre for Molecular Medicine, Karolinska Institutet and Karolinska University Hospital, Solna, Sweden; and Faculty of Medicine (S. Bahmanyar), Golestan University of Medical Sciences, Gorgan, Iran.
authors.forename: Shahram
authors.initials: S
authors.lastname: Bahmanyar