title: Natural killer cell subpopulations are associated with MRI activity in a relapsing-remitting multiple sclerosis patient cohort from Australia.
abstract: BACKGROUND
  The importance of the innate immune system in multiple sclerosis (MS) is increasingly recognized and the role of natural killer (NK) cells in controlling autoimmunity may be an important modulator of disease activity.
  
  
  OBJECTIVE
  To examine NK subsets in MS patients on different treatments and to evaluate the role of NK subsets as indicators for disease activity.
  
  
  METHODS
  We measured NK subset levels in blood obtained from 110 relapsing-remitting MS patients. Patients were either off treatment or on treatment with natalizumab, fingolimod, glatiramer acetate or beta-interferon. Disease activity was defined according to 'No Evidence of Disease Activity' (NEDA) criteria within an observation period of up to 2.4 years. The mean NK subset levels were compared among treatment groups using multivariate analysis of variance (ANOVA) and association analysis with disease activity performed using multi-factor logistic regression.
  
  
  RESULTS
  Our analysis revealed differences in NK cells and subsets on treatment compared to off treatment ( p < 0.0005). A high proportion of bright NK cells were significantly associated with stable magnetic resonance imaging (MRI) imaging after adjusting for treatment effects ( p < 0.05).
  
  
  CONCLUSIONS
  The independent association of NK subsets with MRI stability needs to be confirmed in prospective studies to test their usefulness in predicting disease activity in MS patients.
authors.affiliation: Department of Neurology, John Hunter Hospital, New Lambton, NSW, Australia; Hunter Medical Research Institute, New Lambton, NSW, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Caruana
authors.affiliation: Pathology North, New Lambton, NSW, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Lemmert
authors.affiliation: Department of Neurology, John Hunter Hospital, New Lambton, NSW, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Ribbons
authors.affiliation: Hunter Medical Research Institute, New Lambton, NSW, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Lea
authors.affiliation: Department of Neurology, John Hunter Hospital, New Lambton, NSW, Australia; Hunter Medical Research Institute, New Lambton, NSW, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Lechner-Scott
mesh_terms: D000328:Adult; D000368:Aged; D001315:Australia; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000097:blood* / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: CD56 bright; CD56 dim; Lymphocytes; natural killer cells