title: Effects of dimethyl fumarate on lymphocyte subsets.
abstract: OBJECTIVE
  To evaluate changes in absolute lymphocyte counts, lymphocyte subsets, and infections in patients treated with dimethyl fumarate (DMF) in comparison to the baseline pre-DMF levels.
  
  
  METHODS
  A retrospective chart review was conducted of 23 MS patients treated with DMF. Absolute lymphocyte counts and lymphocyte subsets were obtained at baseline and after at least 3 months of DMF treatment. Data on infections requiring medical attention were also collected.
  
  
  RESULTS
  A total of 23 patients were included in this analysis, 11 male (48%), 12 female (52%), with a mean age of 44.5±14.1 years, disease duration of 13.7±8.9 years, and EDSS of 3.5±1.7. The time between baseline and treatment lymphocyte counts was 3.9±1.2 months. Significant reductions in absolute lymphocyte counts by 35% (p<0.0001), CD3(+) by 34% (p<0.0001), CD4(+) by 34% (p<0.0001), CD8(+) by 40% (p<0.0001), and CD19(+) counts by 48% (p=0.0098) were found. Grade 2 lymphopenia occurred in 24% of patients and grade 3 lymphopenia occurred in 1 patient. Infections occurred in 26% of patients, mainly as urinary tract infections (22%) and one fatal case of West Nile encephalitis in a patient with grade 3 lymphopenia, who had been on DMF for 5 months. A detailed summary of this fatal case is provided.
  
  
  CONCLUSIONS
  Lymphocyte subsets may help to provide better understanding of immunologic and safety impact of DMF.
authors.affiliation: MS Comprehensive Care Center at the University of Southern California Keck School of Medicine of USC, USA. Electronic address: rberkovi@usc.edu.
authors.forename: Regina
authors.initials: R
authors.lastname: Berkovich
authors.affiliation: MS Comprehensive Care Center at the University of Southern California Keck School of Medicine of USC, USA.
authors.forename: Leslie P
authors.initials: LP
authors.lastname: Weiner
mesh_terms: D000328:Adult; D000069462:Dimethyl Fumarate / Q000009:adverse effects / Q000627:therapeutic use*; D017809:Fatal Outcome; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000187:drug effects*; D008231:Lymphopenia / Q000097:blood / Q000139:chemically induced; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000097:blood* / Q000188:drug therapy*; D012189:Retrospective Studies; D014901:West Nile Fever / Q000097:blood
chemical_list: D007166:Immunosuppressive Agents; D000069462:Dimethyl Fumarate
keywords: Dimethyl fumarate; Lymphopenia; Multiple sclerosis