title: Duration of intralipid's suppressive effect on NK cell's functional activity.
abstract: BACKGROUND
  In vitro investigations have revealed the ability of intralipids to suppress natural killer (NK) cytotoxicity. Evidence from both animal and human studies suggests that intralipid administered intravenously may enhance implantation and maintenance of pregnancy when the patient has an abnormal NK cell level or function.
  
  
  OBJECTIVE
  The aim of this study was to establish the duration and efficacy of Intralipids suppressive effect on NK cell functional activity.
  
  
  METHODS
  Fifty patients with abnormal NK activity results (NKa) received intralipid 20% i.v. (9 mg/mL total blood volume -corresponds to 2 mL of intralipid 20% diluted in 250 mL saline; or 18 mg/mL - corresponds to 4 mL of intralipid 20% diluted in 250 mL saline) infusions and their NKa were tested periodically. The determination of NK cell function was performed by flow cytometry using K562 cells as targets.
  
  
  RESULTS
  Fifty women with abnormal NKa-testing received intralipid infusions. 39 (78%) showed NKa suppression within the normal range the first week after infusion, 11 (22%), showed suppression, but still above the normal threshold. They received second infusion 2-3 weeks later. In 10, the Nka activity was normalized the following week. Four patients had three intralipid infusions in 2-week periods in between and after the third infusion, and all showed NKa normal activity. In 47 patients the suppressive effect of the Intralipid after the normalization of NKa lasted between 6 and 9 weeks, in two patients this benefit lasted 5 weeks, and in one patient the effect was 4 weeks.
  
  
  CONCLUSIONS
  Intralipid is effective in suppressing in vivo abnormal NK-cell functional activity. The results suggest that Intralipid can be used successfully as a therapeutic option to modulate abnormal NK activity in women with reproductive failure.
authors.affiliation: Millenova Immunology Laboratories, Chicago, IL, USA. rgroussev@yahoo.com
authors.forename: Roumen G
authors.initials: RG
authors.lastname: Roussev
authors.forename: Brian
authors.initials: B
authors.lastname: Acacio
authors.forename: Siu C
authors.initials: SC
authors.lastname: Ng
authors.forename: Carolyn B
authors.initials: CB
authors.lastname: Coulam
mesh_terms: D000026:Abortion, Habitual / Q000276:immunology*; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D005217:Fat Emulsions, Intravenous / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects
chemical_list: D005217:Fat Emulsions, Intravenous