title: Phlebotomy treatment for elimination of perfluoroalkyl acids in a highly exposed family: a retrospective case-series.
abstract: BACKGROUND
  Perfluoroalkyl acids (PFAAs) are a family of commonly used synthetic chemicals that have become widespread environmental contaminants. In human serum, perfluorohexane sulfonate (PFHxS), perflurooctane sulfonate (PFOS), and perfluorooctanoate (PFOA) are most frequently detected, in part owing to their long elimination half-lives of between 3.8 yrs (PFOA) and 8.5 yrs (PFHxS). These PFAAs also cross the placenta and have been associated with developmental toxicity, and some are considered likely human carcinogens. Interventions to eliminate PFAAs in highly contaminated individuals would reduce future health risks, but minimal research has been conducted on methods to facilitate accelerated human clearance of these persistent substances.
  
  
  METHODS
  Six patients with elevated serum concentrations from a single family were treated by intermittent phlebotomy over a 4-5 year period at intervals similar to, or less frequent than what is done for routine blood donation at Canadian Blood Services. The apparent elimination half-life (HLapp) for PFHxS, PFOS, and PFOA in this treated population was calculated in each patient and compared to the intrinsic elimination half-lives (HLin) from a literature reference population of untreated fluorochemical manufacturing plant retirees (n = 26, age >55 yrs).
  
  
  RESULTS
  For all three PFAAs monitored during phlebotomy, HLapp in each of the family members (except the mother, who had a low rate of venesection) was significantly shorter than the geometric mean HL measured in the reference population, and in some cases were even shorter compared to the fastest eliminator in the reference population.
  
  
  CONCLUSIONS
  This study suggests significantly accelerated PFAA clearance with regular phlebotomy treatment, but the small sample size and the lack of controls in this clinical intervention precludes drawing firm conclusions. Given the minimal risks of intermittent phlebotomy, this may be an effective and safe clinical intervention to diminish the body burden of PFAAs in highly exposed people.
authors.affiliation: Faculty of Medicine and Dentistry. University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Genuis
authors.affiliation: Division of Analytical & Environmental Toxicology, Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Yanna
authors.initials: Y
authors.lastname: Liu
authors.affiliation: MD Program, Faculty of Medicine and Dentistry. University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Quentin I T
authors.initials: QI
authors.lastname: Genuis
authors.affiliation: Division of Analytical & Environmental Toxicology, Department of Laboratory Medicine & Pathology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Martin
mesh_terms: D000293:Adolescent; D004781:Environmental Exposure / Q000009:adverse effects*; D004785:Environmental Pollutants / Q000493:pharmacokinetics*; D005260:Female; D005466:Fluorocarbons / Q000493:pharmacokinetics*; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D018962:Phlebotomy; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D004785:Environmental Pollutants; D005466:Fluorocarbons