title: Contaminated heparin associated with adverse clinical events and activation of the contact system.
abstract: BACKGROUND
  There is an urgent need to determine whether oversulfated chondroitin sulfate (OSCS), a compound contaminating heparin supplies worldwide, is the cause of the severe anaphylactoid reactions that have occurred after intravenous heparin administration in the United States and Germany.
  
  
  METHODS
  Heparin procured from the Food and Drug Administration, consisting of suspect lots of heparin associated with the clinical events as well as control lots of heparin, were screened in a blinded fashion both for the presence of OSCS and for any biologic activity that could potentially link the contaminant to the observed clinical adverse events. In vitro assays for the activation of the contact system and the complement cascade were performed. In addition, the ability of OSCS to recapitulate key clinical manifestations in vivo was tested in swine.
  
  
  RESULTS
  The OSCS found in contaminated lots of unfractionated heparin, as well as a synthetically generated OSCS reference standard, directly activated the kinin-kallikrein pathway in human plasma, which can lead to the generation of bradykinin, a potent vasoactive mediator. In addition, OSCS induced generation of C3a and C5a, potent anaphylatoxins derived from complement proteins. Activation of these two pathways was unexpectedly linked and dependent on fluid-phase activation of factor XII. Screening of plasma samples from various species indicated that swine and humans are sensitive to the effects of OSCS in a similar manner. OSCS-containing heparin and synthetically derived OSCS induced hypotension associated with kallikrein activation when administered by intravenous infusion in swine.
  
  
  CONCLUSIONS
  Our results provide a scientific rationale for a potential biologic link between the presence of OSCS in suspect lots of heparin and the observed clinical adverse events. An assay to assess the amidolytic activity of kallikrein can supplement analytic tests to protect the heparin supply chain by screening for OSCS and other highly sulfated polysaccharide contaminants of heparin that can activate the contact system.
authors.affiliation: Momenta Pharmaceuticals, the Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA.
authors.forename: Takashi Kei
authors.initials: TK
authors.lastname: Kishimoto
authors.forename: Karthik
authors.initials: K
authors.lastname: Viswanathan
authors.forename: Tanmoy
authors.initials: T
authors.lastname: Ganguly
authors.forename: Subbiah
authors.initials: S
authors.lastname: Elankumaran
authors.forename: Sean
authors.initials: S
authors.lastname: Smith
authors.forename: Kevin
authors.initials: K
authors.lastname: Pelzer
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Lansing
authors.forename: Nammalwar
authors.initials: N
authors.lastname: Sriranganathan
authors.forename: Ganlin
authors.initials: G
authors.lastname: Zhao
authors.forename: Zoya
authors.initials: Z
authors.lastname: Galcheva-Gargova
authors.forename: Ali
authors.initials: A
authors.lastname: Al-Hakim
authors.forename: Gregory Scott
authors.initials: GS
authors.lastname: Bailey
authors.forename: Blair
authors.initials: B
authors.lastname: Fraser
authors.forename: Sucharita
authors.initials: S
authors.lastname: Roy
authors.forename: Thomas
authors.initials: T
authors.lastname: Rogers-Cotrone
authors.forename: Lucinda
authors.initials: L
authors.lastname: Buhse
authors.forename: Mark
authors.initials: M
authors.lastname: Whary
authors.forename: James
authors.initials: J
authors.lastname: Fox
authors.forename: Moheb
authors.initials: M
authors.lastname: Nasr
authors.forename: Gerald J
authors.initials: GJ
authors.lastname: Dal Pan
authors.forename: Zachary
authors.initials: Z
authors.lastname: Shriver
authors.forename: Robert S
authors.initials: RS
authors.lastname: Langer
authors.forename: Ganesh
authors.initials: G
authors.lastname: Venkataraman
authors.forename: K Frank
authors.initials: KF
authors.lastname: Austen
authors.forename: Janet
authors.initials: J
authors.lastname: Woodcock
authors.forename: Ram
authors.initials: R
authors.lastname: Sasisekharan
mesh_terms: D000707:Anaphylaxis / Q000139:chemically induced*; D000818:Animals; D002681:China; D002809:Chondroitin Sulfates / Q000009:adverse effects / Q000032:analysis* / Q000494:pharmacology*; D003167:Complement Activation / Q000187:drug effects*; D015926:Complement C3a / Q000096:biosynthesis / Q000187:drug effects; D015936:Complement C5a / Q000096:biosynthesis / Q000187:drug effects; D004340:Drug Contamination; D004345:Drug Industry; D005260:Female; D005858:Germany; D006493:Heparin / Q000009:adverse effects / Q000737:chemistry*; D006801:Humans; D007022:Hypotension / Q000139:chemically induced; D007610:Kallikreins / Q000187:drug effects* / Q000378:metabolism; D008875:Middle Aged; D034421:Sus scrofa; D014481:United States; D014486:United States Food and Drug Administration
chemical_list: D015926:Complement C3a; D015936:Complement C5a; D006493:Heparin; D002809:Chondroitin Sulfates; D007610:Kallikreins