Contaminated heparin associated with adverse clinical events and activation of the contact system.
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.
Kishimoto
Takashi Kei
TK
Momenta Pharmaceuticals, the Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA.
Viswanathan
Karthik
K
Ganguly
Tanmoy
T
Elankumaran
Subbiah
S
Smith
Sean
S
Pelzer
Kevin
K
Lansing
Jonathan C
JC
Sriranganathan
Nammalwar
N
Zhao
Ganlin
G
Galcheva-Gargova
Zoya
Z
Al-Hakim
Ali
A
Bailey
Gregory Scott
GS
Fraser
Blair
B
Roy
Sucharita
S
Rogers-Cotrone
Thomas
T
Buhse
Lucinda
L
Whary
Mark
M
Fox
James
J
Nasr
Moheb
M
Dal Pan
Gerald J
GJ
Shriver
Zachary
Z
Langer
Robert S
RS
Venkataraman
Ganesh
G
Austen
K Frank
KF
Woodcock
Janet
J
Sasisekharan
Ram
R
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
D015926:Complement C3a; D015936:Complement C5a; D006493:Heparin; D002809:Chondroitin Sulfates; D007610:Kallikreins