Contact Activation
July 12, 2003
14:00 to 18:00
Hall 7
The The International Convention Center, Birmingham
Chairman: R. A. DeLa Cadena, USA.
Co-Chairs: M. J. Gallimore, UK; Keith R. McCrae, USA; H. Saito, Japan;
A. H. Schmaier, USA
The meeting was well attended and fulfilling the objectives of the SSC, namely
standardization of plasma, methods, animal models and clinical trials.
We began the session with studies on standardized plasma elegantly presented
by Dr. Schmaier who presented Western-Blots of HK and different deficient
plasmas.
The session proceeded with a presentation of Dr. Pixley update on prekallikrein
activator and high molecular weight kininogen deficient plasmas development
and availability. Prekallikrein activator newly commercially available from
Enzyme Research Laboratories was tested and compared against the previous
lots of World Health Organization (SSC/ISTH secondary coagulation standard
currently limited in availability), and checked for six-month stability and
viability and found to be an excellent appropriate product.
Dr. Jones presentation focused on the SSC plasmas, an important issue from
the angle to Reference plasma for routine patient’s plasma in view of the
new upcoming Lot 3 from NIBSC. Dr. Jones observation emphasized that Plasma
Prekallikrein laboratory determinations should be performed using chromogenic
and immunochemical assays since the clotting assays are insensitive and thus
unsuitable for routine PK analyses.
There were comments raised from the floor about previous use of this limited
available reagent as an activated FXII product standard, which initially
was not the intention of this product. As such it was decided that a FXII
standard should be created and tested by at least ten (10) laboratories around
the world, and companies given the opportunity to provide the standard for
activated FXII products. At least two companies have shown interest in doing
so including Enzyme Research Laboratories and Technoclone.
A motion was made to get WHO approval of the PKa reagent to become certified
as the standard. Enzyme Research Laboratories volunteered to provide the
product for the standardization. Ten (10) laboratories will be selected to
achieve such task.
In view of the upcoming shortage of HK deficient plasma for clinical laboratories
to perform the analysis and provide the service for diagnostic purposes,
synthetic deficient plasmas are commercially available and under development
and data was provided during the session. The currently commercially available
deficient plasma using polyclonal antibodies had an excellent response correlation
to genetically deficient plasmas.
The commercially HK deficient plasma by the use of monoclonal antibodies
showed great promise for standardized market development.
The session then moved into methods elegantly presented by Professor Gallimore
and Dr. Madar with valuable information in the area of fibrinolysis and non-radioactive
techniques.
Standardized animal models clinically relevant to the contact system were
presented, namely by Professor Colman who indicated the importance of the
system and angiogenesis.
A therapeutic reagent with potential promise to treatment of patients afflicted
HAE was nicely presented by Dr. Machie.
At the conclusion of the session a consensus for a new name was voted from
the floor with a proposed new name by Professor Schmaier for the SSC on Contact
System, namely "Plasma Kallikrein- Kinin System".
The meeting was ran on scheduled as posted on the ISTH webside with breaks
schedule according to the Chair’s guidelines provided by the ISTH in anticipation
of the meeting. The session was closed early in view of no discussion related
to the re-naming of the subcommittee that it was anticipated to take a significant
amount of time.
Respectfully prepared and presented by Dr. DeLa Cadena