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Building Better Blood

New Zealand haemophiliacs are to have access to a virus-free source of the blood-clotting protein Factor VIII. The protein, distributed under the name Kogenate, is produced using recombinant genetic engineering techniques, and is free of contamination by disease-causing organisms.

The gene controlling the production of Factor VIII is missing in people who suffer from haemophilia A. To date, the protein has been made by combining large quantities of blood plasma from human donors to produce small quantities of the agent. This has put haemophiliacs at risk of picking up blood-borne viral infections such as Hepatitis C and the HIV virus that leads to AIDS, and infections from contaminated Factor VIII have been reported. In addition, because of the large amounts of plasma required, there have been problems of limited supply.

The production of Kogenate uses cloned baby hamster kidney cells which have had the human gene for Factor VIII inserted into their gene sequence. The host cells produce the protein which is then extracted, purified and concentrated. Large quantities of pure protein can thus be produced under controlled conditions.

The Ministry of Health recently gave approval for Kogenate to be used in New Zealand. It will be imported from overseas by Bayer New Zealand, having been produced in the US by a subsidiary company. Bayer International has been working on a gene therapy for haemophilia with the ultimate aim of being able to insert the missing gene sequence directly into the human body.