Gold rush

Plasma, the liquid part of blood, is useful in a range of medical treatments but demand is in danger of outstripping supply.

- Nicky Pellegrino

They call it "liquid gold". Plasma is critical to the health of increasing numbers of people, but many of us remain unaware of its importance. The liquid part of the blood, plasma carries cells and platelets around the body. Although it is mostly water, this straw-colored fluid also contains other valuable components.

Donated plasma is processed into up to 11 different products to help patients with health problems including auto-immune diseases, blood-clotting issues, damaged immune systems - perhaps from an inherited disorder or following chemotherapy as well as after surgery or trauma. And demand for plasma is growing in New Zealand by about 12% a year.

"Potentially, there is a whole range of diseases that plasma can be useful for; the evidence for some is stronger than others," says Gavin Cho, a transfusion medicine specialist with the New Zealand Blood Service.

Donated plasma helps patients with autoimmune diseases, blood-clotting issues and damaged immune systems.

"But they tend to be chronic conditions and that's one of the problems, really. It's not a one-off treatment, it's something that patients might need on a monthly basis for years." The process of donating plasma is different from giving whole blood. It takes about 90 minutes and is obtained through apheresis - so the blood is taken from the vein and put through a centrifuge machine, which spins it to separate the red bloods cells and platelets from the plasma, then returns them to the donor. This means plasma can be given quite frequently, every two to three weeks.

Plasma potential: Gavin Cho, left, and Doug Gallagher.