Scientists working to find new treatments for the H1N1 flu said an established procedure used to treat other illnesses may also work to treat the flu. Convalescent plasma therapy is a treatment that has been used for many years to treat a variety of diseases, including the 1918 influenza pandemic. Researchers in Hong Kong now believe that this treatment may be helpful in saving the lives of patients with severe cases of the H1N1 flu.
Plasma is the liquid that makes up over half the volume in human blood. It contains water, proteins, hormones, and other components including clotting factors. Other blood cells such as red cells and platelets “swim” in the plasma. When the body produces antibodies to fight off an infection such as the flu, the antibodies are carried throughout the body in blood plasma.
Donated blood is commonly separated into its components including red cells and plasma. When plasma is collected from a patient who has recovered from a severe flu, the antibodies that fought off the flu virus are still present in the plasma and can be donated to someone who is sick. Because flu antibodies are targeted specifically at the flu virus, they will continue to fight the flu even after they are injected into someone else. This boost of antibodies can make the difference for someone whose own body is having a hard time fighting off the flu virus.
During the height of the 2009 H1N1 epidemic, researchers in Hong Kong tested the idea that convalescent plasma therapy could be effective against this type of flu. Ninety-three patients who required intensive care in Hong Kong area hospitals were included in the study. Twenty patients agreed to the plasma therapy. The remaining 73 chose not to receive plasma therapy and were used as the control group for the study. The results showed that 20 percent of patients who received plasma therapy died as a result of the flu, compared to 55 percent of patients who did not receive plasma therapy. None of the patients who received plasma therapy developed any negative side effects as a result of the treatment.