Can transfusions aid Ebola fight?

As the world searches for new tools to fight the Ebola scourge in West Africa, the use of a decades-old, largely unproven therapy—transfusing blood plasma from recovered patients—has surfaced as a potential weapon.

The European Commission announced plans last month to fund a study that would look at the efficacy of using blood plasma from Ebola survivors as a possible treatment. Recently, the World Health Organization issued guidance for health professionals on the best way to collect, store and administer whole blood and plasma transfusions to treat Ebola patients in West Africa.

“While there is no proven treatment available for Ebola virus disease, whole blood collected from patients in the convalescent phase of infection has been used as an empirical treatment with promising results in a small group of EVD cases,” according to the guidelines.

But experts say convalescent therapy would not be viable for use in the U.S. if the nation sees a sudden uptick in the number of Ebola cases. That's because there are currently only a few patients in the U.S. who could donate blood plasma, so it would be impossible to establish and store a large supply for treatment purposes, said Dr. James Landmark, director of clinical laboratory support services at the University of Nebraska Medical Center, Omaha.

Performed for decades, convalescent therapy involves collecting blood from patients who have developed antibodies to a disease and transfusing their plasma into patients with the active disease. The antibodies help patients fight Ebola, giving the patient's immune system time to develop its own defenses.

It's also unclear whether convalescent therapy would be viable in West Africa, where hundreds of Ebola survivors are available to donate blood plasma, Landmark said. Resources are lacking there to provide such treatment to the thousands of patients. Also, transfusions could increase the risk of other infections such as hepatitis and HIV if blood is not properly tested.

In the U.S., several patients have received transfusions. Dr. Kent Brantly, the U.S. physician who contracted Ebola while working in Liberia, reportedly received a transfusion from a recovered patient. Brantly, who recovered, in turn donated his plasma to three other patients—nurse Nina Pham, infected while treating patient Thomas Eric Duncan in Dallas; Dr. Rick Sacra, who contracted the virus while in Liberia; and journalist Ashoka Mukpo, who got sick while reporting from the region. Brantly reportedly offered to donate plasma to Duncan, but did not match his blood type. Duncan died Oct. 8; the others recovered.

Dr. Craig Spencer, who is being treated for Ebola at a New York City hospital, reportedly received a transfusion from former patient Nancy Writebol, an aide worker who contracted Ebola in Liberia and recovered after receiving care at Emory University Hospital, Atlanta.

Whether the transfusions helped is unknown, and convalescent therapy remains a subject of debate.

Scientific evidence to substantiate the therapy's benefit is scarce. The number of patients who have undergone convalescent therapy remains small since transfusion was first used for an Ebola patient in the 1970s. No clinical trials have been done to determine efficacy.

But efficacy, logistics and safety questions haven't stopped the international community from exploring the widespread use of convalescent serum to address the continuing crisis in West Africa, where more than 4,900 people have died from the virus.

Transfusions were given to eight patients in the Democratic Republic of Congo during an Ebola outbreak in 1995; seven of those patients survived. “I don't know if it's really helping or whether it's just serendipity,” said Dr. Lowell Tilzer, a professor of pathology and laboratory medicine at the University of Kansas Hospital, Kansas City.

Tilzer said the crisis in West Africa is too severe to allow a randomized trial of convalescent therapy there. But pharmaceutical firms are developing plasma with high concentrations of antibodies from recovered Ebola patients to produce a convalescent serum.

Landmark said the use of convalescent therapy or serum may buy time for the development of a vaccine. “Convalescent plasma from Ebola survivors may help people who are sick, but it won't prevent new cases,” he said. “Vaccination is the tool we need to stop the epidemic in West Africa.”

Follow Steven Ross Johnson on Twitter: @MHsjohnson