Antibodies help seriously ill H1N1 patients recover

Patients who fell severely ill with the pandemic H1N1 flu responded well when treated with antibodies harvested from survivors of the disease, a study in Hong Kong has found.

The finding, published in the journal Clinical Infectious Diseases, underlines the importance of using antibodies from recovered patients to treat critically ill people who fail to respond to standard drugs, said lead author Kwok-yung Yuen, a virologist at the University of Hong Kong.

"Most (severely ill patients) come to hospital very late, on day 5 or 7 (after onset of symptoms). Our experience has been that antiviral drugs don't work very well," said Yuen.

"That's why convalescent plasma (antibodies) would have a place in saving patients who are very severely ill and not responding to Tamiflu," he told Reuters.

Swiss drug maker Roche's Tamiflu, under license from Gilead Sciences, is the drug of choice to fight the pandemic H1N1 flu virus.

The Hong Kong study involved 93 patients who were admitted to hospital for severe H1N1 infection between September 2009 and June 2010. Of these, 20 agreed to receive antibodies, and the rest who declined were given standard treatment.

Twenty percent of those in the antibody group died compared to nearly 55 percent in the other group.

"It turned out that they survived much better than the group that didn't want the (antibody) treatment. The result is very significant," said Yuen.

"Once the patient got plasma (antibodies), viral load in respiratory secretions dramatically decreased and inflammatory parameters also dropped rapidly."

Seasonal flu kills between 250,000 to 500,000 people each year globally and the H1N1 swine flu may have been slightly more deadly, but actual statistics will take years to gather. It affects younger adults and children more severely compared to seasonal flu, which kills more elderly people.

SOURCE: Clinical Infectious Diseases, online January 19, 2011.