The majority of people who are exposed to dengue virus only have slight symptoms. But some people have life-threatening disease the second time they are infected with it. Why this occurs is not completely understood. A recent study in "Science" now provides clues to the phenomenon. The study, led by The Rockefeller University, Stanford University, Emory University School of Medicine, Mahidol University, National Institutes of Health and Faculty of Medicine Siriraj Hospital, shows that people with severe secondary disease produce large amounts of an antibody and this antibody induces a strong immune response. This does not occurs in people who have slight symptoms. The finding may points to new ways to treat severe secondary infections with dengue virus. Dengue virus is spread by mosquitos, and is responsible for the painful, debilitating disease dengue ferver, or called breakbone fever. Typical symptoms include high fever, severe headache, severe joint and muscle pain, swollen lymph nodes, fatigue, nausea, vomiting, rash, and mild bleeding. The disease is more common in the tropics and subtropics. There is no specific drug for it now. Previously, scientists thought that when dengue virus infects a second time it utilizes pre-existing antibodies that have been induced by the first infection. However, why only 15% people with secondary infection have hemorrhagic fever or shock is unknown. To unravel this question, the researchers investigated the Fc regions of antibodies in blood of patients with mild and severe secondary dengue infections. They found that the structures of these antibodies in these patients are not the same. In patients with severe disease, there are higher levels of antibodies whose Fc regions lack a particular sugar. This type of antibodies can effectively activate immune responses. Cusabio offers rabbit polyclonal antibody.
