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IgG2 or immunoglobulin G subclass 2 are a type of antibody that our immune system produces to fight off invading pathogens. There are 4 type of IgG antibodies, and together they form the bulwark of our defense against bacterial and viral infection.
Last September Australian researchers discovered what they believed was a link between low levels of IgG2 and the severity of H1N1 infection.
In this report from last summer, Jason Gale of Bloomberg News brings us an early glimpse at this research.
Swine Flu Pregnancy Danger Tied to Cell Virus-Fighter (Update1)
By Jason Gale
Sept. 15 (Bloomberg) -- Pregnant women may be more vulnerable to swine flu because an infection-fighting blood cell fails to do its job within this group, Australian doctors said.
The finding emerged after doctors in Melbourne analyzed blood tests to determine why pregnant women made up a majority of their critically ill H1N1 patients. The results, reported at a medical meeting in San Francisco, showed six of seven of the women lacked a cell protein known as immunoglobulin G subclass 2, or IgG2. The antibody deficiency also was noted in seriously ill nonpregnant patients.
Today, in a follow up to that discovery, researchers are coming forth with a study that they say provides some insight into why novel H1N1 can be so severe in a small percentage of cases, and a possible course of treatment.
Researchers pinpoint swine flu death risk
AAPLast updated 00:00 04/02/2010
Australian researchers have found a way to predict whether a person's dose of swine flu is likely to turn life threatening, in a globally significant development.
Melbourne-based Professor Lindsay Grayson said it offered doctors a means to flag those patients who were most likely to experience the worst complications from a swine flu infection.
The discovery also pointed to a potential new treatment and an explanation for the most puzzling aspect of the global A(H1N1) pandemic.
That was, Prof Grayson said, the virus's ability to be a "pretty mild disease" for the majority while also striking young and apparently healthy people.
"The unusual thing about swine flu is that, if you compare it to seasonal influenza, it mainly affects people aged 15 to 35," said Prof Grayson, who is director of infectious diseases at Austin Health.
"It's very unusual for us to see a 22-year-old about to die with (ordinary seasonal) influenza.
"Our thought is there is something special about swine flu and its interaction with immunoglobulin."
Prof Grayson found those swine flu patients who become the sickest were likely to have a pre-existing deficiency of a specific blood protein (immunoglobulin G2 or IgG2) that is crucial to the proper functioning of the immune system.
The study, which is to be published in the journal Clinical Infectious Diseases, does not appear to be available online yet.
