Coughing, runny nose, fever, achy joints. These are some of
the stereotypical symptoms of the flu. Every year during flu season, about 10%
of people will come down with the illness. While most people just take a few
days off from work, sleep, and drink lots of fluids to recover, the flu can be
associated with much more severe disease. I’m sure we all remember the H1N1
outbreak a few years ago, and the severity that came with that. In that
outbreak, as well as previous ones, it was shown that young adult women were
more likely to experience severe outcomes associated with the disease than men.
Interestingly, during the H1N1 outbreak in 2009, women were 2-6 times more
likely to die from the infection than men.
This issue of gender differences in disease has long been of
interest to Dr. Sabra Klein, Associate Professor in the Johns Hopkins School of
Public Health. She has dedicated years of study to the issue, and recently made
an exciting breakthrough that may aid in our treatment of women with influenza.
Dr. Klein’s lab published an article in the American
Journal of Physiology - Lung Cellular and Molecular Physiology in late
December. The study found that estrogen and estrogen-like compounds could
reduce the level of flu virus replication in the human nasal epithelial cells
of women, but not men. This seemed to be caused through the action of the
genomic estrogen receptor 2. Notably, this reduction in virus level was not
associated with an increased production of cytokines, but rather a decrease in
cellular metabolism. Since cytokine storms are often associated with adverse
outcomes for women with the flu, the fact that this antiviral effect was
achieved without excess cytokines is very promising.
The flu virus isn’t the first disease that’s been
found to be inhibited by estrogen. Replication of Human Immunodeficiency Virus
(HIV), Hepatitis C, and even Ebola has been shown to be inhibited by estrogen.
This raises the possibility of new treatments for these diseases. Select
estrogen receptor modulators (SERMs) such as clomiphene and raloxifene
are already approved by the FDA for treatment of osteoporosis and infertility.
It is possible that someday, these or other similar drugs could be repurposed
to treat the flu in women, along with these other viral infections. That would
certainly be one small step for woman, one giant leap for man and womankind.
