Viral infections of the heart are a causative factor of myocarditis as well as of sudden, unexpected deaths of children, yet the mechanisms of pathogenesis remain unclear, in part due to the relatively few animal models of virus-induced myocarditis. In the current study, we examined the ability of polytropic murine retroviruses to infect the heart and induce cardiac dysfunction. In situ hybridization and immunohistochemistry analysis detected virus-infected cardiomyocytes and macrophages in the heart. A significant decrease in left ventricle function, as measured by fractional shortening, was detected in mice infected with the neurovirulent retrovirus Fr98 but not in mice infected with the nonneurovirulent retrovirus Fr54. Virus infection was not associated with consistent findings of fibrosis or substantial cellular infiltrate. Fr98-induced left ventricle dysfunction was associated with a higher virus load, increased mRNA expression of the macrophage marker F4/80, increased chemokine production, and a small number of apoptotic cells in the heart.
"It is of note that progesterone tends to shift the immune balance towards Th2, and that progesterone levels rise to as much as 10 to 15 times normal during the third trimester. So, as a molecular biologist, it leaves me to theorize that if this virus can mimic progesterone, it can create a state that allows the immune system to ignore the virus, very much like it ignores a developing fetus - scary isn't it?"
So, liverock, if I am reading this right, does this explain why more women are affected by this disease? I know women produce certain hormones/androgens that are considered male like testosterone, but do men produce female hormones like progesterone?
Wait, I think I read that wrong. The author says the following:
"Observations reveal that high rates of estrogen, or high rates of testosterone in the absence of progesterone tend to favor the growth of XMRV - progesterone inhibits the formation of DHT. It seems to indicate that succeptibility to ME/CFS is strongly hormone driven, and why ME/CFS and FM are strongly female prevalent."
I am scheduled to get a progesterone only IUD. Now I am wondering if getting more progesterone in my system would actually help rather than harm. Is anybody else coming to the conclusion that progesterone supplementation might be good after reading this, or am I getting this wrong?