|Photo by Fabio Goveia on Flickr.com
In contrast, about 50% of pregnant women with lupus experience a flare of the disease during pregnancy, although this not associated with permanent aggravation of the disease.
Several studies published in the last few months are shedding some light on why this is so.
Within the human body, there are two types of cells, called T-helper-cells, that are important in inflammation. They are called Th1 and Th2. Th1 cells are one of the main factors in RA. Th2 cells are one of the main factors associated with lupus.
During pregnancy there is a progressive increase in estrogens, which reach a peak level in the third trimester of pregnancy. At these high levels, estrogens suppress Th1 mediated responses and stimulate Th2 mediated responses.
That is why RA tends to get better and lupus tends to get worse.
Very interesting work, but so far this is not enough on its own to result in any treatments for RA that might work outside of pregnancy (or for lupus during pregnancy).
Oral contraceptives were tried for RA because they generate a condition of pseudopregnancy. Several controlled studies have found oral contractive pills don't seem to have much effect on either reducing the risk of developing RA or in treating already established RA.
Luckily medical research has resulted in further insights that have resulted in some promising new therapies. I will discuss them in the next article.