Why Autoimmune Diseases Go Into Remission During Pregnancy

Washington, June 18: A biological mechanism that affects the immune system is what makes the experiences of many women of remission of autoimmune diseases like multiple sclerosis and uveitis during pregnancy, according to a study.

The expression of an enzyme known as pyruvate kinase was reduced in immune cells in pregnant women compared with nonpregnant women, according to Dr. Howard R. Petty, a biophysicist at the University of Michigan Kellogg Eye Center and Dr. Roberto Romero, National Institutes of Health.

The study also reported that the expression of the enzyme is lower in pregnant women, compared to those with pre-eclampsia, a condition with inflammatory components.

This study is important because the newly discovered mechanism suggests a way that could be targeted for treatment.

"It is possible to design drugs that suppress the activity of pyruvate kinase little as a way of reproducing the immune status of normal pregnancy," said the Master.

In addition to pre-eclampsia, it is believed that rheumatoid arthritis, type 1 diabetes, uveitis, and may even give in to drugs the same design.

In his quest to explain the phenomenon, the Master was searching for a way or mechanism that has two characteristics: they had to "dial down" the intensity of the normal immune response, an action necessary for a pregnant woman does not reject the fetus , the father of the proteins that are "foreigners" to the mother. At the same time, this mechanism should support the growth of cells necessary for fetal development.

The activity of pyruvate kinase and the enzyme and its product, pyruvate serves two roles: to promote cell growth while modifying the immune response.

Since the activity of pyruvate kinase is depressed during pregnancy, supports cellular metabolism with increased production of lipids, carbohydrates, amino acids and other substances that promote cell growth.

Petty explains that our robust immune response depends on the normal pyruvate to promote calcium signaling, which in turn stimulates the production of messenger molecules called cytokines.

When pyruvate is decreased during pregnancy, calcium signaling is also reduced and the immune response is different from that of non-pregnant.

"Changing the message along this path allows the pregnant woman to maintain the immune response, but at a level that does not harm the fetus," said Petty,

The study involved 21 women in their third trimester of normal pregnancy, 25 women and pre-eclampsia, and a control group of non-pregnant women.

The researchers used a variety of ways to confirm their findings, including fluorescence microscopy and flow cytometry, which used to study cell signaling.

The higher the enzyme seen in women with pre-eclampsia study confirmed the results, said Petty.

"Preeclampsia has characteristics of inflammatory diseases. If you can not reduce levels of pyruvate, you can increase the inflammatory disease, "he added.

Petty hopes to one day enzyme levels can be tested in early pregnancy to predict the likelihood of developing preeclampsia or other complications.

The study appears online ahead of print in the August issue of American Journal of Reproductive Immunology. (ANI)