Improvements have been indicated by a large decrease in the relapse rate during their third trimester of pregnancy.
Women living with multiple sclerosis (MS) can temporarily see improvement in their disease while pregnant.
Improvements have been indicated by a large decrease in the relapse rate during their third trimester of pregnancy, according to a study published in April in the Journal of Neuroinflammation.
Researchers of the study noted pregnancy can cause changes in T cells in both MS and healthy controls, which affects inflammation and MS activity. In particular, researchers found changes in CD4+ and CD8+ T cells in pregnant women living with MS. However, CD4+ and CD8+ are implicated in MS pathogenesis as being key regulators of inflammation and brain lesion formation.
Although T cells are prime candidates for the pregnancy-associated improvement of MS, mechanisms behind the improvements are unclear. According to researchers, changes in pregnant women’s DNA and RNA events that occur in peripheral T cells during pregnancy in MS is lacking.
In the first in-depth investigation of the methylation and expression changes in peripheral CD4+ and CD8+ T cells during pregnancy in MS, researchers took blood samples of 11 women with MS before, during and after pregnancy and compared them to 7 healthy women who also had blood samples taken.
To understand what happens in immune cells, researchers identified the genes used in the T cells at various points in time during pregnancy. Changes regulating how genes are switched on and off, for example, epigenetic changes, were also observed. In the study, the researchers looked more specifically at one such regulation mechanism called DNA methylation.
Sandra Hellberg, assistant professor at the Department of Biomedical and Clinical Sciences at Linköping University and one of the researchers behind the study, said in a release by the University, what was most striking is researchers couldn’t find any real differences between the groups during pregnancy. Hellberg mentioned it seemed a pregnant woman’s immune system with MS looks roughly like one of a healthy pregnant woman.
Researchers found networks of interacting genes that are affected during pregnancy. Their study showed these genes are linked to MS and to important processes in the immune system.
“We can see that the changes in the T cells mirror the amelioration in relapse frequency,” Hellberg said in the release. “The biggest changes happen in the last third of pregnancy, and this is where women with MS improve the most. These changes are then reversed after pregnancy at the point in time when there is a temporary increase in disease activity.”
Sandra and researchers noted it’s important to stress that disease activity goes back to what it was prior to the pregnancy, after a baby is born.
The network of genes affected during pregnancy also included genes regulated by pregnancy hormones, mainly progesterone, the study said. Researchers are now testing various hormones in the lab to mimic the effects observed in the study and to find treatment strategies.