A study of pregnant women with systemic lupus erythematosus has identified early changes in the RNA molecules present in the blood that could be used to determine the likelihood of them developing preeclampsia. The study, published in the Journal of Experimental Medicine, may also help researchers develop treatments to prevent other pregnancy complications associated with lupus, including miscarriage and premature birth.
Lupus is an autoimmune disease in which the immune system attacks the body’s own healthy tissues. The disease predominantly affects women and carries an increased risk of developing complications during pregnancy; approximately one fifth of pregnant lupus patients develop problems ranging from preeclampsia to fetal death and preterm delivery.
To identify potential biomarkers, researchers compared blood samples taken at regular intervals from either pregnant lupus patients or healthy pregnant women. The researchers counted the different types of immune cells present in these samples and, as a measure of which genes were active in these cells, analyzed the RNA molecules they produced over the course of pregnancy and in the postpartum period.
In a healthy pregnancy, the immune system is prevented from attacking the developing fetus. Accordingly, researchers found that several components of the immune system, including antibody-producing plasma cells and the proinflammatory interferon response, were suppressed in healthy pregnant women. An additional analysis of women undergoing assisted reproductive therapy suggested that the interferon response, in particular, is downregulated within days of embryo implantation. At later stages of pregnancy, however, some components of the immune system, such as the number of neutrophil cells, were elevated in healthy pregnant women.
Researchers found that lupus patients with uncomplicated pregnancies showed similar changes in their immune systems. However, neutrophil levels increased earlier than normal in patients that developed preeclampsia. By analyzing the RNAs present in the blood of these patients during early pregnancy, the researchers were able to identify a unique immune signature that could predict the development of preeclampsia more accurately than existing clinical factors.
In addition, the researchers found that patients who developed other complications failed to properly suppress their interferon response and plasma cell activity.
