New research shows how the immune system actually behaves throughout pregnancy — cell by cell. In women with lupus, immune differences also persist after childbirth.
When a new life begins to grow in the mother’s womb, the immune system must perform a difficult balancing act: it must tolerate the fetus, which is genetically half foreign, and at the same time protect the mother from infection.
For most pregnant women, this happens without any problems.
However, for women with autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus, pregnancy puts the immune system under additional stress. This can lead to an increased risk of preeclampsia, premature birth, and miscarriage.
The immune system – cell by cell
Autoimmune diseases vary greatly, and patients react differently to the disease and treatment. Many people have to try several medications before finding the right one for them. “For this reason there is a great need for biomarkers that can enable more personalized treatment, including during pregnancy.”
Hilda Juli Tokli Lin, Postdoctoral Fellow, Department of Clinical and Molecular Medicine at the Norwegian University of Science and Technology (NTNU’s)
She recently completed her doctoral thesis in which she investigated how the immune systems of pregnant women with rheumatoid arthritis and lupus behave during pregnancy – cell by cell.
If left untreated, these diseases react very differently to pregnancy: rheumatoid arthritis patients often experience improvement, while lupus patients have a high risk of deterioration.
To determine the causes at the level of immune cells, Lian collaborated with a multidisciplinary team of immunologists, bioinformaticians, doctors and nurses, who collectively performed advanced analyzes of gene activity in individual cells.
A completely new method has also been developed that can be used in further research.
The need for follow-up in the postpartum period
Preliminary results show clear immune differences between pregnant women with lupus, pregnant women with rheumatoid arthritis, and healthy pregnant women – particularly in terms of immune cell control.
This occurs despite women having excellent follow-up and experiencing minimal changes in disease activity throughout pregnancy.
In women with lupus, the differences also persist after childbirth.
“This underscores the need for close follow-up during the postpartum period. This is the stage that has traditionally received less attention in rheumatology,” Lian explained.
It is important to continue taking the medication
Lian and the research team are now working to understand whether the differences are due to changes in gene activity or in the number of different cell types present. Research is also being conducted into why patients with the same diagnosis have such different symptoms, and what factors lead to changes in disease activity.
“Internationally, there is still significant variation in the use of medications during pregnancy. Although we know that untreated disease generally poses the greatest risk, many women are reluctant to take medication during pregnancy. It is important to continue taking medication during pregnancy,” Lian concluded.
The samples and clinical data used in the study were collected by the Norwegian National Advisory Unit on Pregnancy and Rheumatic Diseases (NKSR).
