Immune cells known as B cells undergo significant changes in women with postpartum depression (PPD). The corresponding study was published in Molecular Psychiatry.
PPD affects around 1 in 7 women and has negative consequences for both mother and child. Its underlying biological mechanisms, however, are unknown. To become a step closer to understanding these mechanisms, the researchers behind the present research conducted the largest transcriptome-wide association study for PPD to date.
Whereas previous studies have only examined whole blood samples, their study dug deeper and analyzed different blood components. To do so, they gathered 1,341 blood samples from racially and ethnically diverse women who had given birth within the last six weeks. Of these, 482 received a PPD diagnosis.
The researchers used RNA sequencing, DNA genotyping, and assessed DNA methylation to analyze the blood samples. In doing so, they found that B cells in women with PPD underwent changes in activation and insulin resistance. B cells are immune cells that activate upon binding to antigens, upon which they produce antibodies and secrete pro- and anti-inflammatory factors.
“There’s a really delicate interplay of the immune system during pregnancy,” said Jerry Guintivano, Ph.D., assistant professor in the University of North Carolina at Chapel Hill’s Department of Psychiatry and lead author of the study.
"It has to prevent infection from a cold, and it also has to finely tune itself so it doesn’t recognize the fetus as a foreign body and attack it. Then in the postpartum period, all these hormones and pathways reset to get back to pre-pregnancy,” he added.
The scientists say their findings are the first step in a ‘long line’ of upcoming research. While they have been able to report changes to B cells, they still don’t know why they are changing.
To this end, they now hope to conduct a longitudinal study to track women for longer periods to see how B cells change over pregnancy and the postpartum period.