“Peripartum cardiomyopathy is difficult to detect because the symptoms that characterize it are very similar to the symptoms associated with end of pregnancy and the months following childbirth: breathing difficulties, extreme fatigue, palpitations …”, explains Ingrid Struman, a research associate at the F.R.S.-FNRS and project director at the Unit of Molecular Biology and Genetic Research at GIGA (University of Liege). Nonetheless, it is a disease which can have dramatic consequences. “It involves the dilation of the left ventricle of the heart which results in reduced pumping function of the heart. There may be an improvement in heart function in the months following the birth but this remains poor among 30% of the women affected by the condition and 10% of them die as a result of it”, continues Ingrid Struman. In addition, the state of the heart worsens in these women during the next pregnancy, with an increased mortality rate of 20%.

The hormone which stimulates milk production is suspected of being at issue

To date, there is no way of determining which women are at risk, nor is there any way of determining which factors trigger peripartum cardiomyopathy. In a study carried out in collaboration with German and South-African researchers, Ingrid Struman’s team has identified a biomarker which makes it possible to distinguish this disease from other cardiac diseases that cause heart failure. The results of this study have been published in the Journal of Clinical Investigation (1). “In 2007, Denise Hilfiker-Kleiner, a German researcher, showed that a prolactin fragment known as 16K-PRL which is produced in the heart, attacks the blood vessels and heart tissues”, says Ingrid Struman. Produced by the pituitary gland, prolactin is a hormone which is involved in the growth of the mammary glands and the stimulation of milk production. 

In the context of her research on tumor angiogenesis, Ingrid Struman studied this hormone and, as part of a program of excellence for the Wallonia region, began to take an interest in microRNAs. “This is why Denise Hilfiker-Kleiner contacted us and how we developed the project on peripartum cardiomyopathy somewhat by accident”, explains the scientist. Although the role played by the 16K-PRL fragment in this disease was well- established, the mechanisms by which it affects the tissues of the heart had remained a total mystery up to now. This is precisely one of the mechanisms which Ingrid Struman and her colleagues have identified.