Research & Development

Women who have suffered unexplained miscarriages may soon have an answer and potential treatment thanks to the work of Canadian Blood Services scientist Dr. Heyu Ni and his research team. The team, based at St. Michael’s Hospital in Toronto, discovered that the same kind of blood clots that cause a heart attack or stroke can be fatal for unborn babies.

This new discovery suggests that massive clotting in the placenta can form when a mother generates antibodies that attack her baby’s platelets. These antibodies have been reported to cause a bleeding disorder called fetal and neonatal immune thrombocytopenia (FNIT). FNIT affects roughly one in 1,000 live births and can lead to bleeding in the brains of fetuses and newborns, causing neurological impairment or death in severe cases. Research on miscarriages as a result of FNIT to date is limited.

“Fifty per cent of pregnancies do not end in a live birth. Our findings may help explain why some women are having miscarriages,” says Dr. Ni. “Furthermore, our treatments could be the answer to carrying a healthy child to term.”

Dr. Ni’s team has pinpointed an antigen linked to miscarriages in more than 83 per cent of mice. Antigens are proteins that antibodies attack because they think they are a foreign substance like bacteria or a virus. Babies are a genetic mix of both biological parents and sometimes that mix can cause the mother’s antibodies to attack protein on the baby’s platelets inherited from the father.

“We found that sometimes the antibodies not only destroy platelets, but also trigger the fetus’ platelets to form massive blood clots in the placenta. The clots destroy the placenta and block the blood supply from mother to baby,” says Dr. Ni.

During the study, researchers were able to successfully demonstrate two therapies in mice to prevent clotting in the placenta. One is transfusing intravenous immunoglobulin (IVIG), a product which is already used to treat several autoimmune diseases. IVIG is made from donated plasma, a component of blood collected by Canadian Blood Services. The second method, developed by Dr. Ni and his team, is transfusing a specific antibody that blocks the mother’s attacking antibodies from crossing the placenta and harming the baby.

These findings were published in the November issue of the prestigious Journal of Clinical Investigation.

“Many successful scientists go their entire careers without making discoveries considered worthy of publication in JCI. It’s an honour for Dr. Ni and Canadian Blood Services,” says Dr. William Sheffield, Associate Director of Research and Senior Scientist with Canadian Blood Services and Professor of Pathology and Molecular Medicine at McMaster University.

Dr. Ni’s group is now collaborating with clinicians to determine if these treatments could be as effective for humans as they have proven to be for mice.