Researchers pinpoint possible new cause for unexplained miscarriages
Researchers at St. Michael's Hospital have identified a potential new cause for unexplained miscarriages in mice.
They also identified two possible treatments to prevent these miscarriages and their work has broader implications for the development of new drugs to treat heart attacks and strokes.
The researchers, led by Dr. Heyu Ni, found that the same kind of blood-clotting in coronary arteries or blood vessels in the brain that causes heart attacks and strokes also happens in the placenta. The massive clotting can destroy the placenta, block blood flow to the fetus and cause miscarriages.
This condition is known as fetal and neonatal immune thrombocytopenia (FNIT), a bleeding disorder in which mothers generate antibodies that attack and destroy platelets in their fetuses and newborns. Platelets are the small cells in the blood that play a key role in clotting. In severe cases, FNIT may lead to bleeding in the brains of the fetuses and newborns and cause neurological impairment or even death.
The condition affects between one in 800 and one in 1,500 live births and is more commonly reported among Caucasians.
Maternal antibodies to one specific platelet antigen, HPA-1 (human platelet antigen) cause 75-95 per cent of FNIT cases. Antigens are the proteins that antibodies attack because they think they are a foreign substance such as bacteria or a virus.
Dr. Ni and his team discovered a novel mechanism that might partially explain this problem. They found that another antigen, HPA-2, causes a type of FNIT never described before that can lead to miscarriages in more than 83 per cent of mice. There have been only six to eight reported live births in the world of humans with FNIT caused by HPA-2. The new research suggests the reason these cases appear to be so rare is that most of the affected fetuses died through miscarriages, before doctors examined them.
Dr. Conglei Li and other researchers in Dr. Ni's laboratory found that sometimes these antibodies not only destroy platelets, but activate them and cause massive clotting in the placentas.
Dr. Ni, an immunologist, is also a scientist with Canadian Blood Services (CBS), one of the funders of this research. His findings appear in the November issue of the prestigious Journal of Clinical Investigation.
Dr. Ni's group demonstrated that, in mice, these miscarriages can be prevented using at least two therapies. One is the transfusion of IgG (IVIG), a CBS product made from plasma from donated blood, which has been widely used to treat several autoimmune diseases. The other is the transfusion of an antibody known as anti-FcRn, which blocks the attacking maternal antibodies from crossing the placenta. This second method was developed by Dr. Ni's group.
"Fifty per cent of pregnancies do not end in a live birth. Our findings may help explain why some women are having miscarriages," said Dr. Ni. "Furthermore, our treatments could be the answer to carrying a healthy child to term."
The observations by Dr. Ni's team of platelet activation and enhancement of clotting may be important in the development of safer anti-thrombotic drugs. These drugs are under development by several companies.
Dr. Ni's group is now collaborating with clinicians to address how relevant these discoveries in mice are in humans.
Provided by St. Michael's Hospital
- Potential new cause of miscarriage and habitual abortion Oct 24, 2011 | not rated yet | 0
- Statins may prevent miscarriages Oct 10, 2008 | not rated yet | 0
- Stop the bleeding: New way to restore numbers of key blood-clotting cells Oct 25, 2010 | not rated yet | 0
- Method for manufacturing patient-specific human platelets Nov 22, 2010 | not rated yet | 0
- New clot-buster found Jan 20, 2009 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013 Hello everyone, Ok Stomach's normal epithelium is simple columnar, now in intestinal type of adenocarcinoma of stomach it undergoes "intestinal...
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
Ratio of Hydrogen of Oxygen in Dessicated Animal Protein
May 13, 2013 As an experiment, for the past few months I've been consuming at least one portion of Jell-O or unflavored Knox gelatin per day. I'm 64, in very...
Alcohol and acetaminophen
May 13, 2013 Edit: sorry for the typo in the title , can't edit I looked around on google quite a bit and it's very hard to find precise information on the...
- More from Physics Forums - Medical Sciences
More news stories
Trends in Helicobacter pylori (H. pylori) and smoking explain a significant proportion of the decline of intestinal-type noncardia gastric adenocarcinoma (NCGA) incidence in US men between 1978 and 2008, and are estimated ...
Medical research 14 hours ago | not rated yet | 0
Widely available in pharmacies and health stores, phosphatidylserine is a natural food supplement produced from beef, oysters, and soy. Proven to improve cognition and slow memory loss, it's a popular treatment for older ...
Medical research 18 hours ago | 5 / 5 (3) | 0 |
Researchers at Emory University have identified a protein that stimulates a pair of "orphan receptors" found in the brain, solving a long-standing biological puzzle and possibly leading to future treatments for neurological ...
Medical research 19 hours ago | 5 / 5 (1) | 0 |
Australian scientists have charted the path of insulin action in cells in precise detail like never before. This provides a comprehensive blueprint for understanding what goes wrong in diabetes.
Medical research 19 hours ago | 4.6 / 5 (7) | 0 |
Researchers at the University of Illinois at Chicago College of Medicine will study gender differences in how the heart uses and stores fat—its main energy source—and how changes in fat metabolism play ...
Medical research 22 hours ago | not rated yet | 0
(AP)—The mayor of Portland, Ore., has conceded defeat in an effort to add fluoride to the city's drinking water.
24 minutes ago | not rated yet | 0
(AP)—Alabama health officials say a mysterious respiratory illness has left five people hospitalized and two dead in the southeastern part of the state.
4 minutes ago | not rated yet | 0
Is it permissible to harm one to save many? Those who tend to say "yes" when faced with this classic dilemma are likely to be deficient in a specific kind of empathy, according to a report published in the scientific journal ...
2 hours ago | not rated yet | 0 |
Phthalates: Study links chemicals widely found in plastics, processed food to elevated blood pressure in children, teens
Plastic additives known as phthalates (pronounced THAL-ates) are odorless, colorless and just about everywhere: They turn up in flooring, plastic cups, beach balls, plastic wrap, intravenous tubing and—according to the ...
3 hours ago | not rated yet | 1 |
(Medical Xpress)—Native peoples in regions where cameras are uncommon sometimes react with caution when their picture is taken. The fear that something must have been stolen from them to create the photo ...
19 hours ago | 4.2 / 5 (5) | 0 |