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Pregnancy and arthritis

Posted: Fri Aug 18, 2006 7:25 am
by dignan
I hope this has implications for MS...



Hutch experts discover why pregnancy curbs arthritis

August 18, 2006 -- Seattle Times -- Denise Swanson, a special-education teacher in Seattle, says all of the symptoms of her rheumatoid arthritis disappeared when she was pregnant.

Rheumatoid arthritis like Denise Swanson's can be debilitating, eventually deforming joints and making walking and using the hands very difficult.

When Denise Swanson developed rheumatoid arthritis nearly three decades ago, it was like a sudden storm of pain, swelling and fatigue.

It was excruciating for the then-21-year-old college student just to pick up her backpack. She couldn't even write. Medication eased her pain and stiffness, but not much.

"I would move like an old lady," said Swanson, now a 49-year-old special-education teacher in Seattle. "It was scary."

But then a few years later Swanson and her husband, Tom, did something that happened to bring total relief from the devastating disease: They decided to have a baby. All of Swanson's symptoms disappeared about a month after she became pregnant.

"With all the things you're supposed to cope with in pregnancy, this was a joy," Swanson said. "I really did well. I felt like [my arthritis] had gone away forever."

Scientists — and many new mothers — have long known that pregnancy relieves rheumatoid arthritis. What hasn't been entirely clear is why.

Now researchers at Seattle's Fred Hutchinson Cancer Research Center have delved deeper toward an answer, for the first time identifying that DNA from dead cells naturally sloughing off the growing fetuses probably results in the pregnant women getting relief from their arthritis.

"The bottom line is we could see a specific effect on the arthritis," said Dr. Lee Nelson, an expert on pregnancy and immunology, and leader of the recent study reported in the journal Arthritis & Rheumatism.

"If we can understand this better, we could possibly work toward specific treatments for autoimmune diseases."

Rheumatoid arthritis occurs when the immune system attacks the synovial membrane, tissue that lines the joints. Some researchers believe this autoimmune reaction happens after an infection in someone who is genetically susceptible to arthritis.

The Fred Hutchinson scientists looked at the amount of DNA from the fetus circulating in the blood of 25 pregnant women with arthritis and found that the fetal DNA was plentiful in the blood of almost all the women. Those with higher DNA levels had significant relief from the disease. Four who had little or no relief had low levels of the DNA.

Then, about two to four months after delivery, almost all the women with arthritis relief experienced a return of the painful disease.

Pregnancy has also been known to relieve the symptoms of multiple sclerosis and Graves' disease, a thyroid disorder, both of which also are autoimmune diseases.

The Hutchinson scientists speculate that the fetal DNA acts as a sort of decoy: The mother's immune system focuses on the fetal DNA instead of the mother's synovial membrane cells. Immune cells decide the fetal DNA is OK, so they back off their attack on the mother's joints.

Fetal DNA is technically "foreign" to the body, but the immune cells are programmed not to attack DNA from cells that have died as the result of a natural process, rather than from infection or another cause, said Drs. Kristina Adams and Zhen Yan, other researchers on the study.

Swanson found arthritis relief through three pregnancies. But after each delivery — with Graham, now 20; Isaac, now 17; and Chris, now 12 — her arthritis returned after about two months. When participating in the Hutchinson study with her last two pregnancies, the researchers found the measured fetal DNA levels dropped soon after delivery, and her hands were soon too stiff to manipulate diaper pins or even hold her baby to nurse.

"I would get stiff and more and more uncomfortable," Swanson said.

Swanson's medications for arthritis have ranged from aspirin and several other anti-inflammatory drugs, to shots of gold, which acts more broadly on the immune system. The medications have controlled her arthritis fairly well, but she has suffered side effects, including mouth sores, stomach problems, raised blood pressure and weight gain.

About 1 percent of the population has rheumatoid arthritis or juvenile arthritis, and women are more than twice as likely to have it as men, experts estimate. The diseases can be debilitating, eventually deforming joints and making walking and using the hands very difficult.

Women with the disease are more likely to deliver prematurely or by Caesarean section and may have longer hospitalizations, other recent research has indicated. A drug that would better target the basic autoimmune process of rheumatoid arthritis would be welcomed by millions of patients like Swanson, Nelson said.

Nelson and her colleagues are the first to examine the role of fetal DNA in arthritis remission during pregnancy. Other scientists have investigated how the genetics of the fetus and biochemicals that regulate the immune system influence arthritis.

Next, the Hutchinson scientists hope to expand the study to examine the activity of immune cells and look more closely at fetal proteins that may help trigger the immune system's response.

Nelson predicts that a medication could be developed in about five years, depending on drug-company interest.

This latest research was financed by the National Institutes of Health and the Washington Women's Foundation, which awards grants for work in health, social services, arts and culture, education and the environment.

http://seattletimes.nwsource.com/html/h ... is18m.html