National Post

Saturday, February 27, 1999

Scientists to study how gender affects disease
Why are women more prone to autoimmune disease?

Brad Evenson
National Post

Canadian scientists will join an international research campaign to pin down why so many women suffer from autoimmune diseases.

Close to 80% of the 10-million North Americans who suffer such illnesses as rheumatoid arthritis, lupus and multiple sclerosis are women.

Ordinarily, the body's immune system only strikes invading toxins, viruses or bacteria. But for reasons that remain unclear, it can sometimes attack healthy tissue.

For the past 18 months, a task force of researchers and clinicians from the U.S. and Canada have pored over medical literature to see why men and women respond differently to these diseases. Their report, published in this week's edition of Science, recommends five distinct research areas.

"One of the big problems we faced was that very few people do studies that are specifically directed at differences between the sexes regarding these diseases," said Dr. Caroline Whitacre, professor of medical microbiology and immunology at Ohio State University, and task force chair.

For example, two to three times as many women get multiple sclerosis and rheumatoid arthritis compared to men. For systemic lupus, a disease that causes inflammation of connective tissue and organs, women outnumber men nine to one.

Dr. Pierre Duquette, a clinical neurologist at Montreal's Notre-Dame Hospital, who specializes in multiple sclerosis, will help examine the gender bias toward women.

Among the questions the researchers hope to answer include the specific sexual differences in immune response, such as why female immune systems tend to produce compounds called cytokines, which increase antibody production, at a more vigorous rate.

Some researchers have suggested that certain sex hormones may control how the immune system responds. For example, multiple sclerosis sufferers tend to have fewer symptoms during pregnancy.

Some of the diseases have genetic roots and it may be possible that specific gene alterations could lead to the onset of autoimmune disease.

Finally, autoimmune diseases affect men and women differently. For example, women tend to get multiple sclerosis symptoms earlier than men, but the disease progresses faster in men than women.

"Our primary goal is to increase researchers' awareness of these differences and suggest that they consider gender differences in designing new studies," said Dr. Whitacre.

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