The presenters hailed from Australia, Finland and New Zealand. The questions from the floor featured accents from Japan, England and France. The moderator was American and the subject universal.
“Answering why some people get autoimmune diseases and others do not is the Nobel Prize question,” said Barbara Brooks-Worrell, a diabetes researcher at the University of Washington in Seattle. “We know everybody has the capability to develop autoimmune disease, but what triggers the illness is not clear. The best guess is it appears to be a combination of genetics, environment and diet that leads to symptoms.”
In contrast to immune-deficiency diseases such as HIV/AIDS, the autoimmune disorders — which include juvenile diabetes, multiple sclerosis, rheumatoid arthritis and lupus — are caused by an immune system that is too aggressive. Rather than killing off foreign invaders such as bacteria or viruses, the system attacks perfectly healthy cells in the body.
Cases of each of the autoimmune illnesses have significantly increased in this country and many other parts of the world. Women are at particular risk, prompting some researchers to explore hormones as a factor.
Patients with juvenile (or Type I) diabetes can suffer kidney failure, nerve damage and even blindness as a result of the disease. It is successfully managed in a majority of patients with daily insulin injections, but others are less fortunate. And nothing seems to halt the disorder’s progression.
According to Kevin Lafferty, director of the School of Medical Research at the Australian National University in Canberra, discovering what “flips the switch” for diabetes on any level, especially more severe conditions, is a major reason why researchers, doctors, nurses and other health professionals gathered at McCormick Place last weekend for the American Diabetes Association’s 58th annual Scientific Sessions.
“There are good studies about identical twins and autoimmune responses,” said Lafferty, the opening presenter during a session about autoimmunity and the environment. “If one twin develops diabetes, the other twin has only a 30 to 40 percent chance. Remember, the twins have the exact same gene pool. They grew up in the same family. So we have to look at other reasons why one twin gets the symptoms.”
Among the potential disease triggers considered by presenters were new strains of viruses and air and water pollution. Dr. Robert B. Elliott of New Zealand reviewed the research literature about the effect of diet, reporting that cow’s milk is a possible link, though studies are not yet conclusive. One research paper from Finnish investigators showed an association between breast feeding and reduced risk for diabetes, while infants who drank cow’s milk formula in the first three months of life were more susceptible.
Lafferty also discussed his pioneering concept that autoimmune dysfunction should be classified as “benign” or “malignant.” He argued that diabetes and related illnesses likely have a period of benign existence in which autoreactive cells are present but inactive. Then a sudden change, even in just a few weeks, results in the destructive cellular activity he calls malignant.
Elliott, however, took issue with Lafferty’s assessment of how suddenly the shift occurs.
“It’s more likely the disease forms over a few years in humans,” he said.
In any case, some curious correlations are associated with autoimmune disease, Lafferty said. People who contract malaria, for example, seem to be protected against diabetes and other autoimmune diseases. His explanation was that these people’s immune systems are likely occupied with the malaria and therefore not able to switch into the higher, more aggressive gear demanded by the diabetes disease state.
In Australia, Lafferty is conducting a pilot study in which humans recently diagnosed with diabetes are immunized with a Q-fever vaccine. In addition to protecting against this common Australian tropical disease, the vaccine may kick in the autoimmune response just enough to halt the diabetic destruction.
Strangely, exposure to some viruses or pollutants might regulate the immune system, he added.
“The incidence of diabetes in Mexico City is less than one person for each 100,000,” Lafferty said during an interview (some studies place the rate closer to 9 per 100,000). “The rate in Finland and other Scandinavian countries is about 40 per 100,000. I know it sounds crazy, but I think the less clean environment in Mexico City could be forcing people’s immune systems to respond at some lower levels.” The Finns’ immune systems, meanwhile, lacking the necessity of fending off lesser toxins, may be more likely to become overly aggressive in response to other triggers.
Brooks-Worrell said worldwide research about what initiates autoimmune responses is stirring tremendous debate about treatment of juvenile diabetes patients and others with autoimmune diseases. Insulin is still the diabetes medication of choice — new developments on oral and inhalant versions were to be presented earlier this week — but now researchers are wondering if there are ways to catch diabetes earlier, in its less destructive phases. Certain vitamins, especially A and E, might play a role in discouraging autoimmune flareups.
“We are discovering many new techniques,” said Brooks-Worrell. “We know so much more than even five years ago.”
