As a concept, autoimmunity can provoke unease – there’s something disconcerting about the thought of the body attacking itself; the processes that are meant to protect us running haywire and causing harm. Equally disconcerting is the fact that the underlying cause(s) of most autoimmune conditions are still unknown.
Autoimmune diseases, a wide range of disorders whereby the immune system’s natural defenses turn on the cells or organs they are meant to protect, affect at least 23.5
million Americans, according to the National Institute for Health (NIH). The American Autoimmune Related Diseases Association estimates that the actual number is closer to 50 million, as many autoimmune conditions go un- or misdiagnosed. As a point of comparison, cancer affects 12.5 million Americans, and around 22 million suffer from heart disease. The NIH estimates that annual healthcare costs for autoimmune diseases are in the range of $100 billion. In addition, women make up close to 75% of all autoimmune diagnoses.
Despite their overwhelming prevalence, autoimmune diseases reign as one of the most misunderstood health problems. Many conditions – including some that are highly common among people of Irish ancestry, such as celiac disease, hemochromatosis and multiple sclerosis – are autoimmune, but are not always widely recognized as such. Lupus, Graves’ disease, Hashimoto’s thyroid disease, Addison’s disease, psoriasis, rheumatoid arthritis, and type 1 diabetes are among the most prevalent autoimmune conditions. At least 80 others are officially recognized, and still more are being discovered.
To set the facts straight, Irish America went straight to the source. Dr. Noel Rose, the “father of autoimmunology” and the director of the Johns Hopkins Autoimmune Disease Research Center, introduced the possibility of autoimmunity as a cause of disease in 1956, when he discovered that chronic (Hashimoto’s) thyroiditis could be reproduced in experimental animals by immunization with thyroglobulin, a major protein constituent of the thyroid gland.
Speaking over the phone from his office in Baltimore, Dr. Rose, who at 85 remains a leading voice in the field, said that he encountered strong resistance when he and his colleagues first brought their findings to the medical community fifty-seven years ago. “They were skeptical,” he said with a small chuckle. “People weren’t really prepared to believe it because it seemed so bizarre that you would develop an immune response to your own body. We had all been taught in medical school that the immune response is only directed to what’s foreign. But now we know that isn’t true.”
Once it became accepted, there was a rush of looking at other diseases that were idiopathic (of unknown causation) and finding that autoimmunity was at play. Now, there is at least one autoimmune disease for every system and organ in the body. Why there are so many remains unknown, but, as Dr. Rose explained, the immune system itself is very diverse because it has to respond to so many different kinds of organisms. “We think it’s the fact that the immune system is always looking for new pathogenic organisms and being very broad in its abilities to recognize organisms that it also responds to things within our own bodies that are of the same or a very similar substance.”
Whether a person will develop an autoimmune disease in his or her lifetime is determined by both genetics and environmental factors. “Some of the genetic risks are general,” he explained, “meaning they make it more likely that you will develop some autoimmune disease, and then other genes are more involved in determining exactly which disease you’re more likely to develop.”
Within families, there is both the chance of passing on specific autoimmune diseases, and of inheriting a general predisposition to developing an autoimmune condition. “The first thing you look for [within a family] is either the same or a closely related disease. So if the patient has, for example, thyroiditis, which is a disease of an endocrine organ, you look for diseases in other endocrine organs, such as type 1 diabetes, Addison’s disease, or diseases of the parathyroid or pituitary gland. But then they also may have some more distant autoimmune diseases like lupus or rheumatoid arthritis.”
Correspondingly, there is often a higher propensity for certain autoimmune diseases among different ethnic groups. “For example, lupus is much more common among African Americans than it is among white European Americans. Hashimoto’s thyroiditis, the common cause of low thyroid, is much more common in white European Americans,” Dr. Rose explained.
In the case of the Irish, he said, “Most autoimmune diseases – not all but most – tend to be more prevalent in people who came from Northern Europe than people who came from Southern Europe, and so my guess is that the Irish – who are Celts, who are fair-skinned people from Northern Europe – probably have a higher prevalence of many autoimmune diseases than people from Italy or Spain or Greece. I don’t know of a study of this in Ireland so it would be good for the Irish Ministry of Health to look into it.”
As significant as genes can be in autoimmunity, they are really the minor part of it, Dr. Rose said. “All of the many genes together make up about only 1/3 of the risk. The other 70% of the risk is something external, usually something we encounter in the environment.”
With most autoimmune diseases, the environmental factor that triggers the immune system’s response is difficult – often impossible – to pinpoint. It can be exposure to a certain medication, toxin, or other substance. With a select few – particularly celiac disease – the environmental trigger is known, and its removal results in a diminishing of symptoms. In this sense, celiac and gluten present the potential for better understanding of other autoimmune conditions.
“Interestingly,” he added, “the gluten free diet may also be helpful for people who don’t have celiac disease but who have other forms of autoimmune disease. It’s just speculative, but as gluten free diets are more available, other people are trying them and often feel better.”
Smoking tobacco is also becoming more prominent as a possible trigger or aggravator. “It’s not only bad for heart disease and cancer but it’s bad for many forms of autoimmune disease, including disease of the thyroid and for rheumatoid arthritis. So it is a general risk factor,” Dr. Rose said.
The majority of autoimmune treatments to date focus on managing symptoms rather than curing diseases. “We still don’t have a cure, but new treatments have been introduced in the past 15, 20 years for autoimmune diseases like lupus and MS that are remarkable and very much improved,” he said with enthusiasm. “As we understand more about the autoimmune response we find more ways of developing drugs that will intervene, that will benefit the patient by at least alleviating the symptoms even if they won’t cure the disease.”
At the same time, research towards better understanding the immune response itself has made significant progress, aided by the genome project and better understanding of environmental factors. Links between autoimmune research and cancer research are also of increasing importance. As Dr. Rose phrased it, “The investigator working on autoimmune disease and the one working on cancer are a little like the old story that Ginger Rogers did everything that Fred Astaire did, but backwards and in high heels. We do the same things that the cancer researchers do, but whereas they’re in the position of trying to enhance an autoimmune response so that the patient responds to his own cancer, we try to decrease or get rid of the autoimmune response so that the disease goes away.”
As awareness and knowledge of autoimmune diseases increases, Dr. Rose’s hope is that more medical centers and doctors dedicated to autoimmune disease as a whole will emerge. “We have a very specialized system of medicine in the U.S. and specialists treat autoimmune diseases or a particular organ system, but we don’t generally study autoimmune diseases broadly,” Dr. Rose said. “From a patient point of view, it would be very helpful if there were critical autoimmune disease centers where patients who have multiple autoimmune diseases could be treated in the same place, by the same group of physicians.
“We will see economic advantage of that,” he maintained. “Our [current] way of doing it is too expensive, with multiple physicians and research often overlapping. So many of the autoimmune diseases are relatively rare, but it’s only if you put them all together that you realize the scope.”