The immune system’s role is to keep the body safe by spotting and destroying infectious agents. Sometimes, however, the process goes haywire an organ tissue comes unwarrentedly to the attention of the immune response, which proceeds to attack part of the body as though it were an infection. The reason for the immune system’s response lies in a component called regulatory T cells. These cells are responsible for distinguishing benign from harmful cells, ramping up the immune system long enough to deal with harmful cells, then ramping it back down afterward. When this doesn’t work as intended, that is when it becomes an autoimmune disease. An estimated five percent of people have some form of autoimmunity. The autoimmune diseases include type 1 diabetes, lupus, Crohn’s disease, Sjögren’s syndrome, Graves disease, Churg-Strauss Syndrome, Hashimoto’s thyroiditis, rheumatoid arthritis, and a number of other conditions.
Autoimmune disease is almost always incurable, but research is ongoing to find treatments that can not only alleviate the symptoms—as current approaches, primarily corticosteroids and drugs to reduce inflammation, do—but actually get to the root of the problem. One interesting and promising approach uses parasites called helminths as treatment. Helminth infects are common in areas where sanitation is unreliable, and researchers have found that in those areas, certain autoimmune diseases are rarer than statistics would suggest. The parasites may be helping distract the immune system so that it doesn’t turn on the body, an idea known as the hygiene hypothesis. This idea has been incorporated into treatment regimens, and now in some cases parasites are deliberately introduced in a controlled way.
More recent research uses not the entire organism, but its genetic code. One type of helminth used for this treatment is called the pig whipworm. The pig whipworm genome has recently been sequenced, that is, scientists now have a complete guide to the parasite’s genetic code. This may help provide insight as to what about whipworm makes it so effective against autoimmunity, and if there is an alternate, more palatable, method of administering the treatment. Pig whipworm is harmless to humans, but few people want to think about what the treatment is even if it is effective.