Autoimmunity is one of the remaining dark frontiers of human disease, and the collection of medical conditions in which the immune system starts to attack a patient's own tissues are largely poorly understood. In the case of rheumatoid arthritis, for example, there is no real consensus on root cause or how the disease mechanisms work in detail, and it even may be a collection of several distinct issues lumped under one heading because the outcome looks the same. The effectiveness of treatments has been improving, but some patients just don't respond to the standard approach of trying to suppress the unwanted immune responses via TNF inhibitors.
Here researchers are making the bold claim of an effective cure for rheumatoid arthritis in mice, with a method that sounds like a more targeted way of suppressing unwanted immune activity rather an advance towards addressing root causes, and are heading for clinical trials:
Researchers have developed a therapy that takes the treatment of rheumatoid arthritis in mice to a new level: after receiving the medication, researchers consider the animals to be fully cured. The drug is a biotechnologically produced active substance consisting of two fused components. One component is the body's own immune messenger interleukin 4 (IL-4); previous studies have shown that this messenger protects mice with rheumatoid arthritis against cartilage and bone damage. [The] scientists have coupled an antibody to IL-4 that, based on the key-lock principle, binds to a form of a protein that is found only in inflamed tissue in certain diseases (and in tumour tissue).
"As a result of combination with the antibody, IL-4 reaches the site of the disease when the fusion molecule is injected into the body.It allows us to concentrate the active substance at the site of the disease. The concentration in the rest of the body is minimal, which reduces side-effects." The researchers tested the new fusion molecule [in] a mouse model in which the animals developed swollen, inflamed toes and paws within a few days. Among other things, the researchers studied the fusion molecule in combination with dexamethasone, a cortisone-like anti-inflammatory drug that is already used to treat rheumatoid arthritis in humans.
When used separately, the new fusion molecule and dexamethasone managed only to slow the progression of the disease in the affected animals. In contrast, the typical signs of arthritis, such as swollen toes and paws, disappeared completely within a few days when both medications were administered at the same time. Concentrations of a whole range of immune messengers in blood and inflamed tissue, which are changed in rheumatoid arthritis, returned to their normal levels. "In our mouse model, this combined treatment creates a long-term cure."