Publicity materials: http://www.eurekalert.org/pub_releases/2016-06/tl-tln060816....

Paper: http://www.thelancet.com/journals/lancet/article/PIIS0140-67...

The latest update for ongoing efforts to test destruction and recreation of the immune system in patients suffering from the autoimmune disease multiple sclerosis demonstrate that this approach is effectively a cure if the initial destruction of immune cells is comprehensive enough. Researchers have been able to suppress or kill much of the immune system and then repopulate it with new cells for about as long as the modern stem cell therapy industry has been underway, something like fifteen years or so. Methodologies have improved, but the destructive side of this process remains unpleasant and risky, something you wouldn't want to try if there was any good alternative. Yet if not for the scientific and commercial success of immunosuppressant biologics such as adalimumab, clearance and recreation of immune cell populations may well have become the major thrust of research for other prevalent autoimmune conditions such as rheumatoid arthritis. Destroying these immune cell populations requires chemotherapy, however, and with avoiding chemotherapy as an incentive for patients, and the ability to sell people drugs for life as an incentive for the medical industry, biologics won. For conditions like rheumatoid arthritis, the aim became control and minimization of symptoms rather than the search for a cure. Only in much more damaging, harmful autoimmune conditions like multiple sclerosis has this research into wiping and rebuilding the immune system continued in any significant way.

It is worthy of note that while these trials were only enrolling a small minority of patients, the approach could be used on every patient. That tends to be the way trials work, picking a small subset. The driving factor for keeping the numbers small is the onerous and risky chemotherapy process.

Beyond being able to pinpoint which tissues are suffering damage due to inappropriately targeted immune cells, the underlying mechanisms of most autoimmune conditions are very poorly understood. Multiple sclerosis, for example, results from immune cells attacking the myelin sheathing essential for proper nerve function. Collectively, the cells of the immune system maintain a memory of what they intend to target, that much is evident, but the structure and nature of that memory is both very complex and yet to be fully mapped to the level of detail that would allow the many types of autoimmunity to be clearly understood. That these autoimmune conditions are all very different is evidenced from the unpredictable effectiveness of today's immunosuppressant treatments - they work for some people, not so well for others. Many autoimmune diseases may well turn out to be categories of several similar conditions with different roots in different portions of the immune system.

Destruction of the immune system offers a way around present ignorance: it is an engineering approach to medicine. If immune cell populations can be removed sufficiently comprehensively, then it doesn't really matter how they are storing the bad data that produces autoimmunity. That data is gone, and won't return when immune cells are restored through cell therapies. The cost of that process today is chemotherapy, which is not to be taken lightly, as the results presented here make clear. A mortality rate of one in twenty is enough to give pause, even if you have multiple sclerosis. In the future, however, much more selective cell destruction mechanisms will be developed, such as some of those emerging from the cancer research community, approaches that will make an immune reboot something that could be undertaken in a clinic with no side-effects rather than in a hospital with all the associated damage of chemotherapy. Autoimmune diseases are far from the only reason we'd want to reboot our immune systems: as we age, the accumulated impact of infections weighs heavily upon the immune system, and its limited capacity fills with uselessly specialized cells rather than those capable of destroying new threats. Failure of the immune response is a large part of age-related frailty, leading to both chronic inflammation and vulnerability to infection, and it is something that could be addressed in large part by an evolution of this approach to autoimmune disease.