IL-6, Lupus and Tocilizumab
Most of us who have lupus know that its destructive inflammation comes from an immune system that is in hyper-drive. The symptoms of an acute and devastating lupus flare can resemble the symptoms of an acute attack of flu. Cytokines, critical actors in the immune response, play a role in both the lupus and flu responses. Doctors have a term for the dramatic release of cytokines during these events: cytokine storm. One cytokine, IL-6 ( (interleuken 6 ) has been implicated especially in acute lupus inflammation; this is particularly true in CNS lupus (see: http://onlinelibrary.wiley.com/doi/10.1002/art.23222/full) and in patients with active proliferating lupus nephritis (see: http://www.hindawi.com/journals/ijr/2012/946048/)
The good news is that tolicizumab, a drug used successfully in rheumatoid arthritis, has proven effective at limiting IL-6 activity in some manifestations of SLE. Clinical trials showed that a significant percent of participants not only had a reduction in serum markers for disease activity, but also experienced a reduction in symptoms. While there were side effects noted, one research article judged these to be “acceptable in a clinical setting” (see hindawi journal cited in the above paragraph).
Tocilizumab is also being considered as a possible therapy for some SLE patients who have arthritis. An article on the National Institutes of Health website describes an SLE patient who had a variety of symptoms, including “polyarthritis”. The 22-year old female patient was not responding well to a number of therapies and had failed at several attempts to lower steroid use to under 10mg a day. When it was noted that the woman had elevated levels of IL-6, Tocilizumab was tried. It worked. The patient experienced a remission of symptoms and was finally able to taper steroid use.(http://www.ncbi.nlm.nih.gov/pubmed/22334272)
While Tocilizumab is today an accepted therapy for RA, it is still being evaluated as a treatment for SLE. Still, this drug holds promise as another approach to dealing with certain kinds of lupus. In some patients with rheumatoid arthritis, tocilizumab therapy has been so effective that the patients eventually were symptom-free and able to stay that way without any kind of drug therapy. Let’s hope tocilizumab offers the same relief to at least some lupus patients.