Inflammation is a healthy response which is known to aid in the cleanup and restoration of damaged muscle. In Duchenne, however, these responses are almost permanently activated and therefore become damaging to the repair process. Researchers are working to understand and interfere with the inflammation that is taking place in and around muscle fibres in Duchenne. The overactive inflammatory cascade in DMD leads to the production of free radicals and ultimately cell death. This upregulated inflammatory cascade affects the musculoskeletal system, cardiovascular, respiratory and immune systems.
A type of drug which you may have heard of, steroids, are commonly used to treat Duchenne. Corticosteroids aim to reduce inflammation as well as increase muscle bulk, and in this way preserve muscle function. Glucocorticoids act along various pathways which makes it controversial about which mechanisms of action provide the efficacy in treating Duchenne and which give detrimental effects. Prednisone has been shown to improve strength and lung function in patients with DMD and could also delay cardiomyopathy (enlarged heart) and improve motor function. Deflazacort is a corticosteroid currently available in the UK and other countries, which has a similar efficacy to prednisone and is associated with less weight gain compared to Prednisolone.
These drugs often have severe side effects such as tolerance to chronic use, weight gain and immunosuppression. Therefore scientists are working to develop new anti-inflammatory therapies with fewer side effects.
