Therapy of myositis: biological and physical

To give an update on reported use and effects of biological and physical therapies in patients with myositis.

The most promising biological treatment in polymyositis, dermatomyositis and juvenile dermatomyositis is B-cell blockade by rituximab. Anti-Jo or anti-Mi-2 antibodies were predictors of response suggesting different molecular pathways in different subsets of myositis. T-cell blockade with abatacept is a new possibility, as is blockade of interleukin-1, interleukin-6 or type I interferon, but controlled studies are needed. Metabolic abnormalities may contribute to muscle impairment, lending support to combine pharmacological therapy with exercise in patients with polymyositis and dermatomyositis. Exercise improved the aerobic milieu in the muscle, along with improved aerobic capacity, and reduced disability. Support is also provided for the safety of exercise in patients with recent-onset polymyositis and dermatomyositis and exercise is well tolerated in patients with juvenile dermatomyositis.

There is a strong need to develop new therapies in patients with myositis. To achieve this, more knowledge is needed on the molecular pathogenesis. Targeted therapies using biologics or exercise can be employed to achieve an improved understanding of molecular pathways, provided that clinical outcome measures are combined with molecular studies on muscle and blood.