Identification of role for proteins in children's muscle disease could open up new treatment options

The specific response has earlier been observed in juvenile idiopathic arthritis, but to date, little is known about the role of HSP60 in inflammatory myositis. Inflammatory myositis (IM) is the name given to a group of diseases that cause inflammation in the muscles of the body, which is mediated by the immune system of the body. The main symptoms are pain and weakness and can cause patient disability because of damage to the muscles. The main types of IM are dermatomyositis and polymyositis.

For children, the conditions of myositis are complex and are characterized by muscle damage due to an inflammatory process of the blood vessels that lie under the skin and muscles. Some of the symptoms include skin changes around the eyelids and over the knuckles and finger joints, as well as weakness in muscles, mainly affecting the large muscles around the hips and shoulders resulting in increased difficulty with walking, climbing stairs, getting up from the floor and lifting the arms. The children also often become uncharacteristically miserable and fractious and they may complain of tummy pain.

Heat shock proteins (HSP) are a group of proteins whose expression is increased when the cells are exposed to elevated temperatures. Production of high levels of heat shock proteins can also be triggered by exposure to different kinds of environmental stress conditions, such as infection, inflammation, exposure of the cell to toxins (e.g. ethanol, arsenic, and ultraviolet light), or water deprivation.

Mrs. Elst, pediatric immunologist at the University Medical Centre Utrecht, said, “We have shown for the first time that HSP60 plays an active part in the control of the inflammatory process in JDM. Thus, therapy aimed at the expansion of T-cells with regulatory capacities reacting to HSP60 could contribute to disease remission in patients with JDM. This conclusion opens up new perspectives for the understanding and approach for antigens in immunotherapy.”