Children with juvenile idiopathic arthritis have premature ageing of immune cells in joints

 Children with juvenile idiopathic arthritis have immune cells in their joints that are similar to those of 90 year olds, says research published in Arthritis and Rheumatism.

A US team looked at immune cells (T-cells) in the blood and joint fluid from 98 children who had JIA aged 1 year to 17 years. The scientists compared the volunteers with 46 children who did not have JIA.

Approximately one-third of the T-cells of the children with JIA had shortened telomeres (the ends of the chromosomes) and these had lost or reduced the ability to multiply.  

“The T-cells of the children with JIA had very short telomeres, about the length we see in a 90-year-old or a young adult with rheumatoid arthritis,” says Dr Abbe de Vallejo, lead author.  “Those same T-cells express unusually high levels of several classic protein markers of cell aging and exhaustion. These kids haven’t lived long enough to have cells that look that old. This is the first indication that premature aging in occurring in this childhood condition.”

The findings could ultimately lead to new therapies.

“JIA is typically treated with broad-spectrum drugs such as steroids and biologics that essentially paralyze the entire immune system, but only a third of the cells are affected and their abnormality seems to be premature aging, rather than autoimmune activity. This study suggests cell-targeted treatments could be developed to prevent this premature immune aging.”