Who is eligible to take part?
Much of the research to date has focused on trying to identify risk factors (both environmental and genetic) for susceptibility to inflammatory arthritis in children. However it is also important to determine whether there are any factors at the time of first presentation which predict long-term outcome. This will help physicians understand the long-term prognosis of an individual child at initial presentation, allowing the personalisation of an individual child’s therapeutic regime.
The aim is to identify the predictors of outcome, both short-term and long-term, following presentation with childhood onset inflammatory arthritis and to identify the relative contributions of socio-demographic, clinical, psychological, laboratory and genetic factors and treatment in explaining outcome.
Inflammatory arthritis is one of the commonest chronic illnesses of childhood, affecting around 1:1000 children in the UK. This is very similar to the frequency of Type 1 diabetes in children (1:700-1000). At least one child in an average sized secondary school will have chronic arthritis at any one time.
The majority of children with inflammatory arthritis will be diagnosed with juvenile idiopathic arthritis (JIA). JIA is an umbrella term for a very variable group of chronic inflammatory arthritides lasting for six weeks or more and beginning before the sixteenth birthday. Children with JIA fall into one of seven categories (systemic onset, persistent oligoarticular, extended oligoarticular, rheumatoid factor negative, rheumatoid factor positive, enthesitis related, psoriatic and undifferentiated JIA).
JIA is a very variable condition which can affect one or many joints at any one time. The joint inflammation can be associated with other inflammatory symptoms; for example children with systemic onset JIA may experience systemic inflammatory symptoms (including fever, rash, swollen glands and fatigue) and children with enthesitis related arthritis may have pain and swelling in the tendons and ligaments. Children with JIA may develop uveitis, a chronic inflammatory eye disease which may be completely asymptomatic.
Long term outcome is variable. It is thought that around one-third of children with JIA will continue to have episodes of active arthritis into the adult years and up to 60% of all children will experience some limitation of their activities of daily living.
The risk factors for developing childhood arthritis are largely unknown but as with many other arthritic diseases, it is thought to be a complex condition dependent upon both genetic and environmental factors.
The Childhood Arthritis Prospective Study (CAPS) is the largest prospective inception cohort study of children with JIA worldwide. The study began recruiting in 2001 and to date has recruited over 1500 patients.
Children and young people aged less than 16 at diagnosis
Inflammatory arthritis of one or more joints
Persistence for more than two weeks
No previous diagnosis of inflammatory arthritis or has been in remission for at least 2 years