Exciting New Funding Award to Tackle Rare Childhood Arthritis Syndrome
Professor Adam Croft has received funding from Great Ormond Street Hospital Charity for a 3-year research project to study a rare genetic condition called Camptodactyly-Arthropathy-Coxa Vara-Pericarditis (CACP) syndrome.
This debilitating condition begins in early childhood, causing joint stiffness, swelling, and difficulty moving. It can also lead to fluid around the heart (pericarditis), impacting children’s daily lives. Currently, there is no cure or specific treatment.
Understanding the Cause
CACP syndrome is caused by changes in a gene called PRG4, which produces a protein called lubricin. Lubricin helps protect and lubricate joints. Without it, children experience painful joint damage and scarring. However, researchers still don’t fully understand why the lack of lubricin causes these symptoms.
This project will investigate how cells in the joint—called fibroblasts and macrophages—normally work together to keep joints healthy, and what goes wrong when lubricin is missing. The research team believes that without lubricin, macrophages can’t function properly, leading to overactive fibroblasts, inflammation, and scar tissue formation.
Who’s Involved?
Led by Prof. Croft at the University of Birmingham, the study brings together a team of experts from Birmingham Children’s Hospital and the UCL Great Ormond Street Institute of Child Health. It also uses precious joint tissue samples already collected through the UK-wide TRICIA (Tissue Research in Childhood Inflammatory Arthritis) network.
Guided by the Voices of Patients and Families
A unique feature of this study is how closely it has been co-developed with young people affected by CACP and their families. Through a series of meetings in spring 2024, young people (aged 13–21) and their parents shaped the study’s direction. Their experiences highlighted the urgent need to understand and treat joint contractures, which most impact daily life.
They also helped researchers decide when and how to collect tissue samples in an ethical and acceptable way, such as during clinical procedures already being done for care.
Families stressed the importance of new treatments and shared their views on side effects, educational impact, and participation in sports. Based on their input, the study now includes a dedicated work package focused on restoring lubricin and testing potential new therapies.
A National Research Effort
The project is part of the MRC-funded TRICIA consortium, which builds capacity for joint tissue research in children and young people across the UK. Samples used in this study were collected through MAPJAG, a TRICIA-linked study using safe, ultrasound-guided biopsies.
Ongoing Involvement and Communication
Three young people with CACP and their families will remain involved through a study advisory group, meeting regularly to guide research and ensure results are shared clearly and accessibly.
Dissemination will include lay summaries, social media updates, press releases, and public events. The study also contributes to training future scientists through the Patient Alliance initiative, where researchers are paired with PRPs to promote meaningful involvement throughout.
