Comorbidity in Juvenile Idiopathic Arthritis (JIA)


Comorbidity can be defined as the presence of two disorders or more occurring at the same time in a single patient. Children with chronic diseases such as JIA can develop complications of the disease itself, a new disease or drug related side effects that have a significant impact on the quality of life. In this project we want to study all significant events occurring before or after the onset of arthritis.

Facts and figures

Project lead
N Wulffraat
UMC Utrecht
FOREUM research grant: € 300.000

Meet the team

N Wulffraat
UMC Utrecht
J Swart
UMC Utrecht
K Hyrich
University of Manchester
M Lunt
University of Manchester
L Kearsley-Fleet
University of Manchester
N Ruperto
Istituto Giannina Gaslini
G Giancane
IRCCS Istituto G. Gaslini
K Minden
Charité Berlin
J Klotsche
Charité Berlin
G Horneff
Charité Berlin
W Costello
European Network for Children with Arthritis ENCA
C Schoemaker
Dutch JIA parent organisation


The purpose of this project is to study the presence of comorbidity and symptoms developing under therapy of patients followed in the 3 largest JIA registries in Europe. We assume that comorbidity in a disease such as JIA significantly increases the burden of the disease and thus has major effects on quality of life.

Patient voice

ENCA (European Network for Children with Arthritis) representatives are part of our steering committee. ENCA has parents trained in research, epidemiology and health care amongst its members.

Patient involvement through ENCA can help us analysing the relevance of these complications for the disease burden. They will be actively involved in ranking the importance of the observed comorbidities/ complications and thus in discussing priorities for further research.

Interim results

Three registries have identified the occurrence of selected comorbidities at registration and final follow-up. Furthermore, incidences on methotrexate and biologic therapy have been established. Currently, the registries are cooperating in the validation of a clinical prediction model for chronic uveitis.


  • A clinical prediction model for estimating the risk of developing uveitis in patients with juvenile idiopathic arthritis
    J.W. van Straalen1, G. Giancane2,3, Y. Amazrhar1, Nikolay Tzaribachev4, Calin Lazar5, Yosef Uziel6, Albena Telcharova – Mihaylovska7, Claudio Len8, Angela Miniaci9, Alina Lucica Boteanu10, Giovanni Filocamo11, Mariel Viviana Mastri12, Thaschawee Arkachaisri13, Maria Greca Magnolia14, Esther Hoppenreijs15, S. de Roock1, N.M. Wulffraat1, Nicolino Ruperto2*, J.F. Swart1* Rheumatology (Oxford) 2020 Dec 4;keaa733. doi: 10.1093/rheumatology/keaa733
    Read more

EULAR Abstracts


  • OP0058: Development of inflammatory bowel disease during treatment with Etanercept in patients with Juvenile Idiopathic Arthritis; Roline Krol, Joost F. Swart, Gabriella Giancane, Sytze De Roock, Troels Herlin, Pavla Dolezalova, Helga Sanner, Gordana Susic, Flávio R. Sztajnbok, D Maritsi, Tamas Constantin, V Vargova, Sujata Sawhney, Marite Rygg, Sheila Knupp D.E. Oliveira, Marco Cattalini, Ellen Norda, Claudia Magalhaes, Alberto Martini, Nico Wulffraat, Nicolino Ruperto

Go to EULAR Abstract Archive


Months 1-3: check if ethical consent is indeed still valid. Contact patient organisations
Months 1-12 Baseline demographics. Start meeting with the 3 registries and patients to define methodologies of data collection, and priorities in analysis of the observed comorbidities. Write Knowledge Translation and Exchange plan. Define division of tasks and responsibilities
Months 13-18:  collect rheumatological core outcome data and comorbidities
Month 18-24: analysis of observed variables, detect differences and limitations of present data.
Month 24: follow up meeting, with discussion of observed comorbidities and possible correlations. Prepare recommendations when needed. Contact adult registries.
Month 24-30: statistical analysis, monitoring of comorbidities (not at the sites). 
Months 24: Plan future design of studies on the impact on quality of life. Meet with adult registries and agree on joint strategies
Month 36: Meeting with stakeholders