The TRAF1/C5 region is a risk factor for polyarthritis in juvenile idiopathic arthritis
- H M Albers1,
- F A S Kurreeman2,
- J J Houwing-Duistermaat3,
- D M C Brinkman1,
- S S M Kamphuis4,
- H J Girschick5,
- C Wouters6,
- M A J Van Rossum7,
- W Verduijn8,
- R E M Toes2,
- T W J Huizinga2,
- M W Schilham1,
- R ten Cate1
- 1Leiden University Medical Center, Department of Paediatrics, Leiden, The Netherlands
- 2Leiden University Medical Center, Department of Rheumatology, Leiden, The Netherlands
- 3Leiden University Medical Center, Department of Medical Statistics, Leiden, The Netherlands
- 4Erasmus Medical Center- Sophia Children’s Hospital, Department of Paediatric Immunology/Rheumatology, Rotterdam, The Netherlands
- 5University of Wuerzburg, Section of Paediatric Rheumatology, Wuerzburg, Germany
- 6University Hospital Gasthuisberg, Department of Paediatric Rheumatology, Leuven, Belgium
- 7Emma Children’s Hospital AMC, Department of Paediatrics, Amsterdam, The Netherlands
- 8Leiden University Medical Center, Department of Immunohaematology and Bloodbank, Leiden, The Netherlands
- R ten Cate, Department of Paediatrics, Leiden University Medical Centre, PO Box 9600, 2300 RC Leiden, the Netherlands;
- Accepted 4 June 2008
- Published Online First 1 July 2008
Objective: Juvenile idiopathic arthritis (JIA) is a chronic disorder in which both genetic and environmental factors are involved. Recently, we identified the TRAF1/C5 region (located on chromosome 9q33–34) as a risk factor for rheumatoid arthritis (RA) (pcombined = 1.4×10−8). In the present study the association of the TRAF1/C5 region with the susceptibility to JIA was investigated.
Methods: A case–control association study was performed in 338 Caucasian patients with JIA and 511 healthy individuals. We genotyped the single nucleotide polymorphism rs10818488 as a marker for the TRAF1/C5 region.
Results: The A allele was associated with the susceptibility to rheumatoid factor-negative polyarthritis with an 11% increase in allele frequency (OR 1.54, 95% CI 1.09 to 2.18; p = 0.012). This association was stronger when combining subtypes with a polyarticular phenotype (OR 1.46, 95% CI 1.12 to 1.90; p = 0.004). In addition, we observed a trend towards an increase in A allele frequency in patients with extended oligoarthritis versus persistent oligoarthritis (49%, 38% respectively); p = 0.055.
Conclusions: Apart from being a well replicated risk factor for RA, TRAF1/C5 also appears to be a risk factor for the rheumatoid factor-negative polyarthritis subtype of JIA and, more generally, seems to be associated with subtypes of JIA characterised by a polyarticular course.
Funding: This study is supported by research grants of the Dutch Arthritis Association (grant number NR-05-1-403 and KFS-04-2-202).
Competing interests: None.