RT Journal Article
SR Electronic
T1 HLA-B27 Predicts a More Extended Disease with Increasing Age at Onset in Boys with Juvenile Idiopathic Arthritis
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP 2055
OP 2061
VO 35
IS 10
A1 LILLEMOR BERNTSON
A1 MICHAEL DAMGÅRD
A1 BOEL ANDERSSON-GÄRE
A1 TROELS HERLIN
A1 SUSAN NIELSEN
A1 ELLEN NORDAL
A1 MARITE RYGG
A1 MAREK ZAK
A1 ANDERS FASTH
YR 2008
UL http://www.jrheum.org/content/35/10/2055.abstract
AB Objective Juvenile idiopathic arthritis (JIA) is a heterogeneous condition with very few clinical and laboratory signs that can help predict the course and severity of the disease in the individual patient. The cell-surface antigen HLA-B27 is well known to be associated with spondyloarthropathies, reactive arthritis, and enthesitis. HLA-B27 plays an important role in the classification of JIA, since evidence of sacroiliitis most often evolves after years of arthritis in other joints. We investigated the associations of HLA-B27 and the clinical manifestations of JIA using a method as close to a population-based study as possible. Methods We studied an incidence-based cohort of 305 patients collected prospectively in 3 Nordic countries (Sweden, Norway, Denmark). Clinical and serological data of the first 3 years of the disease were collected. Results HLA-B27 was found to be positive in 25.5% of the patients, and we found a higher proportion of HLA-B27-positive boys with older age at disease onset (p = 0.034). Regression analysis showed a correlation of 0.7 in the HLA-B27-positive boys, pointing to a higher risk of more joint involvement with older age at disease onset. By Fisher’s exact test, involvement of small joints in the lower extremities was associated with HLA-B27 in boys (p = 0.011), but not in girls (p = 0.687). HLA-B27 was associated with inflammatory back pain in both sexes (p = 0.041 in boys, p = 0.042 in girls), but with enthesitis only in boys (p < 0.001 in boys, p = 0.708 in girls). Conclusion HLA-B27 is of increasing importance with older age at disease onset in boys with JIA, predicting more active joints within the first 3 years of disease, and also involving small joints in the lower extremity to a greater degree than in HLA-B27-negative boys. During the first 3 years of disease the occurrence of HLA-B27 is associated with inflammatory back pain in both sexes, but with enthesitis only in boys. Our data present new challenges for the ILAR classification of JIA.