Patients with juvenile psoriatic arthritis comprise two distinct populations

Abstract

Objective. Psoriatic arthritis (PsA) in children is clinically heterogeneous. We examined a large population of children with juvenile PsA for evidence of phenotypic clustering that could suggest the presence of distinct clinical entities.Methods. We reviewed the medical records of 139 patients meeting the Vancouver criteria for juvenile PsA. To identify segregation into phenotypic groups, we compared younger patients with their older counterparts and subjected the whole population to 2-step cluster analysis.Results. Among patients with juvenile PsA, the age at onset is biphasic, with peaks occurring at approximately 2 years of age and again in late childhood. Compared with children ages 5 years and older, younger patients are more likely to be female, exhibit dactylitis and small joint involvement, and express antinuclear antibodies. Progression to polyarticular disease (>5 joints) is more common in younger children, although joint involvement remains oligoarticular in the majority of children. In contrast, older patents tend to manifest enthesitis, axial joint disease, and persistent oligoarthritis. Uveitis is equally represented in both age groups. Despite a higher utilization of methotrexate therapy, younger patients required, on average, more than twice as long to achieve clinical remission (23 months versus 9.2 months; P ‫؍‬ 0.044). Cluster analysis identified largely overlapping subgroups but suggested that the presence of dactylitis, rather than age, has the greatest capacity to predict essential features of the clinical phenotype.Conclusion. Juvenile PsA comprises 2 distinct populations of patients. Although the pathophysiologic correlate of this finding remains undefined, future studies should avoid the assumption that PsA in childhood constitutes a single etiologic entity.

Juvenile Spondyloarthritis

“…The majority of those patients will have oligoarthritis or polyarthritis of the upper and lower extremities (Stoll, Zurakowski et al 2006;Stoll and Punaro 2011). Psoriasis and adult PsA are strongly associated with HLA-Cw*0602 HLA-B38, and non-MHC genes psors 1 and psors 2, but HLA associations in jPsA are inconsistent, probably due to great variability within jPsA across the pediatric age spectrum (Stoll and Punaro 2011).…”

The irreversible component of the disability index of the health assessment questionnaire: Comment on the article by Aletaha et al

“…I therefore read with much interest the article by Stoll et al (3), which confirms that the current classification criteria for PsA identify at least 2 distinct groups of patients with the same above-mentioned features. In their interpretation of the results, the authors favor the hypothesis that there are 2 broad types of PsA in children.…”

Enthesitis-Related Arthritis: Time to Re-define?

“…JPsA was specifically excluded from the ERA subtype and placed into a separate category. A study evaluating JPsA has shown two distinct phenotypic groups of patients [8]. There is a younger (<5 years of age) group with peak age of onset of 2 years whose arthritis is more likely to exhibit dactylitis and small joint involvement.…”

“…These children are more likely to be female and have a positive anti-nuclear antibody (ANA). An older male group tends to present with more enthesitis, axial disease, and persistent oligoarthritis [8]. Older male pediatric patients who meet the current criteria for JPsA actually share more similarities with ERA patients without psoriasis [8, 9••].…”

“…Older male pediatric patients who meet the current criteria for JPsA actually share more similarities with ERA patients without psoriasis [8, 9••]. In a study examining disease manifestations and course in a group of children with JPsA, they did not appear to form a distinct subgroup of patients; rather, they fell in to one of existing ILAR classifications, suggesting that this category may not be as useful as originally thought [8].…”