Patients with juvenile psoriatic arthritis comprise two distinct populations

A Family History of Psoriasis in a First-degree Relative in Children with JIA: to Include or Exclude?

OBJECTIVE

To determine the consequences of disregarding first-degree relatives with psoriasis (FRP) as a classification criterion in juvenile idiopathic arthritis (JIA).

METHODS

Criteria were examined in children from a prospective cohort with unclassified and psoriatic JIA.

RESULTS

FRP was the most common reason children were unclassified (57/85, 67%); all 57 children could be classified if FRP were disregarded as an exclusion criterion. FRP was a necessary inclusion criterion to classify 11/77 (14.3%) children with psoriatic JIA.

CONCLUSION

Eliminating FRP as an exclusion criterion, but keeping it as an inclusion criterion in psoriatic JIA simplifies classification, though it is unclear whether the resulting classification would be better.

The Epidemiology of Psoriatic Arthritis

Psoriatic arthritis (PsA) is a chronic systemic inflammatory disorder characterized by joint and entheseal inflammation with a prevalence of 0.05% to 0.25% of the population and 6% to 41% of patients with psoriasis. PsA is a highly heterogeneous inflammatory arthritis. In this review, current knowledge is discussed regarding the epidemiology of PsA, including disease manifestations, classification criteria for adult and juvenile PsA, methods for recognizing early PsA, including use of screening tools and knowledge of risk factors for PsA, and medical comorbidities associated with PsA.

Enthesitis-related arthritis: time to re-define?

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood. Enthesitis-related arthritis (ERA) is one of the seven JIA subtypes classified by the International League of Associations for Rheumatology (ILAR). Due to inclusion and exclusion criteria, a pitfall of the ERA category is that it does not include all subsets of juvenile spondyloarthropathy, with many children ending up in the undifferentiated category. The ERA nomenclature also does not have a method for distinguishing between axial and peripheral disease, two phenotypes which vary in presentation and treatment requirements. This distinction is very important given the overall poor prognosis seen in ERA patients, specifically in those with axial involvement. Since axial involvement is more common and presents earlier than previously thought in ERA, the pediatric rheumatology community should develop more accurate and sensitive classification criteria based on disease course to assist in improving timely diagnosis and appropriate management.

Enthesitis as a component of dactylitis in psoriatic juvenile idiopathic arthritis: histology of an established clinical entity

CONTEXT

Imaging of dactylitis in adult psoriatic arthritis suggests a pathophysiological role for enthesitis. However, histological definition of the dactylitic digit is unavailable.

OBJECTIVE

We evaluated the role of enthesitis in dactylitis associated with psoriatic juvenile idiopathic arthritis (psJIA) in a child who underwent detailed imaging and histologic evaluation.

DESIGN

Radiographs, ultrasound and high-resolution magnetic resonance imaging were employed to define the locus of disease in two dactylitic digits from a 14-year-old girl with psJIA. Biopsies were stained with hematoxylin and eosin, CD3, CD20, CD4, CD8 and CD117 and examined via light microscopy.

RESULTS

Radiologic features of dactylitis included enhanced signal at digital entheses without accompanying synovitis or tenosynovitis. Histologically, finger and toe tissue exhibited hypervascular tenosynovium with a fibromyxoid expansion of fibrous tissue. This was accompanied by sparse to moderate perivascular lymphocytic inflammation consisting predominantly of T cells, with occasional admixed B cells and mast cells. Neutrophils and plasma cells were absent. Fibrocartilage exhibited reactive features including increased extracellular myxoid matrix, binucleation, and focal necrosis, without cellular inflammation. Fibrinous synovitis and mild reactive synoviocyte hyperplasia were seen.

CONCLUSIONS

Dactylitis in psJIA bears a radiographic resemblance to the condition in adult psoriatic arthritis. Histologic hallmarks include an expanded mast cell-populated extracellular myxoid matrix, cartilage degeneration, and a T cell-rich perivascular inflammatory infiltrate. These findings help to define enthesitis as a clinicopathologic entity.

Psoriasis in Children and Adolescents: Diagnosis, Management and Comorbidities

Psoriasis is a common chronic immune-mediated inflammatory skin disorder and begins in childhood in almost one-third of the cases. Although children present with the same clinical subtypes of psoriasis seen in adults, lesions may differ in distribution and morphology, and their clinical symptoms at presentation may vary from those reported by adult patients. Nevertheless, diagnosis of psoriasis is primarily based on clinical features. Pediatric psoriasis can have a profound long-term impact on the psychological health of affected children. Additionally, pediatric psoriasis has been associated with certain comorbidities, such as obesity, hypertension, hyperlipidemia, diabetes mellitus and rheumatoid arthritis, making early diagnosis and management essential. As guidelines are lacking and most (systemic) treatments are not approved for use in children, treatment of pediatric psoriasis remains a challenge. A prospective, multicenter, international registry is needed to evaluate these treatments in a standardized manner and ultimately to develop international guidelines on pediatric psoriasis. This article reviews current concepts in pediatric psoriasis including epidemiology, clinical features, diagnosis, the role of topical and systemic agents and the association with other morbidities in childhood.

Age at disease onset: a key factor for understanding psoriatic disease

Psoriasis and PsA are immune-mediated diseases with a strong genetic component. More than 20 new loci have been recently linked to these diseases. However, interactions between these genes and the phenotypic traits of both diseases are poorly understood at present. Stratification of psoriatic disease according to the sex of the patients, genetic factors or age at onset has allowed in the last few years a better understanding of the principles governing the onset and progression of these processes. The age of onset of psoriasis has been used for decades as an appropriate descriptor to define two subpopulations of psoriatic patients (types I and II) whose clinical and immunogenetic characteristics have been very well differentiated. Moreover, in patients with PsA this distinction between type I and II psoriasis also seems equally operative. In patients with PsA expressing the HLA-C*06 antigen, the latency between the onset of psoriasis and onset of joint symptoms is longer than in those without this marker. It is also known that PsA tends to appear earlier in patients with HLA-B*27 positivity, and that these patients also show a shorter interval of time between the onset of cutaneous lesions and the onset of joint disease. This review highlights the growing importance of age at disease onset as a key stratification factor in worldwide clinical and genetic studies of psoriatic disease.

Update on juvenile spondyloarthritis

Spondyloarthritis (SpA) encompasses a group of disorders linked by overlapping clinical manifestations and genetic predisposition. Newer classification systems developed for adults with SpA focus on identifying individuals with axial or predominantly peripheral involvement. All forms of SpA can begin during childhood, and can be considered on a continuum with adult disease. Nevertheless, there are important differences in presentation and outcome that depend on age at onset. This article highlights these differences, what has been learned about genetics and pathogenesis of SpA, and important unmet needs for future studies.

Juvenile Psoriatic Arthritis (JPsA): juvenile arthritis with psoriasis?

BACKGROUND

Following the introduction of the ILAR criteria for juvenile idiopathic arthritis, juvenile psoriatic arthritis (JPsA) has become a better recognized category within the inflammatory arthritides of childhood. There are fewer reports describing the characteristics and long-term outcome of patients with JPsA than other subtypes of JIA.The aim of our study was to determine the long-term outcome and clinical course of patients with juvenile psoriatic arthritis (JPsA) and to define subgroups of JPsA.

METHODS

Clinical records of all patients meeting criteria for JPsA were reviewed and divided into 4 groups depending on their clinical features and onset type. Patient characteristics and clinical features at onset and during follow-up were determined.

RESULTS

The cohort consisted of 119 patients: 65 with oligoarticular-onset (55%; persistent 44 and extended 21), 34 (29%) with RF(-) and 4 (3%) RF(+) polyarticular and 16 (13%) enthesitis-related arthritis (ERA). At diagnosis patients with ERA were oldest and more commonly male (p=0.001 and =0.01 respectively). Patients with a polyarticular course had more involvement of small joints of the hands and wrist when compared to patients with persistent oligoarticular and ERA (p<0.001) while patients with ERA had more hip and sacroiliac arthritis (p<0.001 for both). Nail changes were seen in 66 patients (57%) and were associated with DIP involvement (p=0.0034).

OUTCOME

Time to first inactive disease on, but not off, therapy was significantly longer among patients with polyarticular course when compared to oligoarticular and ERA (p=0.016 and p=0.48 respectively). Patients with polyarticular course more frequently had contractures during follow-up than other groups (p=0.01).

CONCLUSION

The long-term outcome of with JPsA was generally good. Patients with JPsA did not appear to form distinct sub-group of patients but rather resembled JIA patients with onset types without psoriasis.

Multiple juvenile idiopathic arthritis subtypes demonstrate proinflammatory IgG glycosylation

OBJECTIVE

Rheumatoid arthritis is associated with an excess of agalactosylated (G0) IgG that is considered relatively proinflammatory. Assessment of this association in juvenile idiopathic arthritis (JIA) is complicated by age-dependent IgG glycan variation. The aim of this study was to conduct the first large-scale survey of IgG glycans in healthy children and patients with JIA, with a focus on early childhood, the time of peak JIA incidence.

METHODS

IgG glycans from healthy children and disease-modifying antirheumatic drug-naive patients with JIA were characterized using high-performance liquid chromatography. Agalactosylated glycans were quantitated with reference to monogalactosylated (G1) species. Associations were sought between the G0:G1 ratio and disease characteristics.

RESULTS

Among healthy children ages 9 months to 16 years (n = 165), the G0:G1 ratio was highly age dependent, with the ratio peaking to 1.19 in children younger than age 3 years and declining to a nadir of 0.83 after age 10 years (Spearman's ρ = 0.60, P < 0.0001). In patients with JIA (n = 141), the G0:G1 ratio was elevated compared with that in control subjects (1.32 versus 1.02; P < 0.0001). The G0:G1 ratio corrected for age was abnormally high in all JIA subtypes (enthesitis-related arthritis was not assessed), most strikingly in systemic JIA. Glycosylation aberrancy was comparable in patients with and those without antinuclear antibodies and in both early- and late-onset disease and exhibited at most a weak correlation with markers of inflammation.

CONCLUSION

IgG glycosylation is skewed toward proinflammatory G0 variants in healthy children, in particular during the first few years of life. This deviation is exaggerated in patients with JIA. The role for IgG glycan variation in immune function in children, including the predilection of JIA for early childhood, remains to be defined.

It is time to rethink juvenile idiopathic arthritis classification and nomenclature

Juvenile idiopathic arthritis (JIA) is not a disease, but an exclusion diagnosis that encompasses all forms of arthritis that begin before the age of 16 years, persist for more than 6 weeks, and are of unknown origin. This heterogeneous group of chronic arthritides has been classified on clinical and laboratory grounds to try to identify homogeneous, mutually exclusives categories suitable for etiopathogenic studies . Recent advances have shown that while some JIA categories identify quite definite disease entities, others still include heterogeneous conditions. Some aspects of JIA classification and nomenclature need therefore to be reconsidered.

Genetic association with ERAP1 in psoriasis is confined to disease onset after puberty and not dependent on HLA-C*06

HLA-C remains the strongest susceptibility candidate gene in psoriasis. Evidence for interaction between HLA-C and endoplasmic reticulum aminopeptidase 1 (ERAP1) confined to individuals carrying the HLA-C risk allele was recently reported. Psoriasis displays wide variation, and genetic heterogeneity is likely to contribute to clinical diversity. Age at disease onset is a putative discriminator, and separating psoriasis into early- (<40 years) and late-onset disease has been useful. To sharpen the age-dependent phenotype, we compared genotypes for ERAP1 (rs26653, rs30187, and rs27524) and HLA-C*06:02 in healthy controls and cases stratified for onset of psoriasis at <10, 10-20, 20-40, and >40 years of age. This approach revealed that association with ERAP1 was confined to cases with onset between 10 and 20 years (odds ratio 1.59, 95% confidence interval: 1.28-1.98, P=0.00008) and no association was detected in cases with onset below 10 years, reflecting genetic heterogeneity within the childhood psoriasis population. In contrast to earlier findings, association with ERAP1 was neither dependent on nor interacting with HLA-C*06:02. ERAP1 single-nucleotide polymorphism rs26653, which, to our knowledge, has not previously been reported in psoriasis, is nonsynonymous, has suggestive functional consequences, and herein displays strong association with disease.

Juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) encompasses a complex group of disorders with arthritis as a common feature. This article provides the pediatrician with a review of the epidemiology, classification, clinical manifestations, and complications of JIA. It also provides an update on the current understanding of the cause of JIA and recent developments in management and a recent review of the long-term outcome in JIA.

Current medical treatments for juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) differs markedly from adult rheumatoid arthritis. It is not a single disease, but an exclusion diagnosis that gather together all forms of arthritis that begin before the age of 16 years, persist for more than 6 weeks, and are of unknown origin. The advent of the new biological treatments has dramatically changed both the observed responses to treatment and the expectations of therapies. The implementation of an adequate legislation as well as the presence of international research networks of pediatric rheumatology have contributed to foster the conduct of controlled clinical trials and the development of validated outcome measures. This review will currently describe the methodological approach for performing clinical trials in JIA as well as the current available drug treatment.

Juvenile idiopathic arthritis

Juvenile idiopathic arthritis is a heterogeneous group of diseases characterised by arthritis of unknown origin with onset before age of 16 years. Pivotal studies in the past 5 years have led to substantial progress in various areas, ranging from disease classification to new treatments. Gene expression profiling studies have identified different immune mechanisms in distinct subtypes of the disease, and can help to redefine disease classification criteria. Moreover, immunological studies have shown that systemic juvenile idiopathic arthritis is an acquired autoinflammatory disease, and have led to successful studies of both interleukin-1 and interleukin-6 blockade. In other forms of the disease, synovial inflammation is the consequence of a disturbed balance between proinflammatory effector cells (such as T-helper-17 cells), and anti-inflammatory regulatory cells (such as FOXP3-positive regulatory T cells). Moreover, specific soluble biomarkers (S100 proteins) can guide individual treatment. Altogether these new developments in genetics, immunology, and imaging are instrumental to better define, classify, and treat patients with juvenile idiopathic arthritis.

Therapy of psoriasis in childhood and adolescence - a German expert consensus

Psoriasis of childhood shows an annual prevalence of 0.71 % and accordingly has to be regarded as a frequent chronic inflammatory skin disorder of this age. The impact on the quality of life as well as development of the afflicted children and their parents is evident. On the other side, therapy is demanding with regard to the specific juvenile metabolism, physical development and skin penetration of topical drugs. Long-term treatment at an early age has to be critically judged regarding the chronicity of the disease. Topical corticosteroids, alternatively dithranol may be used first-line, followed by vitamin D derivatives. A combination with UV-light, preferably UV-B, has to be decided on an individual basis. Systemic treatment may be initiated in recalcitrant disease with methotrexate and cyclosporine where long-term experience is available from juvenile rheumatology and transplantation medicine. Alternatively fumaric acid esters or retinoids are available. Rehabilitation procedures will help the children and their parents to cope with the disease and its treatment. The different treatment options are presented here as a German expert consensus, as clinical studies are hardly available and only a few therapeutics are licensed for this age. In any case the therapy has to be individually planned and decided together with the patients and their parents to gain maximal safety, comfort and success.

Spondyloarthritis in a pediatric population: risk factors for sacroiliitis

OBJECTIVE

Pediatric rheumatologists may have an opportunity to diagnose sacroiliitis in its early stages, prior to the development of irreversible radiographic changes. Early diagnosis frequently requires magnetic resonance imaging (MRI), the use of which is limited by expense and requirement for sedation. We set out to identify features of juvenile spondyloarthritis (SpA) associated with the highest risk of sacroiliitis, to identify patients who may be candidates for routine MRI-based screening.

METHODS

We reviewed the charts of 143 children seen at Texas Scottish Rite Hospital for Children diagnosed with SpA based on the International League of Associations for Rheumatology criteria for enthesitis-related arthritis or the Amor criteria for SpA. We performed logistic regression analysis to identify risk factors for sacroiliitis.

RESULTS

A group of 143 children were diagnosed with SpA. Consistent with the diagnosis of SpA, 16% had psoriasis, 43% had enthesitis, 9.8% had acute anterior uveitis, and 70% were HLA-B27+. Fifty-three children had sacroiliitis, of which 11 cases were identified by imaging studies in the absence of suggestive symptoms or physical examination findings. Logistic regression analysis revealed that hip arthritis was a positive predictor of sacroiliitis, while dactylitis was a negative predictor.

CONCLUSION

Children with SpA are at risk for sacroiliitis, which may be present in the absence of suggestive symptoms or physical examination findings. The major risk factor for sacroiliitis is hip arthritis, while dactylitis may be protective. Routine screening by MRI should be considered in patients at high risk of developing sacroiliitis.

Classification of juvenile spondyloarthritis: Enthesitis-related arthritis and beyond

Spondyloarthritis (SpA) refers to a spectrum of immune-mediated inflammatory diseases with overlapping features, which differ from other types of inflammatory arthritis in genetic predisposition, pathogenesis and outcome. SpA frequently involves the axial skeleton, and can result in abnormal bone formation with eventual ankylosis of the spine, resulting in substantial disability. SpA often begins as an 'undifferentiated' disease, the presentation of which differs in children and adults; most notably, spinal involvement is uncommon, while hip arthritis and enthesitis are frequently seen in juvenile-onset disease. Currently, the classification of SpA in adults and children is approached differently. Using the International League of Associations for Rheumatology (ILAR) system for juvenile idiopathic arthritis, most childhood SpA is classified as enthesitis-related arthritis. However, in contrast to adult SpA classification, the presence of, or a family history of, psoriasis dictates a separate category of juvenile idiopathic arthritis. More importantly, the ILAR system does not specifically recognize the presence of axial disease in juvenile SpA. Resolution of these issues will improve communication and the transitioning of patients from pediatric to adult clinics, will facilitate research in genetics and pathogenesis, and will be particularly important in the evaluation of tumor necrosis factor inhibitors and other biologic agents for early, axial SpA.

Comparison of patients with juvenile psoriatic arthritis and nonpsoriatic juvenile idiopathic arthritis: how different are they?

OBJECTIVE

To compare the clinical features and outcome between patients with juvenile psoriatic arthritis (JPsA) and non-JPsA juvenile idiopathic arthritis (JIA).

METHODS

Fifty-three children with JPsA, 32 with < 5 joints in the first 6 months of disease (oligo-JPsA) and 21 (> or = 5 joints) polyarticular-onset (poly-JPsA) were compared to 53 patients with JIA who were matched by sex, age, date of diagnosis, and articular onset pattern.

RESULTS

There was no difference in the percentage of patients between the oligoarticular groups who developed extended oligoarthritis or in the percentage of patients who were positive for antinuclear antibodies. The only differences were that 25% of patients with oligo-JPsA had dactylitis compared to 0% of patients with oligo-JIA (p < 0.01) and 50% had nail pitting as compared to 18.7% (p < 0.05). In polyarticular patients the percentages with dactylitis were similar (19% vs 38%; p = 0.25). The frequency of uveitis was identical in the oligoarticular patients but a higher rate was seen in poly-JPsA compared to poly-JIA (23.8% vs 0%; p = 0.02), while contractures were more frequent in poly-JIA compared to poly-JPsA during the course of the illness (47.6% vs 14.3%; p = 0.03) but not at last followup (14.3% vs 4.7%; p = 0.6). At last followup the mean Childhood Health Assessment Questionnaire scores were similar in both the polyarticular and oligoarticular groups.

CONCLUSION

There were only a few differences between patients with JPsA and JIA regarding disease onset, disease course, and outcome. We suggest that large, longterm prospective studies are required to accurately determine whether subdividing JIA according to psoriasis is worthwhile.

Juvenile psoriatic arthritis: longterm outcome and differentiation from other subtypes of juvenile idiopathic arthritis

OBJECTIVE

To compare outcomes in patients with juvenile psoriatic arthritis (PsA) with those in patients with other juvenile idiopathic arthritis (JIA) subtypes, and to evaluate characteristics and genetic markers that may differentiate PsA from other subtypes of JIA.

METHODS

JIA patients first admitted between 1980 and 1985 were clinically examined after a median of 15 years. Health status was reassessed by the Short Form-36 Health Survey (SF-36) after a median of 23 years. Of 336 JIA patients, 31 (9%) had PsA.

RESULTS

Predictors of PsA were psoriasis in the patient (OR 12.06, p = 0.004) or first-degree relative (OR 30.86, p < 0.001), dactylitis (OR 10.97, p < 0.001), and ankle/toe arthritis (OR 3.04, p = 0.038) within the first 6 months. HLA-DRB1*11/12 status (OR 2.69, p = 0.040) and onset after age 6 years (OR 4.41, p = 0.004) differentiated PsA from either oligoarthritis or polyarthritis. After 15 years, PsA patients had poorer physical health than healthy population controls (p = 0.001). After 23 years, the SF-36 physical scores were poorer in PsA patients than in those with either oligoarthritis or polyarthritis (p < 0.045). The need for disease-modifying antirheumatic drugs and/or anti-tumor necrosis factor agents was present in 33% of PsA versus 8% in oligoarthritis and 13% in either oligoarthritis or polyarthritis patients (p < 0.001 and p = 0.002, respectively).

CONCLUSION

In addition to a history of psoriasis, dactylitis, ankle or toe arthritis, and DRB1*11/12 in children with JIA indicate the likelihood of PsA, a subtype associated with unfavorable outcome.