Determinants of Discordance Between Criteria for Inactive Disease and Low Disease Activity in Juvenile Idiopathic Arthritis

OBJECTIVE

To assess concordance among criteria for inactive disease (ID) and low disease activity (LDA) in juvenile idiopathic arthritis (JIA) and to seek factors driving discordance.

METHODS

The frequency of fulfillment of existing criteria was evaluated in information on 10,186 patients extracted from 3 cross-sectional data sets. Patients were divided up according to the functional phenotypes of oligoarthritis and polyarthritis. Concordance between criteria was examined using weighted Venn diagrams. The role of each individual component in explaining discordance between criteria was assessed by calculating the absolute number and percentage of instances in which the component was responsible for discrepancy between definitions.

RESULTS

Criteria for ID were met by 28.6-41.1% of patients with oligoarthritis and by 24.0-33.4% of patients with polyarthritis. Criteria for LDA were met by 44.8-62.4% of patients with oligoarthritis and by 44.6-50.4% of patients with polyarthritis. There was a 57.9-62.3% overlap between criteria for ID and a 67.9-85% overlap between criteria for LDA. Parent and physician global assessments and acute-phase reactants were responsible for the majority of instances of discordance among criteria for ID (8.7-15.5%, 10.0-12.3%, and 10.8-17.3%, respectively).

CONCLUSION

We found fair concordance between criteria for ID and LDA in JIA, with the main drivers of discordance for ID being physician and parent global assessments and acute-phase reactants. This observation highlights the need for further studies aimed to evaluate the impact of subjective physician and parent perception of disease remission and of laboratory measures of inflammatory activity on the definition of ID.

The Georgian version of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR)

The Juvenile Arthritis Multidimensional Assessment Report (JAMAR) is a new parent/patient reported outcome measure that enables a thorough assessment of the disease status in children with juvenile idiopathic arthritis (JIA). We report the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the Georgian language. The reading comprehension of the questionnaire was tested in 10 JIA parents and patients. Each participating centre was asked to collect demographic, clinical data and the JAMAR in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents. The statistical validation phase explored descriptive statistics and the psychometric issues of the JAMAR: the 3 Likert assumptions, floor/ceiling effects, internal consistency, Cronbach's alpha, interscale correlations, test-retest reliability, and construct validity (convergent and discriminant validity). A total of 100 JIA patients (26% systemic, 57% oligoarticular, 16% RF negative polyarthritis, and 1% RF positive polyarthritis) and 100 healthy children, were enrolled at two paediatric rheumatology centre. Notably, none of the enrolled JIA patients is affected with psoriatic arthritis or with enthesitis-related arthritis or with undifferentiated arthritis. The JAMAR components discriminated healthy subjects from JIA patients, except for the school-related problems variable. All JAMAR components revealed good psychometric performances. In conclusion, the Georgian version of the JAMAR is a valid tool for the assessment of children with JIA and is suitable for use both in routine clinical practice and clinical research.

Development and Initial Validation of the Macrophage Activation Syndrome/Primary Hemophagocytic Lymphohistiocytosis Score, a Diagnostic Tool that Differentiates Primary Hemophagocytic Lymphohistiocytosis from Macrophage Activation Syndrome

OBJECTIVE

To develop and validate a diagnostic score that assists in discriminating primary hemophagocytic lymphohistiocytosis (pHLH) from macrophage activation syndrome (MAS) related to systemic juvenile idiopathic arthritis.

STUDY DESIGN

The clinical, laboratory, and histopathologic features of 362 patients with MAS and 258 patients with pHLH were collected in a multinational collaborative study. Eighty percent of the population was assessed to develop the score and the remaining 20% constituted the validation sample. Variables that entered the best fitted model of logistic regression were assigned a score, based on their statistical weight. The MAS/HLH (MH) score was made up with the individual scores of selected variables. The cutoff in the MH score that discriminated pHLH from MAS best was calculated by means of receiver operating characteristic curve analysis. Score performance was examined in both developmental and validation samples.

RESULTS

Six variables composed the MH score: age at onset, neutrophil count, fibrinogen, splenomegaly, platelet count, and hemoglobin. The MH score ranged from 0 to 123, and its median value was 97 (1st-3rd quartile 75-123) and 12 (1st-3rd quartile 11-34) in pHLH and MAS, respectively. The probability of a diagnosis of pHLH ranged from <1% for a score of <11 to >99% for a score of  ≥123. A cutoff value of ≥60 revealed the best performance in discriminating pHLH from MAS.

CONCLUSION

The MH score is a powerful tool that may aid practitioners to identify patients who are more likely to have pHLH and, thus, could be prioritized for functional and genetic testing.

Dissecting the Heterogeneity of Macrophage Activation Syndrome Complicating Systemic Juvenile Idiopathic Arthritis

Objective.

To seek insights into the heterogeneity of macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (sJIA) through the analysis of a large patient sample collected in a multinational survey.

Methods.

International pediatric rheumatologists and hemato-oncologists entered their patient data, collected retrospectively, in a Web-based database. The demographic, clinical, laboratory, histopathologic, therapeutic, and outcome data were analyzed in relation to (1) geographic location of caring hospital, (2) subspecialty of attending physician, (3) demonstration of hemophagocytosis, and (4) severity of clinical course.

Results.

A total of 362 patients were included by 95 investigators from 33 countries. Demographic, clinical, laboratory, and histopathologic features were comparable among patients seen in diverse geographic areas or by different pediatric specialists. Patients seen in North America were given biologics more frequently. Patients entered by pediatric hemato-oncologists were treated more commonly with biologics and etoposide, whereas patients seen by pediatric rheumatologists more frequently received cyclosporine. Patients with demonstration of hemophagocytosis had shorter duration of sJIA at MAS onset, higher prevalence of hepatosplenomegaly, lower levels of platelets and fibrinogen, and were more frequently administered cyclosporine, intravenous immunoglobulin (IVIG), and etoposide. Patients with severe course were older, had longer duration of sJIA at MAS onset, had more full-blown clinical picture, and were more commonly given cyclosporine, IVIG, and etoposide.

Conclusion.

The clinical spectrum of MAS is comparable across patients seen in different geographic settings or by diverse pediatric subspecialists. There was a disparity in the therapeutic choices among physicians that underscores the need to establish uniform therapeutic protocols.

Frequency of radiographic damage and progression in individual joints in children with juvenile idiopathic arthritis

OBJECTIVE

To evaluate the presence and progression of radiographic joint damage, as assessed with the adapted Sharp/van der Heijde score (SHS), in individual joints in the hand and wrist in patients with juvenile idiopathic arthritis (JIA) and to compare progression of damage among different JIA categories.

METHODS

A total of 372 radiographs of both wrists and hands obtained at first observation and at last followup visit (after 1-10 years) in 186 children with polyarticular-course JIA were evaluated. All radiographs were scored using the adapted SHS by 2 independent readers. Radiographic assessment included evaluation of joint space narrowing (JSN) and erosions on baseline and last followup radiographs and of progression of radiographic changes from baseline to last followup radiographs.

RESULTS

Both JSN and erosions occurred in all adapted SHS areas. Overall, radiographic damage and progression were more common in the wrist and less common in metacarpophalangeal (MCP) joints. The hamate and capitate areas appeared particularly vulnerable to cartilage loss. Erosions were identified most frequently in the hamate and capitate bones as well as in the second and third metacarpal bases. Patients with extended oligoarthritis were distinctly less susceptible to JSN in hand joints, whereas patients with polyarthritis showed a greater tendency to developing erosions in hand joints.

CONCLUSION

Radiographic joint damage and progression in our patients with JIA were seen most commonly in the wrist and less commonly in MCP joints. The frequency and localization of structural abnormalities differed markedly across disease categories.

Agreement among musculoskeletal pediatric specialists in the assessment of radiographic joint damage in juvenile idiopathic arthritis

OBJECTIVE

To evaluate agreement among musculoskeletal pediatric specialists in assessing radiographic joint damage in juvenile idiopathic arthritis (JIA).

METHODS

Two pediatric rheumatologists, 2 pediatric radiologists, and 2 pediatric orthopedic surgeons evaluated independently 60 radiographs of both wrists and hands of children with polyarticular-course JIA. Films were scored using an adapted and simplified version of the Larsen score, ranging from 0-5. Study radiographs were selected from 568 films used in a previous study aimed to validate an adapted pediatric version of the Sharp/van der Heijde (SHS) score. To enable comparison of specialists' scores with the adapted SHS score, the 60 radiographs were divided into 6 classes of severity of damage based on quintiles of the adapted SHS score. Agreement was evaluated in terms of absolute agreement and through weighted kappa statistics.

RESULTS

The pediatric radiologists tended to assign lower scores and to provide more frequently scores of 0 than did the other specialists. Weighted kappa for the 3 pairs of specialists ranged from 0.67-0.69, indicating substantial agreement. Absolute agreement ranged from 51.3-55.7%, depending on the pair of specialists examined. Both absolute and weighted kappa concordance between specialists' scores and the adapted SHS score were poorer for the pediatric radiologist than for the other specialists.

CONCLUSION

We observed fair agreement in the assessment of radiographic damage among pediatric specialists involved in the care of children with JIA. The radiologists tended to be more reserved than the rheumatologists and orthopedic surgeons in labeling radiographs as damaged or in considering changes as important.

Phagocyte-specific S100 proteins and high-sensitivity C reactive protein as biomarkers for a risk-adapted treatment to maintain remission in juvenile idiopathic arthritis: a comparative study

OBJECTIVES

Juvenile idiopathic arthritis (JIA) is a chronic inflammatory joint disease affecting children. Even if remission is successfully induced, about half of the patients experience a relapse after stopping anti-inflammatory therapy. The present study investigated whether patients with JIA at risk of relapse can be identified by biomarkers even if clinical signs of disease activity are absent.

METHODS

Patients fulfilling the criteria of inactive disease on medication were included at the time when all medication was withdrawn. The phagocyte activation markers S100A12 and myeloid-related proteins 8/14 (MRP8/14) were compared as well as the acute phase reactant high-sensitivity C reactive protein (hsCRP) as predictive biomarkers for the risk of a flare within a time frame of 6 months.

RESULTS

35 of 188 enrolled patients experienced a flare within 6 months. Clinical or standard laboratory parameters could not differentiate between patients at risk of relapse and those not at risk. S100A12 and MRP8/14 levels were significantly higher in patients who subsequently developed flares than in patients with stable remission. The best single biomarker for the prediction of flare was S100A12 (HR 2.81). The predictive performance may be improved if a combination with hsCRP is used.

CONCLUSIONS

Subclinical disease activity may result in unstable remission (ie, a status of clinical but not immunological remission). Biomarkers such as S100A12 and MRP8/14 inform about the activation status of innate immunity at the molecular level and thereby identify patients with unstable remission and an increased risk of relapse.

Performance of Birmingham Vasculitis Activity Score and disease extent index in childhood vasculitides

OBJECTIVES

To evaluate the performance of the Birmingham Vasculitis Activity Score (BVAS) v3 and the Disease Extent Index (DEI) for the assessment of disease activity in 4 primary childhood (c-) systemic vasculitides.

METHODS

Patients fulfilling the EULAR/PRINTO/PRES (Ankara) c-vasculitis classification criteria for Henoch-Schönlein purpura (HSP), childhood (c) polyarteritis nodosa (c-PAN), c-Wegener's granulomatosis (c-WG) and c-Takayasu arteritis (c-TA) with disease duration at the time of diagnosis ≤3 months were extracted from the PRINTO database. The performance of the BVAS and DEI were examined by assessing convergent validity, the pattern of disease involvement, and responsiveness. We also evaluated alternative unweighted scoring methods for both tools.

RESULTS

The analysis set included 796 patients with 669 HSP, 80 c-PAN, 25 c-WG and 22 c-TA. The median age at diagnosis was 6.9 years (6.6-12) and median delay in making the diagnosis from the onset of signs/symptoms was 0.01 (0.003-0.027) years. A strong correlation was found between the BVAS and DEI (rs=0.78) while correlation with the physician global assessment was moderate (rs=0.48) with BVAS and poor with DEI (rs=0.25). Both the BVAS and DEI sub-scores and total scores were able to descrive the disease involvement in the 4 childhood vasculitides. Responsiveness was large (>1.5) for both tools. The performance characteristics of the BVAS and DEI with the unweighted methods were comparable.

CONCLUSIONS

This study demonstrates that both the BVAS and DEI are valid tools for the assessment of the level of disease activity in a large cohort of childhood acute and chronic vasculitides.

Pediatric drug induced hypersensitivity syndrome: case report

Drug induced hypersensitivity syndrome (DIHS) is a rare but potentially life-threatening adverse drug reaction particularly associated with anticonvulsant drugs. We describe the case of a patient who suffered from DIHS caused by anticonvulsant. Our experience suggests glucocorticoids (GC) may be of benefit to children with severe DIHS.

Development and preliminary validation of a paediatric-targeted MRI scoring system for the assessment of disease activity and damage in juvenile idiopathic arthritis

OBJECTIVES

To develop and validate a paediatric-targeted MRI scoring system for the assessment of disease activity and damage in juvenile idiopathic arthritis (JIA). To compare the paediatric MRI score with the adult-designed. Outcome Measures in Rheumatology Clinical Trials-Rheumatoid Arthritis MRI Score (RAMRIS), whose suitability for assessing growing joints was tested.

METHODS

In 66 patients with JIA the clinically more affected wrist was studied. Thirty-nine patients had a 1-year MRI follow-up. Two readers independently assigned the paediatric score and the RAMRIS to all studies. Validation procedures included analysis of reliability, construct validity and responsiveness to change. A reduced version of the bone erosion score was also developed and tested.

RESULTS

The paediatric score showed an excellent reproducibility (interclass correlation coefficient >0.9). The interobserver agreement of RAMRIS was moderate for bone erosions and excellent for bone marrow oedema (BMO). The paediatric score and RAMRIS provided similar results for construct validity. The responsiveness to change of the paediatric score was moderate for synovitis and bone erosion, and poor for BMO and did not improve when RAMRIS was applied. The reduced version of the bone erosion was valuable for the assessment of joint damage, and provided time-saving advantages.

CONCLUSION

The results demonstrate that the paediatric MRI score is a reliable and valid method for assessing disease activity and damage in JIA. Unexpectedly, the RAMRIS provides acceptable suitability for use in the paediatric age group. Further work, especially in a longitudinal setting, is required before defining the most suitable MRI scale for assessing growing joints.

Adapted versions of the Sharp/van der Heijde score are reliable and valid for assessment of radiographic progression in juvenile idiopathic arthritis

OBJECTIVE

To develop adapted versions of the Sharp/van der Heijde radiographic scoring system for use in juvenile idiopathic arthritis (JIA), and to investigate their validity in JIA patients with polyarticular disease.

METHODS

The study group comprised 177 patients with polyarticular JIA. Radiographs of the wrist/hand of each patient were obtained at baseline (first observation) and then at 1, 3, 5, 7/8, and 10 years and were assessed independently by 2 pediatric rheumatologists according to different adaptations of the Sharp/van der Heijde method. To facilitate score assignment, the radiograph for each patient was compared with a bone age-related standard. Validation procedures included analysis of reliability, construct validity, and score progression over time.

RESULTS

Interobserver and intraobserver agreement on longitudinal score values and score changes was good for all of the adapted scoring versions (intraclass correlation coefficient >0.85). Score changes over time were moderately to strongly correlated with the clinical indicators of long-term joint damage and with the amount of long-term radiographic damage as measured with the carpo:metacarpal ratio, thereby demonstrating good construct validity. A steady increase in scores over time was observed, with joint space narrowing being the most common form of damage throughout the disease course. The inclusion of 5 new areas appeared to increase the overall construct validity of erosion scores.

CONCLUSION

Our results show that the adapted versions of the Sharp/van der Heijde score are reliable and valid for the assessment of radiographic progression in patients with JIA.