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Objective A working group was established to develop a core domain set (CDS) for Chronic Nonbacterial Osteomyelitis (CNO) and Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis (SAPHO) following the OMERACT filter 2.1. Methods A scoping review to identify disease-related manifestations was performed, followed by a special interest group (SIG) session at OMERACT2020 to begin the CNO/SAPHO CDS framework. Results Candidate items were identified from the scoping review and most fell under Life Impact and Pathophysiology Manifestation core areas. A SIG agreed on the need to develop a CDS for CNO and SAPHO (100%) and for children and adults (91%). Conclusion Based on candidate items identified, qualitative research and Delphi surveys will be performed as next steps.

This is a retrospective chart review of 20 patients treated with a consensus-driven treatment algorithm in multisystem inflammatory syndrome in children patients across a wide clinical spectrum. Their treatments and clinical status are described as well as their favorable return to functional baseline by 30 days post presentation.

OBJECTIVE: To provide guidance on the management of multisystem inflammatory syndrome in children (MIS-C), a condition characterized by fever, inflammation, and multiorgan dysfunction that manifests late in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and to provide recommendations for children with hyperinflammation during coronavirus disease 2019 (COVID-19), the acute, infectious phase of SARS-CoV-2 infection. METHODS: A multidisciplinary task force was convened by the American College of Rheumatology (ACR) to provide guidance on the management of MIS-C associated with SARS-CoV-2 and hyperinflammation in COVID-19. The task force was composed of 9 pediatric rheumatologists, 2 adult rheumatologists, 2 pediatric cardiologists, 2 pediatric infectious disease specialists, and 1 pediatric critical care physician. Preliminary statements addressing clinical questions related to MIS-C and hyperinflammation in COVID-19 were developed based on evidence reports. Consensus was built through a modified Delphi process that involved 2 rounds of anonymous voting and 2 webinars. A 9-point scale was used to determine the appropriateness of each statement (median scores of 1-3 for inappropriate, 4-6 for uncertain, and 7-9 for appropriate), and consensus was rated as low, moderate, or high based on dispersion of the votes along the numeric scale. Approved guidance statements were those that were classified as appropriate with moderate or high levels of consensus, as prespecified prior to voting. RESULTS: The ACR task force approved a total of 128 guidance statements addressing the management of MIS-C and hyperinflammation in pediatric COVID-19. These statements were refined into 40 final clinical guidance statements, accompanied by a flow diagram depicting the diagnostic pathway for MIS-C. CONCLUSION: Our understanding of SARS-CoV-2-related syndromes in the pediatric population continues to evolve. The guidance provided in this "living document" reflects currently available evidence, coupled with expert opinion, and will be revised as further evidence becomes available.

Significance In this report we identify genetic susceptibility variants for periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome, the most common periodic fever syndrome in children. PFAPA shares risk loci at IL12A, STAT4, IL10, and CCR1-CCR3 with Behçet’s disease and recurrent aphthous stomatitis, defining a family of Behçet’s spectrum disorders. Differential HLA associations along this spectrum may determine where individual phenotypes fall among the Behçet’s spectrum disorders., Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is the most common periodic fever syndrome in children. The disease appears to cluster in families, but the pathogenesis is unknown. We queried two European–American cohorts and one Turkish cohort (total n = 231) of individuals with PFAPA for common variants previously associated with two other oropharyngeal ulcerative disorders, Behçet’s disease and recurrent aphthous stomatitis. In a metaanalysis, we found that a variant upstream of IL12A (rs17753641) is strongly associated with PFAPA (OR 2.13, P = 6 × 10−9). We demonstrated that monocytes from individuals who are heterozygous or homozygous for this risk allele produce significantly higher levels of IL-12p70 upon IFN-γ and LPS stimulation than those from individuals without the risk allele. We also found that variants near STAT4, IL10, and CCR1-CCR3 were significant susceptibility loci for PFAPA, suggesting that the pathogenesis of PFAPA involves abnormal antigen-presenting cell function and T cell activity and polarization, thereby implicating both innate and adaptive immune responses at the oropharyngeal mucosa. Our results illustrate genetic similarities among recurrent aphthous stomatitis, PFAPA, and Behçet’s disease, placing these disorders on a common spectrum, with recurrent aphthous stomatitis on the mild end, Behçet’s disease on the severe end, and PFAPA intermediate. We propose naming these disorders Behçet’s spectrum disorders to highlight their relationship. HLA alleles may be factors that influence phenotypes along this spectrum as we found new class I and II HLA associations for PFAPA distinct from Behçet’s disease and recurrent aphthous stomatitis.

We describe 10 children with Alagille syndrome and inflammatory arthritis. In our centers, the prevalence of chronic arthritis in patients with Alagille syndrome is approximately 50 times higher compared with the general population. Arthritis was refractory to most treatment. Patients with Alagille syndrome should routinely be screened for musculoskeletal symptoms.

To provide guidance on the management of Multisystem Inflammatory Syndrome in Children (MIS-C), a condition characterized by fever, inflammation, and multiorgan dysfunction that manifests late in the course of SARS-CoV-2 infection. Recommendations are also provided for children with hyperinflammation during COVID-19, the acute, infectious phase of SARS-CoV-2 infection.The Task Force is composed of 9 pediatric rheumatologists and 2 adult rheumatologists, 2 pediatric cardiologists, 2 pediatric infectious disease specialists, and 1 pediatric critical care physician. Preliminary statements addressing clinical questions related to MIS-C and hyperinflammation in COVID-19 were developed based on evidence reports. Consensus was built through a modified Delphi process that involved anonymous voting and webinar discussion. A 9-point scale was used to determine the appropriateness of each statement (median scores of 1-3 for inappropriate, 4-6 for uncertain, and 7-9 for appropriate). Consensus was rated as low, moderate, or high based on dispersion of the votes. Approved guidance statements were those that were classified as appropriate with moderate or high levels of consensus, which were prespecified before voting.The guidance was approved in June 2020 and updated in November 2020 and October 2021, and consists of 41 final guidance statements accompanied by flow diagrams depicting the diagnostic pathway for MIS-C and recommendations for initial immunomodulatory treatment of MIS-C.Our understanding of SARS-CoV-2-related syndromes in the pediatric population continues to evolve. This guidance document reflects currently available evidence coupled with expert opinion, and will be revised as further evidence becomes available.

Systemic autoinflammatory diseases (SAIDs) are characterized by unprovoked exaggerated inflammation on a continuum from benign recurrent oral ulceration to life-threatening strokes or amyloidosis, with renal failure as a potential sequela. The ability to discriminate these diagnoses rests on the genetic and mechanistic defect of each disorder, considering potential overlapping autoinflammation, autoimmunity, and immune deficiency. A comprehensive and strategic genetic investigation influences management as well as the consequential expected prognoses in these subsets of rare diseases. The ever-expanding therapeutic armamentarium reflects international collaborations, which will hasten genetic discovery and consensus-driven treatment.

To provide evidence-based recommendations and expert guidance for the management of Kawasaki disease (KD), focusing on clinical scenarios more commonly addressed by rheumatologists.Sixteen clinical questions regarding diagnostic testing, treatment, and management of KD were developed in the Patient/Population, Intervention, Comparison, and Outcomes (PICO) question format. Systematic literature reviews were conducted for each PICO question. We used the Grading of Recommendations, Assessment, Development and Evaluation method to assess the quality of evidence and formulate recommendations. Each recommendation required consensus from at least 70% of the Voting Panel.We present 1 good practice statement, 11 recommendations, and 1 ungraded position statement to guide the management of KD and clinical scenarios of suspected KD. These recommendations for KD are focused on situations in which input from rheumatologists may be requested by other managing specialists, such as in cases of treatment-refractory, severe, or complicated KD. The good practice statement affirms that all patients with KD should receive initial treatment with intravenous immunoglobulin (IVIG). In addition, we developed 7 strong and 4 conditional recommendations for the management of KD or suspected KD. Strong recommendations include prompt treatment of incomplete KD, treatment with aspirin, and obtaining an echocardiogram in the setting of unexplained macrophage activation syndrome or shock. Conditional recommendations include use of IVIG with other adjuvant agents for patients with KD and high-risk features of IVIG resistance and/or coronary artery aneurysms. These recommendations endorse minimizing risk to the patient by using established therapy promptly at disease onset and identifying situations in which adjunctive therapy may be warranted.These recommendations provide guidance regarding diagnostic strategies, use of pharmacologic agents, and use of echocardiography in patients with suspected or confirmed KD.

Background/objectives The development of psoriasis while on tumor necrosis factor inhibitors (TNFi) is a paradoxical effect of agents that treat psoriasis. There is a paucity of data available on this entity in juvenile idiopathic arthritis (JIA). Our objectives were to determine the prevalence of TNFi-induced psoriasis in patients with JIA at two pediatric centers, and psoriasis response to therapeutic modifications. Methods We performed retrospective chart review on patients with JIA treated with TNFi (adalimumab, etanercept, infliximab) who developed psoriasis. TNFi-induced psoriasis was defined as an incident diagnosis of psoriasis after starting a TNFi. Patients with personal histories of psoriasis prior to TNFi therapy were excluded. Following diagnosis, responses to medication changes were defined based on physician assessments. Results Nine of 166 (5.4%) patients on TNFi for JIA were diagnosed with TNFi-induced psoriasis. All cases were female. One had a family history of psoriasis. The median age was 10 (range 2-16) years. Five (55%) patients experienced scalp psoriasis, including four (44%) with alopecia. Two (22%) patients achieved significant improvement after switching to different classes of biologic agents, while three (33%) patients had significant improvement following discontinuation of biologic therapy. One of five patients who switched to a different TNFi had complete resolution, while four had worsening symptoms or partial improvement. Conclusions Our findings demonstrate the prevalence of TNFi-induced psoriasis in JIA at two centers. Though larger studies are needed, our data suggest discontinuation of TNFi or biologic class switching should be considered as treatment strategies in select patients.

ObjectiveTo investigate the characteristics and risk factors of a novel parenchymal lung disease (LD), increasingly detected in systemic juvenile idiopathic arthritis (sJIA).MethodsIn a multicentre retrospective study, 61 cases were investigated using physician-reported clinical information and centralised analyses of radiological, pathological and genetic data.ResultsLD was associated with distinctive features, including acute erythematous clubbing and a high frequency of anaphylactic reactions to the interleukin (IL)-6 inhibitor, tocilizumab. Serum ferritin elevation and/or significant lymphopaenia preceded LD detection. The most prevalent chest CT pattern was septal thickening, involving the periphery of multiple lobes ± ground-glass opacities. The predominant pathology (23 of 36) was pulmonary alveolar proteinosis and/or endogenous lipoid pneumonia (PAP/ELP), with atypical features including regional involvement and concomitant vascular changes. Apparent severe delayed drug hypersensitivity occurred in some cases. The 5-year survival was 42%. Whole exome sequencing (20 of 61) did not identify a novel monogenic defect or likely causal PAP-related or macrophage activation syndrome (MAS)-related mutations. Trisomy 21 and young sJIA onset increased LD risk. Exposure to IL-1 and IL-6 inhibitors (46 of 61) was associated with multiple LD features. By several indicators, severity of sJIA was comparable in drug-exposed subjects and published sJIA cohorts. MAS at sJIA onset was increased in the drug-exposed, but was not associated with LD features.ConclusionsA rare, life-threatening lung disease in sJIA is defined by a constellation of unusual clinical characteristics. The pathology, a PAP/ELP variant, suggests macrophage dysfunction. Inhibitor exposure may promote LD, independent of sJIA severity, in a small subset of treated patients. Treatment/prevention strategies are needed.

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is considered the most common periodic fever syndrome of childhood. Although it was first described three decades ago, the pathogenesis has been poorly understood. Recent studies on the heritability and immunology of the disorder have begun to shed light into the mechanisms of this autoinflammatory disorder. This review will focus on the pathogenesis of PFAPA, especially as it pertains to the genetic susceptibility, tonsillar immunology, and the role of the microbiome.Recent literature provides insights into the heritability, potential genetic modifiers, and the immunologic and microbiological profile of the tonsils in this syndrome.Evidence is mounting that PFAPA is inherited as a complex genetic disease. Furthermore, tonsillectomy is curative in the majority of patients, including those who do not meet the complete clinical criteria for PFAPA. The tonsils in PFAPA patients may exhibit unique immunologic and microbiological features. The goal of this review is to outline these new developments.

Background/Purpose. Understanding the practices of pediatric rheumatologists in diagnosing and treating chronic nonbacterial osteomyelitis (CNO) can provide important information to guide the development of consensus treatment plans. The objectives of this study were to determine physicians’ approaches to (1) diagnosing and monitoring CNO, (2) ordering a bone biopsy, and (3) making treatment decisions. Methods. A survey was distributed among members of the Childhood Arthritis and Rheumatology Research Alliance using a web-based questionnaire. Results. 121 of 277 (41%) attending physician members completed the survey. Plain radiographs (89%) were most commonly used followed by regional MRI (78%), bone scintigraphy (43%), and whole-body MRI (36%). The top three reasons for performing a biopsy were constitutional findings (66%), unifocal bone lesions (64%), and nocturnal bone pain (45%). Nearly all responders (95%) prescribed nonsteroidal anti-inflammatory drugs (NSAIDs) as initial therapy. For patients who failed NSAID treatment, methotrexate (67%), tumor necrosis factor inhibitors (65%), and bisphosphonates (46%) were the next most commonly used treatments. The presence of a spinal lesion increased the use of bisphosphonate treatment. Conclusion. The diagnostic approach and disease activity monitoring for CNO varied among surveyed physicians. Our survey findings provided important background for the development of consensus treatment plans for CNO.

To assess the practice patterns of pediatric rheumatology and infectious diseases subspecialists in the diagnosis and treatment of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome. An online survey assessing diagnostic and treatment approaches was sent to 424 members of the Childhood Arthritis and Rheumatology Research Alliance (CARRA) and 980 members of the Pediatric Infectious Disease Society (PIDS). 277 physicians (123 from CARRA and 154 from PIDS representing 21% of the total membership) completed the survey. To diagnose PFAPA, most respondents agreed that patients must have the following features of the diagnostic criteria: stereotypical fever episodes (95%), asymptomatic intervals between episodes (93%), and normal growth and development (81%). However, 71% of the respondents did not require age of onset

To determine the relationships among race, income, and disease outcomes in children with juvenile dermatomyositis (JDM).Data from 438 subjects with JDM enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Legacy Registry were analyzed. Demographic data included age, sex, race, annual family income, and insurance status. Clinical outcomes included muscle strength, presence of rash, calcinosis, weakness, physical function, and quality of life measures. Disease outcomes were compared based on race and income.Minority subjects were significantly more likely to have low annual family income and significantly worse scores on measures of physical function, disease activity, and quality of life measures. Subjects with lower annual family income had worse scores on measures of physical function, disease activity, and quality of life scores, as well as weakness. Black subjects were more likely to have calcinosis. Despite these differences in outcome measures, there were no significant differences among the racial groups in time to diagnosis or duration of disease. Using calcinosis as a marker of disease morbidity, black race, annual family income$50 000 per year, negative antinuclear antibody, and delay in diagnosis12 months were associated with calcinosis.Minority race and lower family income are associated with worse morbidity and outcomes in subjects with JDM. Calcinosis was more common in black subjects. Further studies are needed to examine these associations in more detail, to support efforts to address health disparities in subjects with JDM and improve disease outcomes.

The syndrome of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) is the most common periodic fever disease in children. However, the pathogenesis is unknown. Using a systems biology approach we analyzed blood samples from PFAPA patients whose genetic testing excluded hereditary periodic fevers (HPFs), and from healthy children and pediatric HPF patients. Gene expression profiling could clearly distinguish PFAPA flares from asymptomatic intervals, HPF flares, and healthy controls. During PFAPA attacks, complement ( C1QB, C2, SERPING1 ), IL-1–related ( IL-1B, IL-1RN, CASP1, IL18RAP ), and IFN-induced ( AIM2 , IP-10/CXCL10 ) genes were significantly overexpressed, but T cell-associated transcripts ( CD3, CD8B ) were down-regulated. On the protein level, PFAPA flares were accompanied by significantly increased serum levels of chemokines for activated T lymphocytes (IP-10/CXCL10, MIG/CXCL9), G-CSF, and proinflammatory cytokines (IL-18, IL-6). PFAPA flares also manifested a relative lymphopenia. Activated CD4 + /CD25 + T-lymphocyte counts correlated negatively with serum concentrations of IP-10/CXCL10, whereas CD4 + /HLA-DR + T lymphocyte counts correlated positively with serum concentrations of the counterregulatory IL-1 receptor antagonist. Based on the evidence for IL-1β activation in PFAPA flares, we treated five PFAPA patients with a recombinant IL-1 receptor antagonist. All patients showed a prompt clinical and IP-10/CXCL10 response. Our data suggest an environmentally triggered activation of complement and IL-1β/-18 during PFAPA flares, with induction of Th1-chemokines and subsequent retention of activated T cells in peripheral tissues. IL-1 inhibition may thus be beneficial for treatment of PFAPA attacks, with IP-10/CXCL10 serving as a potential biomarker.

Autoinflammatory diseases encompass a growing list of disorders that lead to systemic and organ-specific inflammation. Such diseases can present in the fetal and neonatal periods, mimicking bacterial infections, congenital viral infections, and genetic syndromes. The concept of autoinflammatory diseases was proposed only 10 years ago with the identification of genes underlying periodic fever syndromes. Unlike autoimmune diseases that primarily involve the adaptive immune response, autoinflammatory disorders are caused by excessive activation of the innate immune system. Clinical features of autoinflammatory diseases may include fevers, rash, conjunctivitis, hepatosplenomegaly, peritonitis, osteomyelitis, arthritis, and meningitis. Therefore, affected patients often are misdiagnosed with neonatal infections. Some of the autoinflammatory diseases present with distinct morphologic features that may be mistaken for various genetic syndromes. Many are characterized by recurrent episodes of fevers throughout life, leading to inappropriate use of antibiotics. A new understanding of the innate immune system has allowed for the development of “biologics” or medications that can target dysregulated cytokine production. Early diagnosis of autoinflmmatory diseases allows appropriate management of fevers and other manifestations. In some cases, initiation of anticytokine therapy can significantly alter devastating manifestations, including failure to thrive and neurologic deterioration. This review focuses on autoinflammatory disorders that commonly present in the neonatal period.

Objective.To (1) estimate the health-related quality of life (HRQOL) of children with childhood-onset systemic lupus erythematosus (cSLE) and compare it to that of normative cohorts; (2) assess the relationship of HRQOL with cSLE disease activity and damage; and (3) determine the effects of changes of disease activity on HRQOL.Methods.Patients with cSLE (n = 98) followed every 3 months completed HRQOL measures, the Pediatric Quality of Life Inventory Generic Core scale (PedsQL-GC), the Rheumatology Module (PedsQL-RM), and the Child Health Questionnaire (CHQ). The British Isles Lupus Activity Group Index (BILAG) was used to measure organ-system-specific disease activity. Physicians rated the course of cSLE between visits.Results.At baseline, mean (standard deviation, SD) score [parent report] of the PedsQL-GC and the PedsQL-RM was 75 (17) and 79 (14), respectively; the mean (SD) of the CHQ physical summary score (CHQ-PHS) was 49 (7) and that of the CHQ psychological summary score was 42 (12). Higher BILAG scores, especially in the general, musculoskeletal, neurological, and vascular, but not the mucocutaneous, renal, cardiovascular, or hematological BILAG domains, were associated with a significantly lower HRQOL. Patients with damage had lower HRQOL than those without damage. All HRQOL measures included were at most modestly responsive to clinically important changes with cSLE.Conclusion.HRQOL with cSLE is significantly lower than that reported in healthy populations. Organ-specific involvement with cSLE has a differential effect on HRQOL. Higher disease activity and damage are associated with significantly lower HRQOL as measured by the PedsQL-RM and the CHQ-PHS, and worsening of cSLE leads to a further decline.

Methods PFAPA patients were prospectively recruited. All patients had genetic testing to exclude mutations in the known fever genes (MVK, MEFV, TNFRSF1A, NLRP3, and ELA2). These PFAPA patients have been classified as sporadic or familial cases based on family history. Familial cases included those with a family member having PFAPA or a family member having a feature of PFAPA (recurrent fever, oral ulcer, pharyngitis, or lymphadenopathy). The demographics, symptoms, response to therapies, and clinical characteristics were compared for sporadic and familial cases. Detailed histories were obtained from families with multiple members affected by PFAPA.

Objective To determine the minimal clinically important differences (MCIDs) of validated measures of systemic lupus erythematosus (SLE) disease activity in childhood-onset SLE. Methods Childhood-onset SLE patients (n = 98) were followed every 3 months for up to 7 visits (n = 623 total visits). Disease activity measures (European Consensus Lupus Activity Measure, Systemic Lupus Erythematosus Disease Activity Index, Systemic Lupus Activity Measure, British Isles Lupus Assessment Group, and Responder Index for Lupus Erythematosus [RIFLE]) were completed at the time of each visit. Physician-rated changes in the disease course (clinically relevant improvement, no change, clinically relevant worsening) between visits served as the criterion standard. Results MCIDs defined by mean change scores with improvement and worsening, or those based on the standard error of measurement with stable disease, were both small and did not discriminate well between disease courses (detection rates for improvement or worsening were all

To develop a definition of global flare in juvenile systemic lupus erythematosus (SLE) and derive candidate criteria for measuring juvenile SLE flares.Pediatric rheumatologists answered 2 Delphi questionnaires to achieve consensus on a common definition of juvenile SLE flare and identify variables for use in candidate flare criteria. The diagnostic accuracy of these candidate flare criteria was tested with data from juvenile SLE patients (n = 98; 623 visits total). Physician-rated change in the juvenile SLE course (worsening, yes/no) between visits served as the criterion standard.There was 96% consensus that a "a flare is a measurable worsening of juvenile SLE disease activity in at least one organ system, involving new or worse signs of disease that may be accompanied by new or worse SLE symptoms. Depending on the severity of the flare, more intensive therapy may be required." Variables suggested for use in flare criteria were: physician-rated disease activity (V1), patient well-being, protein:creatinine ratio, a validated disease activity index (V2), the Child Health Questionnaire physical summary score (V3), anti-double-stranded DNA antibodies, erythrocyte sedimentation rate, and complement levels. Using multiple logistic regression, several candidate flare criteria were derived with area under the receiver operating characteristic curve (AUC) as high as 0.92 (sensitivityor=85%, specificityor=85%); classification and regression tree analysis suggested that V1, V2, and V3 suffice to identify juvenile SLE flares (AUC 0.81; sensitivity = 64%, specificity = 86%).Consensus about a definition of global disease flare for juvenile SLE has been obtained and promising candidate flare criteria have been developed. These will need further assessment of their ease of use and accuracy in prospective study.

Objective To prospectively validate the provisional criteria for the evaluation of response to therapy in children with systemic lupus erythematosus (SLE). Methods In this multicenter study, childhood-onset SLE patients (n = 98; 81 girls, 17 boys, 50% white, 88% non-Hispanic) were followed every 3 months for up to 7 visits (total number of visits 623). The 5 childhood-onset SLE core response variables were obtained at the time of each visit: 1) physician assessment of overall disease activity, 2) parent assessment of patient well-being, 3) Child Health Questionnaire, 4) proteinuria, and 5) global disease activity measure score, as measured by the European Consensus Lupus Activity Measure (ECLAM), the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), or the Systemic Lupus Activity Measure (SLAM). Physician-rated relevant changes in the disease course (clinically relevant improvement, no change in disease, or worsening) between visits served as the criterion standard. Mixed models were used to assess the diagnostic accuracy of the 4 highest-ranked provisional definitions of response to therapy. Results There were 89 episodes of clinically relevant improvement between 2 consecutive visits, and 448 episodes without improvement. Irrespective of the choice of the global disease activity measure (ECLAM, SLAM, SLEDAI), sensitivities of all 4 highest-ranked definitions were low (all ≤31%), whereas their specificities were excellent (all >88%). Using logistic models, alternative definitions can be developed with both 80% sensitivity and specificity. Conclusion The provisional criteria of response to therapy in childhood-onset SLE may have considerably lower sensitivity than previously reported. Additional validation in clinical trials is necessary to further evaluate the measurement properties of the provisional Paediatric Rheumatology International Trials Organisation/American College of Rheumatology criteria for response to therapy in children with SLE.