Development and External Validation of a Model Predicting New-Onset Chronic Uveitis at Different Disease Durations in Juvenile Idiopathic Arthritis

OBJECTIVE

To develop and externally validate a prediction model for new-onset chronic uveitis in children with juvenile idiopathic arthritis (JIA) for clinical application.

METHODS

Data from the international Pharmachild registry were used to develop a multivariable Cox proportional hazards model. Predictors were selected by backward selection, and missing values were handled by multiple imputation. The model was subsequently validated and recalibrated in 2 inception cohorts: the UK Childhood Arthritis Prospective Study (CAPS) study and the German Inception Cohort of Newly diagnosed patients with juvenile idiopathic arthritis (ICON) study. Model performance was evaluated by calibration plots and C statistics for the 2-, 4-, and 7-year risk of uveitis. A diagram and digital risk calculator were created for use in clinical practice.

RESULTS

A total of 5,393 patients were included for model development, and predictor variables were age at JIA onset (hazard ratio [HR] 0.83 [95% confidence interval (95% CI) 0.77-0.89]), ANA positivity (HR 1.59 [95% CI 1.06-2.38]), and International League of Associations for Rheumatology category of JIA (HR for oligoarthritis, psoriatic arthritis, and undifferentiated arthritis versus rheumatoid factor-negative polyarthritis 1.40 [95% CI 0.91-2.16]). Performance of the recalibrated prediction model in the validation cohorts was acceptable; calibration plots indicated good calibration and C statistics for the 7-year risk of uveitis (0.75 [95% CI 0.72-0.79] for the ICON cohort and 0.70 [95% CI 0.64-0.76] for the CAPS cohort).

CONCLUSION

We present for the first time a validated prognostic tool for easily predicting chronic uveitis risk for individual JIA patients using common clinical parameters. This model could be used by clinicians to inform patients/parents and provide guidance in choice of uveitis screening frequency and arthritis drug therapy.

Risk factors for haemodynamic compromise in multisystem inflammatory syndrome in children-a multicentre retrospective study

OBJECTIVES

To identify predictors of a severe clinical course of multisystem inflammatory syndrome in children (MIS-C), as defined by the need for inotropic support.

METHODS

This retrospective study included patients diagnosed with MIS-C (according to the CDC definition) in nine Israeli and one US medical centre between July 2020 and March 2021. Univariate and multivariate regression models assessed odds ratio (OR) of demographic, clinical, laboratory and imaging variables during admission and hospitalization for severe disease.

RESULTS

Of 100 patients, 61 (61%) were male; mean age 9.65 ± 4.48 years. Sixty-five patients were hypotensive, 44 required inotropic support. Eleven patients with MIS-C fulfilled Kawasaki disease diagnostic criteria; 87 had gastrointestinal symptoms on admission. Echocardiographic evaluation showed 10 patients with acute coronary ectasia or aneurysm, and 37 with left ventricular dysfunction. In a univariate model, left ventricular dysfunction was associated with severe disease (OR 4.178 [95%CI 1.760-9.917], while conjunctivitis (OR 0.403 [95%CI 0.173-0.938]) and mucosal changes (OR 0.333 [95%CI 0.119-0.931]) at admission were protective. Laboratory markers for a severe disease course were low values of haemoglobin, platelets, albumin and potassium; and high leukocytes, neutrophils, troponin and brain natriuretic peptide. In multivariate analysis, central nervous system involvement and fever >39.5 °C were associated with severe disease. Mucosal involvement showed 6.2-fold lower risk for severe disease. Low haemoglobin and platelet count, and elevated C-reactive protein and troponin levels were identified as risk factors for severe disease.

CONCLUSION

Key clinical and laboratory parameters of MIS-C were identified as risk factors for severe disease, predominantly during the disease course and not at the time of admission; and may prompt close monitoring, and earlier, more aggressive treatment decisions. Patients presenting with a Kawasaki-like phenotype were less likely to require inotropic support.

Effectiveness of the BNT162b2 mRNA COVID-19 vaccine among adolescents with juvenile-onset inflammatory rheumatic diseases

OBJECTIVES

The effectiveness of the BNT162b2 mRNA COVID-19 vaccine for adolescents with juvenile-onset inflammatory or immune rheumatic diseases (IRDs) is unknown. Several studies have suggested attenuated immunogenicity in patients with IRD. This study evaluated the effectiveness of the BNT162b2 mRNA COVID-19 vaccine in preventing COVID-19 infection in adolescents with juvenile-onset IRD compared with controls without immune rheumatic disease.

METHODS

We used data from Clalit Health Services, the largest health-care organization in Israel, to conduct an observational cohort study from February to December 2021, involving 12-18 year-old adolescents diagnosed with IRD. Study outcomes included documented COVID-19 infection in relation to vaccination status and immunomodulatory therapy. We estimated vaccine effectiveness as one minus the risk ratio. Adolescents aged 12-18 years without immune rheumatic disease served as controls.

RESULTS

A total of 1639 adolescents with IRD (juvenile idiopathic arthritis, SLE, or familial Mediterranean fever) were included and compared with 524 471 adolescents in the same age range without IRD. There was no difference in COVID-19 infection rates after the second dose of vaccine between those with IRD and controls (2.1% vs 2.1% respectively, P = 0.99). The estimated vaccine effectiveness for adolescents with IRD was 76.3% after the first dose, 94.8% after the second and 99.2% after the third dose.

CONCLUSION

We found that the BNT162b2 mRNA vaccine was similarly effective against COVID-19 infection in adolescents with and without IRD. Immunomodulatory therapy did not affect its effectiveness. These results can encourage adolescents with IRD to get vaccinated against COVID-19.

Case Series of Myocarditis Following mRNA COVID Vaccine Compared to Pediatric Multisystem Inflammatory Syndrome: Multicenter Retrospective Study

Introduction: Since the development of COVID-19 vaccines, more than 4.8 billion people have been immunized worldwide. Soon after vaccinations were initiated, reports on cases of myocarditis following the second vaccine dose emerged. This study aimed to report our experience with adolescent and young adults who developed post-COVID-19 vaccine myocarditis and to compare these patients to a cohort of patients who acquired pediatric inflammatory multisystem syndrome (PIMS/PIMS-TS) post-COVID-19 infection. Methods: We collected reported cases of patients who developed myocarditis following COVID-19 vaccination (Pfizer mRNA BNT162b2) from all pediatric rheumatology centers in Israel and compared them to a cohort of patients with PIMS. Results: Nine patients with post-vaccination myocarditis were identified and compared to 78 patients diagnosed with PIMS. All patients with post-vaccination myocarditis were males who developed symptoms following their second dose of the vaccine. Patients with post-vaccination myocarditis had a shorter duration of stay in the hospital (mean 4.4 ± 1.9 vs. 8.7 ± 4.7 days) and less myocardial dysfunction (11.1% vs. 61.5%), and all had excellent outcomes as compared to the chronic changes among 9.2% of the patients with PIMS. Conclusion: The clinical course of vaccine-associated myocarditis appears favorable, with resolution of the symptoms in all the patients in our cohort.

Defining colchicine resistance/intolerance in patients with familial Mediterranean fever: a modified-Delphi consensus approach

OBJECTIVES

Colchicine is the main treatment for FMF. Although a number of individuals with FMF are intolerant/resistant to colchicine, there is no standard definition of colchicine resistance/intolerance. We developed a set of evidence-based core statements defining colchicine resistance/intolerance in patients with FMF that may serve as a guide for clinicians and health authorities.

METHODS

A set of statements was identified using a modified-Delphi consensus-based approach. The process involved development of an initial colchicine resistance/intolerance-related questionnaire derived from a systematic literature review. The questionnaire, which was completed by an international panel of 11 adult and paediatric rheumatologists with expertise in FMF, was analysed anonymously. The results informed draft consensus statements that were discussed by a round-table expert panel, using a nominal group technique to agree on the selection and wording of the final statements.

RESULTS

Consensus among the panel was achieved on eight core statements defining colchicine resistance/intolerance in patients with FMF. A definition of resistance was agreed upon that included recurrent clinical attacks (average one or more attacks per month over a 3-month period) or persistent laboratory inflammation in between attacks. Other core statements recognize the importance of assessing treatment adherence, and the impact of active disease and intolerance to colchicine on quality of life.

CONCLUSION

Based on expert opinion, a set of evidence-based core statements defining colchicine resistance/intolerance in patients with FMF were identified to help guide clinicians and health authorities in the management of patients with FMF.

Distinct interferon signatures and cytokine patterns define additional systemic autoinflammatory diseases

BACKGROUNDUndifferentiated systemic autoinflammatory diseases (USAIDs) present diagnostic and therapeutic challenges. Chronic interferon (IFN) signaling and cytokine dysregulation may identify diseases with available targeted treatments.METHODSSixty-six consecutively referred USAID patients underwent underwent screening for the presence of an interferon signature using a standardized type-I IFN-response-gene score (IRG-S), cytokine profiling, and genetic evaluation by next-generation sequencing.RESULTSThirty-six USAID patients (55%) had elevated IRG-S. Neutrophilic panniculitis (40% vs. 0%), basal ganglia calcifications (46% vs. 0%), interstitial lung disease (47% vs. 5%), and myositis (60% vs. 10%) were more prevalent in patients with elevated IRG-S. Moderate IRG-S elevation and highly elevated serum IL-18 distinguished 8 patients with pulmonary alveolar proteinosis (PAP) and recurrent macrophage activation syndrome (MAS). Among patients with panniculitis and progressive cytopenias, 2 patients were compound heterozygous for potentially novel LRBA mutations, 4 patients harbored potentially novel splice variants in IKBKG (which encodes NF-κB essential modulator [NEMO]), and 6 patients had de novo frameshift mutations in SAMD9L. Of additional 12 patients with elevated IRG-S and CANDLE-, SAVI- or Aicardi-Goutières syndrome-like (AGS-like) phenotypes, 5 patients carried mutations in either SAMHD1, TREX1, PSMB8, or PSMG2. Two patients had anti-MDA5 autoantibody-positive juvenile dermatomyositis, and 7 could not be classified. Patients with LRBA, IKBKG, and SAMD9L mutations showed a pattern of IRG elevation that suggests prominent NF-κB activation different from the canonical interferonopathies CANDLE, SAVI, and AGS.CONCLUSIONSIn patients with elevated IRG-S, we identified characteristic clinical features and 3 additional autoinflammatory diseases: IL-18-mediated PAP and recurrent MAS (IL-18PAP-MAS), NEMO deleted exon 5-autoinflammatory syndrome (NEMO-NDAS), and SAMD9L-associated autoinflammatory disease (SAMD9L-SAAD). The IRG-S expands the diagnostic armamentarium in evaluating USAIDs and points to different pathways regulating IRG expression.TRIAL REGISTRATIONClinicalTrials.gov NCT02974595.FUNDINGThe Intramural Research Program of the NIH, NIAID, NIAMS, and the Clinical Center.

Multisystem Inflammatory Syndrome in Children Associated With Severe Acute Respiratory Syndrome Coronavirus-2 in an 8-Week-Old Infant

We describe an 8-week-old infant with severe gastrointestinal symptoms, significant hypoalbuminemia, and mild carditis following asymptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The infant's symptoms, including their temporal appearance, were consistent with multisystem inflammatory syndrome in children (MIS-C). A unique finding on colonic histology which may shed light on the pathogenesis of MIS-C was identified. The patient improved significantly following several anti-inflammatory treatments. The lag between the presentation of MIS-C and initial SARS-CoV-2 exposure, which may often be asymptomatic, together with the young age of our patient, makes this a challenging diagnosis. Clinicians should be aware of this entity, even in the neonatal and infantile age groups, to facilitate timely identification and treatment.

[A REPORT ON THE PRACTICALITIES OF THE JOINT FELLOWSHIP IN PEDIATRIC RHEUMATOLOGY IN ISRAEL]

BACKGROUND

The field of pediatric rheumatology was only recently recognized in Israel as a sub-specialty. To enable a fellowship program in this field comprising mainly uncommon diseases, the Meir and Shaare Zedek medical centers were authorized to implement a joint fellowship program, in which the trainees split their time between the two medical centers.

OBJECTIVES

This article presents the unique experience as a trainee in the joint fellowship program in pediatric rheumatology, while relating to the different characteristics of these centers, patient populations and variable disease exposure.

METHODS

Assessment of the extent of clinical and procedural exposure was achieved by comparing the exposure data of the fellow during the first two years of the joint fellowship to the published data derived from questionnaires answered by 44 fellows in the United States.

RESULTS

All requirements for successfully completing the Israeli fellowship program were fulfilled, but also those of the North American and European programs. We have shown that the extent of both clinical and procedural exposure is high in the joint fellowship program. We also show the differences in the variety of diseases seen in both centers.

DISCUSSION

Possible explanations for these observations are provided in this article. The experience of this joint fellowship can set an example for other fellowship programs in medical areas dealing with uncommon diseases.

Japanese scoring systems to predict resistance to intravenous immunoglobulin in Kawasaki disease were unreliable for Caucasian Israeli children

AIM

This study assessed the validity of using established Japanese risk scoring methods to predict intravenous immunoglobulin (IVIG) resistance to Kawasaki disease in Israeli children.

METHODS

We reviewed the medical records of 282 patients (70% male) with Kawasaki disease from six Israeli medical centres between 2004 and 2013. Their mean age was 2.5 years. The risk scores were calculated using the Kobayashi, Sano and Egami scoring methods and analysed to determine whether a higher risk score predicted IVIG resistance in this population. Factors that predicted a lack of response to the initial IVIG dose were identified.

RESULTS

We found that 18% did not respond to the first IVIG dose. The three scoring methods were unable to reliably predict IVIG resistance, with sensitivities of 23%-32% and specificities of 67%-87%. Calculating a predictive score that was specific for this population was also unsuccessful. The factors that predicted a lacked of response to the first IVIG dose included low albumin, elevated total bilirubin and ethnicity.

CONCLUSION

The established risk scoring methods created for Japanese populations with Kawasaki disease were not suitable for predicting IVIG resistance in Caucasian Israeli children, and we were unable to create a specific scoring method that was able to do this.

JAK1/2 inhibition with baricitinib in the treatment of autoinflammatory interferonopathies

BACKGROUND

Monogenic IFN-mediated autoinflammatory diseases present in infancy with systemic inflammation, an IFN response gene signature, inflammatory organ damage, and high mortality. We used the JAK inhibitor baricitinib, with IFN-blocking activity in vitro, to ameliorate disease.

METHODS

Between October 2011 and February 2017, 10 patients with CANDLE (chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperatures), 4 patients with SAVI (stimulator of IFN genes-associated [STING-associated] vasculopathy with onset in infancy), and 4 patients with other interferonopathies were enrolled in an expanded access program. The patients underwent dose escalation, and the benefit was assessed by reductions in daily disease symptoms and corticosteroid requirement. Quality of life, organ inflammation, changes in IFN-induced biomarkers, and safety were longitudinally assessed.

RESULTS

Eighteen patients were treated for a mean duration of 3.0 years (1.5-4.9 years). The median daily symptom score decreased from 1.3 (interquartile range [IQR], 0.93-1.78) to 0.25 (IQR, 0.1-0.63) (P < 0.0001). In 14 patients receiving corticosteroids at baseline, daily prednisone doses decreased from 0.44 mg/kg/day (IQR, 0.31-1.09) to 0.11 mg/kg/day (IQR, 0.02-0.24) (P < 0.01), and 5 of 10 patients with CANDLE achieved lasting clinical remission. The patients' quality of life and height and bone mineral density Z-scores significantly improved, and their IFN biomarkers decreased. Three patients, two of whom had genetically undefined conditions, discontinued treatment because of lack of efficacy, and one CANDLE patient discontinued treatment because of BK viremia and azotemia. The most common adverse events were upper respiratory infections, gastroenteritis, and BK viruria and viremia.

CONCLUSION

Upon baricitinib treatment, clinical manifestations and inflammatory and IFN biomarkers improved in patients with the monogenic interferonopathies CANDLE, SAVI, and other interferonopathies. Monitoring safety and efficacy is important in benefit-risk assessment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01724580 and NCT02974595.

FUNDING

This research was supported by the Intramural Research Program of the NIH, NIAID, and NIAMS. Baricitinib was provided by Eli Lilly and Company, which is the sponsor of the expanded access program for this drug.

JAK1/2 inhibition with baricitinib in the treatment of autoinflammatory interferonopathies

BACKGROUND. Monogenic IFN–mediated autoinflammatory diseases present in infancy with systemic inflammation, an IFN response gene signature, inflammatory organ damage, and high mortality. We used the JAK inhibitor baricitinib, with IFN-blocking activity in vitro, to ameliorate disease.

METHODS. Between October 2011 and February 2017, 10 patients with CANDLE (chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperatures), 4 patients with SAVI (stimulator of IFN genes–associated [STING-associated] vasculopathy with onset in infancy), and 4 patients with other interferonopathies were enrolled in an expanded access program. The patients underwent dose escalation, and the benefit was assessed by reductions in daily disease symptoms and corticosteroid requirement. Quality of life, organ inflammation, changes in IFN-induced biomarkers, and safety were longitudinally assessed.

RESULTS. Eighteen patients were treated for a mean duration of 3.0 years (1.5–4.9 years). The median daily symptom score decreased from 1.3 (interquartile range [IQR], 0.93–1.78) to 0.25 (IQR, 0.1–0.63) (P < 0.0001). In 14 patients receiving corticosteroids at baseline, daily prednisone doses decreased from 0.44 mg/kg/day (IQR, 0.31–1.09) to 0.11 mg/kg/day (IQR, 0.02–0.24) (P < 0.01), and 5 of 10 patients with CANDLE achieved lasting clinical remission. The patients’ quality of life and height and bone mineral density Z-scores significantly improved, and their IFN biomarkers decreased. Three patients, two of whom had genetically undefined conditions, discontinued treatment because of lack of efficacy, and one CANDLE patient discontinued treatment because of BK viremia and azotemia. The most common adverse events were upper respiratory infections, gastroenteritis, and BK viruria and viremia.

CONCLUSION. Upon baricitinib treatment, clinical manifestations and inflammatory and IFN biomarkers improved in patients with the monogenic interferonopathies CANDLE, SAVI, and other interferonopathies. Monitoring safety and efficacy is important in benefit-risk assessment.

TRIAL REGISTRATION. ClinicalTrials.gov NCT01724580 and NCT02974595.

FUNDING. This research was supported by the Intramural Research Program of the NIH, NIAID, and NIAMS. Baricitinib was provided by Eli Lilly and Company, which is the sponsor of the expanded access program for this drug.

Canakinumab for the Treatment of Autoinflammatory Recurrent Fever Syndromes

BACKGROUND

Familial Mediterranean fever, mevalonate kinase deficiency (also known as the hyperimmunoglobulinemia D syndrome), and the tumor necrosis factor receptor-associated periodic syndrome (TRAPS) are monogenic autoinflammatory diseases characterized by recurrent fever flares.

METHODS

We randomly assigned patients with genetically confirmed colchicine-resistant familial Mediterranean fever, mevalonate kinase deficiency, or TRAPS at the time of a flare to receive 150 mg of canakinumab subcutaneously or placebo every 4 weeks. Patients who did not have a resolution of their flare received an add-on injection of 150 mg of canakinumab. The primary outcome was complete response (resolution of flare and no flare until week 16). In the subsequent phase up to week 40, patients who had a complete response underwent a second randomization to receive canakinumab or placebo every 8 weeks. Patients who underwent a second randomization and had a subsequent flare and all other patients received open-label canakinumab.

RESULTS

At week 16, significantly more patients receiving canakinumab had a complete response than those receiving placebo: 61% vs. 6% of patients with colchicine-resistant familial Mediterranean fever (P<0.001), 35% versus 6% of those with mevalonate kinase deficiency (P=0.003), and 45% versus 8% of those with TRAPS (P=0.006). The inclusion of patients whose dose was increased to 300 mg every 4 weeks yielded a complete response in 71% of those with colchicine-resistant familial Mediterranean fever, 57% of those with mevalonate kinase deficiency, and 73% of those with TRAPS. After week 16, an extended dosing regimen (every 8 weeks) maintained disease control in 46% of patients with colchicine-resistant familial Mediterranean fever, 23% of those with mevalonate kinase deficiency, and 53% of those with TRAPS. Among patients who received canakinumab, the most frequently reported adverse events were infections (173.3, 313.5, and 148.0 per 100 patient-years among patients with colchicine-resistant familial Mediterranean fever, those with mevalonate kinase deficiency, and those with TRAPS, respectively), with a few being serious infections (6.6, 13.7, and 0.0 per 100 patient-years).

CONCLUSIONS

In this trial, canakinumab was effective in controlling and preventing flares in patients with colchicine-resistant familial Mediterranean fever, mevalonate kinase deficiency, and TRAPS. (Funded by Novartis; CLUSTER ClinicalTrials.gov number, NCT02059291 .).

A high and equal prevalence of the Q703K variant in NLRP3 patients with autoinflammatory symptoms and ethnically matched controls

OBJECTIVES

Cryopyrin associated periodic syndromes (CAPS) comprise a spectrum of autoinflammatory disorders of varying severity caused by mutations in the NLRP3 gene. The NLRP3-Q703K allele has been reported both as a functional polymorphism and as a low penetrance mutation.

METHODS

To describe the clinical phenotype of subjects with the Q703K allele and to report the frequency of this allele among patients with autoinflammatory symptoms and healthy controls. To this end, a cohort of 10 ethnically-matched controls per each Q703K-carrying patient, was composed.

RESULTS

Ninety patients suspected of harboring a systemic autoinflammatory disease (SAID), exclusive of FMF, were referred to our center for genotyping between 2012 and 2015. Fourteen of them (15.5%) were found to carry the Q703K allele, compared to 22 of 130 (16.9%) healthy, ethnically matched controls.

CONCLUSIONS

The similar carrier rate of the NLRP3-Q703K allele among patients with manifestations of a SAID and an ethnically matched control group suggest that this variant, does not determine the clinical phenotype. This reiterates the importance of testing a control group to avoid erroneously attributing a causative role to a gene polymorphism.

Comics as an educational tool for children with juvenile idiopathic arthritis

BACKGROUND

This study examined whether the comic book Neta and the Medikidz Explain JIA would improve disease-related knowledge and treatment adherence among patients with juvenile idiopathic arthritis (JIA).

METHODS

In this prospective cohort study, JIA patients answered 20 multiple-choice knowledge questions about their disease, before and after reading the comic book. Demographic, clinical, health-related quality of life and adherence data were recorded and correlated to the responses.

RESULTS

We studied 61 patients with a mean age of 14 ± 3.3 (range 8-18) years, 67% female, 83% Jewish and 17% non-Jewish. Thirty-nine percent had oligoarthritis, 13% systemic, 32% polyarthritis 11% psoriatic and 5% enthesitis-related type JIA. The disease was active in 46%, 40% were treated with biologics/disease modifying anti-rheumatic drugs, and 34% were in remission on medication. Among the 53 patients who completed before and after quizzes, average score increased from 63 to 80% (P < 0.001). Non-Jewish patients initially scored lower than Jewish patients (48%), but their score increased to 79% after reading the comic book. Twenty-seven patients who also completed the quiz 1 year after the first reading retained their knowledge (79%). We did not find a statistically significant correlation between knowledge and age, sex, disease subtype, or Child Health Questionnaire quality of life scores. Adherence to medication use, physical therapy and rheumatology clinic visits were high at baseline; thus, these did not change after reading the comic.

CONCLUSIONS

The comic booklet Neta and the Medikidz Explain JIA is a good educational tool for increasing disease-related knowledge in children with JIA.

Intestinal malrotation as a misdiagnosis of pediatric colchicine resistant familial Mediterranean fever

BACKGROUND

Familial Mediterranean fever (FMF) is a disorder characterized by recurrent attacks of fever and serosal inflammation, particularly abdominal pain. Other disease processes, including medical and surgical emergencies, may mimic FMF, especially in atypical cases.

CASE PRESENTATION

We present a case of an adolescent male, referred to us with a diagnosis of colchicine resistant FMF, ultimately diagnosed with intestinal malrotation and recurrent volvulus.

CONCLUSIONS

In atypical presentations of FMF with potential "red flags", a thorough patient history is extremely important and should result in prompt referral for the appropriate diagnostic tests.

The familial Mediterranean fever (FMF) 50 score: does it work in a controlled clinical trial? Re-analysis of the trial of rilonacept for patients with colchicine-resistant or intolerant FMF

BACKGROUND

The familial Mediterranean fever 50 score (FMF50) score was recently devised to define response to treatment and as an outcome measure for clinical trials of FMF.

OBJECTIVES

To examine the performance of the FMF50 score in a previously published trial of rilonacept for patients whose FMF was resistant or intolerant to colchicine.

METHODS

We re-analyzed the data from our controlled trial of rilonacept vs. placebo in 14 patients with colchicine-resistant or intolerant FMF using the FMF50 score as the primary outcome. The FMF50 score required improvement by ≥ 50 in five of six criteria (attack frequency, attack duration, global patient assessment, global physician assessment, frequency of attacks with arthritis, and levels of acute-phase reactants) without worsening of the sixth criterion.

RESULTS

In the original trial rilonacept was considered effective according to the primary outcome measure (differences in the attack frequency) with eight analyzable patients considered responders and four as non-responders. According to the FMF50 score, only two participants would have been considered respondersto rilonacept, and one to placebo. Only two participants had ≥ 50% differences between rilonacept and placebo in five criteria. The major explanation for non-response to treatment was that with rilonacept the duration of attack decreased by ≥ 50% in only 2 participants and 5 participants had no attacks of arthritis either during screening (before randomization) or during treatment with rilonacept.

CONCLUSIONS

The proposed FMF50 score did not differentiate well between responders and non-responders compared to the a priori defined primary outcome measure in this successful controlled study.

Utility of the PedsQL rheumatology module as an outcome measure in juvenile fibromyalgia

OBJECTIVE

The PedsQL rheumatology module is currently the only available measure of disease-specific quality of life for children and adolescents with juvenile fibromyalgia (FM), but limited information has been published about the psychometric properties of the instrument, specifically in juvenile FM. The objective of this study was to assess there liability, validity, and sensitivity to change of the 5 scales (pain and hurt, daily activities, treatment, worry, and communication) of the patient and parent proxy versions of the PedsQL rheumatology module in the context of a randomized controlled trial in juvenile FM.

METHODS

The entire PedsQL rheumatology module was administered as a supplementary outcome measure at baseline,posttreatment, and 6-month followup assessments of 114 children and adolescents with juvenile FM enrolled in a trial testing the efficacy of cognitive–behavioral therapy.

RESULTS

Internal consistency reliabilities for the scales were adequate to strong (Cronbach’s α = 0.68–0.86). Parent proxy and child reports on most scales (except for daily activities and communication) showed moderate correlations (Spearman’s r = 0.33–0.45). Support for construct validity was found by comparing child and parent reports with other related measures of pain and functioning (visual analog scale pain ratings and the Functional Disability Inventory). Finally, sensitivity to change was demonstrated by significant changes in 4 of the 5 scales (excluding the daily activities scale) after treatment.

CONCLUSION

The PedsQL rheumatology module generally appears to have good utility for use in juvenile FM patients, but there are some caveats to the interpretation of specific scales in this population.

Enhancing crossover trial design for rare diseases: limiting ineffective exposure and increasing study power by enabling patient choice to escape early

BACKGROUND

Addressing the two most important considerations in designing clinical trials, i.e. maximizing study power and minimizing patient exposure to ineffective treatment, is particularly challenging for trials of rare diseases. The familial Mediterranean fever (FMF) rilonacept trial (Hashkes et al., Ann Intern Med 2012;157:533-41) demonstrates a novel crossover design by enabling patient choice to early escape for rare disease.

PURPOSE

To investigate the effect on study power, exposure to the ineffective treatment arm and dropout rate by implementing early escape to crossover design, and to propose a Bayesian modeling approach.

METHOD

Based on the FMF trial data, simulation studies compared study power and dropout rate among three types of designs for crossover trial: traditional without early escape, early escape per-patient-choice, and early escape per-protocol.

RESULTS

The early escape per patient choice or per protocol design achieved 0.89 ± 0.12 and 0.78 ± 0.20 of the study efficiency when compared to the traditional crossover design assuming no dropout. Early escape per patient choice compared to early escape per protocol improved power by 1.29 ± 0.26, and reduced the dropout rate by 8-29%, but with greater patient exposure to the less effective treatment arm.

CONCLUSIONS

The results of the FMF trial and simulation studies suggest that allowing early escape in crossover trial enhanced the design by minimizing patient's exposure to the ineffective treatment arm while maintaining a reasonable study power, which is particularly important for rare disease trials. Choice between the two types of early escape presents tradeoff between study power and exposure to ineffective treatment.