Multisystem Inflammatory Syndrome in Children - Initial Therapy and Outcomes.

BACKGROUND: The assessment of real-world effectiveness of immunomodulatory medications for multisystem inflammatory syndrome in children (MIS-C) may guide therapy. METHODS: We analyzed surveillance data on inpatients younger than 21 years of age who had MIS-C and were admitted to 1 of 58 U.S. hospitals between March 15 and October 31, 2020. The effectiveness of initial immunomodulatory therapy (day 0, indicating the first day any such therapy for MIS-C was given) with intravenous immune globulin (IVIG) plus glucocorticoids, as compared with IVIG alone, was evaluated with propensity-score matching and inverse probability weighting, with adjustment for baseline MIS-C severity and demographic characteristics. The primary outcome was cardiovascular dysfunction (a composite of left ventricular dysfunction or shock resulting in the use of vasopressors) on or after day 2. Secondary outcomes included the components of the primary outcome, the receipt of adjunctive treatment (glucocorticoids in patients not already receiving glucocorticoids on day 0, a biologic, or a second dose of IVIG) on or after day 1, and persistent or recurrent fever on or after day 2. RESULTS: A total of 518 patients with MIS-C (median age, 8.7 years) received at least one immunomodulatory therapy; 75% had been previously healthy, and 9 died. In the propensity-score-matched analysis, initial treatment with IVIG plus glucocorticoids (103 patients) was associated with a lower risk of cardiovascular dysfunction on or after day 2 than IVIG alone (103 patients) (17% vs. 31%; risk ratio, 0.56; 95% confidence interval [CI], 0.34 to 0.94). The risks of the components of the composite outcome were also lower among those who received IVIG plus glucocorticoids: left ventricular dysfunction occurred in 8% and 17% of the patients, respectively (risk ratio, 0.46; 95% CI, 0.19 to 1.15), and shock resulting in vasopressor use in 13% and 24% (risk ratio, 0.54; 95% CI, 0.29 to 1.00). The use of adjunctive therapy was lower among patients who received IVIG plus glucocorticoids than among those who received IVIG alone (34% vs. 70%; risk ratio, 0.49; 95% CI, 0.36 to 0.65), but the risk of fever was unaffected (31% and 40%, respectively; risk ratio, 0.78; 95% CI, 0.53 to 1.13). The inverse-probability-weighted analysis confirmed the results of the propensity-score-matched analysis. CONCLUSIONS: Among children and adolescents with MIS-C, initial treatment with IVIG plus glucocorticoids was associated with a lower risk of new or persistent cardiovascular dysfunction than IVIG alone. (Funded by the Centers for Disease Control and Prevention.).

Severe Features of Systemic Juvenile Idiopathic Arthritis in Patients with Congenital Heart Disease.

OBJECTIVE: To describe the clinical features of patients with congenital heart disease (CHD) who subsequently developed systemic juvenile idiopathic arthritis (sJIA). METHODS: We conducted a retrospective review of patients diagnosed with CHD and sJIA at our institution. Detailed clinical, laboratory and radiographic data were collected from the medical record and reviewed with each patient's primary medical team. RESULTS: Five patients with sJIA and CHD were identified. Each child had a unique cardiac anatomy but all of the patients required surgical repair during the first year of life. Four children had thymectomies at the time of cardiac surgery. Classic signs of sJIA such as fever (n=5), rash (n=5), and arthritis (n=4) developed after surgical intervention in all of the patients. The individuals in this cohort displayed risk factors associated with severe sJIA, including disease onset before 2 years of age (n=5), elevated IL-18 levels (n=5), baseline eosinophilia prior to initiation of biologic disease modifying anti-rheumatic drugs (bDMARDs) (n=4), and positivity for HLA-DRB1*15:01 alleles (n=4). Macrophage activation syndrome (MAS) occurred in 3 patients and sJIA-associated lung disease (sJIA-LD) was identified in 4 patients. Two children died from complications of their cardiac and/or pulmonary disease. CONCLUSION: We identified an association between CHD and severe forms of sJIA. While these findings will need to be confirmed in larger, multi-center cohorts, the results highlight the importance of considering a diagnosis of sJIA in children with CHD and remaining vigilant for complications such as MAS and sJIA-LD.

Multisystem Inflammatory Syndrome in U.S. Children and Adolescents.

BACKGROUND: Understanding the epidemiology and clinical course of multisystem inflammatory syndrome in children (MIS-C) and its temporal association with coronavirus disease 2019 (Covid-19) is important, given the clinical and public health implications of the syndrome. METHODS: We conducted targeted surveillance for MIS-C from March 15 to May 20, 2020, in pediatric health centers across the United States. The case definition included six criteria: serious illness leading to hospitalization, an age of less than 21 years, fever that lasted for at least 24 hours, laboratory evidence of inflammation, multisystem organ involvement, and evidence of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) based on reverse-transcriptase polymerase chain reaction (RT-PCR), antibody testing, or exposure to persons with Covid-19 in the past month. Clinicians abstracted the data onto standardized forms. RESULTS: We report on 186 patients with MIS-C in 26 states. The median age was 8.3 years, 115 patients (62%) were male, 135 (73%) had previously been healthy, 131 (70%) were positive for SARS-CoV-2 by RT-PCR or antibody testing, and 164 (88%) were hospitalized after April 16, 2020. Organ-system involvement included the gastrointestinal system in 171 patients (92%), cardiovascular in 149 (80%), hematologic in 142 (76%), mucocutaneous in 137 (74%), and respiratory in 131 (70%). The median duration of hospitalization was 7 days (interquartile range, 4 to 10); 148 patients (80%) received intensive care, 37 (20%) received mechanical ventilation, 90 (48%) received vasoactive support, and 4 (2%) died. Coronary-artery aneurysms (z scores ≥2.5) were documented in 15 patients (8%), and Kawasaki's disease-like features were documented in 74 (40%). Most patients (171 [92%]) had elevations in at least four biomarkers indicating inflammation. The use of immunomodulating therapies was common: intravenous immune globulin was used in 144 (77%), glucocorticoids in 91 (49%), and interleukin-6 or 1RA inhibitors in 38 (20%). CONCLUSIONS: Multisystem inflammatory syndrome in children associated with SARS-CoV-2 led to serious and life-threatening illness in previously healthy children and adolescents. (Funded by the Centers for Disease Control and Prevention.).

Clinical Course Associated with Aseptic Meningitis Induced by Intravenous Immunoglobulin for the Treatment of Multisystem Inflammatory Syndrome in Children.

Aseptic meningitis is a rare but potentially serious complication of intravenous immunoglobulin treatment. In this case series, meningitic symptoms following intravenous immunoglobulin initiation in patients with multisystem inflammatory syndrome were rare (7/2,086 [0.3%]). However, they required the need for additional therapy and/or readmission.

Insurance Status and Tumor Necrosis Factor Inhibitor Initiation Among Children With Juvenile Idiopathic Arthritis in the CARRA Registry.

OBJECTIVE: Prompt escalation to tumor necrosis factor inhibitors (TNFis) is recommended for children with juvenile idiopathic arthritis (JIA) and ongoing disease activity despite treatment with conventional disease-modifying antirheumatic drugs (cDMARDs). It is unknown whether these recommendations are equitably followed for children with different insurance types. We assessed the association of insurance coverage on the odds and timing of TNFi use. METHODS: We conducted a retrospective study of children with newly diagnosed JIA in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry. We compared the odds of starting a TNFi in the first year and time from cDMARD to TNFi initiation between those with public and private insurance. RESULTS: We identified 1086 children with new JIA diagnoses. Publicly insured children had significantly higher active joint counts and parent/patient global assessment scores at the enrollment visit. They were also more likely to have polyarticular arthritis compared to those with private insurance. Odds of any TNFi use in the first year did not differ between publicly and privately insured children. Publicly insured children were escalated from cDMARD to TNFi more quickly than privately insured children. CONCLUSION: Children who were publicly insured had more severe disease and polyarticular involvement at registry enrollment compared to those who were privately insured. Whereas overall TNFi use did not differ between children with different insurance types, publicly insured children were escalated more quickly, consistent with their increased disease severity. Further research is needed to determine why insurance coverage type is associated with disease severity, including how other socioeconomic factors affect presentation to care.

Real-world use and outcomes of belimumab in childhood-onset lupus: A single-center retrospective study.

BACKGROUND: Studies of real-world effectiveness of belimumab in adults with systemic lupus erythematosus have shown improved disease control and decreased oral glucocorticoid use. However, belimumab use outside of clinical trial settings has not been well studied in childhood-onset systemic lupus erythematosus (cSLE). We aimed to characterize indications for belimumab use and evaluate oral glucocorticoid doses and disease activity scores in the year following belimumab initiation at a single, large pediatric rheumatology center. METHODS: We included children and young adults with cSLE who received ≥ 1 dose of belimumab. Repeated measures one-way ANOVA was used to compare SLEDAI-2K scores and prednisone-equivalent daily oral glucocorticoid doses at baseline, 6 months, and 12 months after belimumab initiation for those who continued therapy for a year. RESULTS: We identified 21 patients with cSLE who received ≥ 1 dose of belimumab. The median disease duration at belimumab initiation was 30.8 months [IQR 21.0-79.1]. At the time of belimumab initiation, 100% of patients were taking an antimalarial, 81% were on oral glucocorticoids, and 91% were on at least one conventional DMARD. Thirteen patients (62%) continued belimumab for ≥6 months and 11 (52%) for ≥12 months. Among those continuing belimumab for ≥12 months, median [IQR] oral prednisone daily doses in milligrams at baseline, 6 months, and 12 months were 12.5 [7.5-17.5], 9 [6.25-10], and 5 [5-9.5], p = 0.037, and median [IQR] SLEDAI-2K scores at baseline, 6 months, and 12 months were 8 [5.5-10.5], 6 [3.5-10], and 6 [6-8.5], p = 0.548, respectively. CONCLUSIONS: In our cohort of pediatric patients with lupus and moderate disease activity treated with belimumab for ≥12 months, daily oral glucocorticoid doses were significantly lower 6 and 12 months after belimumab initiation than baseline. Use in patients with active nephritis was uncommon. Further research is needed in a large, multicenter cohort to determine the real-world effectiveness of belimumab in children and develop guidelines for use.

SARS-CoV-2-specific T cell responses in patients with multisystem inflammatory syndrome in children.

Multisystem inflammatory syndrome in children (MIS-C) is a severe complication of SARS-CoV-2 infections that occurs in the pediatric population. We sought to characterize T cell responses in MIS-C compared to COVID-19 and pediatric hyperinflammatory syndromes. MIS-C was distinct from COVID-19 and hyperinflammatory syndromes due to an expansion of T cells expressing TRBV11-2 that was not associated with HLA genotype. Children diagnosed with MIS-C, but who were negative for SARS-CoV-2 by PCR and serology, did not display Vß skewing. There was no difference in the proportion of T cells that became activated after stimulation with SARS-CoV-2 peptides in children with MIS-C compared to convalescent COVID-19. The frequency of SARS-CoV-2-specific TCRs and the antigens recognized by these TCRs were comparable in MIS-C and COVID-19. Expansion of Vß11-2+ T cells was a specific biomarker of MIS-C patients with laboratory confirmed SARS-CoV-2 infections. Children with MIS-C had robust antigen-specific T cell responses to SARS-CoV-2.

Multiple Emergency Department Visits for a Diagnosis of Kawasaki Disease: An Examination of Risk Factors and Outcomes.

OBJECTIVES: To determine predictors of >1 emergency department (ED) visit for a Kawasaki disease diagnosis in a quaternary care pediatric hospital and compare outcomes between patients with 1 vs >1 visit for Kawasaki disease diagnosis. STUDY DESIGN: Medical records of patients evaluated for Kawasaki disease between January 2006 and August 2018 at Boston Children's Hospital were abstracted for demographic and clinical data. Predictors of >1 visit were explored using logistic regression and classification and regression tree analysis. RESULTS: Of 530 patients diagnosed with Kawasaki disease, 117 (22%) required multiple ED visits for Kawasaki disease diagnosis. Multivariable regression and classification and regression tree analysis identified ≤2 Kawasaki disease criteria (OR 33.9; 95% CI 18.1-63.6), <3 days of fever at the first visit (OR 3.47; 95% CI 1.77-6.84), and non-White race (OR 2.15; 95% CI 1.18-3.95) as predictors of >1 visit. There were no significant differences in duration of hospitalization, day of illness at initial Kawasaki disease treatment, intravenous immunoglobulin resistance, need for adjunctive therapies, or coronary artery outcomes between patients diagnosed with Kawasaki disease at initial visit vs subsequent visits. CONCLUSIONS: Incomplete Kawasaki disease criteria, fewer days of fever, and non-White race were significant predictors of multiple ED visits for Kawasaki disease diagnosis in this single institution study. Our findings underscore the importance of maintaining a high index of suspicion for Kawasaki disease in patients with <4 Kawasaki disease criteria. Further research is needed to determine causes for increased healthcare use in non-White patients to receive a Kawasaki disease diagnosis.

Cardiac manifestations in SARS-CoV-2-associated multisystem inflammatory syndrome in children: a comprehensive review and proposed clinical approach.

Initial reports on COVID-19 described children as largely spared from severe manifestations, with only 2-6% of children requiring intensive care treatment. However, since mid-April 2020, clusters of pediatric cases of severe systemic hyperinflammation and shock epidemiologically linked with COVID-19 have been reported. This condition was named as SARS-Cov-2-associated multisystem inflammatory syndrome in children and showed similarities to Kawasaki disease. Here, we present a narrative review of cases reported in literature and we discuss the clinical acute and follow-up management of these patients. Patients with SARS-Cov-2-associated multisystem inflammatory syndrome frequently presented with persistent fever, gastrointestinal symptoms, polymorphic rash, conjunctivitis, and mucosal changes. Elevated inflammatory markers and evidence of cytokine storm were frequently observed. A subset of these patients also presented with hypotension and shock (20-100%) from either acute myocardial dysfunction or systemic hyperinflammation/vasodilation. Coronary artery dilation or aneurysms have been described in 6-24%, and arrhythmias in 7-60%. Cardiac support, immunomodulation, and anticoagulation are the key aspects for the management of the acute phase. Long-term structured follow-up of these patients is required due to the unclear prognosis and risk of progression of cardiac manifestations.Conclusion: Multisystem inflammatory syndrome is a novel syndrome related to SARS-CoV-2 infection. Evidence is still scarce but rapidly emerging in the literature. Cardiac manifestations are frequent, including myocardial and coronary involvement, and need to be carefully identified and monitored over time. What is Known: • Multisystem inflammatory syndrome in children (MIS-C) has been described associated with SARS-CoV-2. What is New: • Patients with MIS-C often present with fever, gastrointestinal symptoms, and shock. • Cardiac involvement is found in a high proportion of these patients, including ventricular dysfunction, coronary artery dilation or aneurysm, and arrhythmias. • Management is based on expert consensus and includes cardiac support, immunomodulatory agents, and anticoagulation. • Long-term follow-up is required due to the unclear prognosis and risk of progression of cardiac manifestation.

Characteristics and Outcomes of US Children and Adolescents With Multisystem Inflammatory Syndrome in Children (MIS-C) Compared With Severe Acute COVID-19.

Importance: Refinement of criteria for multisystem inflammatory syndrome in children (MIS-C) may inform efforts to improve health outcomes. Objective: To compare clinical characteristics and outcomes of children and adolescents with MIS-C vs those with severe coronavirus disease 2019 (COVID-19). Setting, Design, and Participants: Case series of 1116 patients aged younger than 21 years hospitalized between March 15 and October 31, 2020, at 66 US hospitals in 31 states. Final date of follow-up was January 5, 2021. Patients with MIS-C had fever, inflammation, multisystem involvement, and positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcriptase-polymerase chain reaction (RT-PCR) or antibody test results or recent exposure with no alternate diagnosis. Patients with COVID-19 had positive RT-PCR test results and severe organ system involvement. Exposure: SARS-CoV-2. Main Outcomes and Measures: Presenting symptoms, organ system complications, laboratory biomarkers, interventions, and clinical outcomes. Multivariable regression was used to compute adjusted risk ratios (aRRs) of factors associated with MIS-C vs COVID-19. Results: Of 1116 patients (median age, 9.7 years; 45% female), 539 (48%) were diagnosed with MIS-C and 577 (52%) with COVID-19. Compared with patients with COVID-19, patients with MIS-C were more likely to be 6 to 12 years old (40.8% vs 19.4%; absolute risk difference [RD], 21.4% [95% CI, 16.1%-26.7%]; aRR, 1.51 [95% CI, 1.33-1.72] vs 0-5 years) and non-Hispanic Black (32.3% vs 21.5%; RD, 10.8% [95% CI, 5.6%-16.0%]; aRR, 1.43 [95% CI, 1.17-1.76] vs White). Compared with patients with COVID-19, patients with MIS-C were more likely to have cardiorespiratory involvement (56.0% vs 8.8%; RD, 47.2% [95% CI, 42.4%-52.0%]; aRR, 2.99 [95% CI, 2.55-3.50] vs respiratory involvement), cardiovascular without respiratory involvement (10.6% vs 2.9%; RD, 7.7% [95% CI, 4.7%-10.6%]; aRR, 2.49 [95% CI, 2.05-3.02] vs respiratory involvement), and mucocutaneous without cardiorespiratory involvement (7.1% vs 2.3%; RD, 4.8% [95% CI, 2.3%-7.3%]; aRR, 2.29 [95% CI, 1.84-2.85] vs respiratory involvement). Patients with MIS-C had higher neutrophil to lymphocyte ratio (median, 6.4 vs 2.7, P < .001), higher C-reactive protein level (median, 152 mg/L vs 33 mg/L; P < .001), and lower platelet count (<150 ×103 cells/µL [212/523 {41%} vs 84/486 {17%}, P < .001]). A total of 398 patients (73.8%) with MIS-C and 253 (43.8%) with COVID-19 were admitted to the intensive care unit, and 10 (1.9%) with MIS-C and 8 (1.4%) with COVID-19 died during hospitalization. Among patients with MIS-C with reduced left ventricular systolic function (172/503, 34.2%) and coronary artery aneurysm (57/424, 13.4%), an estimated 91.0% (95% CI, 86.0%-94.7%) and 79.1% (95% CI, 67.1%-89.1%), respectively, normalized within 30 days. Conclusions and Relevance: This case series of patients with MIS-C and with COVID-19 identified patterns of clinical presentation and organ system involvement. These patterns may help differentiate between MIS-C and COVID-19.

Impact of Socioeconomic Status on Outcomes of Patients with Kawasaki Disease.

OBJECTIVE: To evaluate the association of neighborhood socioeconomic status (SES) with time to intravenous immunoglobulin treatment, length of stay (LOS), and coronary artery aneurysms (CAAs) in patients with Kawasaki disease. STUDY DESIGN: We examined the relationship of SES in 915 patients treated at a large academic center between 2000 and 2017. Neighborhood SES was measured using a US census-based score derived from 6 measures related to income, education, and occupation. Linear and logistic regression were used to examine the association of SES with number of days of fever at time of treatment, LOS, and CAA. RESULTS: Patients in the lowest SES quartile were treated later than patients with greater SES (7 [IQR 5, 9] vs 6 [IQR 5, 8] days, P = .01). Patients in the lowest SES quartile were more likely to be treated after 10 days of illness, with an OR 1.9 (95% CI 1.3-2.8). In multivariable analysis, SES remained an independent predictor of the number of days of fever at time of treatment (P = .01). Patients in the lowest SES quartile had longer LOS than patients with greater SES (3 [IQR 2, 5] vs 3 [IQR 2, 4], P = .007). In subgroup analysis of white children, those in the lowest SES quartile vs quartiles 2-4 were more likely to develop large/giant CAA 17 (12%) vs 30 (6%), P = .03. CONCLUSIONS: Lower SES is associated with delayed treatment, prolonged LOS, and increased risk of large/giant CAA. Novel approaches to diagnosis and education are needed for children living in low-SES neighborhoods.

Updated Case Definition of MIS-C and Implications for Clinical Care.

OBJECTIVES: A broad, surveillance case definition was implemented when multisystem inflammatory syndrome in children (MIS-C) emerged in 2020. In 2023, a revised MIS-C case definition was constructed to improve specificity and reduce misclassification with other pediatric inflammatory conditions. This study aims to describe the impact of the updated definition on the classification of patients with MIS-C and Kawasaki Disease (KD). METHODS: Patients hospitalized from March 2020 to November 2022 with clinician-diagnosed KD and MIS-C at a single center were studied retrospectively. Specificity and positive predictive value were assessed; McNemar test was used to compare specificity. RESULTS: Among 119 patients with MIS-C per the 2020 definition, 20 (17%) did not fulfill the 2023 definition. Six of these 20 (30%) had shock or cardiac involvement. Of 59 KD patients, 10 (17%) met the 2020 MIS-C definition. Five patients (8%) met the 2023 MIS-C definition. Specificity for the 2020 and 2023 MIS-C definitions among KD patients were 83.1% and 91.5% respectively (McNemar, P = .0736). Positive predictive value was higher for the 2023 MIS-C case definition compared with the 2020 MIS-C case definition (95.2% vs 92.2%). CONCLUSIONS: Approximately 1 in 5 patients diagnosed with MIS-C using the 2020 case definition did not meet the 2023 definition, including patients with cardiovascular dysfunction. Overlap persisted between patients meeting KD and 2023 MIS-C case definitions, with a false positive rate of 8%. Implications for treatment should be considered, particularly in settings where presumed MIS-C may be treated with corticosteroid monotherapy.

Racial and Ethnic Composition of Populations Served by Freestanding Children's Hospitals and Disparities in Outcomes of Pediatric Lupus.

OBJECTIVE: Health disparities may be driven by hospital-level factors. We assessed whether racial and ethnic composition of populations hospitals serve explain or modify disparities in hospital outcomes of children with systemic lupus erythematosus (SLE). METHODS: In this retrospective cohort study of patients 5 to 26 years old with SLE at 47 children's hospitals in the Pediatric Health Information System (2006-2021), race and ethnicity were assessed at the patient level and hospital level (proportion of total admissions composed of Black or Hispanic patients, respectively). Outcomes included intensive care unit (ICU) admission or adverse renal outcome (end-stage renal disease, dialysis, or transplant) during follow-up. We estimated racial and ethnic disparities, adjusted or stratified by hospital racial or ethnic composition. RESULTS: Of 8,125 patients with SLE, 2,293 (28%) required ICU admission, and 698 (9%) had an adverse renal outcome. Black and non-Hispanic White disparities in ICU admission were observed only at hospitals serving higher proportions of Black patients (odds ratio [OR] 1.29, 95% confidence interval [95% CI] 1.04-1.59 vs OR 1.07, 95% CI 0.83-1.38). Larger Black and non-Hispanic White disparities in adverse renal outcomes were observed at hospitals with higher Black racial composition (OR 2.0, 95% CI 1.4-2.8 vs OR 1.7, 95% CI 1.1-2.4). Conversely, Hispanic versus non-Hispanic disparities in renal outcomes persisted after adjustment for hospital-reported Hispanic ethnic composition but were observed only at hospitals with lower proportions of Hispanic patients. CONCLUSION: Worse Black and White disparities in SLE outcomes are observed at children's hospitals serving more Black children, whereas distinct patterns are observed for Hispanic and non-Hispanic disparities. Reporting of hospital characteristics related to populations served is needed to identify modifiable drivers of hospital-level variation.

Health Equity Implications of Missing Data Among Youths With Childhood-Onset Systemic Lupus Erythematosus: A Proof-of-Concept Study in the Childhood Arthritis and Rheumatology Research Alliance Registry.

OBJECTIVE: Health disparities in childhood-onset systemic lupus erythematosus (SLE) disproportionately impact marginalized populations. Socioeconomically patterned missing data can magnify existing health inequities by supporting inferences that may misrepresent populations of interest. Our objective was to assess missing data and subsequent health equity implications among participants with childhood-onset SLE enrolled in a large pediatric rheumatology registry. METHODS: We evaluated co-missingness of 12 variables representing demographics, socioeconomic position, and clinical factors (e.g., disease-related indices) using Childhood Arthritis and Rheumatology Research Alliance Registry childhood-onset SLE enrollment data (2015-2022; n = 766). We performed logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) for missing disease-related indices at enrollment (Systemic Lupus Erythematosus Disease Activity Index 2000 [SLEDAI-2K] and/or Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index [SDI]) associated with data missingness. We used linear regression to assess the association between socioeconomic factors and SLEDAI-2K at enrollment using 3 analytic methods for missing data: complete case analysis, multiple imputation, and nonprobabilistic bias analyses, with missing values imputed to represent extreme low or high disadvantage. RESULTS: On average, participants were missing 6.2% of data, with over 50% of participants missing at least 1 variable. Missing data correlated most closely with variables within data categories (i.e., demographic). Government-assisted health insurance was associated with missing SLEDAI-2K and/or SDI scores compared to private health insurance (OR 2.04 [95% CI 1.22, 3.41]). The different analytic approaches resulted in varying analytic sample sizes and fundamentally conflicting estimated associations. CONCLUSION: Our results support intentional evaluation of missing data to inform effect estimate interpretation and critical assessment of causal statements that might otherwise misrepresent health inequities.

Immunomodulatory Therapy for MIS-C.

CONTEXT: Studies comparing initial therapy for multisystem inflammatory syndrome in children (MIS-C) provided conflicting results. OBJECTIVE: To compare outcomes in MIS-C patients treated with intravenous immunoglobulin (IVIG), glucocorticoids, or the combination thereof. DATA SOURCES: Medline, Embase, CENTRAL and WOS, from January 2020 to February 2022. STUDY SELECTION: Randomized or observational comparative studies including MIS-C patients <21 years. DATA EXTRACTION: Two reviewers independently selected studies and obtained individual participant data. The main outcome was cardiovascular dysfunction (CD), defined as left ventricular ejection fraction < 55% or vasopressor requirement ≥ day 2 of initial therapy, analyzed with a propensity score-matched analysis. RESULTS: Of 2635 studies identified, 3 nonrandomized cohorts were included. The meta-analysis included 958 children. IVIG plus glucocorticoids group as compared with IVIG alone had improved CD (odds ratio [OR] 0.62 [0.42-0.91]). Glucocorticoids alone group as compared with IVIG alone did not have improved CD (OR 0.57 [0.31-1.05]). Glucocorticoids alone group as compared with IVIG plus glucocorticoids did not have improved CD (OR 0.67 [0.24-1.86]). Secondary analyses found better outcomes associated with IVIG plus glucocorticoids compared with glucocorticoids alone (fever ≥ day 2, need for secondary therapies) and better outcomes associated with glucocorticoids alone compared with IVIG alone (left ventricular ejection fraction < 55% ≥ day 2). LIMITATIONS: Nonrandomized nature of included studies. CONCLUSIONS: In a meta-analysis of MIS-C patients, IVIG plus glucocorticoids was associated with improved CD compared with IVIG alone. Glucocorticoids alone was not associated with improved CD compared with IVIG alone or IVIG plus glucocorticoids.

A case of neonatal sweet syndrome associated with mevalonate kinase deficiency.

BACKGROUND: Sweet syndrome (SS), also known as acute febrile neutrophilic dermatosis, is an immunologic syndrome characterized by widespread neutrophilic infiltration. Histiocytoid Sweet syndrome (H-SS) is a histopathologic variant of SS. While SS most commonly occurs in adults, this case report discusses an infant patient who presented with H-SS. CASE PRESENTATION: Through a multidisciplinary approach, this patient was also found to have very early onset inflammatory bowel disease (VEO-IBD) and Mevalonate kinase-associated disease (MKAD). While prior case studies have characterized an association between VEO-IBD and MKAD, there is no literature describing the association of all three diagnoses this case: H-SS, VEO-IBD and MKAD. Initiation of canakinumab in this patient resulted in successful control of the disease. CONCLUSIONS: This case highlights the importance of a multidisciplinary approach to rare diagnoses, and collaboration during cases with significant diagnostic uncertainty.

Development of a Screening Algorithm for Lung Disease in Systemic Juvenile Idiopathic Arthritis.

OBJECTIVE: Lung disease (LD) is an increasingly recognized complication of systemic juvenile idiopathic arthritis (sJIA). As there are no currently available guidelines for pulmonary screening in sJIA, we sought to develop such an algorithm at our institution. METHODS: A multidisciplinary workgroup was convened, including members representing rheumatology, pulmonary, stem cell transplantation, and patient families. The workgroup leaders drafted an initial algorithm based on published literature and experience at our center. A modified Delphi approach was used to achieve agreement through three rounds of anonymous, asynchronous voting and a consensus meeting. Statements approved by the workgroup were rated as appropriate with moderate or high levels of consensus. These statements were organized into the final approved screening algorithm for LD in sJIA. RESULTS: The workgroup ultimately rated 20 statements as appropriate with a moderate or high level of consensus. The approved algorithm recommends pulmonary screening for newly diagnosed patients with sJIA with clinical features that the workgroup agreed may confer increased risk for LD. These "red flag features" include baseline characteristics (young age of sJIA onset, human leukocyte antigen type, trisomy 21), high disease activity (macrophage activation syndrome [MAS], sJIA-related ICU admission, elevated MAS biomarkers), respiratory symptoms or abnormal pulmonary examination findings, and features of drug hypersensitivity-like reactions (eosinophilia, atypical rash, anaphylaxis). The workgroup achieved consensus on the recommended pulmonary work-up and monitoring guidelines. CONCLUSION: We developed a pulmonary screening algorithm for sJIA-LD through a multidisciplinary consensus-building process, which will be revised as our understanding of sJIA-LD continues to evolve.

Neurological and Psychological Sequelae Associated With Multisystem Inflammatory Syndrome in Children.

Importance: Acute neurological involvement occurs in some patients with multisystem inflammatory syndrome in children (MIS-C), but few data report neurological and psychological sequelae, and no investigations include direct assessments of cognitive function 6 to 12 months after discharge. Objective: To characterize neurological, psychological, and quality of life sequelae after MIS-C. Design, Setting, and Participants: This cross-sectional cohort study was conducted in the US and Canada. Participants included children with MIS-C diagnosed from November 2020 through November 2021, 6 to 12 months after hospital discharge, and their sibling or community controls, when available. Data analysis was performed from August 2022 to May 2023. Exposure: Diagnosis of MIS-C. Main Outcomes and Measures: A central study site remotely administered a onetime neurological examination and in-depth neuropsychological assessment including measures of cognition, behavior, quality of life, and daily function. Generalized estimating equations, accounting for matching, assessed for group differences. Results: Sixty-four patients with MIS-C (mean [SD] age, 11.5 [3.9] years; 20 girls [31%]) and 44 control participants (mean [SD] age, 12.6 [3.7] years; 20 girls [45%]) were enrolled. The MIS-C group exhibited abnormalities on neurological examination more frequently than controls (15 of 61 children [25%] vs 3 of 43 children [7%]; odds ratio, 4.7; 95% CI, 1.3-16.7). Although the 2 groups performed similarly on most cognitive measures, the MIS-C group scored lower on the National Institutes of Health Cognition Toolbox List Sort Working Memory Test, a measure of executive functioning (mean [SD] scores, 96.1 [14.3] vs 103.1 [10.5]). Parents reported worse psychological outcomes in cases compared with controls, particularly higher scores for depression symptoms (mean [SD] scores, 52.6 [13.1] vs 47.8 [9.4]) and somatization (mean [SD] scores, 55.5 [15.5] vs 47.0 [7.6]). Self-reported (mean [SD] scores, 79.6 [13.1] vs 85.5 [12.3]) and parent-reported (mean [SD] scores, 80.3 [15.5] vs 88.6 [13.0]) quality of life scores were also lower in cases than controls. Conclusions and Relevance: In this cohort study, compared with contemporaneous sibling or community controls, patients with MIS-C had more abnormal neurologic examinations, worse working memory scores, more somatization and depression symptoms, and lower quality of life 6 to 12 months after hospital discharge. Although these findings need to be confirmed in larger studies, enhanced monitoring may be warranted for early identification and treatment of neurological and psychological symptoms.