Intravenous immunoglobulin resistance in Kawasaki disease patients: prediction using clinical data.

BACKGROUND: About 10-20% of Kawasaki disease (KD) patients are resistant to the initial infusion of intravenous immunoglobin (IVIG). The aim of this study was to assess whether IVIG resistance in KD patients could be predicted using standard clinical and laboratory features. METHODS: Data were from two cohorts: a Korean cohort of 7101 KD patients from 2015 to 2017 and a cohort of 649 KD patients from San Diego enrolled from 1998 to 2021. Features included laboratory values, the worst Z-score from the initial echocardiogram or during hospitalization, and the five clinical KD signs at presentation. RESULTS: Five machine learning models achieved a maximum median AUC of 0.711 [IQR: 0.706-0.72] in the Korean cohort and 0.696 [IQR: 0.609-0.722] in the San Diego cohort during stratified 10-fold cross-validation using significant laboratory features identified from univariate analysis. Adding the Z-score, KD clinical signs, or both did not considerably improve the median AUC in either cohort. CONCLUSIONS: Using commonly measured clinical laboratory data alone or in conjunction with echocardiographic findings and clinical features is not sufficient to predict IVIG resistance. Further attempts to predict IVIG resistance will need to incorporate additional data such as transcriptomics, proteomics, and genetics to achieve meaningful predictive utility. IMPACT: We demonstrated that laboratory, echocardiographic, and clinical findings cannot predict intravenous immunoglobin (IVIG) resistance to a clinically meaningful extent using machine learning in a homogenous Asian or ethnically diverse population of patients with Kawasaki disease (KD). Visualizing these features using uniform manifold approximation and projection (UMAP) is an important step to evaluate predictive utility in a qualitative manner. Further attempts to predict IVIG resistance in KD patients will need to incorporate novel biomarkers or other specialized features such as genetic differences or transcriptomics to be clinically useful.

Characterization of SARS-CoV-2 and common cold coronavirus-specific T-cell responses in MIS-C and Kawasaki disease children.

The immunopathogenesis of multisystem inflammatory syndrome (MIS-C) in children that may follow exposure to SARS-CoV-2 is incompletely understood. Here, we studied SARS-CoV-2-specific T cells in MIS-C, Kawasaki disease (KD), and SARS-CoV-2 convalescent controls using peptide pools derived from SARS-CoV-2 spike or nonspike proteins, and common cold coronaviruses (CCC). Coordinated CD4+ and CD8+ SARS-CoV-2-specific T cells were detected in five MIS-C subjects with cross-reactivity to CCC. CD4+ and CD8+ T-cell responses alone were documented in three and one subjects, respectively. T-cell specificities in MIS-C did not correlate with disease severity and were similar to SARS-CoV-2 convalescent controls. T-cell memory and cross-reactivity to CCC in MIS-C and SARS-CoV-2 convalescent controls were also similar. The chemokine receptor CCR6, but not CCR9, was highly expressed on SARS-CoV-2-specific CD4+ but not on CD8+ T cells. Only two of 10 KD subjects showed a T-cell response to CCC. Enumeration of myeloid APCs revealed low cell precursors in MIS-C subjects compared to KD. In summary, children with MIS-C mount a normal T-cell response to SARS-CoV-2 with no apparent relationship to antecedent CCC exposure. Low numbers of tolerogenic myeloid DCs may impair their anti-inflammatory response.

Bridging a diagnostic Kawasaki disease classifier from a microarray platform to a qRT-PCR assay.

BACKGROUND: Kawasaki disease (KD) is a systemic vasculitis that mainly affects children under 5 years of age. Up to 30% of patients develop coronary artery abnormalities, which are reduced with early treatment. Timely diagnosis of KD is challenging but may become more straightforward with the recent discovery of a whole-blood host response classifier that discriminates KD patients from patients with other febrile conditions. Here, we bridged this microarray-based classifier to a clinically applicable quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay: the Kawasaki Disease Gene Expression Profiling (KiDs-GEP) classifier. METHODS: We designed and optimized a qRT-PCR assay and applied it to a subset of samples previously used for the classifier discovery to reweight the original classifier. RESULTS: The performance of the KiDs-GEP classifier was comparable to the original classifier with a cross-validated area under the ROC curve of 0.964 [95% CI: 0.924-1.00] vs 0.992 [95% CI: 0.978-1.00], respectively. Both classifiers demonstrated similar trends over various disease conditions, with the clearest distinction between individuals diagnosed with KD vs viral infections. CONCLUSION: We successfully bridged the microarray-based classifier into the KiDs-GEP classifier, a more rapid and more cost-efficient qRT-PCR assay, bringing a diagnostic test for KD closer to the hospital clinical laboratory. IMPACT: A diagnostic test is needed for Kawasaki disease and is currently not available. We describe the development of a One-Step multiplex qRT-PCR assay and the subsequent modification (i.e., bridging) of the microarray-based host response classifier previously described by Wright et al. The bridged KiDs-GEP classifier performs well in discriminating Kawasaki disease patients from febrile controls. This host response clinical test for Kawasaki disease can be adapted to the hospital clinical laboratory.

Exercise Stress Echocardiography in Kawasaki Disease Patients with Coronary Aneurysms.

The most significant sequelae of Kawasaki disease (KD) are coronary artery aneurysms, which can lead to risk of future myocardial ischemia. Exercise stress echocardiography allows for non-invasive assessment of myocardial dysfunction. We reviewed our single center experience with exercise stress echocardiography in patients with previous history of KD with coronary aneurysms. We reviewed the records of 53 KD patients who underwent exercise stress echocardiography from 2000 to 2020. Abnormal stress echocardiograms were defined as those showing no increase in biventricular systolic function post-exercise or regional wall motion abnormalities. Computed tomography angiography and cardiac magnetic resonance imaging were reviewed for patients with abnormal stress echocardiograms. Clinical data were reviewed and correlated with stress echocardiogram results. Of the 53 patients, three (5.7%) had an abnormal exercise stress echocardiogram. All three patients were classified as AHA Risk Level 4 or 5 by coronary Z-score (internal dimension normalized for body surface area) and were confirmed to have coronary aneurysms, stenosis, or myocardial tissue perfusion defects on advanced cardiac imaging that could account for the results seen on stress echocardiogram. Exercise stress echocardiography detected signs of myocardial ischemia in a subset of high-risk patients with Kawasaki disease and coronary aneurysms and may be considered as a useful screening tool for this complex patient cohort.

Endothelial Cell Response in Kawasaki Disease and Multisystem Inflammatory Syndrome in Children.

Although Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) share some clinical manifestations, their cardiovascular outcomes are different, and this may be reflected at the level of the endothelial cell (EC). We performed RNA-seq on cultured ECs incubated with pre-treatment sera from KD (n = 5), MIS-C (n = 7), and healthy controls (n = 3). We conducted a weighted gene co-expression network analysis (WGCNA) using 935 transcripts differentially expressed between MIS-C and KD using relaxed filtering (unadjusted p < 0.05, >1.1-fold difference). We found seven gene modules in MIS-C, annotated as an increased TNFα/NFκB pathway, decreased EC homeostasis, anti-inflammation and immune response, translation, and glucocorticoid responsive genes and endothelial-mesenchymal transition (EndoMT). To further understand the difference in the EC response between MIS-C and KD, stringent filtering was applied to identify 41 differentially expressed genes (DEGs) between MIS-C and KD (adjusted p < 0.05, >2-fold-difference). Again, in MIS-C, NFκB pathway genes, including nine pro-survival genes, were upregulated. The expression levels were higher in the genes influencing autophagy (UBD, EBI3, and SQSTM1). Other DEGs also supported the finding by WGCNA. Compared to KD, ECs in MIS-C had increased pro-survival transcripts but reduced transcripts related to EndoMT and EC homeostasis. These differences in the EC response may influence the different cardiovascular outcomes in these two diseases.

Neutralization of Severe Acute Respiratory Syndrome Coronavirus 2 Omicron and Other Variants in Serum From Children With Vaccination-Induced Myocarditis.

Our study demonstrates that children who developed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination-induced myocarditis and may not receive another vaccination, could be susceptible to infection with Omicron and emerging variants. We observed higher neutralizing antibody titers in myocarditis patients vs. healthy vaccinated children, but significantly lower neutralization titers against Omicron in both groups.

Severe delayed hypersensitivity reactions to IL-1 and IL-6 inhibitors link to common HLA-DRB1*15 alleles.

OBJECTIVES: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe, delayed hypersensitivity reaction (DHR). We observed DRESS to inhibitors of interleukin 1 (IL-1) or IL-6 in a small group of patients with Still's disease with atypical lung disease. We sought to characterise features of patients with Still's disease with DRESS compared with drug-tolerant Still's controls. We analysed human leucocyte antigen (HLA) alleles for association to inhibitor-related DHR, including in a small Kawasaki disease (KD) cohort. METHODS: In a case/control study, we collected a multicentre series of patients with Still's disease with features of inhibitor-related DRESS (n=66) and drug-tolerant Still's controls (n=65). We retrospectively analysed clinical data from all Still's subjects and typed 94/131 for HLA. European Still's-DRESS cases were ancestry matched to International Childhood Arthritis Genetics Consortium paediatric Still's cases (n=550) and compared for HLA allele frequencies. HLA association also was analysed using Still's-DRESS cases (n=64) compared with drug-tolerant Still's controls (n=30). KD subjects (n=19) were similarly studied. RESULTS: Still's-DRESS features included eosinophilia (89%), AST-ALT elevation (75%) and non-evanescent rash (95%; 88% involving face). Macrophage activation syndrome during treatment was frequent in Still's-DRESS (64%) versus drug-tolerant Still's (3%; p=1.2×10-14). We found striking enrichment for HLA-DRB1*15 haplotypes in Still's-DRESS cases versus INCHARGE Still's controls (p=7.5×10-13) and versus self-identified, ancestry-matched Still's controls (p=6.3×10-10). In the KD cohort, DRB1*15:01 was present only in those with suspected anakinra reactions. CONCLUSIONS: DRESS-type reactions occur among patients treated with IL-1/IL-6 inhibitors and strongly associate with common HLA-DRB1*15 haplotypes. Consideration of preprescription HLA typing and vigilance for serious reactions to these drugs are warranted.

Anakinra Treatment in Patients with Acute Kawasaki Disease with Coronary Artery Aneurysms: A Phase I/IIa Trial.

OBJECTIVES: To determine the safety, pharmacokinetics, and immunomodulatory effects of 2-6 weeks of anakinra therapy in patients with acute Kawasaki disease with a coronary artery aneurysm (CAA). STUDY DESIGN: We performed a Phase I/IIa dose-escalation study of anakinra (2-11 mg/kg/day) in 22 patients with acute Kawasaki disease with CAA. We measured interleukin (IL)-1RA concentrations after the first dose and trough levels up to study week 6. Markers of inflammation and coronary artery z-scores were assessed pretreatment and at 48 hours, 2 weeks, and 6 weeks after initiation of therapy. RESULTS: Up to 6 weeks of anakinra (up to 11 mg/kg/day) was safe and well tolerated by the 22 participants (median age, 1.1 years), with no serious adverse events attributable to the study drug. All participants were treated with intravenous immunoglobulin (IVIG), and 20 also received infliximab (10 mg/kg) before initiation of anakinra. Serum levels of IL-6, IL-8, and tumor necrosis factor α decreased similarly in patients with Kawasaki disease treated with IVIG, infliximab, and anakinra compared with age- and sex-matched patients with Kawasaki disease treated only with IVIG and infliximab. Anakinra clearance increased with illness day at diagnosis. Simulations demonstrated that more frequent intravenous (IV) dosing may result in more sustained concentrations without significantly increasing the peak concentration compared with subcutaneous (SC) dosing. CONCLUSIONS: Both IV and SC anakinra are safe in infants and children with acute Kawasaki disease and CAA. IV dosing every 8-12 hours during the acute hospitalization of patients with Kawasaki disease may result in a sustained concentration while avoiding frequent SC injections. The efficacy of a short course of IV therapy during hospitalization should be studied. TRIAL REGISTRATION CLINICALTRIALS.GOV: NCT02179853.

Inflammasome Activation in Children With Kawasaki Disease and Multisystem Inflammatory Syndrome.

[Figure: see text].

Effect of ethanol on astaxanthin and fatty acid production in the red yeast Xanthophyllomyces dendrorhous.

AIM: The effects of detergent, ethanol and ethanol with plant meadowfoam oil on the growth of the red heterobasidomycete Xanthophyllomyces dendrorhous and on the production of astaxanthin (3,3'-dihydroxy-ß,ß-carotene-4,4'-dione) and fatty acids in this red yeast were investigated. METHODS AND RESULTS: Ethanol supplementation at a final concentration of 0.8% (v/v) caused an increase in the growth, astaxanthin production and fatty acid production of treated X. dendrorhous compared with untreated X. dendrorhous. Supplementation of meadowfoam oil with 0.8% ethanol further improved the growth and astaxanthin production of X. dendrorhous. Fatty acid compositions following supplementation with various concentrations of ethanol and oil were also analysed. With 0.8% ethanol supplementation, the ratio of linoleic acid (C18:2) and α-linolenic acid (C18:3ω3, ALA) decreased. Conversely, with 1.8% ethanol supplementation, the ALA ratio increased. CONCLUSIONS: Ethanol can serve as a promoting factor for coproduction of astaxanthin and fatty acids in X. dendrorhous, whereas simultaneous supplementation of ethanol and meadowfoam oil can cause further astaxanthin production. SIGNIFICANCE AND IMPACT OF STUDY: Astaxanthin is widely used in various functional products because of its antioxidant activity. This study shows that X. dendrorhous can coproduce astaxanthin and functional fatty acids at high levels following supplementation with ethanol.

T Cells in Multisystem Inflammatory Syndrome in Children (MIS-C) Have a Predominant CD4+ T Helper Response to SARS-CoV-2 Peptides and Numerous Virus-Specific CD4- CD8- Double-Negative T Cells.

We studied SARS-CoV-2-specific T cell responses in 22 subacute MIS-C children enrolled in 2021 and 2022 using peptide pools derived from SARS-CoV-2 spike or nonspike proteins. CD4+ and CD8+ SARS-CoV-2-specific T cells were detected in 5 subjects, CD4+ T helper (Th) responses alone were detected in 12 subjects, and CD8+ cytotoxic T cell (CTL) responses alone were documented in 1 subject. Notably, a sizeable subpopulation of CD4- CD8- double-negative (DN) T cells out of total CD3+ T cells was observed in MIS-C (median: 14.5%; IQR 8.65-25.3) and recognized SARS-CoV-2 peptides. T cells bearing the Vß21.3 T cell receptor (TcRs), previously reported as pathogenic in the context of MIS-C, were detected in high frequencies, namely, in 2.8% and 3.9% of the CD4+ and CD8+ T cells, respectively. However, Vß21.3 CD8+ T cells that responded to SARS-CoV-2 peptides were detected in only a single subject, suggesting recognition of nonviral antigens in the majority of subjects. Subjects studied 6-14 months after MIS-C showed T cell epitope spreading, meaning the activation of T cells that recognize more SARS-CoV-2 peptides following the initial expansion of T cells that see immunodominant epitopes. For example, subjects that did not recognize nonspike proteins in the subacute phase of MIS-C showed good Th response to nonspike peptides, and/or CD8+ T cell responses not appreciable before arose over time and could be detected in the 6-14 months' follow-up. The magnitude of the Th and CTL responses also increased over time. In summary, patients with MIS-C associated with acute lymphopenia, a classical feature of MIS-C, showed a physiological response to the virus with a prominent role for virus-specific DN T cells.

Temporal Clusters of Kawasaki Disease Cases Share Distinct Phenotypes That Suggest Response to Diverse Triggers.

OBJECTIVE: To test the hypothesis that cases of Kawasaki disease within a temporal cluster have a similar pattern of host response that is distinct from cases of Kawasaki disease in different observed clusters and randomly constructed clusters. STUDY DESIGN: We designed a case-control study to analyze 47 clusters derived from 1332 patients with Kawasaki disease over a 17-year period (2002-2019) from a single clinical site and compared the cluster characteristics with those of 2 control groups of synthetic Kawasaki disease clusters. We defined a "true" Kawasaki disease cluster as at least 5 patients within a 7-day moving window. The observed and synthetic Kawasaki disease clusters were compared with respect to demographic and clinical characteristics and median values for standard laboratory data using univariate analysis and a multivariate, rotated empirical orthogonal function analysis. RESULTS: In a univariate analysis, the median values for age, coronary artery z-score, white blood cell count, erythrocyte sedimentation rate, C-reactive protein, and age-adjusted hemoglobin for several of the true Kawasaki disease clusters exceeded the 95th percentile for the 2 synthetic clusters. REOF analyses revealed distinct patterns of demographic and clinical measures within clusters. CONCLUSIONS: Cases of Kawasaki disease within a cluster were more similar with respect to demographic and clinical features and levels of inflammation than would be expected by chance. These observations suggest that different triggers and/or different intensities of exposures result in clusters of cases of Kawasaki disease that share a similar response pattern. Analyzing cases within clusters or cases who share demographic and clinical features may lead to new insights into the etiology of Kawasaki disease.

Lacosamide-induced sinus node dysfunction followed by severe agranulocytosis.

BACKGROUND: Lacosamide (LCM) is the antiepileptic drug approved by the U.S. Food and Drug Administration in 2008 that facilitates slow activation of the voltage-gated sodium channels. Neutropenia and cardiac events including sinus node dysfunction (SND) and atrioventricular block have been previously reported as adverse effects of LCM. To date, there have been no reports of severe agranulocytosis resulting in death associated with LCM. Additionally, there have been no reports of concomitant SND and agranulocytosis after LCM administration. Herein we report the first case of LCM-induced severe SND followed by agranulocytosis. CASE PRESENTATION: The patient with focal epilepsy was initiated on LCM 100 mg/day and the dose was increased to 200 mg/day on the 9th hospital day. Severe SND developed on the 10th hospital day and LCM was discontinued. Thereafter agranulocytosis appeared on the 11th hospital day, and the patient died from septic shock on the 15th hospital day. CONCLUSIONS: This case illustrates the need for careful follow-up of the electrocardiogram and the complete blood cell counts when initiating LCM. Moreover, it should be noticed that various side effects may occur simultaneously in the early period of LCM use, even for a short time and at low dosages.

Kawasaki Disease Patient Stratification and Pathway Analysis Based on Host Transcriptomic and Proteomic Profiles.

The aetiology of Kawasaki disease (KD), an acute inflammatory disorder of childhood, remains unknown despite various triggers of KD having been proposed. Host 'omic profiles offer insights into the host response to infection and inflammation, with the interrogation of multiple 'omic levels in parallel providing a more comprehensive picture. We used differential abundance analysis, pathway analysis, clustering, and classification techniques to explore whether the host response in KD is more similar to the response to bacterial or viral infections at the transcriptomic and proteomic levels through comparison of 'omic profiles from children with KD to those with bacterial and viral infections. Pathways activated in patients with KD included those involved in anti-viral and anti-bacterial responses. Unsupervised clustering showed that the majority of KD patients clustered with bacterial patients on both 'omic levels, whilst application of diagnostic signatures specific for bacterial and viral infections revealed that many transcriptomic KD samples had low probabilities of having bacterial or viral infections, suggesting that KD may be triggered by a different process not typical of either common bacterial or viral infections. Clustering based on the transcriptomic and proteomic responses during KD revealed three clusters of KD patients on both 'omic levels, suggesting heterogeneity within the inflammatory response during KD. The observed heterogeneity may reflect differences in the host response to a common trigger, or variation dependent on different triggers of the condition.

High-Throughput Screening of Kawasaki Disease Sera for Antiviral Antibodies.

Clinical features of Kawasaki disease (KD) display overlap with common pediatric viral illnesses, leading some to hypothesize that a viral infection is the inciting event for KD. To investigate viral infection history in KD patients, we performed comprehensive serological profiling using a high-throughput phage immunoprecipitation sequencing assay covering the complete reference protein sequences of known viruses with human tropism. KD and matched febrile control sera did not demonstrate differences in antiviral antibody profiles. We conclude that in the acute and subacute phases of disease, KD patients do not exhibit serologic evidence of exposure to known viruses that differs from controls.

Clinical Characteristics of 58 Children With a Pediatric Inflammatory Multisystem Syndrome Temporally Associated With SARS-CoV-2.

Importance: In communities with high rates of coronavirus disease 2019, reports have emerged of children with an unusual syndrome of fever and inflammation. Objectives: To describe the clinical and laboratory characteristics of hospitalized children who met criteria for the pediatric inflammatory multisystem syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (PIMS-TS) and compare these characteristics with other pediatric inflammatory disorders. Design, Setting, and Participants: Case series of 58 children from 8 hospitals in England admitted between March 23 and May 16, 2020, with persistent fever and laboratory evidence of inflammation meeting published definitions for PIMS-TS. The final date of follow-up was May 22, 2020. Clinical and laboratory characteristics were abstracted by medical record review, and were compared with clinical characteristics of patients with Kawasaki disease (KD) (n = 1132), KD shock syndrome (n = 45), and toxic shock syndrome (n = 37) who had been admitted to hospitals in Europe and the US from 2002 to 2019. Exposures: Signs and symptoms and laboratory and imaging findings of children who met definitional criteria for PIMS-TS from the UK, the US, and World Health Organization. Main Outcomes and Measures: Clinical, laboratory, and imaging characteristics of children meeting definitional criteria for PIMS-TS, and comparison with the characteristics of other pediatric inflammatory disorders. Results: Fifty-eight children (median age, 9 years [interquartile range {IQR}, 5.7-14]; 20 girls [34%]) were identified who met the criteria for PIMS-TS. Results from SARS-CoV-2 polymerase chain reaction tests were positive in 15 of 58 patients (26%) and SARS-CoV-2 IgG test results were positive in 40 of 46 (87%). In total, 45 of 58 patients (78%) had evidence of current or prior SARS-CoV-2 infection. All children presented with fever and nonspecific symptoms, including vomiting (26/58 [45%]), abdominal pain (31/58 [53%]), and diarrhea (30/58 [52%]). Rash was present in 30 of 58 (52%), and conjunctival injection in 26 of 58 (45%) cases. Laboratory evaluation was consistent with marked inflammation, for example, C-reactive protein (229 mg/L [IQR, 156-338], assessed in 58 of 58) and ferritin (610 µg/L [IQR, 359-1280], assessed in 53 of 58). Of the 58 children, 29 developed shock (with biochemical evidence of myocardial dysfunction) and required inotropic support and fluid resuscitation (including 23/29 [79%] who received mechanical ventilation); 13 met the American Heart Association definition of KD, and 23 had fever and inflammation without features of shock or KD. Eight patients (14%) developed coronary artery dilatation or aneurysm. Comparison of PIMS-TS with KD and with KD shock syndrome showed differences in clinical and laboratory features, including older age (median age, 9 years [IQR, 5.7-14] vs 2.7 years [IQR, 1.4-4.7] and 3.8 years [IQR, 0.2-18], respectively), and greater elevation of inflammatory markers such as C-reactive protein (median, 229 mg/L [IQR 156-338] vs 67 mg/L [IQR, 40-150 mg/L] and 193 mg/L [IQR, 83-237], respectively). Conclusions and Relevance: In this case series of hospitalized children who met criteria for PIMS-TS, there was a wide spectrum of presenting signs and symptoms and disease severity, ranging from fever and inflammation to myocardial injury, shock, and development of coronary artery aneurysms. The comparison with patients with KD and KD shock syndrome provides insights into this syndrome, and suggests this disorder differs from other pediatric inflammatory entities.

Pediatric tolerogenic DCs expressing CD4 and immunoglobulin-like transcript receptor (ILT)-4 secrete IL-10 in response to Fc and adenosine.

We characterized a novel population of tolerogenic myeloid dendritic cells (tmDCs) defined as CD11c+ CD11b+ CD14+ CD4+ and immunoglobulin-like transcript receptor (ILT)-4+ that are significantly more abundant in the circulation of infants and young children than in adults. TmDCs secrete the immunosuppressive lymphokine interleukin (IL)-10 when stimulated with the heavy constant region of immunoglobulins (Fc) and express high levels of the adenosine A2A receptor (A2A R), which, when activated by adenosine, inhibits the release of pro-inflammatory cytokines from most immune cells. Here we show that stimulation of the A2A R on tmDCs by regadenoson or N-ethylcarboxamidoadenosine (NECA) rapidly increases cyclic AMP accumulation and enhances IL-10 production under Fc stimulatory conditions. In co-culture experiments, tmDCs inhibit the differentiation of naïve T cells to a pro-inflammatory phenotype. In conclusion, although DCs are classically viewed as antigen presenting cells that activate T cells, we show an independent role of tmDCs in pediatric immune regulation that may be important for suppressing T cell responses to neoantigens in infants and young children.

Phase I/IIa Trial of Atorvastatin in Patients with Acute Kawasaki Disease with Coronary Artery Aneurysm.

OBJECTIVES: To determine the safety, tolerability, pharmacokinetics, and immunomodulatory effects of a 6-week course of atorvastatin in patients with acute Kawasaki disease with coronary artery (CA) aneurysm (CAA). STUDY DESIGN: This was a Phase I/IIa 2-center dose-escalation study of atorvastatin (0.125-0.75 mg/kg/day) in 34 patients with Kawasaki disease (aged 2-17 years) with echocardiographic evidence of CAA. We measured levels of the brain metabolite 24(S)-hydroxycholesterol (24-OHC), serum lipids, acute-phase reactants, liver enzymes, and creatine phosphokinase; peripheral blood mononuclear cell populations; and CA internal diameter normalized for body surface area before atorvastatin treatment and at 2 and 6 weeks after initiation of atorvastatin treatment. RESULTS: A 6-week course of up to 0.75 mg/kg/day of atorvastatin was well tolerated by the 34 subjects (median age, 5.3 years; IQR, 2.6-6.4 years), with no serious adverse events attributable to the study drug. The areas under the curve for atorvastatin and its metabolite were larger in the study subjects compared with those reported in adults, suggesting a slower rate of metabolism in children. The 24-OHC levels were similar between the atorvastatin-treated subjects and matched controls. CONCLUSIONS: Atorvastatin was safe and well tolerated in our cohort of children with acute Kawasaki disease and CAA. A Phase III efficacy trial is warranted in this patient population, which may benefit from the known anti-inflammatory and immunomodulatory effects of this drug.

miR-483 Targeting of CTGF Suppresses Endothelial-to-Mesenchymal Transition: Therapeutic Implications in Kawasaki Disease.

RATIONALE: Endothelial-mesenchymal transition (EndoMT) is implicated in myofibroblast-like cell-mediated damage to the coronary arterial wall in acute Kawasaki disease (KD) patients, as evidenced by positive staining for connective tissue growth factor (CTGF) and EndoMT markers in KD autopsy tissues. However, little is known about the molecular basis of EndoMT involved in KD. OBJECTIVE: We investigated the microRNA (miRNA) regulation of CTGF and the consequent EndoMT in KD pathogenesis. As well, the modulation of this process by statin therapy was studied. METHODS AND RESULTS: Sera from healthy children and KD subjects were incubated with human umbilical vein endothelial cells. Cardiovascular disease-related miRNAs, CTGF, and EndoMT markers were quantified using reverse transcriptase quantitative polymerase chain reaction, ELISA, and Western blotting. Compared with healthy controls, human umbilical vein endothelial cell incubated with sera from acute KD patients had decreased miR-483, increased CTGF, and increased EndoMT markers. Bioinformatics analysis followed by functional validation demonstrated that Krüppel-like factor 4 (KLF4) transactivates miR-483, which in turn targets the 3' untranslated region of CTGF mRNA. Overexpression of KLF4 or pre-miR-483 suppressed, whereas knockdown of KLF4 or anti-miR-483 enhanced, CTGF expression in endothelial cells in vitro and in vivo. Furthermore, atorvastatin, currently being tested in a phase I/IIa clinical trial in KD children, induced KLF4-miR-483, which suppressed CTGF and EndoMT in endothelial cells. CONCLUSIONS: KD sera suppress the KLF4-miR-483 axis in endothelial cells, leading to increased expression of CTGF and induction of EndoMT. This detrimental process in the endothelium may contribute to coronary artery abnormalities in KD patients. Statin therapy may benefit acute KD patients, in part, through the restoration of KLF4-miR-483 expression. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01431105.

PRINCESS: Privacy-protecting Rare disease International Network Collaboration via Encryption through Software guard extensionS.

Motivation: We introduce PRINCESS, a privacy-preserving international collaboration framework for analyzing rare disease genetic data that are distributed across different continents. PRINCESS leverages Software Guard Extensions (SGX) and hardware for trustworthy computation. Unlike a traditional international collaboration model, where individual-level patient DNA are physically centralized at a single site, PRINCESS performs a secure and distributed computation over encrypted data, fulfilling institutional policies and regulations for protected health information. Results: To demonstrate PRINCESS' performance and feasibility, we conducted a family-based allelic association study for Kawasaki Disease, with data hosted in three different continents. The experimental results show that PRINCESS provides secure and accurate analyses much faster than alternative solutions, such as homomorphic encryption and garbled circuits (over 40 000× faster). Availability and Implementation: https://github.com/achenfengb/PRINCESS_opensource. Contact: shw070@ucsd.edu. Supplementary information: Supplementary data are available at Bioinformatics online.