Urinary Colorimetric Sensor Array and Algorithm to Distinguish Kawasaki Disease from Other Febrile Illnesses

Objectives

Kawasaki disease (KD) is an acute pediatric vasculitis of infants and young children with unknown etiology and no specific laboratory-based test to identify. A specific molecular diagnostic test is urgently needed to support the clinical decision of proper medical intervention, preventing subsequent complications of coronary artery aneurysms. We used a simple and low-cost colorimetric sensor array to address the lack of a specific diagnostic test to differentiate KD from febrile control (FC) patients with similar rash/fever illnesses.

Study Design

Demographic and clinical data were prospectively collected for subjects with KD and FCs under standard protocol. After screening using a genetic algorithm, eleven compounds including metalloporphyrins, pH indicators, redox indicators and solvatochromic dye categories, were selected from our chromatic compound library (n = 190) to construct a colorimetric sensor array for diagnosing KD. Quantitative color difference analysis led to a decision-tree-based KD diagnostic algorithm.

Results

This KD sensing array allowed the identification of 94% of KD subjects (receiver operating characteristic [ROC] area under the curve [AUC] 0.981) in the training set (33 KD, 33 FC) and 94% of KD subjects (ROC AUC: 0.873) in the testing set (16 KD, 17 FC). Color difference maps reconstructed from the digital images of the sensing compounds demonstrated distinctive patterns differentiating KD from FC patients.

Conclusions

The colorimetric sensor array, composed of common used chemical compounds, is an easily accessible, low-cost method to realize the discrimination of subjects with KD from other febrile illness.

Novel data-mining approach identifies biomarkers for diagnosis of Kawasaki disease

BACKGROUND

As Kawasaki disease (KD) shares many clinical features with other more common febrile illnesses and misdiagnosis, leading to a delay in treatment, increases the risk of coronary artery damage, a diagnostic test for KD is urgently needed. We sought to develop a panel of biomarkers that could distinguish between acute KD patients and febrile controls (FC) with sufficient accuracy to be clinically useful.

METHODS

Plasma samples were collected from three independent cohorts of FC and acute KD patients who met the American Heart Association definition for KD and presented within the first 10 d of fever. The levels of 88 biomarkers associated with inflammation were assessed by Luminex bead technology. Unsupervised clustering followed by supervised clustering using a Random Forest model was used to find a panel of candidate biomarkers.

RESULTS

A panel of biomarkers commonly available in the hospital laboratory (absolute neutrophil count, erythrocyte sedimentation rate, alanine aminotransferase, γ-glutamyl transferase, concentrations of α-1-antitrypsin, C-reactive protein, and fibrinogen, and platelet count) accurately diagnosed 81-96% of KD patients in a series of three independent cohorts.

CONCLUSION

After prospective validation, this eight-biomarker panel may improve the recognition of KD.

Galectin-3 is a marker of myocardial and vascular fibrosis in Kawasaki disease patients with giant aneurysms

BACKGROUNDS

Galectin-3 (Gal-3) is a multifunctional matricellular protein associated with heart failure and cardiovascular events. Gal-3 is required for transforming growth factor-β pathway-mediated myofibroblast activation that is a key process in coronary artery aneurysm formation in Kawasaki Disease (KD). Autopsies from young adults late after KD onset (AKD) have demonstrated bridging fibrosis throughout the myocardium and arteries. In this study, we postulated that Gal-3 may participate in the pathogenesis of myocardial and vascular fibrosis and the remodeling of coronary artery aneurysms following acute KD.

METHODS AND RESULTS

We measured plasma Gal-3 levels in 63 pediatric KD (PKD) and 81 AKD subjects. AKD subjects with giant aneurysms had significantly higher Gal-3 levels compared to the other adult groups (all p<0.05). All PKD groups had significantly higher Gal-3 levels than pediatric healthy controls (HC) (all p<0.05). Histological and immunohistochemical staining was performed on tissues from 10 KD autopsies and one explanted heart. Gal-3 positive staining was detected associated with acute inflammation and in spindle-shaped cells in the myocardium and arterial wall in KD subjects with giant aneurysms.

CONCLUSIONS

AKD subjects with giant aneurysms and PKD subjects had significantly higher plasma Gal-3 levels than HC and Gal-3 expression was increased in the myocardium of KD subjects who died with either acute inflammation or marked myocardial fibrosis. Gal-3 may be a clinically useful biomarker that identifies a subset of KD patients at highest risk of myocardial and vascular fibrosis, and may be an attractive therapeutic target to prevent myocardial dysfunction in this subset.

Evaluating a novel treatment for coronary artery inflammation in acute Kawasaki disease: A Phase I/IIa trial of atorvastatin

INTRODUCTION

Since the 1980s, the primary treatment of acute Kawasaki disease (KD) has been intravenous immunoglobulin and aspirin. However, 5-10% of children with acute KD will develop coronary artery abnormalities despite treatment within the first ten days after fever onset. There is no approved adjunctive therapy to prevent progression of coronary artery damage in these patients.

AREAS COVERED

The rationale and study design of a Phase I/IIa trial of atorvastatin in children with acute KD and coronary artery inflammation is presented. The studies of host genetics and KD pathogenesis leading up to this trial are reviewed.

EXPERT OPINION

The repurposing of well-studied drugs used in the adult population is a cost-effective and efficient strategy to identify new therapies for pediatric diseases. Exploiting the anti-inflammatory, non-lipid-lowering effects of statins may open up new applications for this class of drugs for the pediatric age group.

Fine specificities of natural regulatory T cells after IVIG therapy in patients with Kawasaki disease

The activation of natural regulatory T cells (nTreg) recognizing the heavy constant region (Fc) of IgG is an important mechanism of action of intravenous immunoglobulin (IVIG) therapy in Kawasaki disease (KD). Lack of circulating Fc-specific nTreg in the sub-acute phase of KD is correlated with the development of coronary artery abnormalities (CAA). Here, we characterize the fine specificity of nTreg in sub-acute (2- to 8-week post-IVIG) and convalescent (1- to 10-year post-IVIG) KD subjects by testing the immunogenicity of 64 peptides, 15 amino acids in length with a 10 amino acid-overlap spanning the entire Fc protein. About 12 Fc peptides (6 pools of 2 consecutive peptides) were recognized by nTreg in the cohorts studied, including two patients with CAA. To test whether IVIG expands the same nTreg populations that maintain vascular homeostasis in healthy subjects, we compared these results with results obtained in healthy adult controls. Similar nTreg fine specificities were observed in KD patients after IVIG and in healthy donors. These results suggest that T cell fitness rather than T cell clonal deletion or anergy is responsible for the lack of Fc-specific nTreg in KD patients who develop CAA. Furthermore, we found that adolescents and adults who had KD during childhood without developing CAA did not respond to the Fc protein in vitro, suggesting that the nTreg response induced by IVIG in KD patients is short-lived. Our results support the concept that peptide epitopes may be a viable therapeutic approach to expand Fc-specific nTreg and more effectively prevent CAA in KD patients.

Kawasaki Disease in Latin American Children: Past, Current, and Future Challenges

Kawasaki disease (KD) is the leading cause of acquired cardiac disease in children in developed countries and Asia. However, there is a paucity of data available from Latin America. In response to the gap in knowledge about KD in Latin America, a group of pediatric infectious disease researchers from the Kawasaki Disease Research Center at the University of California San Diego and the Sociedad Latinoamericana de Infectología Pediátrica joined efforts during the last decade to address this problem. The Red de Enfermedad de Kawasaki en América Latina (Latin American Kawasaki Disease Network) was launched in 2013 to study the epidemiology of KD among children from the major pediatric tertiary referral hospitals in Latin America. This multinational multicenter network is primarily composed of pediatric infectious diseases, cardiology, rheumatology, and immunology subspecialists and pediatricians from 20 countries, and it is one of the world's largest networks to study the general epidemiology of KD. The first 2 prospective and retrospective multinational multicenter studies looking at the epidemiology of KD in the region were initiated in 2014. Future plans for the network include establishing collaborative research alliances and projects with other centers around the world. To date [ 1], there have been no published studies describing the overall incidence and prevalence of KD in Latin American children. The most important and recent epidemiological study addressing this issue, related to Chile, was published in 2012 [ 2]. Of these, the most recent relevant study addressed the seasonality of KD in different parts of the globe, including some Latin American and Caribbean countries [ 4]. In this document, we briefly summarize relevant available information from Latin America. Although there have been other publications from individual countries that are outside the scope of this communication, the majority of these reports are single case reports, or case series that have been published predominantly in local journals that are not indexed in PubMed and instead are in regional Spanish, Portuguese, and English databases.

Global gene expression profiling identifies new therapeutic targets in acute Kawasaki disease

Background

Global gene expression profiling can provide insight into the underlying pathophysiology of disease processes. Kawasaki disease (KD) is an acute, self-limited vasculitis whose etiology remains unknown. Although the clinical illness shares certain features with other pediatric infectious diseases, the occurrence of coronary artery aneurysms in 25% of untreated patients is unique to KD.

Methods

To gain further insight into the molecular mechanisms underlying KD, we investigated the acute and convalescent whole blood transcriptional profiles of 146 KD subjects and compared them with the transcriptional profiles of pediatric patients with confirmed bacterial or viral infection, and with healthy control children. We also investigated the transcript abundance in patients with different intravenous immunoglobulin treatment responses and different coronary artery outcomes.

Results

The overwhelming signature for acute KD involved signaling pathways of the innate immune system. Comparison with other acute pediatric infections highlighted the importance of pathways involved in cell motility including paxillin, relaxin, actin, integrins, and matrix metalloproteinases. Most importantly, the IL1β pathway was identified as a potential therapeutic target.

Conclusion

Our study revealed the importance of the IL-1 signaling pathway and a prominent signature of innate immunity and cell migration in the acute phase of the illness.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-014-0102-6) contains supplementary material, which is available to authorized users.

Lipoprotein particle concentrations in children and adults following Kawasaki disease

OBJECTIVE

To test the hypothesis that children and adults with a history of Kawasaki disease (KD) are more likely to have abnormal lipoprotein particle profiles that could place them at increased risk for developing atherosclerosis later in life.

STUDY DESIGN

Fasting serum samples were obtained from 192 children and 63 adults with history of KD and 90 age-similar healthy controls. Lipoprotein particle concentrations and sizes were measured by nuclear magnetic resonance spectroscopy (LipoScience Inc, Raleigh, North Carolina), and serum was assayed for total cholesterol (TC), triglycerides, and high-density lipoprotein (HDL) cholesterol (HDL-C). Low-density lipoprotein (LDL) cholesterol was estimated using the Friedewald formula. Data were analyzed in a least-square means model, with adjustment for age and sex and with the use of Holm correction for multiple comparisons.

RESULTS

Compared with respective control groups, both adult and pediatric subjects with KD had significantly lower mean very low-density lipoprotein-chylomicron particles, intermediate-density lipoproteins, triglycerides, and TC concentrations. Pediatric subjects with KD had significantly lower LDL particle and LDL cholesterol concentrations and lower mean TC/HDL-C ratio (P < .001). In contrast, the adult subjects with KD had significantly lower HDL particle, small HDL particle, and HDL-C concentrations (P < .001), but HDL-C was within normal range.

CONCLUSIONS

Nuclear magnetic resonance lipoprotein particle analysis suggests that pediatric and adult subjects with KD, regardless of their aneurysm status, are no more likely than age-similar, healthy controls to have lipid patterns associated with increased risk of atherosclerosis.

Optimizing Pediatric Esmolol Dosing Using Computerized Practitioner Order Entry

OBJECTIVES: The aims of this study were to 1) describe the cardiovascular dose-response of esmolol and dose-limiting adverse effects in pediatric patients; 2) assess an institutional guideline for protocol adherence, efficacy, and achievement of therapeutic targets for pediatric patients with tachyarrhythmias or systemic hypertension; and 3) revise the protocol accordingly.

METHODS: In this prospective study, pediatric/neonatal subjects were identified using a medication utilization report in the electronic medical record and treated with esmolol for blood pressure or rhythm control at Rady Children's Hospital San Diego between November 1, 2012, and February 28, 2013. Inclusion criteria required subjects to be under intensive care and have bedside telemetry monitoring. Data collection consisted of patient demographic information, administration history of esmolol, concurrent administration of other cardiovascular medications, patient cardiovascular goals, and vital signs.

RESULTS: A total of 8 subjects representing 10 administrations of esmolol were included in the study. Whereas esmolol was found to be safe and effective overall for control of hypertension and tachyarrhythmia, protocol adherence was poor, leading to subtherapeutic dosing schemes, dose changes prior to achievement of presumed steady-state pharmacokinetics, and erratic dosing to target effect.

CONCLUSIONS: After the review, the data were revealed at a program-wide conference and consensus was reached on a new, data-driven protocol. As a result of this quality improvement initiative, the new protocol provides more precise dosing and clearly delineated therapeutic targets and is designed to reflect specific esmolol pharmacokinetics. The effort emphasizes the need to construct foundations for follow-up quality improvement efforts in intensive care pharmacology.

Infliximab for intensification of primary therapy for Kawasaki disease: a phase 3 randomised, double-blind, placebo-controlled trial

BACKGROUND

Kawasaki disease, the most common cause of acquired heart disease in developed countries, is a self-limited vasculitis that is treated with high doses of intravenous immunoglobulin. Resistance to intravenous immunoglobulin in Kawasaki disease increases the risk of coronary artery aneurysms. We assessed whether the addition of infliximab to standard therapy (intravenous immunoglobulin and aspirin) in acute Kawasaki disease reduces the rate of treatment resistance.

METHODS

We undertook a phase 3, randomised, double-blind, placebo-controlled trial in two children's hospitals in the USA to assess the addition of infliximab (5 mg per kg) to standard therapy. Eligible participants were children aged 4 weeks-17 years who had a fever (temperature ≥38·0°C) for 3-10 days and met American Heart Association criteria for Kawasaki disease. Participants were randomly allocated in 1:1 ratio to two treatment groups: infliximab 5 mg/kg at 1 mg/mL intravenously over 2 h or placebo (normal saline 5 mL/kg, administered intravenously). Randomisation was based on a randomly permuted block design (block sizes 2 and 4), stratified by age, sex, and centre. Patients, treating physicians and staff, study team members, and echocardiographers were all masked to treament assignment. The primary outcome was the difference between the groups in treatment resistance defined as a temperature of 38·0°C or higher at 36 h to 7 days after completion of the infusion of intravenous immunoglobulin. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, NCT00760435.

FINDINGS

196 patients were enrolled and randomised: 98 to the infliximab group and 98 to placebo. One patient in the placebo group was withdrawn from the study because of hypotension before receiving treatment. Treatment resistance rate did not differ significantly (11 [11·2%] for infliximab and 11 [11·3%] for placebo; p=0·81). Compared with the placebo group, participants given infliximab had fewer days of fever (median 1 day for infliximab vs 2 days for placebo; p<0·0001). At week 2, infliximab-treated patients had greater mean reductions in erythrocyte sedimentation rate (p=0·009) and a two-fold greater decrease in Z score of the left anterior descending artery (p=0·045) than did those in the placebo group, but this difference was not significant at week 5. Participants in the infliximab group had a greater mean reduction in C-reactive protein concentration (p=0·0003) and in absolute neutrophil count (p=0·024) at 24 h after treatment than did those given placebo, but by week 2 this difference was not significant. At week 5, none of the laboratory values differed significantly compared with baseline. No significant differences were recorded between the two groups at any timepoint in proximal right coronary artery Z scores, age-adjusted haemoglobin values, duration of hospital stay, or any other laboratory markers of inflammation measured. No reactions to intravenous immunoglobulin infusion occurred in patients treated with infliximab compared with 13 (13·4%) patients given placebo (p<0·0001). No serious adverse events were directly attributable to infliximab infusion.

INTERPRETATION

The addition of infliximab to primary treatment in acute Kawasaki disease did not reduce treatment resistance. However, it was safe and well tolerated and reduced fever duration, some markers of inflammation, left anterior descending coronary artery Z score, and intravenous immunoglobulin reaction rates.

FUNDING

US Food and Drug Administration, Robert Wood Johnson Foundation, and Janssen Biotech.

[Origin and importance of the Latin American Kawasaki Disease Network (REKAMLATINA)]

Kawasaki disease is the leading cause of acquired cardiac disease in children. Although the epidemiology of the disease has been well described in Japan, other Asian countries, Europe, Australia and North America, the epidemiology and disease burden in Latin American children is unknown. For this reason, the idea of establishing a research network on Kawasaki disease in children from Latin America was born, becoming this the largest Kawasaki disease international multinational research network and in which 20 countries of the region will be integrated.

Specificity of regulatory T cells that modulate vascular inflammation

Intravenous immunoglobulin therapy (IVIG) is the treatment of choice for many immune-mediated diseases, yet its mechanisms of action are incompletely elucidated. We investigated the possibility that IVIG played a direct role in the expansion of regulatory T cells (Treg) that recognize the heavy chain constant region of immunoglobulin G (Fc) as a mechanism for the recovery of Kawasaki disease (KD), a T cell mediated pediatric vasculitis of the coronary arteries. We successfully generated Fc-specific Treg clones from sub-acute KD subjects that did not develop arterial complications after IVIG and defined an unusual functional phenotype: Fc-specific Treg secrete IL-10 and small amounts of IL-4 but not TGF-β. Antigen presentation studies demonstrated that these Treg clones can be activated by autologous B cells that express IgG on their cell surface in the absence of exogenous Fc. The IgG molecule has to be canonically processed and presented by autologous MHC molecules to be recognized by Treg. In support of the importance of this novel Treg population in downsizing vascular inflammation, KD patients with dilated coronary arteries or aneurysms despite IVIG treatment failed to expand Fc-specific Treg. Our results point to a specificity of a previously un-described Treg population for the clinical benefit provided by IVIG therapy in children.

Immune-monitoring in Kawasaki disease patients treated with infliximab and intravenous immunoglobulin

The expansion of regulatory T cells (Treg ) controls inflammation in children with acute Kawasaki disease (KD). Blockade of tumour necrosis factor (TNF)-α is an emerging therapy for KD patients with refractory inflammation, but there is concern that this therapy could impede the host immune regulation. To define the effect of TNF-α blockade, we conducted ex-vivo immune-monitoring in KD subjects who participated in a randomized, double-blind, placebo-controlled clinical trial of the addition of infliximab to standard intravenous immunoglobulin (IVIG) therapy. We enumerated circulating myeloid and plasmocytoid dendritic cells (DC), regulatory T cells (Treg ) and memory T cells (Tmem ) in 14 consecutive, unselected KD patients (seven treated with IVIG, seven with IVIG + infliximab) at three time-points: (i) acute phase prior to treatment, (ii) subacute phase and (iii) convalescent phase. Myeloid DC (mDC), but not plasmacytoid DC (pDC), were numerous in the peripheral blood in acute KD subjects and decreased in the subacute phase in both IVIG(-) and IVIG (+)  infliximab-treated groups. The co-stimulatory molecule for antigen presentation to T cells and CD86 decreased in mDC from acute to subacute time-points in both treatment groups, but not in the single patient who developed coronary artery aneurysms. We also defined tolerogenic mDC that expand in the subacute phase of KD not impaired by infliximab treatment. Treg and Tmem expanded after treatment with no significant differences between the two groups. Treatment of KD patients with infliximab does not adversely affect generation of tolerogenic mDC or the development of T cell regulation and memory.

Treatment response in Kawasaki disease is associated with sialylation levels of endogenous but not therapeutic intravenous immunoglobulin G

Objectives

Although intravenous immunoglobulin (IVIG) is highly effective in Kawasaki disease (KD), mechanisms are not understood and 10-20% of patients are treatment-resistant, manifesting a higher rate of coronary artery aneurysms. Murine models suggest that α2-6-linked sialic acid (α2-6Sia) content of IVIG is critical for suppressing inflammation. However, pro-inflammatory states also up-regulate endogenous levels of β-galactoside:α2-6 sialyltransferase-I (ST6Gal-I), the enzyme that catalyzes addition of α2-6Sias to N-glycans. We asked whether IVIG failures correlated with levels of α2-6Sia on infused IVIG or on the patient’s own endogenous IgG.

Methods

We quantified levels of α2-6Sia in infused IVIG and endogenous IgG from 10 IVIG-responsive and 10 resistant KD subjects using multiple approaches. Transcript levels of ST6GAL1, in patient whole blood and B cell lines were evaluated by RT-PCR. Plasma soluble (s)ST6Gal-I levels were measured by ELISA.

Results

There was no consistent difference in median sialylation levels of infused IVIG between groups. However, α2-6Sia levels in endogenous IgG, ST6GAL1 transcript levels, and ST6Gal-I protein in serum from IVIG-resistant KD subjects were lower than in responsive subjects at both pre-treatment and one-year time points (p <0.001, respectively).

Conclusions

Our data indicate sialylation levels of therapeutic IVIG are unrelated to treatment response in KD. Rather, lower sialylation of endogenous IgG and lower blood levels of ST6GALI mRNA and ST6Gal-I enzyme predict therapy resistance. These differences were stable over time, suggesting a genetic basis. Because IVIG-resistance increases risk of coronary artery aneurysms, our findings have important implications for the identification and treatment of such individuals.

Seasonality of Kawasaki disease: a global perspective

Background

Understanding global seasonal patterns of Kawasaki disease (KD) may provide insight into the etiology of this vasculitis that is now the most common cause of acquired heart disease in children in developed countries worldwide.

Methods

Data from 1970-2012 from 25 countries distributed over the globe were analyzed for seasonality. The number of KD cases from each location was normalized to minimize the influence of greater numbers from certain locations. The presence of seasonal variation of KD at the individual locations was evaluated using three different tests: time series modeling, spectral analysis, and a Monte Carlo technique.

Results

A defined seasonal structure emerged demonstrating broad coherence in fluctuations in KD cases across the Northern Hemisphere extra-tropical latitudes. In the extra-tropical latitudes of the Northern Hemisphere, KD case numbers were highest in January through March and approximately 40% higher than in the months of lowest case numbers from August through October. Datasets were much sparser in the tropics and the Southern Hemisphere extra-tropics and statistical significance of the seasonality tests was weak, but suggested a maximum in May through June, with approximately 30% higher number of cases than in the least active months of February, March and October. The seasonal pattern in the Northern Hemisphere extra-tropics was consistent across the first and second halves of the sample period.

Conclusion

Using the first global KD time series, analysis of sites located in the Northern Hemisphere extra-tropics revealed statistically significant and consistent seasonal fluctuations in KD case numbers with high numbers in winter and low numbers in late summer and fall. Neither the tropics nor the Southern Hemisphere extra-tropics registered a statistically significant aggregate seasonal cycle. These data suggest a seasonal exposure to a KD agent that operates over large geographic regions and is concentrated during winter months in the Northern Hemisphere extra-tropics.

Coronary artery outcomes among children with Kawasaki disease in the United States and Japan

OBJECTIVE

It has been claimed that the aneurysm rate for Kawasaki disease (KD) patients in Japan is lower than in the U.S. However it has been difficult to compare coronary artery (CA) outcomes between the two countries because of different definitions for CA abnormalities. Therefore, we compared CA internal diameters between Japanese and U.S. KD patients using standard definitions and methods.

STUDY DESIGN

We retrospectively reviewed CA outcomes in 1082 KD patients from 2 centers in the U.S. and 3 centers in Japan and compared Z-max scores (maximum internal diameter for the left anterior descending or right coronary artery expressed as standard deviation units from the mean (Z-score) normalized for body surface area) obtained within 12 weeks after onset and calculated using two different regression equations from Canada (Dallaire) and Japan (Fuse). We defined a Z-max of < 2.5 as normal and a Z-max of ≥ 10 as giant aneurysm.

RESULT

The median Z-max for the U.S. and Japanese subjects was 1.9 and 2.3 SD units, respectively (p < 0.001). There was no significant difference in rates of patients with Z-max ≥ 5.0 between the countries. In a multivariable model adjusting for age, sex, and treatment response, being Japanese was still associated with a higher Z-max score.

CONCLUSION

Previously reported differences in aneurysm rates between Japan and the U.S. likely resulted from use of different definitions and nomenclature. Adoption of Z-scores as a standard for reporting CA internal diameters will allow meaningful comparisons among different countries and will facilitate international, collaborative clinical trials.

Lymph-node-first presentation of Kawasaki disease compared with bacterial cervical adenitis and typical Kawasaki disease

OBJECTIVE

To identify characteristics differentiating the node-first presentation of Kawasaki disease (NFKD) from bacterial cervical lymphadenitis (BCL) and typical Kawasaki disease (KD).

STUDY DESIGN

From our prospectively collected database, we compared clinical, laboratory, and imaging characteristics of NFKD and BCL cohorts and performed multivariable logistic regression to identify variables that distinguish NFKD from BCL. We then compared outcomes of patients with NFKD and patients with typical KD treated during the same period.

RESULTS

Over 7 years, 57 patients were hospitalized for NFKD, 78 for BCL, and 287 for typical KD. Patients with NFKD were older and had more medical encounters and longer duration of illness before the correct diagnosis was made than did patients with BCL. Of patients with NFKD, 33% had an admission diagnosis of bacterial adenitis or abscess. Compared with patients with BCL, patients with NFKD had lower leukocyte (white blood cell), hemoglobin, and platelet counts and higher absolute band counts (ABCs), C-reactive protein (CRP), alanine transaminase and γ-glutamyl transpeptidase levels, and erythrocyte sedimentation rates. In the multivariable analysis, smaller nodes, lower white blood cell count, and higher ABC and CRP were independently associated with NFKD. Patients with NFKD had multiple enlarged solid nodes and comparable rates of retropharyngeal edema. Compared with patients with typical KD, patients with NFKD were older, had more severe inflammation, and had similar rates of coronary artery abnormalities and resistance to intravenous immune globulin.

CONCLUSIONS

High ABC and CRP values and multiple enlarged solid nodes in febrile patients with cervical adenopathy should prompt consideration of NFKD to prevent delayed diagnosis of KD. Retropharyngeal edema on radiography should not dissuade from the diagnosis of NFKD.

Developmental pharmacokinetic changes of Lamivudine in infants and children

Lamivudine is a nucleoside reverse transcriptase inhibitor widely used in infants and children in combination antiretroviral therapy to treat human immunodeficiency virus (HIV) infection. Developmental changes in lamivudine pharmacokinetic disposition were assessed by combining data from 7 studies of lamivudine (Pediatric AIDS Clinical Trials Group 300, 353, 356, 358, 386, 1056, and 1069) representing subjects across the pediatric age continuum. A population pharmacokinetic model was developed to identify factors that influence lamivudine disposition. Age and Thai race were independent predictors of apparent clearance (CL/F), whereas the use of a fixed drug combination formulation (GPO-VIR) was an independent predictor of bioavailability, with CL/F more than doubling from birth to adolescence. Serum creatinine was not associated with CL/F. Monte Carlo simulations were used to compare the lamivudine exposure achieved with World Health Organization (WHO) weight band and Food and Drug Administration (FDA) label dosing recommendations. WHO dosing yielded higher exposure during the first few months of life, but this difference was less pronounced between 6 months and 14 years of age. Overall, both FDA and WHO dosing provided similar AUC values to those previously reported in HIV-infected adults. Lamivudine WHO weight band dosing results in therapeutic exposure in infants and children and may improve drug dosing in resource-limited countries.

Calcineurin inhibitor treatment of intravenous immunoglobulin-resistant Kawasaki disease

OBJECTIVE

To describe the clinical course and outcome of 10 patients with Kawasaki disease (KD) treated with a calcineurin inhibitor after failing to respond to multiple therapies.

STUDY DESIGN

Demographic and clinical data were prospectively collected using standardized case report forms. T-cell phenotypes were determined by flow cytometry, and KD risk alleles in ITPKC (rs28493229), CASP3 (rs72689236), and FCGR2A (rs1801274) were genotyped.

RESULTS

Intravenous followed by oral therapy with cyclosporine (CSA) or oral tacrolimus was well tolerated and resulted in defervescence and resolution of inflammation in all 10 patients. There were no serious adverse events, and a standardized treatment protocol was developed based on our experiences with this patient population. Analysis of T-cell phenotype by flow cytometry in 2 subjects showed a decrease in circulating activated CD8(+) and CD4(+) T effector memory cells after treatment with CSA. However, suppression of regulatory T-cells was not seen, suggesting targeting of specific, proinflammatory T-cell compartments by CSA.

CONCLUSION

Treatment of refractory KD with a calcineurin inhibitor appears to be a safe and effective approach that achieves rapid control of inflammation associated with clinical improvement.

Prolonged urticaria and fever in a toddler

We describe a 14-month-old girl who initially presented with 8 days of fever, conjunctival injection, rash, and irritability, admitted with a presumptive diagnosis of Kawasaki disease. Further history revealed intermittent urticarial-like rash since 3 months of age and pathological evaluation showed a perivascular infiltrate of neutrophils and lymphocytes. Here, we discuss the key points surrounding her diagnostic workup and our therapeutic approach.

Cardiovascular biomarkers in acute Kawasaki disease

BACKGROUND

Endomycocardial biopsies have demonstrated that subclinical myocarditis is a universal feature of acute Kawasaki disease (KD).

METHODS

We investigated biochemical evidence of myocardial strain, oxidative stress, and cardiomyocyte injury in 55 acute KD subjects (30 with paired convalescent samples), 54 febrile control (FC), and 50 healthy control (HC) children by measuring concentrations of cardiovascular biomarkers.

RESULTS

Levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and soluble ST2 (sST2) were elevated in acute vs. convalescent KD, FC, and HC (p≤0.002), while γ-glutamyl transferase and alanine amino transferase as measures of oxidative stress were increased in acute vs. FC (p≤0.0002). Cardiac troponin I (cTnI) levels, using a highly sensitive assay, were elevated in 30% and 40% of paired acute and convalescent KD subjects, respectively, and normalized within two years of disease onset. NT-proBNP and sST2 negatively correlated with deceleration time, but only NT-proBNP correlated with MV E:A ratio and internal diameter of the coronary arteries (RCA/LAD Zworst).

CONCLUSIONS

NT-proBNP and sST2 were elevated in acute KD subjects and correlated with impaired myocardial relaxation. These findings, combined with elevated levels of cTnI, suggest that both cardiomyocyte stress and cell death are associated with myocardial inflammation in acute KD.

Recurrent fever syndromes in patients after recovery from Kawasaki syndrome

The recurrence of fever in a child with a history of Kawasaki syndrome (KS) poses a dilemma for clinicians who must consider the possibility of recurrent KS. In this report we present the cases of 4 patients who presented with classical symptoms of KS, were successfully treated with intravenous immunoglobulin, and later experienced a reappearance of inflammatory symptoms in a pattern consistent with a recurrent fever syndrome. The association of these syndromes within the same patient suggests that some patients may have a genetic propensity toward altered immune responses and autoinflammatory syndromes. We propose that these 2 syndromes exist within a family of febrile disorders related to innate immune dysregulation.

Transforming growth factor-beta signaling pathway in patients with Kawasaki disease

BACKGROUND

Transforming growth factor (TGF)-β is a multifunctional peptide that is important in T-cell activation and cardiovascular remodeling, both of which are important features of Kawasaki disease (KD). We postulated that variation in TGF-β signaling might be important in KD susceptibility and disease outcome.

METHODS AND RESULTS

We investigated genetic variation in 15 genes belonging to the TGF-β pathway in a total of 771 KD subjects of mainly European descent from the United States, the United Kingdom, Australia, and the Netherlands. We analyzed transcript abundance patterns using microarray and reverse transcriptase-polymerase chain reaction for these same genes, and measured TGF-β2 protein levels in plasma. Genetic variants in TGFB2, TGFBR2, and SMAD3 and their haplotypes were consistently and reproducibly associated with KD susceptibility, coronary artery aneurysm formation, aortic root dilatation, and intravenous immunoglobulin treatment response in different cohorts. A SMAD3 haplotype associated with KD susceptibility replicated in 2 independent cohorts and an intronic single nucleotide polymorphism in a separate haplotype block was also strongly associated (A/G, rs4776338) (P=0.000022; odds ratio, 1.50; 95% confidence interval, 1.25 to 1.81). Pathway analysis using all 15 genes further confirmed the importance of the TGF-β pathway in KD pathogenesis. Whole-blood transcript abundance for these genes and TGF-β2 plasma protein levels changed dynamically over the course of the illness.

CONCLUSIONS

These studies suggest that genetic variation in the TGF-β pathway influences KD susceptibility, disease outcome, and response to therapy, and that aortic root and coronary artery Z scores can be used for phenotype/genotype analyses. Analysis of transcript abundance and protein levels further support the importance of this pathway in KD pathogenesis.

Memory T-cells and characterization of peripheral T-cell clones in acute Kawasaki disease

Kawasaki disease (KD) is a pediatric self-limited vasculitis characterized by immune-mediated destruction of the arterial wall and myocardium. Neither the trigger that incites the inflammation nor the switch that turns it off is known. To further our understanding of KD pathogenesis and the role of regulatory T-cells in modulating the inflammatory response, we studied circulating effector memory T-cells (CCR7- and IL-15+ T(em)) and central memory T-cells (CCR7+ and IL-15+ T(cm)) in six KD subjects. In two of the subjects, we cloned the remaining T-cell population by limiting dilution. TaqMan analysis of T(em) studied in two KD subjects suggested that T(em) are pro-inflammatory CD4+T-helper 1 cells and CD8+ cytotoxic T-cells. Following memory T-cells over time, we defined that circulating T(em) and T(cm) are detectable during the acute phase in some KD subjects before treatment with intravenous immunoglobulin. Both T(em) and T(cm) expand rapidly within 2 weeks of treatment. The circulating T(em) pool contracts, while T(cm) further proliferate in the convalescent phase. Following depletion of memory T-cells, numerous T-cell clones were derived from two acute KD subjects. The large majority of these T-cells displayed the functional phenotype of peripherally induced regulatory T-cells (T(reg)). These findings provide insight into the nature and kinetics of the adaptive immune response in KD.

Transcript abundance patterns in Kawasaki disease patients with intravenous immunoglobulin resistance

Intravenous immunoglobulin (IVIG)-resistant Kawasaki disease (KD) patients comprise at least 20% of treated patients and are at high risk for coronary artery abnormalities. If identified early in the course of the disease, such patients may benefit from additional anti-inflammatory therapy. The aim of this study was to compare the transcript abundance between IVIG resistant and -responsive KD patients, to identify biomarkers that might differentiate between these two groups and to generate new targets for therapies in IVIG resistant KD patients. We compared the transcript abundance profiles of whole-blood RNA on Agilent arrays from acute and convalescent KD subjects and age-similar, healthy controls. KD subjects were stratified as IVIG resistant or -responsive based on response to initial IVIG therapy. Transcript abundance was higher for IL-1 pathway genes (IL-1 receptor, interleukin receptor associated kinase, p38 mitogen-activated protein kinase), and MMP-8. These findings point to candidate biomarkers that may predict IVIG resistance in acute KD patients. The results also underscore the importance of the IL-1 pathway as a mediator of inflammation in KD and suggest that IL-1 or its receptor may be reasonable targets for therapy, particularly for IVIG resistant patients.

Recognition of a Kawasaki disease shock syndrome

OBJECTIVE

We sought to define the characteristics that distinguish Kawasaki disease shock syndrome from hemodynamically normal Kawasaki disease.

METHODS

We collected data prospectively for all patients with Kawasaki disease who were treated at a single institution during a 4-year period. We defined Kawasaki disease shock syndrome on the basis of systolic hypotension for age, a sustained decrease in systolic blood pressure from baseline of > or =20%, or clinical signs of poor perfusion. We compared clinical and laboratory features, coronary artery measurements, and responses to therapy and analyzed indices of ventricular systolic and diastolic function during acute and convalescent Kawasaki disease.

RESULTS

Of 187 consecutive patients with Kawasaki disease, 13 (7%) met the definition for Kawasaki disease shock syndrome. All received fluid resuscitation, and 7 (54%) required vasoactive infusions. Compared with patients without shock, patients with Kawasaki disease shock syndrome were more often female and had larger proportions of bands, higher C-reactive protein concentrations, and lower hemoglobin concentrations and platelet counts. Evidence of consumptive coagulopathy was common in the Kawasaki disease shock syndrome group. Patients with Kawasaki disease shock syndrome more often had impaired left ventricular systolic function (ejection fraction of <54%: 4 of 13 patients [31%] vs 2 of 86 patients [4%]), mitral regurgitation (5 of 13 patients [39%] vs 2 of 83 patients [2%]), coronary artery abnormalities (8 of 13 patients [62%] vs 20 of 86 patients [23%]), and intravenous immunoglobulin resistance (6 of 13 patients [46%] vs 32 of 174 patients [18%]). Impairment of ventricular relaxation and compliance persisted among patients with Kawasaki disease shock syndrome after the resolution of other hemodynamic disturbances.

CONCLUSIONS

Kawasaki disease shock syndrome is associated with more-severe laboratory markers of inflammation and greater risk of coronary artery abnormalities, mitral regurgitation, and prolonged myocardial dysfunction. These patients may be resistant to immunoglobulin therapy and require additional antiinflammatory treatment.

Resistance to intravenous immunoglobulin in children with Kawasaki disease

OBJECTIVES

To explore the increased incidence of intravenous immunoglobulin- (IVIG) resistance among San Diego County patients with Kawasaki disease (KD) in 2006 and to evaluate a scoring system to predict IVIG-resistant patients with KD.

STUDY DESIGN

We performed a retrospective review of patients with KD treated within 10 days of fever onset. With multivariate analysis, independent predictors of IVIG-resistance were combined into a scoring system.

RESULTS

In 2006, 38.3% of patients with KD in San Diego County were IVIG-resistant, a significant increase over previous years. IVIG-resistance was not associated with a particular brand or lot of IVIG. Resistant patients were diagnosed earlier, had higher percent bands, and higher concentrations of C-reactive protein, alanine aminotransferase, and gamma-glutamyl transferase. They also had lower platelet counts and age-adjusted hemoglobin concentrations and were more likely to have aneurysms (P = .0008). A scoring system developed to predict IVIG-resistant patients using illness day, percent bands, gamma-glutamyl transferase, and age-adjusted hemoglobin had a sensitivity of 73.3% and specificity of 61.9%.

CONCLUSIONS

An unexplained increase in IVIG-resistance was noted among patients with KD in San Diego County in 2006. Scoring systems based on demographic and laboratory data were insufficiently accurate to be clinically useful in our ethnically diverse population.

Population pharmacokinetics of lamivudine in human immunodeficiency virus-exposed and -infected infants

This study aimed to determine lamivudine disposition in infants and to construct an appropriate dose adjustment for age, given the widespread use of lamivudine for both the prevention of mother-to-child transmission of human immunodeficiency virus (HIV) and the treatment of HIV-infected infants. Using a pooled-population approach, the pharmacokinetics of lamivudine in HIV-exposed or -infected infants from four Pediatric AIDS Clinical Trials Group studies were assessed. Ninety-nine infants provided 559 plasma samples for measurement of lamivudine concentrations. All infants received combination antiretroviral therapy including lamivudine dosed at 2 mg/kg of body weight every 12 h (q12h) for the first 4 to 6 weeks of life and at 4 mg/kg q12h thereafter. Lamivudine's apparent clearance was 0.25 liter/h/kg at birth, doubling by 28 days. In the final model, age and weight were the only significant covariates for lamivudine clearance. While lamivudine is predominantly renally eliminated, the serum creatinine level was not an independent covariate in the final model, possibly because it was confounded by age. Inclusion of interoccasion variability for bioavailability improved the individual subject clearance prediction over the age range studies. Simulations based on the final model predicted that by the age of 4 weeks, 90% of infant lamivudine concentrations with the standard 2 mg/kg dose of lamivudine fell below the adult median concentration. This population pharmacokinetic analysis affirms that adjusting the dose of lamivudine from 2 mg/kg to 4 mg/kg q12 h at the age of 4 weeks for infants with normal maturation of renal function will provide optimal lamivudine exposure, potentially contributing to more successful therapy.

Novel therapies for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease that causes significant morbidity and mortality. The pathogenesis outlined to date in RA consists of a cascade of pro-inflammatory cytokines and chemokines leading to the recruitment of inflammatory cells and the self perpetuation of inflammation, ultimately leading to cartilage and bone destruction. The dramatic progress in understanding the molecular immunology in RA has led to a transition from conventional treatment with aggressive immune suppression to targeted biological-based therapies that control the inflammatory pathways associated with RA. This article reviews the current biological and small-molecule therapies approved for the treatment of RA and those in development, including antibodies, tolerising agents and vaccines.

Albendazole therapy for Microsporidium diarrhea in immunocompetent Costa Rican children

BACKGROUND

Microsporidia comprise a large group of obligate intracellular parasites. Although several species have emerged as opportunistic agents in immunocompromised patients, cases have also been reported in immunocompetent patients.

METHODS

During 21 months, we conducted a randomized, open label study in 200 children hospitalized with Microsporidium subacute diarrhea. Patients had prolonged, nonbloody, nonmucoid diarrhea, with > or =10 bowel movements/day for >10 days. Patients had negative rotavirus tests, bacterial stool cultures and sugar reductive tests in feces. Stool examinations to rule out Giardia intestinalis and intestinal nematodes were performed. Microsporidium was identified by light microscopy in stool specimens stained with Giemsa and Weber techniques. One hundred patients received oral albendazole (15 mg/kg/day twice a day for 7 days) and 100 patients received only supportive therapy.

RESULTS

Both groups were comparable regarding gender, age, clinical evolution and weight. Median (range) age was 24 (6-36) months. All children had abdominal pain, nausea, vomiting and anorexia. The primary endpoint, defined as clinical improvement within 48 h of initial therapy, occurred in 95 and 30% of the albendazole-treated and untreated patients, respectively (P < 0.05). There was a significant decrease in stool frequency, reduction of clinical findings and decrease in Microsporidium parasites in stool specimens of children treated with albendazole compared with the untreated group. Median (range) duration of diarrhea was 5 (3-7) days in albendazole-treated patients versus 10 (8-15) days in untreated patients (P < 0.05).

CONCLUSION

Albendazole therapy was effective in improving the clinical manifestations and decreasing the duration of the illness of children with diarrhea caused by Microsporidium.