Cardiovascular biomarkers in acute Kawasaki disease

Expansion of a Novel Subset of L-Selectin+ Classical Monocytes in Kawasaki Disease

Purpose

Kawasaki disease (KD) is an acute systemic vasculitis that is associated with dysregulated immune responses. Monocytes play a central role in innate immunity. Our previous single-cell RNA sequencing of peripheral blood mononuclear cells (PBMC) revealed a new subset of monocytes in children with KD called L-Selectin+ classical monocytes (SELL+ CM). Therefore, we aimed to investigate the correlation between KD and SELL+ CM.

Patients and Methods

Peripheral blood samples were collected from 81 KD patients, 18 febrile patients and 36 healthy children before treatment. Among them, ten KD patients were followed up, and samples were obtained before and after intravenous immunoglobulin (IVIG) treatment. Analysis of SELL+ CM was performed using flow cytometry. Additionally, ROC curve analysis was conducted to assess the diagnostic value of SELL+ CM for KD.

Results

Classical monocytes (CM) expressed the highest levels of L-selectin in children with KD. The ratio of SELL+ CM in CM was significantly higher in KD patients than in febrile and healthy children. Following IVIG treatment, the ratio of SELL+ CM in CM showed a downward trend. The receiver operating characteristic (ROC) curve analysis (the area under the curve, AUC = 0.71) indicated the potential diagnostic value of SELL+ CM in KD. The correlation analysis suggested that SELL+ CM may serve as a new clinical index for patients with KD.

Conclusion

In KD, the ratio of SELL+ CM in CM significantly increases during the acute phase, which may become a potential biomarker and help facilitate KD diagnosis based on clinical features.

Markers of Endothelial Dysfunction in Kawasaki Disease: An Update

Kawasaki disease (KD) is a medium vessel vasculitis that has a special predilection for coronary arteries. Cardiovascular complications include the development of coronary artery abnormalities (CAAs) and myocarditis. Endothelial dysfunction (ED) is now recognized to be a key component in the pathogenesis of KD and is believed to contribute to the development of CAAs. ED has been evaluated by several clinical parameters. However, there is paucity of literature on laboratory markers for ED in KD. The evaluation of ED can be aided by the identification of biomarkers such as oxidative stress markers, circulating cells and their progenitors, angiogenesis factors, cytokines, chemokines, cell-adhesion molecules, and adipokines. If validated in multicentric studies, these biomarkers may be useful for monitoring the disease course of KD. They may also provide a useful predictive marker for the development of premature atherosclerosis that is often a concern during long-term follow-up of KD. This review provides insights into the current understanding of the significance of ED in KD.

Kawasaki Disease-Associated Cytokine Storm Syndrome

Kawasaki disease (KD) is a hyperinflammatory syndrome manifesting as an acute systemic vasculitis characterized by fever, nonsuppurative conjunctival injection, rash, oral mucositis, extremity changes, and cervical lymphadenopathy. KD predominantly affects young children and shares clinical features and immunobiology with other hyperinflammation syndromes including systemic juvenile idiopathic arthritis (sJIA) and multisystem inflammatory syndrome in children (MIS-C). Cytokine storm syndrome (CSS) is an acute complication in ~2% of KD patients; however, the incidence is likely underestimated as many clinical and laboratory features of both diseases overlap. CSS should be entertained when a child with KD is unresponsive to IVIG therapy with recalcitrant fever. Early recognition and prompt institution of immunomodulatory treatment can substantially reduce the mortality and morbidity of CSS in KD. Given the known pathogenetic role of IL-1β in both syndromes, the early use of IL-1 blockers in refractory KD with CSS deserves consideration.

The effect of full blood count and cardiac biomarkers on prognosis in carbon monoxide poisoning in children

AIMS

In this study, cardiac biomarkers, blood parameters, electrocardiography (ECG), and echocardiography were investigated in children with carbon monoxide (CO) poisoning, and the diagnostic value of these parameters was investigated.

METHODS

The demographical, clinical, and laboratory data of children aged 0-18 years who were admitted to the pediatric emergency department due to CO poisoning between January 2019 and January 2022 were retrospectively scanned from medical records. The patients were divided into two groups as troponin-I positive and troponin-I negative.

RESULTS

There were 107 children aged 0-18 years (average age, 10.46 ± 5.77 years; 51% female) with CO poisoning. There were 13 patients with troponin-I positive myocardial injury. Troponin-I was positive in 3 patients whose carboxyhemoglobin (COHb) level was below 2% at the time of admission. In one patient, troponin-I, which was normal at admission, increased by the 24th hour of hospitalization. Hyperbaric oxygen therapy was given due to headache in one patient, although the COHb level of that patient was below 25%. An NT-proBNP level of ≥ 219.5 ng/L predicted the development of troponin-I positivity with a sensitivity of 70% and a specificity of 86.7% (AUC, 0.967 (0.58-0.994); p = 0.017). White blood cell (WBC), neutrophil, neutrophil-to-lymphocyte ratio (NLR), immature granulocyte (IG), and IG% levels were found to be significantly higher in the troponin-positive patient group. DISCUSSION AND CONCLUSION: NT-proBNP has been shown to be an early diagnostic marker for myocardial dysfunction. Additionally, when cardiac markers are not available, full blood parameters may assist clinicians for patient treatment and referral.

Transient anti-cytokine autoantibodies superimpose the hyperinflammatory response in Kawasaki disease and multisystem inflammatory syndrome in children: a comparative cohort study on correlates of disease

BACKGROUND

Children with SARS-CoV-2 related Multisystem Inflammatory Syndrome in Children (MIS-C) often present with clinical features that resemble Kawasaki disease (KD). Disease severity in adult COVID-19 is associated to the presence of anti-cytokine autoantibodies (ACAAs) against type I interferons. Similarly, ACAAs may be implicated in KD and MIS-C. Therefore, we explored the immunological response, presence of ACAAs and disease correlates in both disorders.

METHODS

Eighteen inflammatory plasma protein levels and seven ACAAs were measured in KD (n = 216) and MIS-C (n = 56) longitudinally by Luminex and/or ELISA. Levels (up to 1 year post-onset) of these proteins were related to clinical data and compared with healthy paediatric controls.

FINDINGS

ACAAs were found in both patient groups. The presence of ACAAs lagged behind the inflammatory plasma proteins and peaked in the subacute phase. ACAAs were mostly directed against IFN-γ (>80%) and were partially neutralising at best. KD presented with a higher variety of ACAAs than MIS-C. Increased levels of anti-IL-17A (P = 0·02) and anti-IL-22 (P = 0·01) were inversely associated with ICU admission in MIS-C. Except for CXCL10 in MIS-C (P = 0·002), inflammatory plasma proteins were elevated in both KD and MIS-C. Endothelial angiopoietin-2 levels were associated with coronary artery aneurysms in KD (P = 0·02); and sCD25 (P = 0·009), angiopoietin-2 (P = 0·001), soluble IL-33-receptor (ST2, P = 0·01) and CXCL10 (P = 0·02) with ICU admission in MIS-C.

INTERPRETATION

Markers of endothelial activation (E-selectin, angiopoietin-2), and innate and adaptive immune responses (macrophages [CD163, G-CSF], neutrophils [lipocalin-2], and T cells [IFN-γ, CXCL10, IL-6, IL-17]), are upregulated in KD and MIS-C. ACAAs were detected in both diseases and, although only partly neutralising, their transient presence and increased levels in non-ICU patients may suggest a dampening role on inflammation.

FUNDING

The Kawasaki study is funded by the Dutch foundation Fonds Kind & Handicap and an anonymous donor. The sponsors had no role in the study design, analysis, or decision for publication.

Interleukin-33/ST2 Axis as Potential Biomarker and Therapeutic Target in Kawasaki Disease

Kawasaki disease (KD) is an acute, self-limiting, febrile systemic vasculitis of unknown cause associated with the development of coronary artery lesions (CALs) during childhood. Damage-associated molecular patterns (DAMPs) from cell death and oxidative stress have been shown to be involved in the development of KD vasculitis. Interleukin (IL)-33 is released from damaged endothelial cells and acts as a DAMP. We studied whether IL-33 and its receptor (ST2) might be involved in KD pathogenesis. Serum levels of soluble ST2 (sST2) in KD patients were measured before their first therapy. Furthermore, we investigated the impact of IL-33 on human coronary artery endothelial cells (HCAECs). Serum levels of sST2 were significantly higher in KD patients with CALs than in those with normal coronary arteries. In vitro, IL-33 upregulated the expression of ST2L and increased production of sST2, IL-6, IL-8, and monocyte chemoattractant protein-1 in HCAECs in a time- and concentration-dependent manner. Moreover, IL-33 induced significantly greater production of IL-6 and IL-8 in HCAECs compared to the condition stimulated with isoconcentration of tumor necrosis factor-α. The results of the present study suggest that the IL-33/ST2 axis might be involved in the development of KD vasculitis. The IL-33/ST2 axis may be a therapeutic target for the treatment of KD.

Clinical Manifestations and Laboratory Findings of Kawasaki Disease: Beyond the Classic Diagnostic Features

Kawasaki disease (KD) has shown a marked increase in trend over the globe, especially within the last two decades. Kawasaki disease is often seen in the paediatric population below five years old, while it is rare for those who are beyond that age. Up to this date, no exact causes has been identified although KD was found more than half a century ago. The underlying pathogenesis of the disease is still unelucidated, and researchers are trying to unlock the mystery of KD. To further complicate the diagnosis and the prompt management, a specific biomarker for the diagnosis of KD is yet to be discovered, making it hard to differentiate between KD and other diseases with a similar presentation. Nonetheless, since its discovery, clinicians and scientists alike had known more about the different clinical aspects of typical KD. Thus, this article intends to revisit and review the various clinical manifestations and laboratory characteristics of KD in order to guide the diagnosis of KD.

Multisystem Inflammatory Syndrome of a Neonate From a COVID-19-Infected Mother: A Case Report

In neonates, the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 - COVID-19) is lower. There is the potential for vertical transmission of SARS-CoV-2. To date, only a few reports suggest this possibility. Neonates usually have mild symptoms, but some develop multisystem involvement, which is a concern. COVID-19 infections have been reported both in pregnant women and their neonates. However, the evidence of vertical or horizontal transmission modes has not been fully established. We recorded a case study where a 33-year-old mother was tested positive for COVID-19 infection by RT-PCR during her 27^th week of gestation and needed ventilator support for her respiratory distress at that time for 11 days. Subsequently, she gave birth to a female baby at the 35^th week via a lower uterine segment cesarean section. The neonate manifested a severe multisystem inflammatory syndrome associated with her possible COVID-19 infection. Sharing her uncommon clinical presentation, immunological syndrome, and disease outcome are noteworthy for similar unforeseen pediatric case management to help guide future investigations and care.

Elevated Plasma Apurinic/Apyrimidinic Endonuclease 1/Redox Effector Factor-1 Levels in Refractory Kawasaki Disease

Kawasaki disease (KD) refers to systemic vasculitis of medium-sized vessels accompanied by fever. The multifunctional protein apurinic/apyrimidinic endonuclease-1/redox factor-1 (APE1/Ref-1) is a new biomarker for vascular inflammation. Here, we investigated the association between APE1/Ref-1 and KD. Three groups, including 32 patients with KD (KD group), 33 patients with fever (Fever group), and 19 healthy individuals (Healthy group), were prospectively analyzed. APE1/Ref-1 levels were measured, and the clinical characteristics of KD were evaluated. The mean age of all patients was 2.7 ± 1.8 years, but the Healthy group participants were older than the other participants. Fever duration was longer in the KD group than in the fever group. APE1/Ref-1 levels were significantly higher in the KD group (p = 0.004) than in the other two groups, but there was no difference between the healthy and fever groups. APE1/Ref-1 levels did not differ according to fever duration or coronary arterial lesion but were higher in refractory KD cases than in non-refractory cases. APE1/Ref-1 levels were significantly higher during the acute phase of KD. We propose that APE1/Ref-1 could be a beneficial biological marker for the diagnosis and prognosis of KD, especially in refractory KD.

Identification of novel locus associated with coronary artery aneurysms and validation of loci for susceptibility to Kawasaki disease

Kawasaki disease (KD) is a paediatric vasculitis associated with coronary artery aneurysms (CAA). Genetic variants influencing susceptibility to KD have been previously identified, but no risk alleles have been validated that influence CAA formation. We conducted a genome-wide association study (GWAS) for CAA in KD patients of European descent with 200 cases and 276 controls. A second GWAS for susceptibility pooled KD cases with healthy paediatric controls from vaccine trials in the UK (n = 1609). Logistic regression mixed models were used for both GWASs. The susceptibility GWAS was meta-analysed with 400 KD cases and 6101 controls from a previous European GWAS, these results were further meta-analysed with Japanese GWASs at two putative loci. The CAA GWAS identified an intergenic region of chromosome 20q13 with multiple SNVs showing genome-wide significance. The risk allele of the most associated SNV (rs6017006) was present in 13% of cases and 4% of controls; in East Asian 1000 Genomes data, the allele was absent or rare. Susceptibility GWAS with meta-analysis with previously published European data identified two previously associated loci (ITPKC and FCGR2A). Further meta-analysis with Japanese GWAS summary data from the CASP3 and FAM167A genomic regions validated these loci in Europeans showing consistent effects of the top SNVs in both populations. We identified a novel locus for CAA in KD patients of European descent. The results suggest that different genes determine susceptibility to KD and development of CAA and future work should focus on the function of the intergenic region on chromosome 20q13.

Prediction of repeated intravenous immunoglobulin resistance in children with Kawasaki disease

BACKGROUND

Repeated intravenous immunoglobulin (IVIG) resistance prediction is one of the pivotal topics in Kawasaki disease (KD). Those non-responders of repeated IVIG treatment might be improved by an early-intensified therapy to reduce coronary artery lesion and medical costs. This study investigated predictors of resistance to repeated IVIG treatment in KD.

METHODS

A total of 94 children with IVIG-resistant KD treated at our hospital between January 2016 and August 2020 were retrospectively analyzed. According to the therapeutic effect of a second dose IVIG treatment, the children were divided into repeated IVIG-responsive group and repeated IVIG-resistant group, and the clinical and laboratory data were compared. Predictors of repeated IVIG resistance and the optimal cut-off value were determined by multiple logistic regression analysis and receiver operating characteristic (ROC) curve analysis.

RESULTS

The Pre-IVIG laboratory data showed the percentage of neutrophils (N%) and levels of serum procalcitonin (PCT), N-terminal pro-brain natriuretic peptide (NT-proBNP) were significantly higher in repeated IVIG-resistant group compared with repeated IVIG-responsive group, while levels of serum sodium and albumin (ALB) were significantly lower (P < 0.05). The post-IVIG laboratory values of N% and C-reactive protein (CRP) were significantly higher in the repeated IVIG-resistant group compared with repeated IVIG-responsive group, while hemoglobin and ALB were lower (P < 0.05). Pre-IVIG PCT and post-IVIG CRP exhibited AUC of 0.751 and 0.778 respectively in predicting repeated IVIG resistance in KD. Pre-IVIG PCT > 1.81ng/ml (OR 4.1, 95 % CI 1.4 ~ 12.0, P < 0.05) and post-IVIG CRP > 45 mg/L (OR 4.6, 95 % CI 1.3 ~ 16.2, P < 0.05) were independent predictors of repeated IVIG resistance in KD.

CONCLUSIONS

Our study illustrates the serum PCT level before initial IVIG treatment and CRP after initial IVIG could be used to predict repeated IVIG resistance in KD.

Early Measurement of Blood sST2 Is a Good Predictor of Death and Poor Outcomes in Patients Admitted for COVID-19 Infection

Although several biomarkers have shown correlation to prognosis in COVID-19 patients, their clinical value is limited because of lack of specificity, suboptimal sensibility or poor dynamic behavior. We hypothesized that circulating soluble ST2 (sST2) could be associated to a worse outcome in COVID-19. In total, 152 patients admitted for confirmed COVID-19 were included in a prospective non-interventional, observational study. Blood samples were drawn at admission, 48-72 h later and at discharge. sST2 concentrations and routine blood laboratory were analyzed. Primary endpoints were admission at intensive care unit (ICU) and mortality. Median age was 57.5 years [Standard Deviation (SD: 12.8)], 60.4% males. 10% of patients (n = 15) were derived to ICU and/or died during admission. Median (IQR) sST2 serum concentration (ng/mL) rose to 53.1 (30.9) at admission, peaked at 48-72 h (79.5(64)) and returned to admission levels at discharge (44.9[36.7]). A concentration of sST2 above 58.9 ng/mL was identified patients progressing to ICU admission or death. Results remained significant after multivariable analysis. The area under the receiver operating characteristics curve (AUC) of sST2 for endpoints was 0.776 (p = 0.001). In patients admitted for COVID-19 infection, early measurement of sST2 was able to identify patients at risk of severe complications or death.

Big Tests in Little People

Can laboratory tests that are routinely used in adult patients also be used in pediatric patients? Does the current literature support the routine use of troponin, brain natriuretic peptide, D-dimer, and lactate in children? Adult problems such as acute coronary syndrome and pulmonary embolism are rare in pediatrics, and there is a paucity of literature on how blood tests commonly used to help diagnose these conditions in adults play a role in the diagnosis and management of children. This article presents the literature about 4 common blood tests and examines the clinical applications of each.

Imperfect storm: is interleukin-33 the Achilles heel of COVID-19?

The unique cytokine signature of COVID-19 might provide clues to disease mechanisms and possible future therapies. Here, we propose a pathogenic model in which the alarmin cytokine, interleukin (IL)-33, is a key player in driving all stages of COVID-19 disease (ie, asymptomatic, mild-moderate, severe-critical, and chronic-fibrotic). In susceptible individuals, IL-33 release by damaged lower respiratory cells might induce dysregulated GATA-binding factor 3-expressing regulatory T cells, thereby breaking immune tolerance and eliciting severe acute respiratory syndrome coronavirus 2-induced autoinflammatory lung disease. Such disease might be initially sustained by IL-33-differentiated type-2 innate lymphoid cells and locally expanded γδ T cells. In severe COVID-19 cases, the IL-33-ST2 axis might act to expand the number of pathogenic granulocyte-macrophage colony-stimulating factor-expressing T cells, dampen antiviral interferon responses, elicit hyperinflammation, and favour thromboses. In patients who survive severe COVID-19, IL-33 might drive pulmonary fibrosis by inducing myofibroblasts and epithelial-mesenchymal transition. We discuss the therapeutic implications of these hypothetical pathways, including use of therapies that target IL-33 (eg, anti-ST2), T helper 17-like γδ T cells, immune cell homing, and cytokine balance.

Utility of color Doppler echocardiography combined with clinical markers in diagnosis and prediction of prognosis of coronary artery lesions in Kawasaki disease

The utility of color Doppler echocardiography in the diagnosis and follow-up of Kawasaki disease (KD) with coronary artery lesions (CAL) was analyzed, and the clinical parameters associated with the disease were examined. The general data, the color Doppler echocardiography data and the biochemical indexes from 102 children with KD were analyzed. The patients were divided into a CAL group and a non-coronary artery lesion (NCAL) group based on the presence or absence of CAL. The risk factors for CAL in KD were screened by univariate and multivariate analyses. Among the 102 cases, CAL complications were identified in 47 cases (46.08%). Compared with the NCAL group, the CAL group showed significantly higher incidences of fever duration, increased levels of N-terminal pro B-type natriuretic peptide (NT-proBNP), cardiac troponin I (cTnI), C-reactive protein (CRP), intravenous immunoglobulin resistance, erythrocyte sedimentation rate (ESR), platelets, alanine aminotransferase and aspartate aminotransferase, and significantly lower serum albumin levels (P<0.05). According to the multivariate analysis, fever duration [odds ratio (OR)=2.014], NT-proBNP (OR=3.004), cTnI level (OR=2.638), ESR (OR=1.461) and CRP elevation (OR=1.094) were predictors of CAL in KD. During convalescence, the left and right coronary artery diameters in the CAL group significantly decreased (P<0.05). Color Doppler echocardiography can observe the condition of coronary artery disease in patients with KD in real time and predicts its outcomes, which may be helpful for early diagnosis and long-term follow-up. Fever duration, cTnI, NT-proBNP and ESR levels were correlated with coronary artery diameter, of which the comprehensive use may be more accurate in determining the occurrence of CAL in KD.

Biomarkers of Inflammation and Fibrosis in Kawasaki Disease Patients Years After Initial Presentation With Low Ejection Fraction

Background Coronary artery aneurysms and myocarditis are well-recognized complications of Kawasaki disease (KD) but no systematic evaluation of the consequences of myocarditis has been performed in the subset presenting with low ejection fraction (EF). We postulated that more severe myocardial inflammation as evidenced by low EF during the acute phase could lead to late myocardial fibrosis. Methods and Results We measured the carboxyterminal propeptide of procollagen type I (PIPC), soluble suppressor of tumorigenicity 2, galectin-3 (Gal-3), growth-differentiation factor-15, and calprotectin by ELISA in late convalescent blood samples from 16 KD patients who had an EF ≤55% on their initial echocardiogram. Results were compared with samples from sex- and age-matched KD patients with initial EF >60%. In the univariate analysis, the median Gal-3 and PIPC levels in the low EF group were significantly higher than those in the normal EF group (Gal-3: low EF 6.216 versus normal EF 4.976 mg/dL P=0.038, PIPC: low EF 427.4 versus normal EF 265.2 mg/dL, P=0.01). In a multivariable analysis, there were significant differences for Gal-3 and PIPC levels between the low and normal EF groups, adjusting for age, sex, and worst z score. Conclusions Convalescent KD patients with a history of low EF during the acute illness had significantly elevated levels of Gal-3 and PIPC when compared with matched-control KD patients with normal EF. These findings raise concern for myocardial fibrosis as a potential late sequela of the more severe myocarditis experienced by a subset of KD patients during the acute phase.

Characteristics and Indications of Kawasaki Disease Among Infants Under 6 Months

Objectives: To explore the characteristics of Kawasaki disease (KD) under 6 months and to investigate the possible indications of incomplete KD (iKD). Methods: The medical records of KD patients hospitalized in Children's Hospital of Soochow University from January 2007 to December 2017 were retrospectively reviewed and analyzed. A total of 50 cases of urinary tract infection (UTI) and 50 cases of adenovirus (ADV)-infected patients under 6 months that were age and gender-matched with the main complaint of high fever were selected as controls. Results: A total of 1,872 KD patients were enrolled. Among them, 194 (10.4%) were infantile patients under 6 months. There were 72 (37.1%) and 494 (29.4%) iKD in patients younger and older than 6 months, respectively (P < 0.05). Although patients under 6 months had a shorter fever duration before immunoglobulin (IVIG) treatment, a larger proportion of these patients had IVIG resistance and coronary artery lesions. They also tended to have higher platelet (PLT) counts and C-reactive protein (CRP) and lower hemoglobin (Hb), percentage of neutrophils (N%), albumin and serum sodium. When we compared iKD under 6 months with UTI and ADV-infected patients, significant differences were found in white blood cells (WBC), Hb, PLT, CRP, N% and serum albumin (P < 0.05). After adjusting the confounders, Hb < 105.5 g/L, CRP > 22.7 mg/L, N% > 47.4 and PLT > 496 × 10⁹/L were indications of iKD when compared with ADV infection (area under the curve [AUC]: 0.872, 0.939, 0.707, and 0.684, respectively). N% > 51.8 and albumin < 39.0 g/L were indications of iKD when compared with UTI (AUC: 0.627 and 0.832, respectively). Conclusions: Infantile KD patients under 6 months had their own particularity. Laboratory variables could be good indications of iKD when compared with UTI and ADV infection.

Cardiovascular Involvement in Kawasaki Disease Is Much More Than Mere Coronary Arteritis

Kawasaki disease (KD) is now a common cause of acquired heart disease in children. Coronary artery involvement is the most serious complication in children with KD. Several non-coronary complications have now been identified in this condition but these are often overlooked. Myocarditis is an integral component of KD and may be more common than coronary artery abnormalities. Pericardial involvement and valvular abnormalities have also been observed in patients with KD. KD shock syndrome is now being increasingly recognized and may be difficult to differentiate clinically from toxic shock syndrome. Endothelial dysfunction has been reported both during acute stage and also on follow-up. This may be a potentially modifiable cardiovascular risk factor.

Biomarkers for Kawasaki Disease: Clinical Utility and the Challenges Ahead

Kawasaki disease (KD) has replaced acute rheumatic fever as the most common cause of acquired heart disease in children in the developed world and is increasingly being recognized from several developing countries. It is a systemic vasculitis with a predilection for coronary arteries. The diagnosis is based on a constellation of clinical findings that appear in a temporal sequence. Quite understandably, this can become a problem in situations wherein the clinical features are not typical. In such situations, it can be very difficult, if not impossible, to arrive at a diagnosis. Several biomarkers have been recognized in children with acute KD but none of these has reasonably high sensitivity and specificity in predicting the course of the illness. A line up of inflammatory, proteomic, gene expression and micro-RNA based biomarkers has been studied in association with KD. The commonly used inflammatory markers e.g. erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and total leucocyte counts (TLC) lack specificity for KD. Proteomic studies are based on the identification of specific proteins in serum, plasma and urine by gel electrophoresis. A host of genetic studies have identified genes associated with KD and some of these genes can predict the course and coronary outcomes in the affected individuals. Most of these tests are in the early stages of their development and some of these can predict the course, propensity to develop coronary artery sequelae, intravenous immunoglobulin (IVIg) resistance and the severity of the illness in a patient. Development of clinical criteria based on these tests will improve our diagnostic acumen and aid in early identification and prevention of cardiovascular complications.

Kawasaki disease: a comprehensive review

Kawasaki disease is an acute systemic vasculitis that was first reported in 1961. Over the last 5 decades multiple papers have been published to further understand this disease. The diagnosis of Kawasaki disease is made based on the clinical findings. Atypical Kawasaki disease includes patients who do not meet all the criteria for diagnosis. The main complication of Kawasaki disease is coronary aneurysm, and the treatment is intravenous immunoglobulin and aspirin. A second dose of immunoglobulin is given if the patient does not improve, and several other treatment options have been proposed over the last few years as second and third line options.

Elevation of Serum APE1/Ref-1 in Experimental Murine Myocarditis

Myocarditis is an inflammatory disease of the myocardium that causes cardiogenic shock and death. However, endomyocardial biopsy that is, the gold standard for a diagnosis is limited. Apurinic/apyrimidinic endonuclease 1/redox effector factor-1 (APE1/Ref-1) is a multifunctional protein, which is involved in DNA-based excision repair pathway, and in redox signaling, its changes are observed in various cardiovascular diseases including hypertension and coronary artery disease. We analyzed serum APE1/Ref-1 in experimental murine myocarditis. To induce myocarditis, coxsackievirus B3 was injected intraperitoneally to BALB/c mice. The serum APE1/Ref-1, N-terminal pro-B-type natriuretic peptide (NT-proBNP) and troponin I were measured. The histology and virus titers measurements were performed. The troponin I and inflammation were significantly elevated at day 3, peaked to day 7 and decreased at day 10. The NT-proBNP and virus titers were significantly peaked at day 3, and dropped at day 7 and 10. The serum APE1/Ref-1 was gradually raised and its elevation is still maintained until a later time, namely day 10. Also, its level was positively correlated with myocardial inflammation, reflecting severity of myocardial injury. We suggest that serum APE1/Ref-1 can be used to assess for myocardial injury in viral myocarditis without endomyocardial biopsy.

Factors Predicting Resistance to Intravenous Immunoglobulin Treatment and Coronary Artery Lesion in Patients with Kawasaki Disease: Analysis of the Korean Nationwide Multicenter Survey from 2012 to 2014

Background and Objectives

Approximately 10–15% of children with Kawasaki disease (KD) do not respond to initial intravenous immunoglobulin (IVIG) and have higher risk for coronary artery lesion (CAL). The aim of this study was to identify predictive factors from laboratory findings in patients who do not respond to IVIG treatment and develop CAL from KD.

Methods

We retrospectively collected nationwide multicenter data from the Korean Society of Kawasaki Disease and included 5,151 patients with KD between 2012 and 2014 from 38 hospitals.

Results

Among 5,151 patients with KD, 524 patients belonged to the IVIG-resistant group. The patients in the IVIG-resistant group had a significantly higher serum N-terminal pro-brain natriuretic peptide (NT-proBNP) level (1,573.91±3,166.46 vs. 940.62±2,326.10 pg/mL; p<0.001) and a higher percentage of polymorphonuclear neutrophils (PMNs) (70.89±15.75% vs. 62.38±32.94%; p<0.001). Multivariate logistic regression analyses revealed that significantly increased PMN, NT-proBNP, C-reactive protein (CRP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were the predictors of IVIG resistance (p<0.05). Multivariate logistic regression analyses also showed that only CRP was associated with the risk of CAL (p<0.01), while PMN, NT-proBNP, AST, and ALT were not.

Conclusions

Elevated PMN, serum NT-proBNP, CRP, AST, and ALT levels are significantly associated with IVIG resistance in patients with KD. Moreover, serum CRP is significantly increased in patients with KD with CAL.

Association of Toll-like receptor 2-positive monocytes with coronary artery lesions and treatment nonresponse in Kawasaki disease

Purpose

Activation of Toll-like receptor 2 (TLR2) present on circulating monocytes in patients with Kawasaki disease (KD) can lead to the production of proinflammatory cytokines and interleukin-10 (IL-10). We aimed to determine the association of the frequency of circulating TLR2+/CD14+ monocytes (FTLR2%) with the outcomes of KD, as well as to compare FTLR2% to the usefulness of sIL-10.

Methods

The FTLR2% in patients with KD was measured by flow cytometry. Serum levels of IL-10 (sIL-10) were determined in 31 patients with KD before the initial treatment with intravenous immunoglobulin (IVIG) and in 21 febrile controls by using enzyme-linked immunosorbent assay. Patients were classified as having coronary artery lesions (CALs) based on the maximal internal diameters of the proximal right coronary artery and proximal left anterior descending coronary artery one month after the initial diagnosis.

Results

We found that FTLR2% greater than 92.62% predicted CALs with 80% sensitivity and 68.4% specificity, whereas FTLR2% more than 94.61% predicted IVIG resistance with 66.7% sensitivity and 71.4% specificity. Moreover, sIL-10 more than 15.52 pg/mL predicted CALs and IVIG resistance with 40% and 66.7% sensitivity, respectively, and 73.7% and 76.2% specificity, respectively.

Conclusion

We showed that measuring FTLR2% before the initial treatment could be useful in predicting CAL development with better sensitivity than sIL-10 and with results comparable to sIL-10 results for the prediction of IVIG resistance in patients with KD. However, further studies are necessary to validate FTLR2% as a marker of prognosis and severity of KD.

Sets of serum exosomal microRNAs as candidate diagnostic biomarkers for Kawasaki disease

Although Kawasaki disease is the main cause of acquired heart disease in children, no diagnostic biomarkers are available. We aimed to identify candidate biomarkers for diagnosing Kawasaki disease using serum exosomal microRNAs (miRNAs). Using frozen serum samples from a biobank, high-throughput microarray technologies, two-stage real-time quantitative PCR, and a self-referencing strategy for data normalization, we narrowed down the list of biomarker candidates to a set of 4 miRNAs. We further validated the diagnostic capabilities of the identified miRNAs (namely, CT(miR-1246)-CT(miR-4436b-5p) and CT(miR-197-3p)-CT(miR-671-5p)) in 79 samples from two hospitals. We found that this 4-miRNA set could distinguish KD patients from other febrile patients as well as from healthy individuals in a single pass, with a minimal rate of false positives and negatives. We thus propose, for the first time, that serum exosomal miRNAs represent candidate diagnostic biomarkers for Kawasaki disease. Additionally, we describe an effective strategy of screening for biomarkers of complex diseases even when little mechanistic knowledge is available.

Kawasaki Shock Syndrome in a 12-Year-Old Girl Mimicking Septic Shock

Kawasaki disease is diagnosed when fever lasts for more than 5 days with the presence of four out of five of the following clinical features: bilateral conjunctival congestion, changes in the lips and oral cavity, polymorphous exanthem, changes in peripheral extremities, and acute nonpurulent cervical lymphadenopathy (Nakamura et al., 2012). The average age of onset is 2 years and 90% of patients are below 5 years of age. Boys are more affected than girls (Cox and Sallis, 2009). This case report describes an adolescent female who was initially managed as having septic shock and subsequently found to have Kawasaki shock syndrome.

Predictive factors of resistance to intravenous immunoglobulin and coronary artery lesions in Kawasaki disease

Purpose

We conducted a study to determine which factors may be useful as predictive markers in identifying Kawasaki disease (KD) patients with a high risk of resistance to intravenous immunoglobulin (IVIG) and developing coronary artery lesions (CAL).

Methods

We enrolled 287 patients in acute phase of KD at a single center. The demographic, clinical and laboratory data were collected retrospectively.

Results

There were 34 patients in the IVIG resistant group. The IVIG resistant group had significantly higher serum N-terminal-pro-brain natriuretic protein (NT-proBNP) levels (P<0.01) and polymorphonuclear neutrophil (PMN) percentage (P<0.01) in comparison to the IVIG responders. The results yielded sensitivity (78.8%, 60.6%), specificity (58.2%, 90%) and cutoff value (628.6 pg/mL, 80.3%) of NT-proBNP and PMN respectively, in predicting IVIG resistance. Despite IVIG administration, 13 of the 287 patients developed CAL. The patients in the CAL group had higher NT-proBNP levels (P<0.01) and higher PMN percentage (P<0.01). In these patients, the results yielded sensitivity (73.3%, 56.7%), specificity (67.9%, 88.9%) and cutoff value (853.4 pg/mL, 80.3%) of NT-proBNP and PMN respectively, for predicting CAL. The area under the curve (AUC) for predicting resistance to IVIG was NT-proBNP 0.712, PMN 0.802. The AUC for predicting CAL was NT-proBNP 0.739, and PMN 0.773.

Conclusion

Serum NT-proBNP levels and PMN percentage were significantly elevated in patients with KD with IVIG resistance and CAL. Thus, they may be useful predicting markers for IVIG resistance and development of CAL in KD patients.

Diagnostic performance and reference values of novel biomarkers of paediatric heart failure

OBJECTIVE

Biomarkers play a pivotal role in heart failure (HF) management. Reference values and insights from studies in adults cannot be extrapolated to the paediatric population due to important differences in pathophysiology and compensatory reserve. We assessed the diagnostic utility of four novel biomarkers in paediatric HF.

METHODS

Midregional (MR) pro-atrial natriuretic peptide (proANP), soluble ST2 (sST2), growth differentiation factor-15 (GDF-15), MR-pro-adrenomedullin (proADM) and N-terminal pro-B natriuretic peptide (NT-proBNP) were measured in 114 patients and 89 controls. HF was defined as the presence of HF symptoms and/or abnormal systolic ventricular function. Receiver-operating characteristics were plotted, and the area under the curve (AUC) was measured. This was repeated for subgroups with cardiomyopathy and congenital heart disease (CHD). Ventricular systolic function was measured by magnetic resonance or echocardiography. Reference values were calculated according to the current guidelines.

RESULTS

The AUC for diagnosing HF was 0.76 for MR-proANP (CI 0.70 to 0.84) and 0.82 for NT-proBNP (CI 0.75 to 0.88). These parameters performed similarly in the subgroups with CHD and cardiomyopathy. By contrast, MR-proADM, GDF-15 and sST2 performed poorly. When used in conjunction with NT-proBNP, no parameter added significantly to its diagnostic accuracy. NT-proBNP, MR-proANP, GDF-15 and sST2 could accurately discriminate between patients with preserved and patients with poor functional status. In a subset of patients with dilated cardiomyopathy, NT-proBNP, MR-proANP, MR-proADM and GDF-15 were associated with poor LV function.

CONCLUSIONS

MR-proANP could accurately detect HF in children and adolescents. Its diagnostic performance was comparable with that of NT-proBNP, regardless of the underlying condition. Reference values are presented.

Myocardial Strain and Strain Rate in Kawasaki Disease: Range, Recovery, and Relationship to Systemic Inflammation/Coronary Artery Dilation

BACKGROUND

Kawasaki Disease (KD), a systemic vasculitis of medium sized vessels, is the most common cause of acquired heart disease among children in the developed world. Some KD patients demonstrate echocardiographic evidence of depressed myocardial mechanics. However, the incidence, etiology, and reversibility of abnormal mechanics in KD patients remain undefined.

METHODS AND RESULTS

We retrospectively studied 41 KD patients and measured myocardial strain and strain rate by velocity vector imaging from pre-treatment and convalescent echocardiograms. Pre-treatment procalcitonin, C-reactive protein (CRP), and coronary artery z-scores were obtained in all patients and compared between the groups with preserved versus depressed acute phase mechanics. The change in mechanics between the acute and convalescent phases was also assessed. Patients with initially low longitudinal strain improved by the convalescent period (mean difference - 4.0%; p<0.005) with the greatest improvement occurring in patients with the lowest initial strain (-7.3%; p<0.05). Patients with higher initial strain did not change significantly by the convalescent period. Patients with lower longitudinal and circumferential strain demonstrated higher median procalcitonin levels (1.2 vs. 0.3 ng/mL; p<0.05 and 1.8 vs. 0.4 ng/mL; p<0.05 respectively) and a trend towards higher CRP, but no difference in coronary artery z-scores. Strain rate was not associated with inflammatory markers or coronary artery z-scores.

CONCLUSIONS

The range of strain found in our cohort was large. Improvement in mean strain was driven primarily by patients with lower initial strain. Lower strain was associated with increased markers of systemic inflammation, but not proximal coronary artery changes.

Pro-brain natriuretic peptide (ProBNP) levels in North Indian children with Kawasaki disease

The diagnosis of Kawasaki disease (KD), a common pediatric vasculitis, is based solely on clinical criteria. There is a need for a robust laboratory marker that can help differentiate KD from other acute, febrile, childhood illnesses and also to predict cardiac involvement. We conducted a cross-sectional study of 25 consecutive patients admitted with diagnosis of KD from January 2013 to April 2014 and compared them with age- and sex-matched febrile controls. We studied the serum pro-brain natriuretic peptide (ProBNP) [ProBNP and N-terminal pro-B-type natriuretic peptide (NT-ProBNP) levels], a marker of myocardial dysfunction, in children with KD in acute and convalescent phases of disease. These levels were also estimated in febrile controls for comparison. The ProBNP (ProBNP and NT-ProBNP) levels were much higher in the acute phase of the KD patients compared to levels in the convalescent phase of KD (p = 0.000014). Similarly, the levels in the acute phase were higher when compared to the age- and sex-matched febrile controls (p = 0.000126). The receiver operating curve (ROC) analysis for the ProBNP levels in the acute phase of KD yielded an area under the curve of 0.954 ± 0.034 (p < 0.000, 95 % CI 0.886-1.0). Based on ROC analysis, a cutoff of 1025 pg/mL for ProBNP levels in the acute phase of KD had 88 % sensitivity and 96 % specificity for the diagnosis of KD. A lower cut-off of 514 pg/mL yielded a 100 % sensitivity and 80 % specificity for the diagnosis of KD. The ProBNP levels were higher in those with coronary artery abnormalities (CAA) compared to those without CAA in both acute (p = 0.013) and convalescent (p = 0.045) phases. ProBNP levels may be used as a surrogate marker for the differentiation of KD from other febrile, infectious illnesses and may also predict the involvement of coronary arteries.

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.

N-terminal pro-brain natriuretic peptide in acute Kawasaki disease correlates with coronary artery involvement

BACKGROUND

We have lately documented the importance of N-terminal pro-brain natriuretic peptide in aiding the diagnosis of Kawasaki disease.

OBJECTIVES

We sought to investigate the potential value of N-terminal pro-brain natriuretic peptide pertaining to the prediction of coronary artery dilatation (Z-score>2.5) and/or of resistance to intravenous immunoglobulin therapy. We hypothesised that increased serum N-terminal pro-brain natriuretic peptide level correlates with increased coronary artery dilatation and/or resistance to intravenous immunoglobulin.

METHODS

We carried out a prospective study involving newly diagnosed patients treated with 2 g/kg intravenous immunoglobulin within 5-10 days of onset of fever. Echocardiography was performed in all patients at onset, then weekly for 3 weeks, then at month 2, and month 3. Coronary arteries were measured at each visit, and coronary artery Z-score was calculated. All the patients had N-terminal pro-brain natriuretic peptide serum level measured at onset, and the Z-score calculated.

RESULTS

There were 109 patients enrolled at 6.58±2.82 days of fever, age 3.79±2.92 years. High N-terminal pro-brain natriuretic peptide level was associated with coronary artery dilatation at onset in 22.2 versus 5.6% for normal N-terminal pro-brain natriuretic peptide levels (odds ratio 4.8 [95% confidence interval 1.05-22.4]; p=0.031). This was predictive of cumulative coronary artery dilatation for the first 3 months (p=0.04-0.02), but not during convalescence at 2-3 months (odds ratio 1.28 [95% confidence interval 0.23-7.3]; p=non-significant). Elevated N-terminal pro-brain natriuretic peptide levels did not predict intravenous immunoglobulin resistance, 15.3 versus 13.5% (p=1).

CONCLUSION

Elevated N-terminal pro-brain natriuretic peptide level correlates with acute coronary artery dilatation in treated Kawasaki disease, but not with intravenous immunoglobulin resistance.

Noncoronary inflammation in Kawasaki disease is associated with abnormal myocardial deformation in the acute phase

BACKGROUND

Patients with Kawasaki disease (KD) are at risk for developing coronary artery lesions, but the association of noncoronary changes such as mitral regurgitation (MR) and/or pericardial effusion (PE) with cardiac mechanics in the acute phase of KD has not been previously described. The aim of this study was to test the hypothesis that these noncoronary markers for carditis are associated with abnormalities in strain (ε) and strain rate (SR) in patients with MR or PE not appreciated by conventional echocardiography.

METHODS

Longitudinal and circumferential ε and SR analyses were retrospectively performed on patients with KD. Patients with and without MR or PE were compared. Strain values were also compared between patients with and without coronary artery lesions. Values for ejection fraction, shortening fraction, and clinical laboratory parameters were correlated with MR or PE. Follow-up echocardiographic outcomes were recorded at the first encounter after initial diagnosis. Follow-up ε and SR data were also obtained in the group with MR or PE and altered ventricular mechanics at diagnosis.

RESULTS

Of the 110 patients reviewed, 92 had appropriate image quality for either longitudinal ε and SR or circumferential ε and SR analysis. Twenty-eight patients (30%) had either MR or PE. Longitudinal ε and SR were significantly decreased in patients with MR or PE compared with patients without MR or PE (ε: -16.4 ± 4.0% vs -19.0 ± 3.7%, P = .004; SR: -1.3 ± 0.7 vs -1.6 ± 0.4 sec(-1), P = .03). No significant difference in longitudinal ε or SR was noted between patients with and without coronary artery lesions (ε: -17.9 ± 4.1% vs -17.8 ± 3.8%, P = .50; SR: -1.5 ± 0.3 vs -1.6 ± 0.8 sec(-1), P = .50). In the group with abnormal coronary arteries, presence of MR or PE was correlated with decreased longitudinal ε (-16.1 ± 3.6% vs -18.9 ± 3.4%, P = .02), without a significant difference in longitudinal SR (-1.6 ± 0.4 vs -1.5 ± 0.4 sec(-1), P = .20). At approximately 3-week follow-up (21.3 ± 15.8 days), longitudinal ε and SR for the group with MR or PE had increased significantly compared with diagnosis (ε: -16.4 ± 4.3% vs -18.6 ± 0.5%, P = .03; SR: -1.3 ± 0.6 vs -1.8 ± 0.4 sec(-1), P = .008), coincident with resolution of MR or PE. In both groups, erythrocyte sedimentation rate and C-reactive protein were elevated (85.3 ± 36.2 mm/h vs 75.1 ± 33.1 mm/h [P = .34] and 12.3 ± 6.7 vs 11.7 ± 8.2 mg/dL [P = .83]), but only modest correlations were noted between longitudinal ε and elevated erythrocyte sedimentation rate (r = 0.52, P = .01; confidence interval, 0.10-0.80) and C-reactive protein (r = 0.50, P = .02; confidence interval, 0.10-0.80) in patients with MR or PE. Shortening fraction and ejection fraction were within the normal range in both groups.

CONCLUSIONS

Patients presenting with KD with MR or PE at diagnosis are likely to have altered ventricular mechanics compared with patients with KD without MR or PE despite normal conventional echocardiographic measures of function. There is no significant difference in ventricular mechanics when comparing patients with KD with coronary ectasia or aneurysms and those without coronary lesions. Presence of abnormal ε in patients with KD with altered ventricular mechanics correlates modestly with laboratory inflammatory markers. Peak systolic longitudinal ε and SR increased significantly at 3-week follow-up compared with initial diagnosis, coincident with resolution of MR or PE.

Soluble ST2--analytical considerations

Suppression of tumorigenicity 2 (ST2, also known as interleukin [IL]-1 receptor-like-1) is an IL-1 receptor family member with transmembrane (ST2L) and soluble isoforms (sST2). ST2L is a membrane-bound receptor, and IL-33 is the functional ligand for ST2L. sST2, a soluble truncated form of ST2L, is secreted into the circulation and functions as a "decoy" receptor for IL-33, inhibiting IL-33/ST2L signaling. Blood concentrations of sST2 are increased in inflammatory diseases and heart disease and are considered a valuable prognostic marker in both conditions. In multiple clinical trials, sST2 has emerged as a clinically useful prognostic biomarker in patients with cardiac diseases. Interestingly, sST2 even provides prognostic information in low-risk community-based populations. In this review, we will discuss analytical considerations of measuring circulating sST2 including pre-analytical issues, such as in vitro stability of sST2, biological variation of sST2, and postanalytical issues, such as reference ranges and comparisons to diseased cohorts.

Cardiac biomarkers and acute kidney injury after cardiac surgery

OBJECTIVES

To examine the relationship of cardiac biomarkers with postoperative acute kidney injury (AKI) among pediatric patients undergoing cardiac surgery.

METHODS

Data from TRIBE-AKI, a prospective study of children undergoing cardiac surgery, were used to examine the association of cardiac biomarkers (N-type pro-B-type natriuretic peptide, creatine kinase-MB [CK-MB], heart-type fatty acid binding protein [h-FABP], and troponins I and T) with the development of postoperative AKI. Cardiac biomarkers were collected before and 0 to 6 hours after surgery. AKI was defined as a ≥ 50% or 0.3 mg/dL increase in serum creatinine, within 7 days of surgery.

RESULTS

Of the 106 patients included in this study, 55 (52%) developed AKI after cardiac surgery. Patients who developed AKI had higher median levels of pre- and postoperative cardiac biomarkers compared with patients without AKI (all P < .01). Preoperatively, higher levels of CK-MB and h-FABP were associated with increased odds of developing AKI (CK-MB: adjusted odds ratio 4.58, 95% confidence interval [CI] 1.56-13.41; h-FABP: adjusted odds ratio 2.76, 95% CI 1.27-6.03). When combined with clinical models, both preoperative CK-MB and h-FABP provided good discrimination (area under the curve 0.77, 95% CI 0.68-0.87, and 0.78, 95% CI 0.68-0.87, respectively) and improved reclassification indices. Cardiac biomarkers collected postoperatively did not significantly improve the prediction of AKI beyond clinical models.

CONCLUSIONS

Preoperative CK-MB and h-FABP are associated with increased risk of postoperative AKI and provide good discrimination of patients who develop AKI. These biomarkers may be useful for risk stratifying patients undergoing cardiac surgery.

Soluble ST2 in heart failure

In addition to routine clinical laboratory tests (including natriuretic peptides and cardiac troponins), other biomarkers are gaining attention for their utility in heart failure (HF) management. Among them, soluble ST2 (sST2) a novel biomarker integrating inflammation, fibrosis, and cardiac stress has been included in the 2013 ACCF/AHA guideline for additive risk stratification of patients with acute and chronic HF. sST2 is an interleukin-1 (IL-1) receptor family member, is secreted into the circulation and functions as a "decoy" receptor for IL-33, inhibiting IL-33/ST2 signaling. Blood concentrations of sST2 are increased in various diseases such as inflammatory diseases and heart diseases and are considered a valuable prognostic marker in both conditions. sST2 lacks disease specificity and, therefore, is not a valuable marker for the diagnosis of HF. In acute and chronic HF, however, sST2 is strongly associated with measures of HF severity and poor outcome. Several studies in patients with HF indicate that serial measurement of sST2 has prognostic value and could have a potential role in future biomarker-directed therapy. In this review, the role of sST2 as a HF biomarker will be discussed, specifically addressing analytical considerations of measuring sST2 as well as the clinical applications of measurement of sST2 for the diagnosis, prognosis and monitoring of acute and chronic HF.

Periostin is upregulated in coronary arteriopathy in Kawasaki disease and is a potential diagnostic biomarker

Periostin was upregulated 11-fold in acute and chronic Kawasaki disease coronary arteries compared with controls (P = 0.003). Kawasaki disease patients had significantly elevated serum periostin values compared with febrile controls (P = 0.0086). There was no relationship between serum periostin values and age, gender or acute phase reactants; there was a relationship between serum periostin and maximal coronary artery Z scores that did not reach significance (P = 0.08). Periostin may prove to be useful as a component of a future diagnostic biomarker panel for Kawasaki Disease.

Soluble ST2 and N-terminal pro-brain natriuretic peptide combination. Useful biomarker for predicting outcome of childhoodpulmonary arterial hypertension

BACKGROUND

Some potential biomarkers have been reported recently in patients with pulmonary arterial hypertension (PAH), but the most clinically useful among these potential biomarkers, especially in childhood PAH, has not been identified. Therefore, this study investigated which biomarker is useful in assessing severity of and patient prognosis in childhood idiopathic PAH (IPAH)/heritable PAH (HPAH).

METHODS AND RESULTS

Fifty-nine patients who were younger than 16 years at onset of IPAH/HPAH were selected. The following 10 biomarker candidates were quantified: high-sensitivity troponin T, human heart fatty acid-binding protein, N-terminal pro-brain natriuretic peptide (NT-proBNP), pentraxin-3, soluble ST2 (sST2), angiopoietin-2 (Ang-2), matrix metalloproteinase 2, tenascin C, endostatin (ES), and thymidine kinase. Functional characteristics and clinical outcomes were analyzed retrospectively. NT-proBNP, sST2, Ang-2, and ES correlated well with New York Heart Association class. On area under the receiver operating characteristic curve analysis, sST2 had a significantly good relationship with prognosis. On Kaplan-Meier curve and univariate Cox regression analyses, elevated sST2 and NT-proBNP level predicted poor outcome of the present patients with childhood IPAH/HPAH. Furthermore, patients with elevated sST2 had significantly worse prognosis among those with high NT-proBNP.

CONCLUSIONS

The sST2 and NT-proBNP combination is a useful biomarker to predict clinical condition and outcome in patients with childhood IPAH/HPAH.  

An update on Kawasaki disease II: clinical features, diagnosis, treatment and outcomes

This is the second of two updates on Kawasaki disease. The first review focused on epidemiology and aetio-pathogenesis. Here, we review the clinical features and diagnosis of Kawasaki disease, as well as recent evidence on treatment, follow-up and cardiovascular outcomes.

Natriuretic Peptides in Kawasaki Disease: the Myocardial Perspective

Making a diagnosis of Kawasaki disease with certainty may be challenging, especially since the recognition of cases with incomplete diagnostic criteria and its consequences. In order to build the diagnostic case in daily practice, clinicians rely on clinical criteria established over four decades ago, aided by non specific laboratory tests, and above all inspired by experience. We have recently studied the diagnostic value of N-terminal pro B-type natriuretic peptide to improve the diagnostic certainty of cases with complete or incomplete clinical criteria. Our working hypothesis was based on the fact that myocarditis is present in nearly all Kawasaki disease patients supported by histology data. In this paper, we review these facts and the myocardial perspective from the diagnostic and the mechanistic standpoints.

Urine proteomics for discovery of improved diagnostic markers of Kawasaki disease

Kawasaki disease (KD) is a systemic vasculitis of unknown etiology. Absence of definitive diagnostic markers limits the accuracy of clinical evaluations of suspected KD with significant increases in morbidity. In turn, incomplete understanding of its molecular pathogenesis hinders the identification of rational targets needed to improve therapy. We used high-accuracy mass spectrometry proteomics to analyse over 2000 unique proteins in clinical urine specimens of patients with KD. We discovered that urine proteomes of patients with KD, but not those with mimicking conditions, were enriched for markers of cellular injury such as filamin and talin, immune regulators such as complement regulator CSMD3, immune pattern recognition receptor muclin, and immune cytokine protease meprin A. Significant elevations of filamin C and meprin A were detected in both the serum and urine in two independent cohorts of patients with KD, comprised of a total of 236 patients. Meprin A and filamin C exhibited superior diagnostic performance as compared to currently used markers of disease in a blinded case-control study of 107 patients with suspected KD, with receiver operating characteristic areas under the curve of 0.98 (95% confidence intervals [CI] of 0.97-1 and 0.95-1, respectively). Notably, meprin A was enriched in the coronary artery lesions of a mouse model of KD. In all, urine proteome profiles revealed novel candidate molecular markers of KD, including filamin C and meprin A that exhibit excellent diagnostic performance. These disease markers may improve the diagnostic accuracy of clinical evaluations of children with suspected KD, lead to the identification of novel therapeutic targets, and allow the development of a biological classification of Kawasaki disease.

Kawasaki disease

Kawasaki disease is a systemic vasculitis and the leading cause of acquired heart disease in North American and Japanese children. The epidemiology, cause, and clinical characteristics of this disease are reviewed. The diagnostic challenge of Kawasaki disease and its implications for coronary artery outcomes are discussed, as are the recommended treatment, ongoing treatment controversies, concerns associated with treatment resistance, and the importance of ongoing follow up.