Immune Abnormalities in Patients With Single Ventricle Circulation Precede the Fontan Procedure

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

OBJECTIVE

To describe the clinical features of patients with congenital heart disease (CHD) who subsequently developed systemic juvenile idiopathic arthritis (sJIA).

METHODS

We conducted a retrospective review of patients diagnosed with CHD and sJIA at our institution. Detailed clinical, laboratory, and radiographic data were collected from the medical record and reviewed with each patient's primary medical team.

RESULTS

Five patients with sJIA and CHD were identified. Each child had a unique cardiac anatomy, but all the patients required surgical repair during the first year of life. Four children had thymectomies at the time of cardiac surgery. Classic signs of sJIA such as fever (n = 5), rash (n = 5), and arthritis (n = 4) developed after surgical intervention in all the patients. The individuals in this cohort displayed risk factors associated with severe sJIA, including disease onset before 2 years of age (n = 5), elevated interleukin 18 levels (n = 5), baseline eosinophilia prior to initiation of biologic disease-modifying antirheumatic drugs (n = 4), and positivity for HLA-DRB1*15:01 alleles (n = 4). Macrophage activation syndrome (MAS) occurred in 3 patients and sJIA-associated lung disease (sJIA-LD) was identified in 4 patients. Two children died from complications of their cardiac and/or pulmonary disease.

CONCLUSION

We identified an association between CHD and severe forms of sJIA. Although these findings will need to be confirmed in larger, multicenter cohorts, the results highlight the importance of considering a diagnosis of sJIA in children with CHD and remaining vigilant for complications such as MAS and sJIA-LD.

The proteomic fingerprint in infants with single ventricle heart disease in the interstage period: evidence of chronic inflammation and widespread activation of biological networks

Introduction

Children with single ventricle heart disease (SVHD) experience significant morbidity across systems and time, with 70% of patients experiencing acute kidney injury, 33% neurodevelopmental impairment, 14% growth failure, and 5.5% of patients suffering necrotizing enterocolitis. Proteomics is a method to identify new biomarkers and mechanisms of injury in complex physiologic states.

Methods

Infants with SVHD in the interstage period were compared to similar-age healthy controls. Serum samples were collected, stored at -80°C, and run on a panel of 1,500 proteins in single batch analysis (Somalogic Inc., CO). Partial Least Squares-Discriminant Analysis (PLS-DA) was used to compare the proteomic profile of cases and controls and t-tests to detect differences in individual proteins (FDR <0.05). Protein network analysis with functional enrichment was performed in STRING and Cytoscape.

Results

PLS-DA readily discriminated between SVHD cases (n = 33) and controls (n = 24) based on their proteomic pattern alone (Accuracy = 0.96, R2 = 0.97, Q2 = 0.80). 568 proteins differed between groups (FDR <0.05). We identified 25 up-regulated functional clusters and 13 down-regulated. Active biological systems fell into six key groups: angiogenesis and cell proliferation/turnover, immune system activation and inflammation, altered metabolism, neural development, gastrointestinal system, and cardiac physiology and development.

Conclusions

We report a clear differentiation in the circulating proteome of patients with SVHD and healthy controls with >500 circulating proteins distinguishing the groups. These proteomic data identify widespread protein dysregulation across multiple biologic systems with promising biological plausibility as drivers of SVHD morbidity.

Current diagnostic and therapeutic strategies for the management of lymphatic insufficiency in patients with hypoplastic left heart syndrome

Children with hypoplastic left heart syndrome share unique hemodynamic features that alter lymphatic integrity at all stages of palliation. Lymphatic congestion is almost universal in this patient group to some extent. It may lead to reversal of lymphatic flow, the development of abnormal lymphatic channels and ultimately decompression and loss of protein rich lymphatic fluid into extra lymphatic compartments in prone individuals. Some of the most devastating complications that are associated with single ventricle physiology, notably plastic bronchitis and protein losing enteropathy, have now been proven to be lymphatic in origin. Based on the new pathophysiologic concept new diagnostic and therapeutic strategies have recently been developed. Dynamic contrast magnetic resonance lymphangiography is now mainstay in diagnosis of lymphatic insufficiency and allows a thorough assessment of anatomy and function of the main lymphatic compartments through intranodal, intrahepatic and intramesenteric lymphatic imaging. Contrast enhanced ultrasound can evaluate thoracic duct patency and conventional fluoroscopic lymphangiography has been refined for evaluation of patients where magnetic resonance imaging cannot be performed. Novel lymphatic interventional techniques, such as thoracic duct embolization, selective lymphatic duct embolization and liver lymphatic embolization allow to seal abnormal lymphatic networks minimally invasive and have shown to resolve symptoms. Innominate vein turn-down procedures, whether surgical or interventional, have been designed to reduce lymphatic afterload and increase systemic preload effectively in the failing Fontan circulation. Outflow obstruction can now be managed with new microsurgical techniques that create lympho-venous anastomosis. Short term results for all of these new approaches are overall promising but evidence is sparse and long-term outcome still has to be defined. This review article aims to summarize current concepts of lymphatic flow disorders in single ventricle patients, discuss new emerging diagnostic and therapeutic strategies and point out lacks in evidence and needs for further research on this rapidly growing topic.

Increased risk of infections in pediatric Fontan patients after heart transplantation

BACKGROUND

Infectious complications are a major cause of morbidity and mortality after HT. Fontan patients may be more susceptible to post-HT infections.

METHODS

This was a single-center, retrospective cohort analysis of pediatric patients undergoing HT for FF physiology or DCM, who underwent induction with ATG. The primary endpoint was an infection in the first 180 days post-HT, defined as positive (1) blood/urine/respiratory culture; (2) viral PCR; (3) skin or wound infection; and/or (4) culture-negative infection if ≥5 days of antibiotics were completed. Secondary endpoints included (1) cell counts after ATG; (2) PTLD; and (3) rejection (≥Grade 2R ACR or pAMR2) in the first 180 days post-HT.

RESULTS

A total of 59 patients (26 FF, 33 DCM) underwent HT at 14.7 (IQR 10.6, 19.5) and 11.7 (IQR 1.4, 13.6) years of age, respectively. The median total ATG received was 7.4 (IQR 4.9, 7.7) vs 7.5 (IQR 7.3, 7.6) mg/kg (p = NS) for FF and DCM patients, respectively. Twenty-three patients (39%) developed an infection 180 days post-HT, with a higher rate of infection in FF patients (54% vs 27%, p = .03). Adjusted for pre-transplant absolute lymphocyte count, FF patients had a higher risk of infection at 30 days post-HT (OR 7.62, 95% CI 1.13-51.48, p = .04). There was no difference in the incidence of PTLD (12% vs 0%; p = .08) or rejection (12% vs 21%; p = .49).

CONCLUSION

Compared to DCM patients, FF patients have a higher risk of infection. Modifications to induction therapy for FF patients should be considered.

Do children with congenital heart defects meet the vaccination recommendations? Immunisation in children with congenital heart defects

INTRODUCTION

Congenital heart defects (CHDs) are the most common congenital malformations. Patients with CHD have a higher morbidity and mortality rate and are at greater risk for infectious diseases. The risk might even be higher if complex CHD occurs and if CHD is associated with additional co-morbidities. Therefore, immunisations in these children are essential.

MATERIALS AND METHODS

Individuals were recruited at the outpatient centre of the Department of Congenital Heart Defects and Pediatric Cardiology at the German Heart Center Munich in the time between February 2016 and February 2017. Included were children between 23 months and 17 years and a diagnosis of CHD. The vaccination certificate aimed to assess the immunization status.

RESULTS

In total, 657 children with CHD were included and analysed. Regarding primary immunisation, only 34 % (n = 221) of the children reached the complete vaccination status within the allowed catch-up time. Among these primary immunisation rates, vaccinations against Hepatitis B, Meningococci, Varicella and Pneumococci were found to have the lowest coverage with all being below 80%. The vaccination rate was partly influenced by the previously performed number of surgeries but not by the diagnosis of specific genetic diseases. At the age of school entry, the immunisation rate in children with CHD was also lower than in the comparable healthy population.

CONCLUSION

The vaccination coverage rate in children with CHD is lower than in comparable healthy children, although this is a vulnerable patient group. Further education of parents and treating physicians of children with CHD regarding vaccination is still needed.

Plastic Bronchitis—A Serious Rare Complication Affecting Children Only after Fontan Procedure?

Background: Plastic bronchitis (PB) may occur not only in children following palliative Fontan procedure but also in those without underlying heart disease. We aim to assess the clinical course, therapeutic measures, outcome, and follow-up of PB in children with congenital heart disease (CHD) and children without cardiac problems. Methods: This retrospective case series assessed children with PB admitted to hospital between 2015 and 2019. Parents or guardians of patients were contacted by e-mail or telephone between September 2017 and June 2019 to enquiry about recurrence of PB and strategy of treatment. The diagnosis of PB was based on the expectoration (spontaneous or during bronchoscopy) of endobronchial plugs. Results: This study delineated the clinical, histological, and laboratory features of plastic bronchitis in children following Fontan procedure (Group A) and in those without heart defects (Group B, non-CHD children). The main symptoms were cough accompanied by dyspnea, and hypoxemia with a decrease in oxygen saturation, often leading to acute respiratory failure. In children with CHD, the first episode of PB occurred at a relatively young age. Although chronic, i.e., lasting more than 3 weeks, inhaled therapy was implemented in both groups of patients, the recurrences of PB were observed. The mean time to PB recurrence after the first episode in Group A was longer than that in Group B (1.47 vs. 0.265 years, p = 0.2035). There was no re-episode with recurrence of PB in 3 cases out of 10 in total in Group A (30%) and 1 case out of 4 in total in Group B (25%). While the majority of children in Group A usually developed bronchial casts on the right side, the patients in Group B (without CHD) suffered from bronchial casts located only on the left side. Conclusions: Despite many similarities, clinical, histological, and laboratory studies in the children with plastic bronchitis after Fontan’s surgery and in children without heart defects suggest that there are differences in the course of the disease in patients without CHD, such as a more advanced age of the first episode of PB, the location of plastic casts on the left side, and a stronger role of inflammatory factors and mechanisms. Further research is needed to understand the pathophysiology of PB and choose the most appropriate therapy.

Fontan-Associated Liver Disease: Pathophysiology, Staging, and Management

Fontan-associated liver disease is the term used to encompass the disorders arising from abnormal hemodynamic alterations and systemic venous congestion after the Fontan procedure. The histological changes produced in the liver are similar but not equivalent to those seen in other forms of cardiac liver disease. While the natural history of this form of liver disease is poorly established, many Fontan patients ultimately develop portal hypertension-related complications such as ascites, esophageal varices, malnutrition, and encephalopathy. Fontan survivors also show an elevated risk of hepatocellular carcinoma. Adequate staging of the liver damage is essential to anticipate screening strategies and improve global management.

Proteomic profiling identifies key differences between inter-stage infants with single ventricle heart disease and healthy controls

Despite significant morbidity among infants with single ventricle heart disease (SVHD), clinical monitoring is limited by poor understanding of the underlying pathobiology. Proteomics can identify novel biomarkers and important pathways in complex disease. No prior study has evaluated whether the proteome of SVHD infants differs from healthy controls, how it shifts after stage 2 palliation, or whether differences can predict post-operative outcomes. We present a prospective cohort study of cardiovascular proteomic phenotyping in infants with SVHD undergoing stage 2 palliation. Twenty-nine pre-stage-2 SVHD infants and 25 healthy controls were enrolled. Outcomes included postoperative hypoxemia and endotracheal intubation time. Serum samples were drawn pre-operatively (systemic and pulmonary vein) and at 24 hours postoperation. Targeted cardiovascular proteomic analysis included 184 proteins. Partial least squares discriminant analysis distinguished cases from controls (Accuracy = 0.98, R² = 0.93, Q² = 0.81) with decreased inflammatory mediators and increased modulators of vascular tone. Partial least squares discriminant analysis also distinguished cases pre-operation vs. post-operation (Accuracy=0.98, R²=0.99, Q² = 0.92) with postoperative increase in both inflammatory and vascular tone mediators. Pre-operation pulmonary vein tissue inhibitor of metalloproteinase-1 (1.8x-fold, p=1.6 × 10^-4) and nidogen-1 (1.5x-fold, p=1.7 × 10^-4) were higher in subjects with longer endotracheal intubation time. Postoperation matrix metalloproteinase 7 levels were higher in subjects with greater postoperative hypoxemia (1.5x-fold, P= 1.97 × 10^-5). Proteomic analysis identifies significant changes among SVHD infants pre- and post-stage 2, and healthy controls. Tissue inhibitor of metalloproteinase-1, nidogen-1, and matrix metalloproteinase 7 levels are higher in SVHD cases with greater morbidity suggesting an important role for regulation of extracellular matrix production. Proteomic profiling may identify high-risk SVHD infants.

Lymphocyte Immune Response and T Cell Differentiation in Fontan Patients with protein-losing enteropathy

Background  Protein-losing enteropathy (PLE) is a severe complication of the Fontan circulation. There is increasing discussion about whether lymphatic dysregulation is involved as pathomechanism of PLE. This investigation focuses on the interplay between alteration of lymphatic cells and immunologic pathway alterations.

Methods  Micro-ribonucleic acid (miRNA) expression profiling was performed in 49 patients ( n  = 10 Fontan patients with PLE, n  = 30 Fontan patients without PLE, and n  = 9 patients with dextro-transposition of the great arteries (dTGA). miRNA pathway analysis was performed to identify significantly enriched pathways. To determine lymphocyte populations and subtypes multiparameter flow cytometry was used.

Results  miRNAs pathway analysis of Fontan patients with PLE revealed 20 significantly changed networks of which four of the ten largest were associated with immunologic processes. This finding is supported by significant T cell deficiency with decreased CD4+ count ( p  = 0.0002), altered CD4 +/CD8+ ratio, and significantly modified CD4+ ( p  < 0.0001) and CD8+ ( p  = 0.0002) T cell differentiation toward effector and terminal differentiated T cells in Fontan patients with PLE. Analyses of CD4+ T cell subsets demonstrated significantly increased frequencies of CD4+ CD25+ CD127– regulatory T cells (Treg) in Fontan patients with PLE ( p  = 0.0011).

Conclusion  PLE in Fontan patients is associated with severe lymphopenia, T cell deficiency, significant alterations of T cell differentiation, and increased Treg frequency reflecting an immune status of chronic inflammation and shortened protection against pathogens and autoimmunity. These cellular alterations seemed to be dysregulated by several miRNA controlled immunological pathways.

Association of Lymphatic Abnormalities with Early Complications after Fontan Operation

Background  Increased central venous pressure is inherent in Fontan circulation but not strongly related to Fontan complication. Abnormalities of the lymphatic circulation may play a crucial role in early Fontan complications.

Methods  This was a retrospective, single-center study of patients undergoing Fontan operation from 2008 to 2015. The primary outcome was significant early Fontan complication defined as secondary in-hospital treatment due to peripheral edema, ascites, pleural effusions, protein-losing enteropathy, or plastic bronchitis. All patients received T2-weighted magnetic resonance images to assess abdominal and thoracic lymphatic perfusion pattern 6 months after Fontan completion with respect to localization, distribution, and extension of lymphatic perfusion pattern (type 1–4) and with application of an area score (0–12 points).

Results  Nine out of 42 patients developed early Fontan complication. Patients with complication had longer chest tube drainage (mean 28 [interquartile range [IQR]: 13–60] vs. 13 [IQR: 2–22] days, p  = 0.01) and more often obstructions in the Fontan circuit 6 months after surgery (56 vs. 15%, p  = 0.02). Twelve patients showed little or no abnormalities of lymphatic perfusion (lymphatic perfusion pattern type 1). Most frequently magnetic resonance imaging showed lymphatic congestion in the supraclavicular region (24/42 patients). Paramesenteric lymphatic congestion was observed in eight patients. Patients with early Fontan complications presented with higher lymphatic area score (6 [min–max: 2–10] vs. 2 [min–max: 0–8]), p  = 0.001) and greater distribution and extension of thoracic lymphatic congestion (type 3–4: n  = 5/9 vs. n  = 1/33, p  = 0.001).

Conclusion  Early Fontan complication is related to hemodynamic factors such as circuit obstruction and to the occurrence and extent of lymphatic congestion.

Expression of Blood Cells Associated CD Markers and Cardiovascular Diseases: Clinical Applications in Prognosis

BACKGROUND

Cardiovascular diseases (CVDs) are a major cause of mortality worldwide. The results of various studies have shown that abnormality in the frequency and function of blood cells can be involved in CVD complications. In this review, we have focused on abnormalities in the expression of the CD (cluster of differentiation) markers of blood cells to assess the association of these abnormalities with CVD prognosis.

METHODS

We identified the relevant literature through a PubMed search (1990-2018) of English-language articles using the terms "Cardiovascular diseases", "CD markers", "leukocytes", "platelets", and "endothelial cells".

RESULTS

There is a variety of mechanisms for the effect of CD-marker expressions on CVDs prognosis, ranging from proinflammatory processes to dysfunctional effects in blood cells.

CONCLUSION

Considering the possible effects of CD-marker expression on CVDs prognosis, particularly prognosis of acute myocardial infarction and atherosclerosis, long-term studies in large cohorts are required to identify the prognostic value of CD markers and to target them with appropriate therapeutic agents.