Infants with Down syndrome and congenital heart disease have altered peri-operative immune responses

The Usefulness of Intraoperative Indocyanine Green Fluorescence Imaging in Surgical Treatment of Refractory Chylothorax in Pediatric Patients: A Case Report

INTRODUCTION

Chylothorax is one of the complications in cardiovascular surgery. Although prolonged chylothorax leads to critical status and is associated with high mortality, its treatment has not been well established. We present a successful case of surgical treatment of chylothorax in a neonate using indocyanine green to identify the site of lymphatic leakage.

CASE PRESENTATION

The patient with complete atrioventricular septal defect, patent ductus arteriosus, pulmonary hypertension, and chromosomal abnormality with trisomy 21 underwent pulmonary artery banding and patent ductus arteriosus ligation through median sternotomy. The postoperative course was complicated with chylothorax; conservative treatment was not effective, so surgical treatment was selected. Indocyanine green was injected subcutaneously between the first and second toes on the left side 30 min before surgery to identify the site of leakage. We could detect the lymphatic leakage from the para-aortic lymph node by indocyanine green camera in the left thoracic cavity, and the leakage sites could be closed with interrupted sutures.

CONCLUSION

Identification of lymphatic leakage sites using indocyanine green could be an effective technique in the surgical treatment of chylothorax in pediatric patients.

Epigenomic signature of major congenital heart defects in newborns with Down syndrome

Background

Congenital heart defects (CHDs) affect approximately half of individuals with Down syndrome (DS) but the molecular reasons for incomplete penetrance are unknown. Previous studies have largely focused on identifying genetic risk factors associated with CHDs in individuals with DS, but comprehensive studies of the contribution of epigenetic marks are lacking. We aimed to identify and characterize DNA methylation differences from newborn dried blood spots (NDBS) of DS individuals with major CHDs compared to DS individuals without CHDs.

Methods

We used the Illumina EPIC array and whole-genome bisulfite sequencing (WGBS) to quantitate DNA methylation for 86 NDBS samples from the California Biobank Program: 1) 45 DS-CHD (27 female, 18 male) and 2) 41 DS non-CHD (27 female, 14 male). We analyzed global CpG methylation and identified differentially methylated regions (DMRs) in DS-CHD vs DS non-CHD comparisons (both sex-combined and sex-stratified) corrected for sex, age of blood collection, and cell type proportions. CHD DMRs were analyzed for enrichment in CpG and genic contexts, chromatin states, and histone modifications by genomic coordinates and for gene ontology enrichment by gene mapping. DMRs were also tested in a replication dataset and compared to methylation levels in DS vs typical development (TD) WGBS NDBS samples.

Results

We found global CpG hypomethylation in DS-CHD males compared to DS non-CHD males, which was attributable to elevated levels of nucleated red blood cells and not seen in females. At a regional level, we identified 58, 341, and 3,938 CHD-associated DMRs in the Sex Combined, Females Only, and Males Only groups, respectively, and used machine learning algorithms to select 19 Males Only loci that could distinguish CHD from non-CHD. DMRs in all comparisons were enriched for gene exons, CpG islands, and bivalent chromatin and mapped to genes enriched for terms related to cardiac and immune functions. Lastly, a greater percentage of CHD-associated DMRs than background regions were differentially methylated in DS vs TD samples.

Conclusions

A sex-specific signature of DNA methylation was detected in NDBS of DS-CHD compared to DS non-CHD individuals. This supports the hypothesis that epigenetics can reflect the variability of phenotypes in DS, particularly CHDs.