Monoclonal Abs against CD20 reduce the number of relapses in multiple sclerosis (MS); commonly this effect is solely attributed to depletion of B cells. Recently, however, a subset of CD3⁺CD20⁺ T cells has been described that is also targeted by the anti-CD20 mAb rituximab. Because the existence of cells coexpressing CD3 and CD20 is controversial and features of this subpopulation are poorly understood, we studied this issue in detail. In this study, we confirm that 3–5% of circulating human T cells display CD20 on their surface and transcribe both CD3 and CD20. We report that these CD3⁺CD20⁺ T cells pervade thymus, bone marrow, and secondary lymphatic organs. They are found in the cerebrospinal fluid even in the absence of inflammation; in the cerebrospinal fluid of MS patients they occur at a frequency similar to B cells. Phenotypically, these T cells are enriched in CD8⁺ and CD45RO⁺ memory cells and in CCR7⁻ cells. Functionally, they show a higher frequency of IL-4–, IL-17–, IFN-γ–, and TNF-α–producing cells compared with T cells lacking CD20. CD20-expressing T cells respond variably to immunomodulatory treatments given to MS patients: they are reduced by fingolimod, alemtuzumab, and dimethyl fumarate, whereas natalizumab disproportionally increases them in the blood. After depletion by rituximab, they show earlier and higher repopulation than CD20⁺ B cells. Taken together, human CD3⁺CD20⁺ T cells pervade lymphatic organs and the cerebrospinal fluid, have a strong ability to produce different cytokines, and respond to MS disease modifying drugs.

Genetic factors undoubtedly affect the development of congenital heart disease (CHD) but still remain ill defined. We sought to identify genetic risk factors associated with CHD and to accomplish a functional analysis of SNP-carrying genes. We performed a genome-wide association study (GWAS) of 4034 White patients with CHD and 8486 healthy controls. One SNP on chromosome 5q22.2 reached genome-wide significance across all CHD phenotypes and was also indicative for septal defects. One region on chromosome 20p12.1 pointing to the MACROD2 locus identified 4 highly significant SNPs in patients with transposition of the great arteries (TGA). Three highly significant risk variants on chromosome 17q21.32 within the GOSR2 locus were detected in patients with anomalies of thoracic arteries and veins (ATAV). Genetic variants associated with ATAV are suggested to influence the expression of WNT3, and the variant rs870142 related to septal defects is proposed to influence the expression of MSX1. We analyzed the expression of all 4 genes during cardiac differentiation of human and murine induced pluripotent stem cells in vitro and by single-cell RNA-Seq analyses of developing murine and human hearts. Our data show that MACROD2, GOSR2, WNT3, and MSX1 play an essential functional role in heart development at the embryonic and newborn stages.

Background: Complex molecular programs in specific cell lineages govern human heart development. Hypoplastic left heart syndrome (HLHS) is the most common and severe manifestation within the spectrum of left ventricular outflow tract obstruction defects occurring in association with ventricular hypoplasia. The pathogenesis of HLHS is unknown, but hemodynamic disturbances are assumed to play a prominent role. Methods: To identify perturbations in gene programs controlling ventricular muscle lineage development in HLHS, we performed whole-exome sequencing of 87 HLHS parent–offspring trios, nuclear transcriptomics of cardiomyocytes from ventricles of 4 patients with HLHS and 15 controls at different stages of heart development, single cell RNA sequencing, and 3D modeling in induced pluripotent stem cells from 3 patients with HLHS and 3 controls. Results: Gene set enrichment and protein network analyses of damaging de novo mutations and dysregulated genes from ventricles of patients with HLHS suggested alterations in specific gene programs and cellular processes critical during fetal ventricular cardiogenesis, including cell cycle and cardiomyocyte maturation. Single-cell and 3D modeling with induced pluripotent stem cells demonstrated intrinsic defects in the cell cycle/unfolded protein response/autophagy hub resulting in disrupted differentiation of early cardiac progenitor lineages leading to defective cardiomyocyte subtype differentiation/maturation in HLHS. Premature cell cycle exit of ventricular cardiomyocytes from patients with HLHS prevented normal tissue responses to developmental signals for growth, leading to multinucleation/polyploidy, accumulation of DNA damage, and exacerbated apoptosis, all potential drivers of left ventricular hypoplasia in absence of hemodynamic cues. Conclusions: Our results highlight that despite genetic heterogeneity in HLHS, many mutations converge on sequential cellular processes primarily driving cardiac myogenesis, suggesting novel therapeutic approaches.

Da Silva's cone repair is a novel technique for surgical reconstruction of the tricuspid valve and the right ventricle (RV) in Ebstein's anomaly. The technique consists of extensive leaflet mobilization, longitudinal plication of the atrialized ventricle and cone-shaped reconstruction of the tricuspid valve, allowing for leaflet-to-leaflet coaptation. We evaluated the influence of Da Silva's cone repair on tricuspid competency, right ventricular size and function. From February 2010 until July 2013, 20 patients (median age 30.0 years, range 6.6–68.3 years) underwent Da Silva's cone repair. A 4- to 6-mm interatrial communication was left in all patients. Echocardiographic studies and magnetic resonance imaging (MRI) before and after the repair were evaluated. Median follow-up was 11 (0.5–36) months. There were 2 early deaths and no late death. Echocardiography at follow-up revealed mild or absent tricuspid regurgitation in 16 patients. Two patients showed moderate tricuspid insufficiency. MRI studies showed that the mean functional RV end-diastolic volume decreased after surgery (pre 334 [135–656] ml; post 175 [115–404] ml, P < 0.001). The mean RV ejection fraction decreased (pre 47 ± 10%; post 35 ± 13%, P = 0.001), and the mean antegrade net stroke volume of the RV increased (pre 65 ± 28 ml; post 75 ± 30 ml, P = 0.057). Da Silva's cone repair for Ebstein's anomaly creates excellent valve function in all patients. Consecutively, the size of the RV decreases and the antegrade net stroke volume increases 6 months after the operation.

Objective: Trans-catheter aortic valve implantation (TAVI) technology is rapidly evolving, with 412 procedures having been performed at our institution. Herein, we report a complete, prospective analysis of complications occurring during transvascular and trans-apical implantations with two different prostheses. Methods: Between June 2007 and June 2010, 412 patients (258 female, mean age 80.3 ± 7.2 years, logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation) 20.2% ± 13.0%) underwent TAVI through either a retrograde (n = 252 transfemoral, n = 28 transaxillary, and n = 5 transaortic) or antegrade (n = 127 trans-apical) approach at our institution. The trans-apical access was chosen only in cases where transvascular implantation was not possible. As many as 283 CoreValve and 129 Edwards Sapien prostheses were implanted. Results: Thirty-day survival was 90.9%. Vascular complications occurred in 42 patients (10.2%). In four patients, lethal aortic root (n = 3) or abdominal (n = 1) aortic rupture occurred. Pericardial effusion developed in 53 patients (12.8%), which resulted in cardiac tamponade in 12 patients (2.9%). Twenty-three patients (5.6%) with valve malplacement were treated interventionally. In five patients (1.2%), emergency institution of cardiopulmonary bypass was required during the procedure for temporary support; all patients survived. Seventeen patients underwent re-intervention on the catheter valve (4.1%). Conclusions: With growing experience, complications with TAVI may be avoided by proper patient selection and skillful management. Other complications, when they occur, require a specific treatment algorithm to avoid delay in decision making. A considerable number of complications after TAVI require surgical treatment. Therefore, the ideal environment for TAVI procedures is a hybrid operating room, where a multidisciplinary team of surgeons, cardiologists, and anesthesiologists is best fitted to meet the current needs associated with TAVI technology. A reduction in complications was seen after 300 cases. This finding attests to the complexity of the procedure in addition to the experience required to reduce the incidence of complications.