CD5 levels define functionally heterogeneous populations of naïve human CD4+ T cells.

Studies in murine models show that subthreshold TCR interactions with self-peptide are required for thymic development and peripheral survival of naïve T cells. Recently, differences in the strength of tonic TCR interactions with self-peptide, as read-out by cell surface levels of CD5, were associated with distinct effector potentials among sorted populations of T cells in mice. However, whether CD5 can also be used to parse functional heterogeneity among human T cells is less clear. Our study demonstrates that CD5 levels correlate with TCR signal strength in human naïve CD4+ T cells. Further, we describe a relationship between CD5 levels on naïve human CD4+ T cells and binding affinity to foreign peptide, in addition to a predominance of CD5hi T cells in the memory compartment. Differences in gene expression and biases in cytokine production potential between CD5lo and CD5hi naïve human CD4+ T cells are consistent with observations in mice. Together, these data validate the use of CD5 surface levels as a marker of heterogeneity among human naïve CD4+ T cells with important implications for the identification of functionally biased T- cell populations that can be exploited to improve the efficacy of adoptive cell therapies.

Treatment of isolated ventricular septal defects in children: Amplatzer versus surgical closure.

BACKGROUND: Isolated hemodynamically significant ventricular septal defects (VSD) were previously treated surgically. Since the introduction of percutaneous (PC) devices, the management of isolated VSD has evolved. In our center, Amplatzer devices have been implanted for selected isolated perimembranous VSD since 2002. METHODS: The charts of all isolated PC perimembranous VSD closures and all surgical closures performed since 2002 were reviewed retrospectively. Clinical, electrocardiographic, and echocardiographic data were analyzed. The preclosure, immediate postclosure, and 1-month, 6-month, and 12-month postclosure results were assessed. RESULTS: Thirty-seven patients underwent PC closure, and 34 had surgical treatment. Mean follow-up was 42.1 ± 26.0 months. The PC group was significantly older (p < 0.01) and larger in size (p < 0.001). Surgical patients had more severe congestive heart failure and a significantly lower VSD gradient (p < 0.004). At follow-up, there were no differences in the incidence of residual shunting between the two groups (p = 0.92). All valvular regurgitations improved over time, except for 3 aortic regurgitations (5.4%) in the PC group that got worse. Two permanent pacemakers were implanted for early complete heart block in the PC group, and one was implanted in the surgical group (p = 0.94). CONCLUSIONS: The surgical results in our population were excellent. The selection of patients with perimembranous VSD remains a challenge to avoid post-PC intervention complications such as heart block and aortic insufficiency. For isolated VSD, PC closure, which avoids the morbidity of open heart surgery, should be considered as part of the therapeutic armamentarium.

Experience in a single centre with percutaneous aortic valvoplasty in children, including those with associated cardiovascular lesions.

BACKGROUND: We report the experience in a single institution with balloon aortic valvoplasty for congenital aortic stenosis. Unlike most other reported series, we included patients with associated lesions involving the left side of the heart. METHODS: Between November, 1986, and November, 2006, we performed 161 interventions on 143 patients, of whom 33 were neonates, 33 infants, and 77 children, just over one-quarter (28.6%) having associated lesions. RESULTS: The overall reduction in peak-to-peak gradient of 60 ± 24% (p < 0.01), was more effective in primary versus secondary intervention (63 ± 24% versus 47 ± 23%; p < 0.03), and in those with fused bifoliate as opposed to truly bifoliate valves (66 ± 17% versus 53 ± 30%; p = 0.01). Patients with associated lesions were younger (40.89 ± 60.92 months versus 81.9 ± 72.9 months; p = 0.001), and were less likely to achieve a final pressure gradient of less than 20 mmHg (35.0% versus 61.2%; p < 0.01). Overall mortality was higher in cases with associated lesions (27.5% versus 1.9%; p < 0.0001) but not catheter-related death (2.5% versus 1.9%; p = 1.0). Reintervention was more frequently required in infants (p = 0.02) but not in cases with associated lesions (p = 0.35). CONCLUSIONS: Balloon valvoplasty is a safe and effective method for the treatment of congenital aortic stenosis. Prior surgery to the aortic valve, reintervention, associated cardiovascular lesions, and the anatomy of the valve predict a less effective reduction in the gradient. Major complications and catheterization-related death are mainly secondary to very young age, but not to associated cardiac lesions.