SARS-CoV-2 infection of thymus induces loss of function that correlates with disease severity.

BACKGROUND: Lymphopenia, particularly when restricted to the T-cell compartment, has been described as one of the major clinical hallmarks in patients with coronavirus disease 2019 (COVID-19) and proposed as an indicator of disease severity. Although several mechanisms fostering COVID-19-related lymphopenia have been described, including cell apoptosis and tissue homing, the underlying causes of the decline in T-cell count and function are still not completely understood. OBJECTIVE: Given that viral infections can directly target thymic microenvironment and impair the process of T-cell generation, we sought to investigate the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on thymic function. METHODS: We performed molecular quantification of T-cell receptor excision circles and κ-deleting recombination excision circles to assess, respectively, T- and B-cell neogenesis in SARS-CoV-2-infected patients. We developed a system for in vitro culture of primary human thymic epithelial cells (TECs) to mechanistically investigate the impact of SARS-CoV-2 on TEC function. RESULTS: We showed that patients with COVID-19 had reduced thymic function that was inversely associated with the severity of the disease. We found that angiotensin-converting enzyme 2, through which SARS-CoV-2 enters the host cells, was expressed by thymic epithelium, and in particular by medullary TECs. We also demonstrated that SARS-CoV-2 can target TECs and downregulate critical genes and pathways associated with epithelial cell adhesion and survival. CONCLUSIONS: Our data demonstrate that the human thymus is a target of SARS-CoV-2 and thymic function is altered following infection. These findings expand our current knowledge of the effects of SARS-CoV-2 infection on T-cell homeostasis and suggest that monitoring thymic activity may be a useful marker to predict disease severity and progression.

The Effects of Physical Inactivity and Exercise at Home in Young Patients with Congenital Heart Disease during the COVID-19 Pandemic.

Background: The COVID-19 pandemic had a significant impact on the population's ability to be physically active. Purpose: Evaluate the effect of the COVID-19 mitigation measures on exercise tolerance in patients with congenital heart disease (CHD). Materials and methods: All subjects (880, 6-18 years old) who performed a stress test at our hospital from October 2020 to February 2021 and had a similar test one year earlier were enrolled. A questionnaire on the degree of physical activity carried out in 2020 concerning the period prior to the pandemic was compiled. Exercise tolerance and the main anthropometric parameters between the first and second tests were compared. Results: 110 subjects (11.9 ± 4.1 years) were included in the study. The percentage of patients engaged in regular physical activity (RPA) decreased significantly during the pandemic (p < 0.001), and BMI increased significantly (p < 0.001), except among the subjects who began RPA during the lockdown, whereas test duration did not decrease significantly overall but increased in this last subgroup (p < 0.05) Conclusions: The COVID-19 lockdown led to a less active lifestyle with a significant increase in BMI in our group of CHD. These data could have negative effects on the risk profile of this population. RPA practiced at home seems to be effective in counteracting such effects.

Impact of COVID-19 Pandemic on the Italian Humanitarian Congenital Cardiac Surgery Activity: What No One Tells You.

More than 4 millions of children with congenital heart disease (CHD) are waiting for cardiac surgery around the world. Few of these patients are treated only thanks to the support of many non-governmental organizations (NGOs). Starting in December 2019, the so-called coronavirus disease 2019 (COVID-19) has rapidly become a worldwide pandemic and has dramatically impacted on all the international humanitarian activities for congenital heart disease. We analyzed data from all the Italian congenital cardiac surgery centers with the aim to quantify the impact of the pandemic on their charities. Fifteen Italian centers participated in the study and contributed to data collection. We analyzed and compared data regarding humanitarian activities carried out abroad and on site from two periods: year 2019 (pre-COVID-19) and year 2020 (COVID-19 pandemic). In 2019, 53 international missions were carried out by Italian congenital cardiac surgeons, resulting in the treatment of 471 CHD patients. In the same period 11 Italian cardiac centers operated on 251 foreign patients in Italy. In 2020, the pandemic led to a reduction of this activity by 96% for the surgery performed overseas and 86% for the interventions carried out in Italy. In conclusion our study shows the important quantitative impact of the pandemic on the Italian humanitarian cardiac surgical activity overseas and in Italy. This shocking result highlights the failure of the systems adopted so far to solve the problem of CHD in developing countries.

Impact of the coronavirus disease 2019 (COVID-19) pandemic on the Italian congenital cardiac surgery system: a national survey.

OBJECTIVES: Italy has been one of the countries most severely affected by the coronavirus disease 2019 (COVID-19). The Italian government was forced to introduce quarantine measures quickly, and all elective health services were stopped or postponed. This emergency has dramatically changed the management of paediatric and adult patients with congenital heart disease. We analysed data from 14 Italian congenital cardiac surgery centres during lockdown, focusing on the impact of the pandemic on surgical activity, patients and healthcare providers and resource allocation. METHODS: Fourteen centres participated in this study. The period analysed was from 9 March to 4 May. We collected data on the involvement of the hospitals in the treatment of patients with COVID-19 and on limitations on regular activity and on the contagion among patients and healthcare providers. RESULTS: Four hospitals (29%) remained COVID-19 free, whereas 10 had a 39% reduction in the number of beds for surgical patients, especially in the northern area. Two hundred sixty-three surgical procedures were performed: 20% elective, 62% urgent, 10% emergency and 3% life-saving. Hospital mortality was 0.4%. Compared to 2019, the reduction in surgical activity was 52%. No patients operated on had positive test results before surgery for severe acute respiratory syndrome coronavirus 2, the virus responsible for COVID-19. Three patients were infected during the postoperative period. Twenty-nine nurses and 12 doctors were infected. Overall, 80% of our infected healthcare providers were in northern centres. CONCLUSIONS: Our study shows that the pandemic had a different impact on the various Italian congenital cardiac surgery centres based on the different patterns of spread of the virus across the country. During the lockdown, the system was able to satisfy all emergency clinical needs with excellent results.