BACKGROUNDA potential association between the use of angiotensin-receptor blockers (ARBs) and angiotensin-converting-enzyme (ACE) inhibitors and the risk of coronavirus disease 2019 (Covid-19) has not been well studied. METHODSWe carried out a population-based case-control study in the Lombardy region of Italy. A total of 6272 case patients in whom infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was confirmed between February 21 and March 11, 2020, were matched to 30,759 beneficiaries of the Regional Health Service (controls) according to sex, age, and municipality of residence. Information about the use of selected drugs and patients' clinical profiles was obtained from regional databases of health care use. Odds ratios and 95% confidence intervals for associations between drugs and infection, with adjustment for confounders, were estimated by means of logistic regression. RESULTSAmong both case patients and controls, the mean (±SD) age was 68±13 years, and 37% were women. The use of ACE inhibitors and ARBs was more common among case patients than among controls, as was the use of other antihypertensive and non-antihypertensive drugs, and case patients had a worse clinical profile. Use of ARBs or ACE inhibitors did not show any association with Covid-19 among case patients overall (adjusted odds ratio, 0.95 [95% confidence interval {CI}, 0.86 to 1.05] for ARBs and 0.96 [95% CI, 0.87 to 1.07] for ACE inhibitors) or among patients who had a severe or fatal course of the disease (adjusted odds ratio, 0.83 [95% CI, 0.63 to 1.10] for ARBs and 0.91 [95% CI, 0.69 to 1.21] for ACE inhibitors), and no association between these variables was found according to sex. CONCLUSIONSIn this large, population-based study, the use of ACE inhibitors and ARBs was more frequent among patients with Covid-19 than among controls because of their higher prevalence of cardiovascular disease. However, there was no evidence that ACE inhibitors or ARBs affected the risk of COVID-19.

Previous studies have shown an increased number of inflammatory cells and, in particular, CD8+ve cells in the airways of smokers with chronic obstructive pulmonary disease (COPD). In this study we investigated whether a similar inflammatory process is also present in the lungs, and particularly in lung parenchyma and pulmonary arteries. We examined surgical specimens from three groups of subjects undergoing lung resection for localized pulmonary lesions: nonsmokers (n = 8), asymptomatic smokers with normal lung function (n = 6), and smokers with COPD (n = 10). Alveolar walls and pulmonary arteries were examined with immunohistochemical methods to identify neutrophils, eosinophils, mast cells, macrophages, and CD4+ve and CD8+ve cells. Smokers with COPD had an increased number of CD8+ve cells in both lung parenchyma (p < 0.05) and pulmonary arteries (p < 0.001) as compared with nonsmokers. CD8+ve cells were also increased in pulmonary arteries of smokers with COPD as compared with smokers with normal lung function (p < 0.01). Other inflammatory cells were no different among the three groups. The number of CD8+ve cells in both lung parenchyma and pulmonary arteries was significantly correlated with the degree of airflow limitation in smokers. These results show that an inflammatory process similar to that present in the conducting airways is also present in lung parenchyma and pulmonary arteries of smokers with COPD.

We analyzed 28 thymic epithelial tumors (TETs) using next-generation sequencing and identified a missense mutation (chromosome 7 c.74146970T>A) in GTF2I at high frequency in type A thymomas, a relatively indolent subtype. In a series of 274 TETs, we detected the GTF2I mutation in 82% of type A and 74% of type AB thymomas but rarely in the aggressive subtypes, where recurrent mutations of known cancer genes have been identified. Therefore, GTF2I mutation correlated with better survival. GTF2I β and δ isoforms were expressed in TETs, and both mutant isoforms were able to stimulate cell proliferation in vitro. Thymic carcinomas carried a higher number of mutations than thymomas (average of 43.5 and 18.4, respectively). Notably, we identified recurrent mutations of known cancer genes, including TP53, CYLD, CDKN2A, BAP1 and PBRM1, in thymic carcinomas. These findings will complement the diagnostic assessment of these tumors and also facilitate development of a molecular classification and assessment of prognosis and treatment strategies.

Key Points• Chloride channels are important for proper hydration of the airway surface.• TMEM16A protein is an important component of calcium-activated chloride channels.• Interleukin-4, a cytokine that induces mucous cell metaplasia, also upregulates calcium-dependent chloride secretion in human bronchial epithelial cells.• In bronchial epithelial cells treated with interleukin-4, we found that TMEM16A protein becomes highly expressed in goblet but not in ciliated cells.• Upregulation of TMEM16A by interleukin-4 may be important for secretion and proper expansion of mucins. AbstractThe TMEM16A protein has a potential role as a Ca 2+ -activated Cl − channel (CaCC) in airway epithelia where it may be important in the homeostasis of the airway surface fluid. We investigated the function and expression of TMEM16A in primary human bronchial epithelial cells and in a bronchial cell line (CFBE41o-). Under resting conditions, TMEM16A protein expression was relatively low. However, TMEM16A silencing with short-interfering RNAs caused a marked inhibition of CaCC activity, thus demonstrating that a low TMEM16A expression is sufficient to support Ca 2+ -dependent Cl − transport. Following treatment for 24-72 h with interleukin-4 (IL-4), a cytokine that induces mucous cell metaplasia, TMEM16A protein expression was strongly increased in approximately 50% of primary bronchial epithelial cells, with a specific localization in the apical membrane. IL-4 treatment also increased the percentage of cells expressing MUC5AC, a marker of goblet cells. Interestingly, MUC5AC was detected specifically in cells expressing TMEM16A. In particular, MUC5AC was found in 15 and 60% of TMEM16A-positive cells when epithelia were treated with IL-4 for 24 or 72 h, respectively. In contrast, ciliated cells showed expression of the cystic fibrosis transmembrane conductance regulator Cl − channel but not of TMEM16A. Our results indicate that TMEM16A protein is responsible for CaCC activity in airway epithelial cells, particularly in cells treated with IL-4, and that TMEM16A upregulation by IL-4 appears as an early event of goblet cell differentiation. These findings suggest that TMEM16A expression is particularly required under conditions of mucus hypersecretion to ensure adequate secretion of electrolytes and water.

The attraction of T lymphocytes into the pulmonary parenchyma represents an essential step in mechanisms ultimately leading to lung allograft rejection. In this study we evaluated whether IP-10 (CXCL10), a chemokine that is induced by interferon-gamma and stimulates the directional migration of activated T cells, plays a role in regulating the trafficking of effector T cells during lung allograft rejection episodes. Immunohistochemical examination showed that areas characterized by acute cellular rejection (grades 1 to 4) and active obliterative bronchiolitis (chronic rejection, Ca) were infiltrated by T cells expressing CXCR3, i.e., the specific receptor for CXCL10. In parallel, T cells accumulating in the bronchoalveolar lavage of lung transplant recipients with rejection episodes were CXCR3+ and exhibited a strong in vitro migratory capability in response to CXCL10. In lung biopsies, CXCL10 was abundantly expressed by graft-infiltrating macrophages and occasionally by epithelial cells. Alveolar macrophages expressed and secreted definite levels of CXCL10 capable of inducing chemotaxis of the CXCR3+ T-cell line 300-19; the secretory capability of alveolar macrophages was up-regulated by preincubation with interferon-gamma. Interestingly, striking levels of CXCR3 ligands could be demonstrated in the fluid component of the bronchoalveolar lavage in individuals with rejection episodes. These data indicate the role of the CXCR3/CXCL10 interactions in the recruitment of lymphocytes at sites of lung rejection and provide a rationale for the use of agents that block the CXCR3/CXCL10 axis in the treatment of lung allograft rejection.