In December 2019, an initial cluster of interstitial bilateral pneumonia emerged in Wuhan, China. A human-to-human transmission was assumed and a previously unrecognized entity, termed coronavirus disease-19 (COVID-19) due to a novel coronavirus (SARS-CoV-2) was described. The infection has rapidly spread out all over the world and Italy has been the first European country experiencing the endemic wave with unexpected clinical severity in comparison with Asian countries. It has been shown that SARS-CoV-2 utilizes angiotensin converting enzyme 2 (ACE2) as host receptor and host proteases for cell surface binding and internalization. Thus, a predisposing genetic background can give reason for interindividual disease susceptibility and/or severity. Taking advantage of the Network of Italian Genomes (NIG), here we mined whole-exome sequencing data of 6930 Italian control individuals from five different centers looking for ACE2 variants. A number of variants with a potential impact on protein stability were identified. Among these, three more common missense changes, p.(Asn720Asp), p.(Lys26Arg), and p.(Gly211Arg) were predicted to interfere with protein structure and stabilization. Rare variants likely interfering with the internalization process, namely p.(Leu351Val) and p.(Pro389His), predicted to interfere with SARS-CoV-2 spike protein binding, were also observed. Comparison of ACE2 WES data between a cohort of 131 patients and 258 controls allowed identifying a statistically significant (P value < 0.029) higher allelic variability in controls compared with patients. These findings suggest that a predisposing genetic background may contribute to the observed interindividual clinical variability associated with COVID-19, allowing an evidence-based risk assessment leading to personalized preventive measures and therapeutic options.

The anti-malarial drugs chloroquine (CQ) and primarily the less toxic hydroxychloroquine (HCQ) are currently used to treat autoimmune diseases for their immunomodulatory and anti-thrombotic properties. They have also been proposed for the treatment of several viral infections, due to their anti-viral effects in cell cultures and animal models, and, currently, for the treatment of coronavirus disease 2019 (COVID-19), the pandemic severe acute respiratory syndrome caused by coronavirus 2 (Sars-Cov-2) infection that is spreading all over the world. Although in some recent studies a clinical improvement in COVID-19 patients has been observed, the clinical efficacy of CQ and HCQ in COVID-19 has yet to be proven with randomized controlled studies, many of which are currently ongoing, also considering pharmacokinetics, optimal dosing regimen, therapeutic level and duration of treatment and taking into account patients with different severity degrees of disease. Here we review what is currently known on the mechanisms of action of CQ and HCQ as anti-viral, anti-inflammatory and antithrombotic drugs and discuss the up-to-date experimental evidence on the potential mechanisms of action of CQ/HCQ in Sars-Cov2 infection and the current clinical knowledge on their efficacy in the treatment of COVID-19 patients. Given the role of iron in several human viral infections, we also propose a different insight into a number of CQ and HCQ pharmacological effects, suggesting a potential involvement of iron homeostasis in Sars-Cov-2 infection and COVID-19 clinical course.

Introduction During the COVID-19 pandemic, hospitals faced increasing pressure, where people living with HIV risked to either acquire SARS-CoV-2 and to interrupt the HIV continuum of care. Methods This is a retrospective, observational study. We compared the numbers of medical visits performed, antiretroviral drugs dispensed and the number of new HIV diagnosis and of hospitalizations in a cohort of people living with HIV (PLWH) followed by the Spedali Civili of Brescia between the bimester of the COVID-19 pandemic peak and the bimester of October–November 2019. Data were retrieved from administrative files and from paper and electronic clinical charts. Categorical variables were described using frequencies and percentages, while continuous variables were described using mean, median, and interquartile range (IQR) values. Means for continuous variables were compared using Student’s t-tests and the Mann–Whitney test. Proportions for categorical variables were compared using the χ2 test. Results As of December 31st, 2019, a total of 3875 PLWH were followed in our clinic. Mean age was 51.4 ± 13 years old, where 28% were females and 18.8% non-Italian. Overall, 98.9% were on ART (n = 3834), 93% were viro-suppressed. A total of 1217 and 1162 patients had their visit scheduled at our out-patient HIV clinic during the two bimesters of 2019 and 2020, respectively. Comparing the two periods, we observed a raise of missed visits from 5 to 8% (p < 0.01), a reduction in the number of new HIV diagnosis from 6.4 in 2019 to 2.5 per month in 2020 (p = 0.01), a drop in ART dispensation and an increase of hospitalized HIV patients due to COVID-19. ART regimens including protease inhibitors (PIs) had a smaller average drop than ART not including PIs (16.6 vs 21.6%, p < 0.05). Whether this may be due to the perception of a possible efficacy of PIs on COVID19 is not known. Conclusions Our experience highlights the importance of a resilient healthcare system and the need to implement new strategies in order to guarantee the continuum of HIV care even in the context of emergency.