Background Hydroxychloroquine (HCQ) was proposed as potential treatment for COVID-19. Objective We set-up a multicenter Italian collaboration to investigate the relationship between HCQ therapy and COVID-19 in-hospital mortality. Methods In a retrospective observational study, 3,451 unselected patients hospitalized in 33 clinical centers in Italy, from February 19, 2020 to May 23, 2020, with laboratory-confirmed SARS-CoV-2 infection, were analyzed. The primary end-point in a time-to event analysis was in-hospital death, comparing patients who received HCQ with patients who did not. We used multivariable Cox proportional-hazards regression models with inverse probability for treatment weighting by propensity scores, with the addition of subgroup analyses. Results Out of 3,451 COVID-19 patients, 76.3% received HCQ. Death rates (per 1,000 person-days) for patients receiving or not HCQ were 8.9 and 15.7, respectively. After adjustment for propensity scores, we found 30% lower risk of death in patients receiving HCQ (HR=0.70; 95%CI: 0.59 to 0.84; E-value=1.67). Secondary analyses yielded similar results. The inverse association of HCQ with inpatient mortality was particularly evident in patients having elevated C-reactive protein at entry. Conclusions HCQ use was associated with a 30% lower risk of death in COVID-19 hospitalized patients. Within the limits of an observational study and awaiting results from randomized controlled trials, these data do not discourage the use of HCQ in inpatients with COVID-19.

Molnupiravir and nirmatrelvir were the first available oral antivirals (OAs) active against SARS-CoV-2. Trials evaluating the efficacy of OAs involved patients unvaccinated and infected with variants different from those currently circulating. We conducted a retrospective study on patients with confirmed SARS-CoV-2 infection treated with OAs during the omicron surge in Italy in order to provide real-life data on the efficacy and safety of OAs during the omicron surge of the COVID-19 pandemic. Among 257 patients, 56.8% received molnupiravir, while 43.2% received nirmatrelvir/ritonavir. Patients in the molnupiravir group were older, had a lower body mass index, and had a higher rate of chronic heart disease than those treated with nirmatrelvir/ritonavir. Three hospitalizations were recorded in the molnupiravir (2.1%) group and one in the nirmatrelvir/ritonavir (0.9%) group. One patient treated with molnupiravir died. The median time to negativity was 8 days in the nirmatrelvir/ritonavir group vs. 10 days in the molnupiravir group, p < 0.01. We recorded 37 ADRs (mainly dysgeusia, diarrhea, and nausea) in 31 individuals (12.1%). Only two patients (0.8%) treated with molnupiravir terminated treatment due to ADRs. In conclusion, in a population of mostly vaccinated patients treated with OAs, we observed a low rate of hospitalization, death, and adverse drug reactions. These rates were lower than those reported in pivotal trials.

Aims This study aims to cast light on immunocytometric alterations in COVID-19, a potentially fatal viral infection with heterogeneous clinical expression and a not completely defined pathophysiology. Methods We studied 35 COVID patients at hospital admission testing by cytofluorimetry a large panel of lymphocyte subpopulations and serum tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-17A and the soluble receptor of IL-17A (IL-17RA). Key findings At hospital admission, total lymphocytes and most T and B subpopulations were reduced in 50–80% of patients, with close relationship to disease severity. While activated T helper 1 (TH1) and TH17 cells resulted normal or higher. Serum IL-6 was increased in all patients, while TNF-α and IL-17A were higher in advanced stages. A patient subset with low severity had very high IL-17RA levels. Tocilizumab treatment caused an increase of IL-17A in 3/6 patients and a reduction in 3 others, while the lymphocyte number increased in 3 patients and did not change in the others. Significance Cytofluorimetry revealed a functional exhaustion of most lymphocyte populations in COVID patients not involving activated TH1 and TH17. Consequently, there was a relevant cytokines production that contributes to impair the respiratory inflammation. The increase of TH17 and IL-17 in a subset of cases and the evidence of a significant increase of IL-17RA (that prevents the interaction of IL-17 with the cell receptor) in patients with low severity suggest that some patients could benefit from monoclonal antibodies treatment targeting IL-17 pathway. Immunocytofluorimetric markers may contribute to a personalized therapy in COVID patients.

The hypothesis that been set forward that use of Renin Angiotensin Aldosterone System (RAAS) inhibitors is associated with COVID−19 severity. We setup a multicenter Italian collaboration (CORIST Project, ClinicalTrials.gov ID: NCT04318418) to retrospectively investigate the relationship between RAAS inhibitors and COVID−19 in-hospital mortality. We also carried out an updated meta-analysis on the relevant studies. Methods: We analyzed 4069 unselected patients with laboratory-confirmed SARS-CoV-2 infection and hospitalized in 34 clinical centers in Italy from February 19, 2020 to May 23, 2020. The primary end-point in a time-to event analysis was in-hospital death, comparing patients who received angiotensin-converting-enzyme inhibitors (ACEeI) or angiotensin-receptor blockers (ARB) with patients who did not. Articles for the meta-analysis were retrieved until July 13th, 2020 by searching in web-based libraries, and data were combined using the general variance-based method. Results: Out of 4069 COVID−19 patients, 13.5% and 13.3% received ACE-I or ARB, respectively. Use of neither ACE-I nor ARB was associated with mortality (multivariable hazard ratio (HR) adjusted also for COVID−19 treatments: 0.96, 95% confidence interval 0.77-1.20 and HR = 0.89, 0.67-1.19 for ACE-I and ARB, respectively). Findings were similar restricting the analysis to hypertensive (N = 2057) patients (HR = 1.00, 0.78-1.26 and HR = 0.88, 0.65-1.20) or when ACE-I or ARB were considered as a single group. Results from the meta-analysis (19 studies, 29,057 COVID−19 adult patients, 9700 with hypertension) confirmed the absence of association. Conclusions: In this observational study and meta-analysis of the literature, ACE-I or ARB use was not associated with severity or in-hospital mortality in COVID−19 patients.

Iron is an essential micronutrient required for the growth of almost all aerobic organisms; the iron uptake pathway in bacteria therefore represents a possible target for novel antimicrobials, including hybrids between antimicrobials and siderophores. Siderophores are low molecular weight iron chelators that bind to iron and are actively transported inside the cell through specific binding protein complexes. These binding protein complexes are present both in Gram negative bacteria, in their outer and inner membrane, and in Gram positive bacteria in their cytoplasmic membrane. Most bacteria have the ability to produce siderophores in order to survive in environments with limited concentrations of free iron, however some bacteria synthetize natural siderophore-antibiotic conjugates that exploit the siderophore-iron uptake pathway to deliver antibiotics into competing bacterial cells and gain a competitive advantage. This approach has been referred to as a Trojan Horse Strategy. To overcome the increasing global problem of antibiotic resistance in Gram negative bacteria, which often have reduced outer membrane permeability, siderophore-antibiotic hybrid conjugates have been synthetized in vitro. Cefiderocol is the first siderophore-antibiotic conjugate that progressed to late stage clinical development so far. In studies on murine models the iron-siderophore uptake pathway has been also exploited for diagnostic imaging of infectious diseases, in which labelled siderophores have been used as specific probes. The aim of this review is to describe the research progress in the field of siderophore-based therapeutic and diagnostic approaches in infectious diseases.