Daily Respiratory Research Analysis

BACKGROUND: The antitussive potential of flupentixol-melitracen, an anti-anxiety and anti-depression compound, has been observed previously. We aimed to further evaluate its efficacy and safety in patients with refractory chronic cough (RCC) who were unresponsive to any other available treatments. METHODS: This randomised, double-blinded, placebo-controlled clinical trial was conducted at a single specialist cough clinic in Tongji Hspital, Shanghai, China. Adults aged 18-69 years with RCC and persistent cough despite at least two weeks of neuromodulator therapy were enrolled. Participants were randomly assigned (1:1) to receive either oral flupentixol-melitracen (flupentixol 0.5 mg + melitracen 10 mg), one tablet twice daily, or matching placebo, for two weeks, followed by a one week of off-treatment safety monitoring. Randomisation was computer-generated, with masking of participants, investigators, and outcome assessors. The co-primary endpoints were cough resolution rate (≥50% reduction in cough symptom score [CSS]) at visit four and placebo-adjusted change in CSS over time. The full analysis set (FAS) was used following the modified intention-to-treat (mITT) principle for demographic baseline analysis and efficacy analysis. The safety set (SS) was used for safety analysis and included all patients who took at least one dose of treatment and had post-dose safety records. The FAS and SS were equivalent in this study. The trial is registered with the Chinese Clinical Trial Registry, ChiCTR2000035304. FINDINGS: Between March 9th, 2021 and December 1st, 2023, 102 patients were enrolled and randomised. A total of 99 patients received at least one dose of treatment and were included in the primary and safety analyses (49 taking flupentixol-melitracen and 50 taking placebo). At visit four, flupentixol-melitracen arm reached significantly higher cough resolution rate (65.3% [32/49] vs 32.0% [16/50]; p = 0.0009). The adjusted mean reduction in CSS was 0.144 points greater in the flupentixol-melitracen group than in the placebo group over time (p = 0.0034). Treatment-emergent adverse events occurred in 51.0% (15/49) of patients in the flupentixol-melitracen group and 34.0% (17/50) in the placebo group. No serious adverse events or treatment-related deaths were reported. All adverse events were mild and resolved after discontinuation. INTERPRETATION: Our findings suggest that short-term use of flupentixol-melitracen may be an effective and well-tolerated treatment for RCC. However, the findings should be interpreted with caution due to key limitations, including the absence of objective cough frequency measurement and limited generalisability beyond a single-centre population. These factors may influence the precision and applicability of the observed treatment effect. Further trials using objective endpoints and longer follow-up in broader populations are needed to confirm efficacy and safety. FUNDING: The Project of Science and Technology Commission of Shanghai Municipality.

UNLABELLED: Many plus-strand RNA viruses, including coronaviruses, orchestrate the formation of specialized replication organelles in the cytoplasm of infected cells by specific membrane-associated viral nonstructural proteins (nsp's). This process involves a massive reorganization of intracellular membrane compartments and is thought to depend on a specific set of cellular enzymes that synthesize or modify cellular lipids. Here, we investigated the potential role(s) of specific sphingolipids and related enzymes in coronavirus replication. We observed in cells infected with three different coronaviruses a comparable increase in global ceramide levels, whereas sphingomyelin levels were reduced, suggesting an enhanced conversion of sphingomyelin to ceramide by sphingomyelinases. To test this hypothesis, we targeted cellular sphingomyelinases using pharmacological and genetic approaches. The data obtained in these experiments led us to conclude that neutral sphingomyelinase 2 plays a critical role in an early (but not the entry) step of coronavirus replication in Huh-7-ACE2 cells. Furthermore, neutral sphingomyelinase 2 inhibited the formation of viral replication organelles, indicating the involvement of ceramide in the formation of these membrane structures. We also confirmed colocalization of neutral sphingomyelinase 2 and ceramide, but not sphingomyelin, with replication organelles that were produced in coronavirus-infected cells or induced by co-expression of coronavirus nsp3 and nsp4. A colocalization of ceramides with coronaviral replication organelles could be consistently demonstrated for different epithelial cell systems using genetically diverse coronaviruses, describing potential cell- and virus-type independence. IMPORTANCE: Coronaviruses are enveloped plus-strand RNA viruses with a broad host range, including humans. Human coronaviruses are not only associated with endemic, mild upper respiratory tract infections but also have pandemic potential and can be associated with a severe disease burden. The recent SARS-CoV-2 pandemic especially highlighted the urgent need to identify ideal broad-spectrum and host-targeted antiviral strategies. Since lipids are involved in every step of viral replication, we compared changes in the sphingolipid metabolism of cells infected with three different coronaviruses to identify similarities and related cellular enzymes involved in facilitating viral replication. We observed increased ceramide levels while sphingomyelin levels decreased, suggesting enhanced sphingomyelin-to-ceramide conversion by cellular sphingomyelinases upon infection. Impairment of neutral sphingomyelinase 2 reduced viral replication and the formation of virus-induced membranous replication organelles. Furthermore, we found that neutral sphingomyelinase 2 and its product ceramide were associated with viral replication organelles. Ceramides consistently appeared to be integral lipid building blocks of replication organelles across different human pathogenic coronaviruses and cell types. In conclusion, our study provides new insights into novel potentially conserved druggable sphingolipid-related host factors involved in coronaviral replication, offering potential new targets for antiviral therapies against newly emerging coronaviruses.

BACKGROUND: Coronavirus disease 2019 (COVID-19) infection and vaccination have unclear impacts on type 2 inflammatory diseases. Although viral infections can drive immune dysregulation, the extent to which COVID-19 infection and vaccination affect type 2 inflammatory diseases in various organ systems remains underexplored. OBJECTIVE: We sought to assess the risk of new-onset type 2 inflammatory diseases after COVID-19 infection and vaccination. METHODS: We conducted a large-scale retrospective matched cohort study using a US electronic health records database of more than 118 million patients. Three cohorts were defined: individuals with COVID-19 infection (n = 973,794), individuals with COVID-19 vaccination (n = 691,270), and unexposed controls (n = 4,388,409). Propensity score matching balanced demographic and clinical covariates. We calculated hazard ratios (HRs) for incident asthma, allergic rhinitis, chronic rhinosinusitis, atopic dermatitis, and eosinophilic esophagitis over 3-month follow-up. RESULTS: COVID-19 infection significantly increased the risks of asthma (HR 1.656, 95% CI 1.590-1.725), allergic rhinitis (HR 1.272, 95% CI 1.214-1.333), and chronic rhinosinusitis (HR 1.744, 95% CI 1.671-1.821). Risks for atopic dermatitis or eosinophilic esophagitis remained unchanged. In contrast, vaccination lowered the risks of asthma (HR 0.678, 95% CI 0.636-0.722) and chronic rhinosinusitis (HR 0.799, 95% CI 0.752-0.850). Direct comparison showed a 2- to 3-fold greater risk of respiratory type 2 inflammatory diseases with infection than with vaccination. CONCLUSIONS: COVID-19 infection is associated with a heightened risk of respiratory type 2 inflammatory diseases, whereas vaccination appears protective.