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The nasopharynx is the initial site of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection, and neutrophils play a critical role in preventing viral transmission into the lower airways or lungs during the early phases of infection. However, neutrophil dynamics, functional signatures, and predictive roles in the nasopharynx of coronavirus disease 2019 (COVID‐19) patients have not yet been elucidated. In this study, we carried out RNA sequencing of nasopharyngeal swabs from a cohort of COVID‐19 patients with mild, moderate, severe outcomes and healthy donors as controls. Over 32.7% of the differentially expressed genes associated with COVID‐19 severity were neutrophil‐related, including those involved in migration, neutrophil extracellular traps formation, and inflammasome activation. Multicohort single‐cell RNA sequencing analysis further confirmed these findings and identified a population of neutrophils expressing Vacuolar‐type ATPase (V‐ATPase) and the chemokine receptor CXCR4 in the nasopharynx. This population of neutrophils preferentially expressed pro‐inflammatory genes relevant to phagosomal maturation as well as local reactive oxygen species and reactive nitrogen species production in the nasopharynx of patients with severe outcomes. A four‐gene panel defined as a neutrophil signature associated with COVID‐19 progression (NSAP) was identified as an early diagnostic predictor of severe COVID‐19, which potentially distinguished severe patients from mild cases with influenza, respiratory syncytial virus, dengue virus, or hepatitis B virus infection. NSAP is mainly expressed on CXCR4high neutrophils and exhibits a significant association with the cell fraction of this neutrophil population. This study highlights novel potential therapeutic targets or diagnostic tools for predicting patients at a higher risk of severe outcomes. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) is caused by Mycobacterium tuberculosis and is one of the primary causes of death worldwide. Rapid and accurate diagnosis of TB is one of the most direct means to reduce the incidence of TB. In this study, urinary proteomic profiling of TB patients and non‐TB individual controls (HCs) was performed, and differentially expressed urinary proteins between TB and HCs were compared and exclusively expressed proteins in TB patients were selected to establish a clinically useful disease marker panel. In total, these top 11 targeted proteins with 265 peptides were scheduled for multiple reaction monitoring validation analysis by using urine samples from 52 TB patients and 52 HCs. The result demonstrated that a three‐protein combination out of the five‐protein panel (namely P22352, Q9P121, P15151, Q13291, and Q8NDA2) exhibited sensitivity rate of 82.7% in the diagnosis of TB. Furthermore, the three‐protein combination could differentiate TB from the latent tuberculosis (LTB) effectively, which exhibited specificity rate of 92.3% for the diagnosis of TB from the LTB category. Although more numbers of clinical samples are required for further verification, the results provided preliminary evidence that this "three‐protein combination" out of the five‐protein panel could probably be a novel TB diagnostic biomarker in clinical application. [ABSTRACT FROM AUTHOR]

Rationale: In order to characterize the intracellular pharmacokinetic properties of tigecycline, we developed and fully validated a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for quantification of tigecycline in human lung epithelial (BEAS‐2B) cells and polymorphonuclear neutrophils (PMNs). Methods: Tetracycline was used as an internal standard and chromatographic separation was achieved on a C18 Hypersil Gold aQ column using two mobile phases, a solution of water (containing 0.1% formic acid) and acetonitrile. The flow rate was 0.4 mL/min for 5.0 min. Tigecycline drug uptake was evaluated by incubating the BEAS‐2B cells and the PMNs for up to 3 h at tigecycline concentrations of 1 mg/L. Results: The assay was linear over the tested concentration range of 0.01–2 mg/L for tigecycline in BEAS‐2B cells and PMNs (r2 >0.99). The inter‐ and inter‐day precisions (RSD, %) were <10.02% and the accuracies (%) were within the range of 85–115%. The uptake study showed that after incubation with tigecycline (1 mg/L) for 3 h at 37°C, the intracellular peak concentration of BEAS‐2B cells was 14.44 ± 7.12 mg/L at 1 h, and 41.43 ± 25.66 mg/L in PMNs at 20 min. The mean intracellular concentrations fluctuated in the range of 0.8–14.44 mg/L in BEAS‐2B cells and 10.14–41.43 mg/L in PMNs for 1 mg/L tigecycline exposure. Conclusions: Validated LC/MS/MS is a simple, rapid, and sensitive method for determining the intracellular concentration of tigecycline, and tigecycline has good penetrations both in human BEAS‐2B cells and PMNs. The method can be efficiently used for future studies of the intracellular pharmacokinetics of tigecycline. [ABSTRACT FROM AUTHOR]

Invasive pulmonary aspergillosis (IPA), most caused by Aspergillus fumigatus, is a serious life-threatening infection in immunocompromised patients. Voriconazole is used to prevent and treat IPA. However, little is known about the pharmacological characteristics of voriconazole in pulmonary epithelial cells, which are the target site for the prophylaxis and early treatment of IPA. The aim of the study was to evaluate the kinetics and activity of voriconazole against A. fumigatus in A549 cells. High-performance liquid chromatography/tandem mass spectrometry and time-kill method were used to study the cellular pharmacokinetic and pharmacodynamics of voriconazole. Voriconazole exerted a concentration-dependent toxic effect on A549 cells and could penetrate into cells, reaching plateau concentrations of 1.14 ± 0.64, 3.72 ± 1.38 and 6.36 ± 0.95 ng/mg protein after A549 cells were exposed to voriconazole at extracellular concentrations of 2, 8 and 16 mg/L for 2 h, respectively. The efflux of voriconazole was rapid, with a half-life of 10.2 min. Voriconazole can decrease the A. fumigatus conidia invade cells, and the number of viable A. fumigatus conidia in cells can be decreased 2.1- to 20.6-fold when A549 cells were cultured in medium containing voriconazole. After 24-h incubation, 75.6% and 80.5% of intracellular A. fumigatus were killed when extracellular voriconazole concentration was 8 and 16 mg/L, respectively. This study illustrated a new application for the prophylaxis and early treatment of IPA from the cellular pharmacokinetics and pharmacodynamics and emphasized the importance of monitoring concentrations of voriconazole in epithelial lining fluid in immunocompromised patients receiving voriconazole therapy. [ABSTRACT FROM AUTHOR]

Invasive fungal disease ( IFD) is a significant cause of morbidity and mortality in hospitalized patients. To maximize the efficacy of voriconazole treatment, the study established the relationship between voriconazole pharmacokinetic/pharmacodynamic ( PK/ PD) and probability of response and optimized voriconazole dosage regimen in patients with IFD based on Monte Carlo simulation. Forty-four patients proven with IFD were involved in this study. Among them, the overall cure rate was 75% (33/44) and there was a significant difference between Cmin/ MIC values in patients with lack of response ( n = 11) and those with successful response ( n = 33) (mean value: 1.91 vs. 11.33; P < 0.05). Logistic regression model showed a high correlation between voriconazole Cmin/ MIC ratio and clinical response ( P = 0.044, OR = 1.349). According to Monte Carlo simulation results under different voriconazole dosing regimens, we could draw a conclusion that 200 mg voriconazole administered intravenously or orally twice daily for Candida infections and 300 mg administered orally or with 200 mg administered intravenously twice daily for Aspergillus infections were rational, which could achieve a value of the cumulative fraction of response >90%. This study built the relationship between voriconazole PK/ PD and clinical response and obtained the reasonable empirical dosage regimen, which can be used to customize individual dosage regimen and improve the efficacy of voriconazole treatment. [ABSTRACT FROM AUTHOR]

Study Objectives To determine the incidence of hepatotoxicity in critically ill patients who were treated with voriconazole and to identify potential risk factors for voriconazole-associated hepatotoxicity in these patients. Design Single-center prospective observational study. Setting Intensive care unit ( ICU) in a university-affiliated hospital in Xi'an, China. Patients Sixty-three adults, admitted to the ICU between January 2010 and July 2015, who had an ICU length of stay longer than 3 days, had received voriconazole treatment for at least 3 days, and had at least one trough voriconazole plasma concentration ( VPC) measurement. Intervention All patients received CYP2C19 genotyping and were evaluated for the development of hepatotoxicity by assessing liver function tests performed before, during, and after voriconazole therapy. Measurements and Main Results Hepatotoxicity was classified according to the National Cancer Institute Common Terminology Criteria for Adverse Events ( CTCAE) grade scores and was defined as a CTCAE grade score that had increased by at least 2 grade scores over the baseline score. Hepatotoxicity occurred in 12 (19%) of the 63 patients. Characteristics of the patients who developed hepatotoxicity were compared with those of the patients who did not develop hepatotoxicity by univariate and multivariate Cox regression analyses. In the univariate analysis, Acute Physiology and Chronic Health Evaluation II score, invasive fungal infection classification, CYP2C19 genotype, and trough VPC were identified as the variables, and they were subsequently combined in the multivariate regression analysis. Multivariate Cox regression analysis revealed that hepatotoxicity was independently associated with trough VPC (hazard ratio 1.76, p<0.001). The relationships between trough VPCs and probability of hepatotoxicity were explored by using logistic regression analysis, and a target VPC upper limit of 4 mg/L was identified. The Kaplan-Meier method for the cumulative incidence of hepatotoxicity showed a significant difference between patients with trough VPCs of 4 mg/L or higher and those with VPCs lower than 4 mg/L (p<0.001). Conclusion Trough VPC was an independent risk factor associated with a greater risk of developing hepatotoxicity in critically ill patients, with a potentially toxic target trough concentration threshold of 4 mg/L identified for this complex population. [ABSTRACT FROM AUTHOR]

Study Objectives To assess the pharmacokinetic and pharmacodynamic ( PK/ PD) properties of voriconazole and to investigate the relationship between PK/ PD parameters and the efficacy of a fixed-dose oral regimen in the treatment of invasive fungal infections ( IFIs). Design Prospective and observational PK/ PD study. Setting A university-affiliated medical center. Patients Fifteen hospitalized patients with proven IFIs who were treated with oral voriconazole for at least 2 weeks. Methods We investigated the PK/ PD properties of voriconazole using a noncompartmental analysis in 15 patients. Results Marked interpatient variation in voriconazole pharmacokinetic properties was noted including peak plasma concentrations (median 2.31 mg/L, range 1.06-4.01 mg/L), 12-hour area under the plasma concentration-time curve ( AUCτ) (median 21.18 hr mg/L, range 7.71-42.07 hr mg/L), ratio of the unbound drug AUC over 24 hours ( fAUC24) divided by the minimum inhibitory concentration ( fAUC24: MIC; median 62.61, range 6.48-415.30), and the free trough plasma concentration (Cmin) divided by the MIC ( fCmin: MIC; median 1.81, range 0.46-15.52). There was a good correlation between voriconazole Cmin and AUCτ ( R2 = 0.805). Voriconazole therapy was effective in 66.7% of patients (10/15). No significant difference was observed with regard to successful clinical response between the patients with a fAUC24: MIC and fCmin: MIC values higher than 25 and higher than 1 (10/12 vs 10/13, respectively; χ2 = 1.61, p=0.688). Conclusion There is substantial interpatient variability in the PK/ PD properties of voriconazole. fAUC24: MIC values higher than 25 and fCmin: MIC values higher than 1 may predict clinical response in patients with IFIs. Designing an optimal dosage regimen based on individual PK/ PD properties will improve the efficacy in patients with IFIs. [ABSTRACT FROM AUTHOR]

The effector functions of CD8+ T cells are influenced by tissue inflammatory microenvironments. IL-33, a member of the IL-1 family, acts as a danger signal after its release during cell necrosis. The IL-33/ST2 axis has been implicated in various Th2 responses. Its role in CD8+ T-cell-mediated immune response is, however, not known. Here we find that type 1 cytotoxic T (Tc1) cells cultured in vitro unexpectedly express high levels of the IL-33 receptor ST2. Interestingly, the expression of ST2 in Tc1 cells is dependent on T-bet, a master Th1/Tc1 transcription factor. In addition, IL-33 enhances TCR-triggered IFN-γ production. IL-33 together with IL-12 can stimulate IFN-γ production in Tc1 cells. Moreover, IL-33 synergizes with IL-12 to promote CD8+ T-cell effector function. The synergistic effect of IL-33 and IL-12 is partly mediated by Gadd45b. Together, these in vitro data establish a novel role of IL-33 in promoting effector type 1 adaptive immune responses. [ABSTRACT FROM AUTHOR]