Risk factors for ventilator-associated lower respiratory tract infection in COVID-19, a retrospective multicenter cohort study in Sweden.

BACKGROUND: Ventilator-associated lower respiratory tract infections (VA-LRTI) increase morbidity and mortality in intensive care unit (ICU) patients. Higher incidences of VA-LRTI have been reported among COVID-19 patients requiring invasive mechanical ventilation (IMV). The primary objectives of this study were to describe clinical characteristics, incidence, and risk factors comparing patients who developed VA-LRTI to patients who did not, in a cohort of Swedish ICU patients with acute hypoxemic respiratory failure due to COVID-19. Secondary objectives were to decipher changes over the three initial pandemic waves, common microbiology and the effect of VA-LTRI on morbidity and mortality. METHODS: We conducted a multicenter, retrospective cohort study of all patients admitted to 10 ICUs in southeast Sweden between March 1, 2020 and May 31, 2021 because of acute hypoxemic respiratory failure due to COVID-19 and were mechanically ventilated for at least 48 h. The primary outcome was culture verified VA-LRTI. Patient characteristics, ICU management, clinical course, treatments, microbiological findings, and mortality were registered. Logistic regression analysis was conducted to determine risk factors for first VA-LRTI. RESULTS: Of a total of 536 included patients, 153 (28.5%) developed VA-LRTI. Incidence rate of first VA-LRTI was 20.8 per 1000 days of IMV. Comparing patients with VA-LRTI to those without, no differences in mortality, age, sex, or number of comorbidities were found. Patients with VA-LRTI had fewer ventilator-free days, longer ICU stay, were more frequently ventilated in prone position, received corticosteroids more often and were more frequently on antibiotics at intubation. Regression analysis revealed increased adjusted odds-ratio (aOR) for first VA-LRTI in patients treated with corticosteroids (aOR 2.64 [95% confidence interval [CI]] [1.31-5.74]), antibiotics at intubation (aOR 2.01 95% CI [1.14-3.66]), and days of IMV (aOR 1.05 per day of IMV, 95% CI [1.03-1.07]). Few multidrug-resistant pathogens were identified. Incidence of VA-LRTI increased from 14.5 per 1000 days of IMV during the first wave to 24.8 per 1000 days of IMV during the subsequent waves. CONCLUSION: We report a high incidence of culture-verified VA-LRTI in a cohort of critically ill COVID-19 patients from the first three pandemic waves. VA-LRTI was associated with increased morbidity but not 30-, 60-, or 90-day mortality. Corticosteroid treatment, antibiotics at intubation and time on IMV were associated with increased aOR of first VA-LRTI.

Population Pharmacokinetics and Dose Evaluation of Cycloserine among Patients with Multidrug-Resistant Tuberculosis under Standardized Treatment Regimens.

Although cycloserine is a recommended drug for the treatment of multidrug-resistant tuberculosis (MDR-TB) according to World Health Organization (WHO), few studies have reported on pharmacokinetics (PK) and/or pharmacodynamics (PD) data of cycloserine in patients with standardized MDR-TB treatment. This study aimed to estimate the population PK parameters for cycloserine and to identify clinically relevant PK/PD thresholds, as well as to evaluate the current recommended dosage. Data from a large cohort with full PK curves was used to develop a population PK model. This model was used to estimate drug exposure in patients with MDR-TB from a multicentre prospective study in China. The classification and regression tree was used to identify the clinically relevant PK/PD thresholds. Probability of target attainment was analyzed to evaluate the currently recommended dosing strategy. Cycloserine was best described by a two-compartment disposition model. A percentage of time concentration above MICs (T>MIC) of 30% and a ratio of area under drug concentration-time curve (AUC0-24h) over MIC of 36 were the valid predictors for 6-month sputum culture conversion and final treatment outcome. Simulations showed that with WHO-recommended doses (500 mg and 750 mg for patients weighing <45 kg and ≥45 kg), the probability of target attainment exceeded 90% at MIC ≤16 mg/L in MGIT for both T>MIC of 30% and AUC0-24h/MIC of 36. New clinically relevant PK/PD thresholds for cycloserine were identified in patients with standardized MDR-TB treatment. WHO-recommended doses were considered adequate for the MGIT MIC distribution in our cohort of Chinese patients with MDR-TB.

Cognitive dysfunction in post-COVID-19 condition: Mechanisms, management, and rehabilitation.

The long-term effects of COVID-19 on cognitive function have become an area of increasing concern. This paper provides an overview of characteristics, risk factors, possible mechanisms, and management strategies for cognitive dysfunction in post-COVID-19 condition (PCC). Prolonged cognitive dysfunction is one of the most common impairments in PCC, affecting between 17% and 28% of the individuals more than 12 weeks after the infection and persisting in some cases for several years. Cognitive dysfunctions can be manifested as a wide range of symptoms including memory impairment, attention deficit, executive dysfunction, and reduced processing speed. Risk factors for developing PCC, with or without cognitive impairments, include advanced age, preexisting medical conditions, and the severity of acute illness. The underlying mechanisms remain unclear, but proposed contributors include neuroinflammation, hypoxia, vascular damage, and latent virus reactivation not excluding the possibility of direct viral invasion of the central nervous system, illustrating complex viral pathology. As the individual variation of the cognitive impairments is large, a neuropsychological examination and a person-centered multidimensional approach are required. According to the World Health Organization, limited evidence on COVID-19-related cognitive impairments necessitates implementing rehabilitation interventions from established practices of similar conditions. Psychoeducation and compensatory skills training are recommended. Assistive products and environmental modifications adapted to individual needs might be helpful. In specific attention- and working memory dysfunctions, cognitive training-carefully monitored for intensity-might be effective for people who do not suffer from post-exertional malaise. Further research is crucial for evidence-based interventions specific to COVID-19-related cognitive impairments.

Specific T-cell responses for guiding treatment with convalescent plasma in severe COVID-19 and humoral immunodeficiency: a case report.

BACKGROUND: The immune response to SARS-CoV-2 virus, the cause of COVID-19, is complex. Antibody mediated responses are important for viral clearance but may also drive hyperinflammation in severe COVID-19. We present a case of an individual with a genetic inability to produce antibodies and severe COVID-19, receiving no other specific anti-viral treatment than convalescent COVID-19 plasma, illustrating that hyperinflammation can occur in the absence of a humoral anti-viral response. In addition, the case illustrates that the assessment of SARS-CoV-2 T cell responses can facilitate clinical decision making in patients with COVID-19 and weak or absent humoral immune responses. CASE PRESENTATION: A male with X-linked agammaglobulinemia on regular immunoglobulin replacement therapy, hospitalized for 35 days due to severe COVID-19. Systemic inflammatory parameters were highly elevated. After treatment with convalescent COVID-19 plasma he became afebrile and the fatigue diminished. He was discharged on day 42 and nasopharyngeal SARS-CoV-2 PCR eventually was negative on day 49. Evidence of SARS-CoV-2 specific T cells prior to administration of plasma therapy suggested that antibodies were crucial for viral clearance. Regular assessment showed robust and persistent SARS-CoV-2 specific T-cell responses after recovery suggested that prophylactic administration of convalescent COVID-19 plasma was unnecessary. CONCLUSION: Assessment of SARS-CoV-2T-cell responses can facilitate the clinical management of COVID-19 patients with humoral immunodeficiencies.

Improved 60-day survival but impaired general health in Swedish ICU-COVID patients: An ambidirectional population-based study.

BACKGROUND: Survival among critically ill COVID-19 patients varies between countries and time periods. Mortality rates up to 60% have been reported in intensive care units (ICUs). Standard-of-care has evolved throughout the pandemic. The purpose of the study was to explore management and mortality of COVID-19 ICU-patients during the first pandemic wave and assess their post-ICU health status. METHODS: We conducted an exploratory observational ambidirectional population-based study of ICU-patients with COVID-19 in a Swedish county during 1 March-30 June 2020. Primary outcome was 60-day mortality with secondary outcomes including treatments, complications, self-reported general health and dyspnoea post-discharge. Patients were consecutively divided into equal tertiles with cut-offs on April 4 and April 20, 2020, to analyse time trends. RESULTS: One hundred patients, median age was 63 years, were included, and 60-day mortality rate was 22%. Ninety-one percent had moderate/severe ARDS and 88% required mechanical ventilation. In the first tertile of patients 60-day mortality was 33%, declining to 15% and 18% in the following two. This reduction paralleled increased use of thromboprophylaxis, less steep rise of treated ICU-patients per day and expanded ICU resources. Four months post-discharge, 63% of survivors reported self-assessed decline in general health retrospectively compared to prior COVID-19. CONCLUSIONS: In this cohort, the initial 60-day mortality quickly declined, despite continuous admittance of critically ill patients. This was parallel to adaptation to increased workload and more intense thromboembolic prophylaxis. A majority of survivors reported declined general health four months after discharge. Further studies on long-term health status of ICU-survivors are indicated.

Individualised dosing algorithm and personalised treatment of high-dose rifampicin for tuberculosis.

AIMS: To propose new exposure targets for Bayesian dose optimisation suited for high-dose rifampicin and to apply them using measured plasma concentrations coupled with a Bayesian forecasting algorithm allowing predictions of future doses, considering rifampicin's auto-induction, saturable pharmacokinetics and high interoccasion variability. METHODS: Rifampicin exposure targets for Bayesian dose optimisation were defined based on literature data on safety and anti-mycobacterial activity in relation to rifampicin's pharmacokinetics i.e. highest plasma concentration up to 24 hours and area under the plasma concentration-time curve up to 24 hours (AUC0-24h ). Targets were suggested with and without considering minimum inhibitory concentration (MIC) information. Individual optimal doses were predicted for patients treated with rifampicin (10 mg/kg) using the targets with Bayesian forecasting together with sparse measurements of rifampicin plasma concentrations and baseline rifampicin MIC. RESULTS: The suggested exposure target for Bayesian dose optimisation was a steady state AUC0-24h of 181-214 h × mg/L. The observed MICs ranged from 0.016-0.125 mg/L (mode: 0.064 mg/L). The predicted optimal dose in patients using the suggested target ranged from 1200-3000 mg (20-50 mg/kg) with a mode of 1800 mg (30 mg/kg, n = 24). The predicted optimal doses when taking MIC into account were highly dependent on the known technical variability of measured individual MIC and the dose was substantially lower compared to when using the AUC0-24h -only target. CONCLUSIONS: A new up-to-date exposure target for Bayesian dose optimisation suited for high-dose rifampicin was derived. Using measured plasma concentrations coupled with Bayesian forecasting allowed prediction of the future dose whilst accounting for the auto-induction, saturable pharmacokinetics and high between-occasion variability of rifampicin.

Plasma Levels of Rifampin Correlate with the Tuberculosis Drug Activity Assay.

The plasma tuberculosis drug activity (TDA) assay may be an alternative tool for therapeutic drug monitoring in resource-limited settings. In tuberculosis (TB) patients (n = 30), TDA and plasma levels of first-line drugs were analyzed 2 h postdose, 2 weeks after treatment initiation. Patients with plasma levels of rifampin lower than 8 mg/liter had a significantly lower median TDA (1.40 versus 1.68, P = 0.0013). TDA may be used to identify TB patients with suboptimal rifampin levels during TB treatment.

Distribution of plasma concentrations of first-line anti-TB drugs and individual MICs: a prospective cohort study in a low endemic setting.

Background: Therapeutic drug monitoring (TDM) could improve current TB treatment, but few studies have reported pharmacokinetic data together with MICs. Objectives: To investigate plasma concentrations of rifampicin, isoniazid, pyrazinamide and ethambutol along with MICs. Methods: Drug concentrations of rifampicin, isoniazid, pyrazinamide and ethambutol were analysed pre-dose and 2, 4 and 6 h after drug intake at week 2 in 31 TB patients and MICs in BACTEC 960 MGIT were determined at baseline. The highest plasma concentrations at 2, 4 and 6 h post-dose (Chigh) were determined, as well as estimates of Chigh/MIC and area under the concentration-time curve (AUC0-6)/MIC including the corresponding ratios based on calculated free-drug concentrations. This trial was registered at www.clinicaltrials.gov (NCT02042261). Results: After 2 weeks of treatment, the median Chigh values for rifampicin, isoniazid, pyrazinamide and ethambutol were 10.0, 5.3, 41.1 and 3.3 mg/L respectively. Lower than recommended drug concentrations were detected in 42% of the patients for rifampicin (<8 mg/L), 19% for isoniazid (<3 mg/L), 27% for pyrazinamide (<35 mg/L) and 16% for ethambutol (<2 mg/L). The median Chigh/MIC values for rifampicin, isoniazid, pyrazinamide and ethambutol were 164, 128, 1.3 and 2.5, respectively, whereas the AUC0-6/MIC was 636 (range 156-2759) for rifampicin and 351 (range 72-895) for isoniazid. Conclusions: We report low levels of first-line TB drugs in 16%-42% of patients, in particular for rifampicin. There was a wide distribution of the ratios between drug exposures and MICs. The future use of MIC determinations in TDM is dependent on the development of a reference method and clinically validated pharmacokinetic/pharmacodynamic targets.

Susceptibility testing breakpoints for Mycobacterium tuberculosis categorize isolates with resistance mutations in gyrA as susceptible to fluoroquinolones: implications for MDR-TB treatment and the definition of XDR-TB.

OBJECTIVES: Fluoroquinolones (FQs) are important in the treatment of MDR-TB and in the definition of XDR-TB. Our objective was to investigate how discrepancies in the phenotypic and genotypic methods for antimicrobial susceptibility testing could affect the interpretation of antimicrobial susceptibility test results. METHODS: We analysed MICs of ofloxacin and levofloxacin in Middlebrook 7H10 broth (7H10) as well as sequencing of the quinolone resistance-determining region of the gyrA gene and the MTBDRsl assay in 75 resistant isolates, including MDR and XDR strains of Mycobacterium tuberculosis. RESULTS: Among 75 resistant isolates, 27 had mutations associated with FQ resistance. Among isolates with resistance mutations in gyrA, 26% (seven of 27) were susceptible to levofloxacin and ofloxacin by phenotypic testing at 1 mg/L and 2 mg/L. The most common mutation was in codon 94 and these isolates had significantly increased MICs of levofloxacin (2-8 mg/L) compared with isolates with mutations in codon 90 (0.25-2 mg/L, P < 0.05). The sensitivity and specificity for the MTBDRsl assay compared with gyrA sequencing were 96% and 98%, respectively. CONCLUSION: Current critical concentrations may classify up to 26% of isolates with gyrA mutations as susceptible to FQs due to a close relationship between susceptible and resistant populations. These results should be considered while improving clinical breakpoints for M. tuberculosis and may have an impact on the definition of XDR-TB.

Second-line antituberculosis drug exposure thresholds predictive of adverse events in multidrug-resistant tuberculosis treatment.

OBJECTIVES: This study aimed to investigate the association between drug exposure and adverse events (AEs) during the standardized multidrug-resistant tuberculosis (MDR-TB) treatment, as well as to identify predictive drug exposure thresholds. METHODS: We conducted a prospective, observational multicenter study among participants receiving standardized MDR-TB treatment between 2016 and 2019 in China. AEs were monitored throughout the treatment and their relationships to drug exposure (e.g., the area under the drug concentration-time curve from 0 to 24 h, AUC0-24 h) were analyzed. The thresholds of pharmacokinetic predictors of observed AEs were identified by boosted classification and regression tree (CART) and further evaluated by external validation. RESULTS: Of 197 study participants, 124 (62.9%) had at least one AE, and 15 (7.6%) experienced serious AEs. The association between drug exposure and AEs was observed including bedaquiline, its metabolite M2, moxifloxacin and QTcF prolongation (QTcF >450 ms), linezolid and mitochondrial toxicity, cycloserine and psychiatric AEs. The CART-derived thresholds of AUC0-24 h predictive of the respective AEs were 3.2 mg·h/l (bedaquiline M2); 49.3 mg·h/l (moxifloxacin); 119.3 mg·h/l (linezolid); 718.7 mg·h/l (cycloserine). CONCLUSIONS: This study demonstrated the drug exposure thresholds predictive of AEs for key drugs against MDR-TB treatment. Using the derived thresholds will provide the knowledge base for further randomized clinical trials of dose adjustment to minimize the risk of AEs.

Two-year follow-up of patients with post-COVID-19 condition in Sweden: a prospective cohort study.

Background: Few studies have reported the long-term health effects of COVID-19. The regional population-based Linköping COVID-19 study (LinCoS) included all patients hospitalised due to COVID-19 during the first pandemic wave. Four months post-discharge, over 40% (185/433) experienced persisting symptoms and activity/participation limitations, indicating post-COVID-19 condition (PCC). The present follow-up study aimed to determine the long-term recovery among these patients 24 months post-admission. Methods: This prospective cohort study included all patients from LinCoS with PCC at four months post-discharge. We repeated the same structured interview at a 24-month follow-up to identify persisting symptoms and their impact on daily life. Intercurrent health issues were identified by reviewing medical records. Findings: Of 185 patients with PCC at 4 months post-discharge, 181 were alive at the 24-month assessment and 165 agreed to participate. Of those, 21% (35/165) had been readmitted to hospital for various causes in the interim period. The majority of patients (139/165, 84%) reported persisting problems affecting everyday life at 24 months. Significant improvements were seen in the prevalence and magnitude of some symptoms/limitations compared with four months post-discharge. Cognitive, sensorimotor, and fatigue symptoms were the most common persisting symptoms at 24 months. No clear difference was evident between individuals treated in the intensive care unit (ICU) and non-ICU-treated individuals. Approximately half of those who were on sick leave related to PCC at four months after infection were on sick leave at 24 months. Interpretation: This is one of the first studies to report 2-year outcomes in patients with PCC following COVID-19 hospitalisation. Despite some improvements over time, we found a high prevalence of persisting symptoms and a need for long-term follow-up and rehabilitation post COVID-19 infection. Funding: The study was funded by Region Östergötland.

Population pharmacokinetics and model-based dosing evaluation of bedaquiline in multidrug-resistant tuberculosis patients.

Aims: Bedaquiline is now recommended to all patients in the treatment of multidrug-resistant tuberculosis (MDR-TB) using standard dosing regimens. As the ability to measure blood drug concentrations is very limited, little is known about drug exposure and treatment outcome. Thus, this study aimed to model the population pharmacokinetics as well as to evaluate the currently recommended dosage. Methodology: A bedaquiline population pharmacokinetic (PK) model was developed based on samples collected from the development cohort before and 1, 2, 3, 4, 5, 6, 8, 12, 18, and 24 h after drug intake on week 2 and week 4 of treatment. In a prospective validation cohort of patients with MDR-TB, treated with bedaquiline-containing standardized regimen, drug exposure was assessed using the developed population PK model and thresholds were identified by relating to 2-month and 6-month sputum culture conversion and final treatment outcome using classification and regression tree analysis. In an exploratory analysis by the probability of target attainment (PTA) analysis, we evaluated the recommended dosage at different MIC levels by Middlebrook 7H11 agar dilution (7H11). Results: Bedaquiline pharmacokinetic data from 55 patients with MDR-TB were best described by a three-compartment model with dual zero-order input. Body weight was a covariate of the clearance and the central volume of distribution, albumin was a covariate of the clearance. In the validation cohort, we enrolled 159 patients with MDR-TB. The 7H11 MIC mode (range) of bedaquiline was 0.06 mg (0.008-0.25 mg/L). The study participants with AUC0-24h/MIC above 175.5 had a higher probability of culture conversion after 2-month treatment (adjusted relative risk, aRR:16.4; 95%CI: 5.3-50.4). Similarly, those with AUC0-24h/MIC above 118.2 had a higher probability of culture conversion after 6-month treatment (aRR:20.1; 95%CI: 2.9-139.4), and those with AUC0-24h/MIC above 74.6 had a higher probability of successful treatment outcome (aRR:9.7; 95%CI: 1.5-64.8). Based on the identified thresholds, simulations showed that the WHO recommended dosage (400 mg once daily for 14 days followed by 200 mg thrice weekly) resulted in PTA >90% for the majority of isolates (94%; MICs ≤0.125 mg/L). Conclusion: We established a population PK model for bedaquiline in patients with MDR-TB in China. Based on the thresholds and MIC distribution derived in a clinical study, the recommended dosage of bedaquiline is sufficient for the treatment of MDR-TB.

Anakinra or tocilizumab in patients admitted to hospital with severe covid-19 at high risk of deterioration (IMMCoVA): A randomized, controlled, open-label trial.

BACKGROUND: Anakinra and tocilizumab are used for severe Covid-19, but only one previous randomized controlled trial (RCT) has studied both. We performed a multi-center RCT comparing anakinra or tocilizumab versus usual care (UC) for adults at high risk of deterioration. METHODS: The study was conducted June 2020 to March 2021. Eligibility required ≥ 5 liters/minute of Oxygen to maintain peripheral oxygen saturation at ≥ 93%, CRP > 70 mg/L, ferritin > 500 µg/L and at least two points where one point was awarded for lymphocytes < 1x 109/L; D-dimer ≥ 0.5 mg/L and; lactate dehydrogenase ≥ 8 microkatal/L. Patients were randomly assigned 1:1:1 to receive either a single dose of tocilizumab (8 mg/kg) or anakinra 100 mg IV QID for seven days or UC alone. The primary outcome was time to recovery. RESULTS: Recruitment was ended prematurely when tocilizumab became part of usual care. Out of a planned 195 patients, 77 had been randomized, 27 to UC, 28 to anakinra and 22 to tocilizumab. Median time to recovery was 15, 15 and 11 days. Rate ratio for recovery for UC vs anakinra was 0.91, 0.47 to 1.78, 95% [CI], p = 0.8 and for UC vs tocilizumab 1.13, 0.55 to 2.30; p = 0.7. There were non-significant trends favoring tocilizumab (and to limited degree anakinra) vs UC for some secondary outcomes. Safety profiles did not differ significantly. CONCLUSION: Premature closure of trial precludes firm conclusions. Anakinra or tocilizumab did not significantly shorten time to clinical recovery compared to usual care. (IMMCoVA, NCT04412291, EudraCT: 2020-00174824).

Rehabilitation needs following COVID-19: Five-month post-discharge clinical follow-up of individuals with concerning self-reported symptoms.

BACKGROUND: This report describes and objectivizes reported problems among a cohort of previously hospitalized COVID-19 patients by clinical examination and determination of the required level of rehabilitation sevices. METHODS: This report forms part of the Linköping COVID-19 Study (LinCoS) that included 745 individuals from one of 21 Swedish healthcare regions, Region Östergötland (RÖ), admitted to hospital for COVID-19 during March 1st-May 31st, 2020. In this descriptive ambidirectional cohort study, all 185 individuals who had reported concerning persisting symptoms were invited to a multi-professional clinical assessment of somatic, functional, affective, neuropsychological status and rehabilitation needs. Rehabilitation needs were assessed using three sub-scales of the Rehabilitation Complexity Scale-Extended. FINDINGS: Among the 158 (85·4%) cases consenting and included in the analysis, we found a broad array of symptoms and signs attributable to COVID-19 involving respiratory, visual, auditory, motor, sensory and cognitive functions that could be confirmed clinically at five months post-discharge. This translated into 16% [95% CI 13-20] of survivors (70/433) of the total regional cohort of hospitalised patients requiring further rehabilitative interventions at follow-up. Weakness in extremities was reported in 28·5% [21·6, 36·2] (45/158). On examination, clinically overt muscle weakness could be corroborated in 15 individuals (10·5%) [6·1, 16·4]. 48% [40, 56] (76/158) reported cognitive symptoms, while the physician noted overt cognitive impairments in only 3% [1·1, 7·5]. In neuropsychological testing, 37% [28-46] (45/122) performed 1.5 SD below the norm, indicating neurocognitive deficits. Fifty-five individuals (34·8%) [27·4, 42·8] reported new or aggravated pain. In three fourths of them, it exerted a 'moderate' or worse detrimental effect on their ability to work. INTERPRETATION: Our study underscores the importance of providing extensive examination of cases with persisting problems after COVID-19, especially since symptoms such as fatigue and breathlessness are highly nonspecific, but may represent significant underlying functional impairments. Robust neurocognitive testing should be performed, as cognitive problems may easily be overlooked during routine medical consultation. In the Swedish context, most rehabilitative interventions could be provided in a primary care setting. A substantial minority of patients should be triaged to specialized rehabilitation services.

Population pharmacokinetics and dose evaluations of linezolid in the treatment of multidrug-resistant tuberculosis.

Background: The pharmacokinetic/pharmacodynamics (PK/PD) target derived from the hollow-fiber system model for linezolid for treatment of the multidrug-resistant tuberculosis (MDR-TB) requires clinical validation. Therefore, this study aimed to develop a population PK model for linezolid when administered as part of a standardized treatment regimen, to identify the PK/PD threshold associated with successful treatment outcomes and to evaluate currently recommended linezolid doses. Method: This prospective multi-center cohort study of participants with laboratory-confirmed MDR-TB was conducted in five TB designated hospitals. The population PK model for linezolid was built using nonlinear mixed-effects modeling using data from 168 participants. Boosted classification and regression tree analyses (CART) were used to identify the ratio of 0- to 24-h area under the concentration-time curve (AUC0-24h) to the minimal inhibitory concentration (MIC) threshold using the BACTEC MGIT 960 method associated with successful treatment outcome and validated in multivariate analysis using data from a different and prospective cohort of 159 participants with MDR-TB. Furthermore, based on the identified thresholds, the recommended doses were evaluated by the probability of target attainment (PTA) analysis. Result: Linezolid plasma concentrations (1008 samples) from 168 subjects treated with linezolid, were best described by a 2-compartment model with first-order absorption and elimination. An AUC0-24h/MIC > 125 was identified as a threshold for successful treatment outcome. Median time to sputum culture conversion between the group with AUC0-24h/MIC above and below 125 was 2 versus 24 months; adjusted hazard ratio (aHR), 21.7; 95% confidence interval (CI), (6.4, 72.8). The boosted CART-derived threshold and its relevance to the final treatment outcome was comparable to the previously suggested target of AUC0-24h/MIC (119) using MGIT MICs in a hollow fiber infection model. Based on the threshold from the present study, at a standard linezolid dose of 600 mg daily, PTA was simulated to achieve 100% at MGIT MICs of ≤ .25 mg which included the majority (81.1%) of isolates in the study. Conclusion: We validated an AUC0-24h/MIC threshold which may serve as a target for dose adjustment to improve efficacy of linezolid in a bedaquiline-containing treatment. Linezolid exposures with the WHO-recommended dose (600 mg daily) was sufficient for all the M. tb isolates with MIC ≤ .25 mg/L.

Safety and pharmacokinetics-pharmacodynamics of a shorter tuberculosis treatment with high-dose pyrazinamide and rifampicin: a study protocol of a phase II clinical trial (HighShort-RP).

INTRODUCTION: Increased dosing of rifampicin and pyrazinamide seems a viable strategy to shorten treatment and prevent relapse of drug-susceptible tuberculosis (TB), but safety and efficacy remains to be confirmed. This clinical trial aims to explore safety and pharmacokinetics-pharmacodynamics of a high-dose pyrazinamide-rifampicin regimen. METHODS AND ANALYSIS: Adult patients with pulmonary TB admitted to six hospitals in Sweden and subjected to receive first-line treatment are included. Patients are randomised (1:3) to either 6-month standardised TB treatment or a 4-month regimen based on high-dose pyrazinamide (40 mg/kg) and rifampicin (35 mg/kg) along with standard doses of isoniazid and ethambutol. Plasma samples for measurement of drug exposure determined by liquid chromatography tandem-mass spectrometry are obtained at 0, 1, 2, 4, 6, 8, 12 and 24 hours, at day 1 and 14. Maximal drug concentration (Cmax) and area under the concentration-time curve (AUC0-24h) are estimated by non-compartmental analysis. Conditions for early model-informed precision dosing of high-dose pyrazinamide-rifampicin are pharmacometrically explored. Adverse drug effects are monitored throughout the study and graded according to Common Terminology Criteria for Adverse Events V.5.0. Early bactericidal activity is assessed by time to positivity in BACTEC MGIT 960 of induced sputum collected at day 0, 5, 8, 15 and week 8. Minimum inhibitory concentrations of first-line drugs are determined using broth microdilution. Disease severity is assessed with X-ray grading and a validated clinical scoring tool (TBscore II). Clinical outcome is registered according to WHO definitions (2020) in addition to occurrence of relapse after end of treatment. Primary endpoint is pyrazinamide AUC0-24h and main secondary endpoint is safety. ETHICS AND DISSEMINATION: The study is approved by the Swedish Ethical Review Authority and the Swedish Medical Products Agency. Informed written consent is collected before study enrolment. The study results will be submitted to a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT04694586.

A Phase 2 Trial of the Effect of Antiandrogen Therapy on COVID-19 Outcome: No Evidence of Benefit, Supported by Epidemiology and In Vitro Data.

BACKGROUND: Men are more severely affected by COVID-19. Testosterone may influence SARS-CoV-2 infection and the immune response. OBJECTIVE: To clinically, epidemiologically, and experimentally evaluate the effect of antiandrogens on SARS-CoV-2 infection. DESIGNS, SETTINGS, AND PARTICIPANTS: A randomized phase 2 clinical trial (COVIDENZA) enrolled 42 hospitalized COVID-19 patients before safety evaluation. We also conducted a population-based retrospective study of 7894 SARS-CoV-2-positive prostate cancer patients and an experimental study using an air-liquid interface three-dimensional culture model of primary lung cells. INTERVENTION: In COVIDENZA, patients were randomized 2:1 to 5 d of enzalutamide or standard of care. OUTCOME MEASUREMENTS: The primary outcomes in COVIDENZA were the time to mechanical ventilation or discharge from hospital. The population-based study investigated risk of hospitalization, intensive care, and death from COVID-19 after androgen inhibition. RESULTS AND LIMITATIONS: Enzalutamide-treated patients required longer hospitalization (hazard ratio [HR] for discharge from hospital 0.43, 95% confidence interval [CI] 0.20-0.93) and the trial was terminated early. In the epidemiological study, no preventive effects were observed. The frail population of patients treated with androgen deprivation therapy (ADT) in combination with abiraterone acetate or enzalutamide had a higher risk of dying from COVID-19 (HR 2.51, 95% CI 1.52-4.16). In vitro data showed no effect of enzalutamide on virus replication. The epidemiological study has limitations that include residual confounders. CONCLUSIONS: The results do not support a therapeutic effect of enzalutamide or preventive effects of bicalutamide or ADT in COVID-19. Thus, these antiandrogens should not be used for hospitalized COVID-19 patients or as prevention for COVID-19. Further research on these therapeutics in this setting are not warranted. PATIENT SUMMARY: We studied whether inhibition of testosterone could diminish COVID-19 symptoms. We found no evidence of an effect in a clinical study or in epidemiological or experimental investigations. We conclude that androgen inhibition should not be used for prevention or treatment of COVID-19.

COVIDENZA - A prospective, multicenter, randomized PHASE II clinical trial of enzalutamide treatment to decrease the morbidity in patients with Corona virus disease 2019 (COVID-19): a structured summary of a study protocol for a randomised controlled trial.

OBJECTIVES: The main goal of the COVIDENZA trial is to evaluate if inhibition of testosterone signalling by enzalutamide can improve the outcome of patients hospitalised for COVID-19. The hypothesis is based on the observation that the majority of patients in need of intensive care are male, and the connection between androgen receptor signalling and expression of TMPRSS2, an enzyme important for SARS-CoV-2 host cell internalization. TRIAL DESIGN: Hospitalised COVID-19 patients will be randomised (2:1) to enzalutamide plus standard of care vs. standard of care designed to identify superiority. PARTICIPANTS: Included participants, men or women above 50 years of age, must be hospitalised for PCR confirmed COVID-19 symptoms and not in need of immediate mechanical ventilation. Major exclusion criteria are breast-feeding or pregnant women, hormonal treatment for prostate or breast cancer, treatment with immunosuppressive drugs, current symptomatic unstable cardiovascular disease (see Additional file 1 for further details). The trial is registered at Umeå University Hospital, Region Västerbotten, Sweden and 8 hospitals are approved for inclusion in Sweden. INTERVENTION AND COMPARATOR: Patients randomised to the treatment arm will be treated orally with 160 mg (4x40 mg) enzalutamide (Xtandi®) daily, for five consecutive days. The study is not placebo controlled. The comparator is standard of care treatment for patients hospitalised with COVID-19. MAIN OUTCOMES: The primary endpoints of the study are (time to) need of mechanical ventilation or discharge from hospital as assessed by a clinical 7-point ordinal scale (up to 30 days after inclusion). RANDOMISATION: Randomisation was stratified by center and sex. Each strata was randomized separately with block size six with a 2:1 allocation ratio (enzalutamide + "standard of care": "standard of care"). The randomisation list, with consecutive subject numbers, was generated by an independent statistician using the PROC PLAN procedure of SAS version 9.4 software (SAS Institute, Inc, Cary, North Carolina) BLINDING (MASKING): This is an open-label trial. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): The trial is designed to have three phases. The first, an exploration phase of 45 participants (30 treatment and 15 control) will focus on safety and includes a more extensive laboratory assessment as well as more frequent safety evaluation. The second prolongation phase, includes the first 100 participants followed by an interim analysis to define the power of the study. The third phase is the continuation of the study up to maximum 600 participants included in total. TRIAL STATUS: The current protocol version is COVIDENZA v2.0 as of September 10, 2020. Recruitment started July 29, 2020 and is presently in safety pause after the first exploration phase. Recruitment is anticipated to be complete by 31 December 2021. TRIAL REGISTRATION: Eudract number 2020-002027-10 ClinicalTrials.gov Identifier: NCT04475601 , registered June 8, 2020 FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Development and validation of a simple LC-MS/MS method for simultaneous determination of moxifloxacin, levofloxacin, prothionamide, pyrazinamide and ethambutol in human plasma.

Treatment of multidrug-resistant tuberculosis (MDR-TB) is challenging due to high treatment failure rate and adverse drug events. This study aimed to develop and validate a simple LC-MS/MS method for simultaneous measurement of five TB drugs in human plasma and to facilitate therapeutic drug monitoring (TDM) in MDR-TB treatment to increase efficacy and reduce toxicity. Moxifloxacin, levofloxacin, prothionamide, pyrazinamide and ethambutol were prepared in blank plasma from healthy volunteers and extracted using protein precipitation reagent containing trichloroacetic acid. Separation was achieved on an Atlantis T3 column with gradient of 0.1% formic acid in water and acetonitrile. Drug concentrations were determined by dynamic multiple reaction monitoring in positive ion mode on a LC-MS/MS system. The method was validated according to the United States' Food and Drug Administration (FDA) guideline for bioanalytical method validation. The calibration curves for moxifloxacin, levofloxacin, prothionamide, pyrazinamide and ethambutol were linear, with the correlation coefficient values above 0.993, over a range of 0.1-5, 0.4-40, 0.2-10, 2-100 and 0.2-10 mg/L, respectively. Validation showed the method to be accurate and precise with bias from 6.5% to 18.3% for lower limit of quantification and -5.8% to 14.6% for LOW, medium (MED) and HIGH drug levels, and with coefficient of variations within 11.4% for all levels. Regarding dilution integrity, the bias was within 7.2% and the coefficient of variation was within 14.9%. Matrix effect (95.7%-112.5%) and recovery (91.4%-109.7%) for all drugs could be well compensated by their isotope-labelled internal standards. A benchtop stability test showed that the degradation of prothionamide was over 15% after placement at room temperature for 72 h. Clinical samples (n = 224) from a cohort study were analyzed and all concentrations were within the analytical range. The signal of prothionamide was suppressed in samples with hemolysis which was solved by sample dilution. As the method is robust and sample preparation is simple, it can easily be implemented to facilitate TDM in programmatic MDR-TB treatment.