Influenza-associated invasive aspergillosis in patients admitted to the intensive care unit in Sweden: a prospective multicentre cohort study.

BACKGROUND: The purpose of this study was to prospectively investigate the incidence of influenza-associated pulmonary aspergillosis (IAPA) in influenza patients admitted to intensive care units in Sweden. METHODS: The study included consecutive adult patients with PCR-verified influenza A or B in 12 Swedish intensive care units (ICUs) over four influenza seasons (2019-2023). Patients were screened using serum galactomannan and ß-d-glucan tests and fungal culture of a respiratory sample at inclusion and weekly during the ICU stay. Bronchoalveolar lavage was performed if clinically feasible. IAPA was classified according to recently proposed case definitions. RESULTS: The cohort included 55 patients; 42% were female, and the median age was 59 (IQR 48-71) years. All patients had at least one galactomannan test, ß-d-glucan test and respiratory culture performed. Bronchoalveolar lavage was performed in 24 (44%) of the patients. Five (9%, 95% CI 3.8% - 20.4%) patients were classified as probable IAPA, of which four lacked classical risk factors. The overall ICU mortality was significantly higher among IAPA patients than non-IAPA patients (60% vs 8%, p = 0.01). CONCLUSIONS: The study represents the first prospective investigation of IAPA incidence. The 9% incidence of IAPA confirms the increased risk of invasive pulmonary aspergillosis among influenza patients admitted to the ICU. Therefore, it appears reasonable to implement a screening protocol for the early diagnosis and treatment of IAPA in influenza patients receiving intensive care. TRIAL REGISTRATION: ClinicalTrials.gov NCT04172610, registered November 21, 2019.

Effects of remdesivir on SARS-CoV-2 viral dynamics and mortality in viraemic patients hospitalized for COVID-19.

BACKGROUND: Studies on the antiviral effects of remdesivir have shown conflicting results. SARS-CoV-2 viraemia could identify patients in whom antiviral treatment may be particularly beneficial. OBJECTIVES: To investigate antiviral effects and clinical outcomes of remdesivir treatment in viraemic patients. METHODS: Viraemic patients hospitalized for COVID-19 with ratio of arterial oxygen partial pressure to fractional inspired oxygen of ≤300, symptom duration ≤10 days, and estimated glomerular filtration rate ≥30 mL/min were included in a cohort. The rate of serum viral clearance and serum viral load decline, 60 day mortality and in-hospital outcomes were estimated. A subgroup analysis including patients with symptom duration ≤7 days was performed. RESULTS: A total of 318 viraemic patients were included. Thirty-three percent (105/318) received remdesivir. The rate of serum viral clearance [subhazard risk ratio (SHR) 1.4 (95% CI 0.9-2.0), P = 0.11] and serum viral load decline (P = 0.11) were not significantly different between remdesivir-treated patients and controls. However, the rate of serum viral clearance was non-significantly higher [SHR 1.6 (95% CI 1.0-2.7), P = 0.051] and the viral load decline was faster (P = 0.03) in remdesivir-treated patients with symptom duration ≤7 days at admission. The 60 day mortality [HR 1.0 (95% CI 0.6-1.8), P = 0.97] and adverse in-hospital outcomes [OR 1.4 (95% CI 0.8-2.4), P = 0.31] were not significantly different between remdesivir-treated patients and controls. CONCLUSIONS: Remdesivir treatment did not significantly change the duration of SARS-CoV-2 viraemia, decline of serum viral load, 60 day mortality or in-hospital adverse outcomes in patients with ≤10 days of symptoms at admission. Remdesivir appeared to reduce the duration of viraemia in a subgroup of patients with ≤7 days of symptoms at admission.

First Sampled High-Sensitive Cardiac Troponin T is Associated With One-Year Mortality in Sepsis Patients and 30- to 365-Day Mortality in Sepsis Survivors.

BACKGROUND: Previous studies using cardiac troponin levels to investigate the relationship between myocardial injury and mortality in sepsis patients have been conflicting. Our aim was to investigate the relationship between plasma high-sensitive cardiac troponin T (hs-cTnT) level and 30-day and 1-year mortality in sepsis patients and 30- to 365-day mortality in sepsis survivors. METHODS: Sepsis patients requiring vasopressor support and admitted to our institution between 2012 and 2021 (n = 586) were included in this retrospective cohort study. Elevated hs-cTnT values (≥15 ng/L) were divided into quartiles (Q): Q1 15-35 ng/L; Q2 36-61 ng/L; Q3 62-125 ng/L; Q4 126-8630 ng/L. Stratified Kaplan-Meier curves and multivariable Cox regression were used for survival analyses. RESULTS: First sampled hs-cTnT was elevated in 529 (90%) patients. One-year mortality was 45% (n = 264). Increasing level of hs-cTnT was independently associated with higher adjusted hazard ratios (HR) for 1-year mortality compared with normal levels: Q1 HR 2.9 (95% confidence interval [CI], 1.03-8.1); Q2 HR 3.5 (95% CI, 1.2-9.8); Q3 HR 4.8 (95% CI, 1.7-13.4); Q4 HR 5.7 (95% CI, 2.1-16). In acute phase survivors, first sampled hs-cTnT was an independent predictor of 30- to 365-day mortality (HR 1.3; 95% CI, 1.1-1.6 per loge hs-cTnT). CONCLUSIONS: First sampled plasma hs-cTnT in critically ill sepsis patients was independently associated with 30-day and 1-year mortality. Importantly, first sampled hs-cTnT was associated with mortality during the convalescence phase (30- to 365-day) and could be a feasible marker to identify acute phase survivors at high risk of death.

Correlation of SARS-CoV-2 Nasopharyngeal CT Values With Viremia and Mortality in Adults Hospitalized With COVID-19.

Background: Both severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viremia and nasopharyngeal viral load have been suggested to be predictors of unfavorable outcome in coronavirus disease 2019 (COVID-19). This study aimed to investigate whether nasopharyngeal viral load is correlated with viremia and unfavorable outcome. Methods: The presence of SARS-CoV-2 RNA was determined in paired nasopharyngeal and serum samples collected at admission from patients hospitalized for COVID-19. Standardized cycle threshold values (CT values) were used as an indicator of viral load. An adjusted logistic regression was used to estimate the risk of viremia at different nasopharyngeal CT values. A Cox regression was used to estimate the risk of 60-day mortality. Results: A total of 688 patients were included. Viremia at admission was detected in 63% (146/230), 46% (105/226), and 31% (73/232) of patients with low, intermediate, and high nasopharyngeal CT values. The adjusted odds ratios of being viremic were 4.4 (95% CI, 2.9-6.8) and 2.0 (95% CI, 1.4-3.0) for patients with low and intermediate CT values, compared with high CT values. The 60-day mortality rate was 37% (84/230), 15% (36/226), and 10% (23/232) for patients with low, intermediate, and high nasopharyngeal CT values at admission, respectively. Adjusted hazard ratios were 2.6 (95% CI, 1.6-4.2) and 1.4 (95% CI, 0.8-2.4) for patients with low and intermediate CT values compared with high CT values. Conclusions: There was a dose-dependent correlation between nasopharyngeal CT values and viremia at admission for COVID-19. Moreover, there was an increased risk of 60-day mortality for patients with low, compared with high, nasopharyngeal CT values.

Impaired Microvascular Function in Patients With Critical COVID-19.

Severe coronavirus disease 2019 is characterized by infected microvascular endothelial cells. The primary aim of this study was to investigate microvascular function in patients with critical coronavirus disease 2019. DESIGN: A prospective observational study was conducted in which patients with critical and severe COVID-19 were investigated during acute disease phase and at least 3 months after disease onset. SETTING: Single-center study at Danderyd University Hospital. PATIENTS: Twenty-three patients with critical coronavirus disease 2019 treated with noninvasive or invasive mechanical ventilation, seven patients with severe COVID-19 with dyspnea or need of oxygen supply up to 8 L/min, and 15 noncoronavirus disease controls. INTERVENTIONS: None. MEASUREMENTS: Skin perfusion was investigated through laser speckle contrast imaging before and after iontophoresis of acetylcholine and sodium nitroprusside for determination of the endothelial-dependent and the endothelial-independent vasodilation, respectively. MAIN RESULTS: Patients with critical COVID-19 had higher basal skin perfusion during both the acute (34 ± 9 perfusion unit; p = 0.0003) and the postinfectious phase (29 ± 8 perfusion unit; p = 0.04), compared with noncoronavirus disease controls (23 ± 7 perfusion unit). In addition, endothelial-dependent and endothelial-independent vasodilation were reduced in patients with critical COVID-19 during the acute disease phase (p < 0.001 for both), whereas no significant differences between patients and controls were found during the postinfectious phase. In patients with severe COVID-19, basal skin perfusion and endothelial-dependent vasodilatation were not significantly changed, whereas endothelial-independent vasodilatation was reduced (p = 0.02) compared with controls. CONCLUSIONS: Changes in skin microcirculation in patients with critical COVID-19 indicate that the infection induces a systemic microvascular impairment with persisting long-term effects on the microvascular function.

Duration of SARS-CoV-2 viremia and its correlation to mortality and inflammatory parameters in patients hospitalized for COVID-19: a cohort study.

SARS-CoV-2 viremia at admission is associated with high risk for mortality. However, longitudinal data on viremia duration are limited. Viremic patients hospitalized for COVID-19 were included in a cohort. Time to serum viral clearance and the effect of viremia duration on the odds of mortality were calculated. One hundred and twenty-one viremic patients were included. Median age was 62 (IQR 52-71) years and 68% were males. The total in-hospital mortality of the cohort was 33%. Median time from admission to serum viral clearance was 7 (95% CI 6-8) days. Duration of viremia showed a relative risk ratio of 1.40 (95% CI 1.02-1.92) for the odds of mortality in an adjusted multinomial logistic regression. Serum viral clearance coincided with defervescence and decreasing C-reactive protein. Median time to serum viral clearance was 7 days after admission. The odds of mortality increased with 40% for each additional day of viremia.

Microvascular Dysfunction in Patients with Critical Covid-19, a Pilot Study.

BACKGROUND: Endothelial and microvascular dysfunction may be a key pathogenic feature of severe COVID-19. The aim of this study was to investigate endothelial-dependent and endothelial-independent skin microvascular reactivity in patients with critical COVID-19. METHODS: Twelve patients with COVID-19 treated with non-invasive or invasive mechanical ventilation were included in the study. We investigated skin microvascular reactivity on 2 separate days during hospitalization (study day 1 and 2) and at least 3 months after disease onset (study day 3). Twelve controls with no confirmed or suspected COVID-19 infection during 2020 were also examined. Skin perfusion was investigated through Laser Speckle Contrast Imaging before and after iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) to determine the endothelial-dependent and the endothelial-independent vasodilation, respectively. RESULTS: Compared to controls, patients with critical COVID-19 had higher basal skin perfusion and reduced responses to endothelial-dependent (ACh, P = 0.002) and endothelial-independent (SNP, P = 0.01) vasodilator drugs on study day 1. In addition, the ACh/SNP ratio was significantly reduced in patients (0.50 ±â€Š0.36 vs. 0.91 ±â€Š0.49 in controls, P = 0.02). Three months after disease onset, surviving patients tended to have reduced ACh-mediated vasodilation compared to controls (P = 0.08). CONCLUSIONS: This small-sized pilot study demonstrates that critical COVID-19 infection is associated with microvascular impairment and, in particular, a markedly reduced endothelial function. Our results also suggest that microvascular function may not be fully recovered 3 months after disease onset.

Severe Acute Respiratory Syndrome Coronavirus 2 RNA in Serum as Predictor of Severe Outcome in Coronavirus Disease 2019: A Retrospective Cohort Study.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). This study aimed to determine if SARS-CoV-2 RNA in serum at admission correlated with clinical outcome in COVID-19. METHODS: COVID-19 patients admitted to the infectious diseases department of a tertiary level Swedish hospital and sampled for SARS-CoV-2 RNA in serum at admission during 10 April to 30 June 2020 were included. Primary outcomes were day 28 all-cause mortality and progress to critical disease. RESULTS: The cohort (N = 167) consisted of 106 SARS-CoV-2 RNA serum-negative and 61 serum-positive patients. Median sampling time for initial SARS-CoV-2 in serum was 1 day (interquartile range [IQR], 1-2 days) after admission, corresponding to day 10 (IQR, 8-12) after symptom onset. Median age was 53 years (IQR, 44-67 years) and 63 years (IQR, 52-74 years) for the serum-negative and -positive patients, respectively. In the serum-negative and -positive groups, 3 of 106 and 15 of 61 patients died, respectively.The hazard ratios for critical disease and all-cause mortality were 7.2 (95% confidence interval [CI], 3.0-17) and 8.6 (95% CI, 2.4-30), respectively, for patients with serum-positive compared to serum-negative results. CONCLUSIONS: SARS-CoV-2 RNA in serum at hospital admission indicates a high risk of progression to critical disease and death.

Risk factors for death in adult COVID-19 patients: Frailty predicts fatal outcome in older patients.

OBJECTIVES: This study investigated demographics, comorbidities, and death rate in hospitalized patients with confirmed COVID-19. In addition, we hypothesized that functional status, according to the Clinical Frailty Scale (CFS), in patients aged 65 years or older is a better predictor of poor outcome than age and comorbidities. METHODS: A total of 255 randomly selected COVID-19 patients admitted to a university hospital were included and followed up for 60 days. Patient data were extracted manually from the electronic health records with use of a standardized protocol. RESULTS: The age of the study population ranged between 20 and 103 years (mean age 66 years ± 17 years). Hypertension, diabetes mellitus, and obesity were the three most prevalent comorbidities. At the 60-day follow-up, 70 patients (27%) had died. In multivariate analyses, age, chronic kidney disease, and previous stroke were associated with death. Most fatal cases (90%) occurred in patients aged 65 years or older. Among such patients, CFS level was the only predictor of death in multivariate analyses. CONCLUSIONS: This study shows that increasing age, chronic kidney disease, and previous stroke significantly contribute to a fatal outcome in hospitalized patients with COVID-19. In patients aged 65 years or older, CFS level was the strongest prognostic factor for death.

Performance of plasma measurement of neutrophil gelatinase-associated lipocalin as a biomarker of bacterial infections in the intensive care unit.

PURPOSE: To assess the value of dimeric neutrophil-gelatinase associated lipocalin (NGAL) as an early marker of bacterial infection and its response to antibiotic therapy in intensive care unit (ICU) patients. MATERIALS & METHODS: We measured daily plasma dNGAL in 198 patients admitted to a mixed ICU. Likelihood of infection was determined with International Sepsis Forum criteria. We measured dNGAL in 145 healthy controls to establish normal values. RESULTS: ICU patients had higher dNGAL than healthy controls. A suspected or confirmed infection was independently associated with 90% (95% CI 15-215%) higher dNGAL than absence of infection. We observed no association between acute kidney injury and dNGAL. Diagnostic accuracy at antibiotic treatment initiation, assessed with area under the receiver-operating characteristics curve (AUC-ROC), for dNGAL was 0.70 (95% CI 0.60-0.79). AUC-ROC for dNGAL 24 h before antibiotic treatment initiation was 0.54 (95% CI 0.41-0.66). The mean (95% CI) change of dNGAL in the first 2 days after appropriate antibiotic therapy initiation was -31 (-49,-13)%. CONCLUSIONS: In our cohort of ICU patients, plasma dNGAL was associated with presence of bacterial infections independent of AKI but it performed poor as a predictor of infections. Following antibiotic therapy, dNGAL markedly decreased-supporting further exploration of dNGAL-guided antibiotic de-escalation.

Calprotectin as an early biomarker of bacterial infections in critically ill patients: an exploratory cohort assessment.

BACKGROUND: Calprotectin is the most abundant protein in the cytosolic fraction of neutrophils, and neutrophil degranulation is a major response to bacterial infections. OBJECTIVES: To assess the value of plasma calprotectin as an early marker of bacterial infections in critically ill patients and compare it with the corresponding values for procalcitonin (PCT), C-reactive protein (CRP) and white blood cell count (WBC). METHODS: We measured daily plasma calprotectin levels in 110 intensive care unit patients using a newly developed turbidimetric assay run on clinical chemistry analysers. The likelihood of infection was determined according to the International Sepsis Forum criteria. RESULTS: Overall, 58 patients (52.7%) developed a suspected or confirmed bacterial infection. Plasma calprotectin predicted such infections within 24 hours with an area under the receiver operating characteristics curve (ROC area) of 0.78 (95% CI, 0.68-0.89). The ROC area for calprotectin was significantly greater than the corresponding ROC areas for WBC (P < 0.001) and PCT (P = 0.02) but only marginally better than the ROC area for CRP (0.71; 95% CI, 0.68-0.89). CONCLUSION: Plasma calprotectin appears to be a useful early marker of bacterial infections in critically ill patients, with better predictive characteristics than WBC and PCT.

Nuclease-assisted suppression of human DNA background in sepsis.

Sepsis is a severe medical condition characterized by a systemic inflammatory response of the body caused by pathogenic microorganisms in the bloodstream. Blood or plasma is typically used for diagnosis, both containing large amount of human DNA, greatly exceeding the DNA of microbial origin. In order to enrich bacterial DNA, we applied the C0t effect to reduce human DNA background: a model system was set up with human and Escherichia coli (E. coli) DNA to mimic the conditions of bloodstream infections; and this system was adapted to plasma and blood samples from septic patients. As a consequence of the C0t effect, abundant DNA hybridizes faster than rare DNA. Following denaturation and re-hybridization, the amount of abundant DNA can be decreased with the application of double strand specific nucleases, leaving the non-hybridized rare DNA intact. Our experiments show that human DNA concentration can be reduced approximately 100,000-fold without affecting the E. coli DNA concentration in a model system with similarly sized amplicons. With clinical samples, the human DNA background was decreased 100-fold, as bacterial genomes are approximately 1,000-fold smaller compared to the human genome. According to our results, background suppression can be a valuable tool to enrich rare DNA in clinical samples where a high amount of background DNA can be found.

Severe sepsis and systemic inflammatory response syndrome in emergency department patients with suspected severe infection.

BACKGROUND: Severe sepsis is a common condition with a reported high mortality, but most studies have been confined to intensive care unit (ICU) populations. The systemic inflammatory response syndrome (SIRS) has been used to define sepsis, however its usefulness has been questioned. Our aim was to describe the prevalence and clinical impact of severe sepsis and SIRS in patients admitted from the emergency department (ED) with a suspected serious infection. METHODS: Four hundred and four adult patients were enrolled prospectively from the ED. Variables defining severe sepsis and SIRS were measured and the relationship between severe sepsis, SIRS, and the clinical course was analyzed. RESULTS: Infections were diagnosed in 344 patients (85%). The overall mortality rate at 28 days was 2.7%, and 4.5% of patients were treated in the ICU. Patients with severe sepsis within 24 h of admission (42%) were more likely to suffer a critical course (ICU admission 9.0%, death 5.1%; p < 0.001). While SIRS was observed in 72% of the subjects at presentation, it was not associated with severe sepsis within 24 h or a subsequent critical course. Furthermore, 23% of patients with severe sepsis within 24 h did not present with SIRS. CONCLUSIONS: Severe sepsis was a common condition among ED patients with a clinically suspected serious infection. Mortality was low compared with results from the ICU setting, suggesting that severe sepsis is a more benign disease than earlier reported. As a tool for the definition of sepsis and for the selection of patients for clinical sepsis trials, SIRS lacks acceptable discriminative ability in an ED population with a high prevalence of serious infections.

Circulating monocytes are not the major source of plasma cytokines in patients with sepsis.

In sepsis, large quantities of inflammatory cytokines are released into the bloodstream. The cellular source of these cytokines is unclear, and we have here investigated to what extent circulating cells in blood contributed to this production. We used the enzyme-linked immunospot technique to study the spontaneous as well as the lipopolysaccharide (LPS)-induced secretion of the proinflammatory cytokines interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), granulocyte-macrophage colony-stimulating factor, IL-1ß, IL-12p40, and the anti-inflammatory cytokine IL-10 from whole-blood cells. The study comprised 32 septic patients (24 with septic shock) and 30 healthy controls. Despite significantly increased plasma cytokine levels in the septic patients, the number of spontaneous cytokine-secreting cells was small or nonexistent and did not differ between the two groups. Lipopolysaccharide stimulation of cells from the same samples triggered substantially increased numbers of cytokine-producing cells in both patients and controls. However, although the numbers of IL-6- and tumor necrosis factor α-secreting monocytes were very similar in both groups, significantly fewer IL-1ß-, IL-10-, IL-12p40-, and granulocyte-macrophage colony-stimulating factor-secreting monocytes were seen in samples from septic patients as compared with healthy controls. The reduced number of cytokine-secreting cells in response to LPS stimulation correlated with disease severity, as expressed by Sequential Organ Failure Assessment score and the stage of sepsis. In summary, circulating leukocytes did not appear to be responsible for the increased plasma levels of cytokines observed in sepsis. A selective sepsis-induced downregulation of cytokine secretion in response to LPS underscores the complexity of cytokine regulation in sepsis.

Clinical and laboratory variables identifying bacterial infection and bacteraemia in the emergency department.

BACKGROUND: While early antimicrobial treatment is of critical importance to patients with severe infections, excessive use of antibiotics has caused escalating bacterial resistance. Better diagnostic tools are needed to secure antibiotic stewardship. METHODS: The diagnostic value of clinical and laboratory variables in predicting infections that require antibiotic treatment was evaluated in a prospective observational study of 404 adult patients admitted from the emergency department (ED) with suspected severe infections. We also investigated the association of these variables with bacteraemia and severe sepsis. RESULTS: In a univariate analysis, increased levels of C-reactive protein (CRP), procalcitonin (PCT), interleukin 6 (IL-6), lipopolysaccharide binding protein (LBP), white blood cell count (WBC), neutrophils, respiratory rate (RR) (p ≤ 0.001), and a decreased haemoglobin (Hb) level (p = 0.005) were associated with an indicated demand for antibiotics (n = 286). In a multivariate analysis, only WBC, Hb, RR, and CRP remained independent predictors. When compared to the clinician's ability to make accurate antibiotic decisions, all variables tested had inferior diagnostic accuracy except CRP. Increased levels of PCT, IL-6, LBP, CRP, bilirubin, and RR were significantly associated with bacteraemia (n = 68) (p ≤ 0.001). Of these, PCT and IL-6 were also associated with severe sepsis (n = 156) (p < 0.001). In a multivariate analysis, CRP, RR, PCT, and bilirubin remained associated with bacteraemia. CONCLUSIONS: Special attention should be directed to CRP, WBC, RR, and Hb when selecting patients for antibiotic treatment in the emergency department. PCT, IL-6, and LBP did not provide additional guidance on antibiotic decisions and better tests are required in order to improve antibiotic stewardship.

ELISpot analysis of LPS-stimulated leukocytes: human granulocytes selectively secrete IL-8, MIP-1beta and TNF-alpha.

Granulocytes and monocytes/macrophages represent key effector cells of the innate immune system. While human monocytes have been recognized as capable of secreting a broad spectrum of cytokines, the situation has been less clear in granulocytes with studies often showing conflicting results. In this study, lipopolysaccharide (LPS)-induced cytokine secretion from polymorphonuclear cells (PMN) and peripheral blood mononuclear cells (PBMC) was analyzed at the single cell level with the enzyme-linked immunospot (ELISpot) assay. This method allowed us to establish the cytokine profiles for both PBMC and PMN based on the frequency and pattern of cytokine secreting cells, rather than on the amount of produced cytokine detectable in solution by ELISA. As a result, low levels of contaminating mononuclear cells present in our PMN preparations could be discriminated from granulocytes. Using this technique, neutrophils were found to secrete the two chemokines, IL-8 and MIP-1beta in response to LPS. Also TNF-alpha was secreted but in lower amounts and by significantly fewer cells. However, and as opposed to several other reports, we were unable to detect secretion of IL-1beta, IL-6, IL-10, IL-12 and GM-CSF. In contrast to the limited cytokine production by PMN, PBMC secreted considerably larger amounts of the investigated cytokines with CD14(+) monocytes being the primary source of production. Finally, we believe that the cytokine ELISpot technique may provide a powerful tool by which cells of the innate immune system can be studied from a functional perspective at the single cell level.