Type I Interferon Autoantibodies Correlate With Cellular Immune Alterations in Severe COVID-19.

BACKGROUND: Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to severe disease with increased morbidity and mortality among certain risk groups. The presence of autoantibodies against type I interferons (aIFN-Abs) is one mechanism that contributes to severe coronavirus disease 2019 (COVID-19). METHODS: This study aimed to investigate the presence of aIFN-Abs in relation to the soluble proteome, circulating immune cell numbers, and cellular phenotypes, as well as development of adaptive immunity. RESULTS: aIFN-Abs were more prevalent in critical compared to severe COVID-19 but largely absent in the other viral and bacterial infections studied here. The antibody and T-cell response to SARS-CoV-2 remained largely unaffected by the presence aIFN-Abs. Similarly, the inflammatory response in COVID-19 was comparable in individuals with and without aIFN-Abs. Instead, presence of aIFN-Abs had an impact on cellular immune system composition and skewing of cellular immune pathways. CONCLUSIONS: Our data suggest that aIFN-Abs do not significantly influence development of adaptive immunity but covary with alterations in immune cell numbers.

Dynamic MAIT Cell Recovery after Severe COVID-19 Is Transient with Signs of Heterogeneous Functional Anomalies.

Mucosal-associated invariant T (MAIT) cells are an abundant population of unconventional T cells in humans and play important roles in immune defense against microbial infections. Severe COVID-19 is associated with strong activation of MAIT cells and loss of these cells from circulation. In the present study, we investigated the capacity of MAIT cells to recover after severe COVID-19. In longitudinal paired analysis, MAIT cells initially rebounded numerically and phenotypically in most patients at 4 mo postrelease from the hospital. However, the rebounding MAIT cells displayed signs of persistent activation with elevated expression of CD69, CD38, and HLA-DR. Although MAIT cell function was restored in many patients, a subgroup displayed a predominantly PD-1high functionally impaired MAIT cell pool. This profile was associated with poor expression of IFN-γ and granzyme B in response to IL-12 + L-18 and low levels of polyfunctionality. Unexpectedly, although the overall T cell counts recovered, normalization of the MAIT cell pool failed at 9-mo follow-up, with a clear decline in MAIT cell numbers and a further increase in PD-1 levels. Together, these results indicate an initial transient period of inconsistent recovery of MAIT cells that is not sustained and eventually fails. Persisting MAIT cell impairment in previously hospitalized patients with COVID-19 may have consequences for antimicrobial immunity and inflammation and could potentially contribute to post-COVID-19 health problems.

SARS-CoV-2 vaccination enhances the effector qualities of spike-specific T cells induced by COVID-19.

T cells are critical for immune protection against severe COVID-19, but it has remained unclear whether repeated exposure to SARS-CoV-2 antigens delivered in the context of vaccination fuels T cell exhaustion or reshapes T cell functionality. Here, we sampled convalescent donors with a history of mild or severe COVID-19 before and after SARS-CoV-2 vaccination to profile the functional spectrum of hybrid T cell immunity. Using combined single-cell technologies and high-dimensional flow cytometry, we found that the frequencies and functional capabilities of spike-specific CD4+ and CD8+ T cells in previously infected individuals were enhanced by vaccination, despite concomitant increases in the expression of inhibitory receptors such as PD-1 and TIM3. In contrast, CD4+ and CD8+ T cells targeting non-spike proteins remained functionally static and waned over time, and only minimal effects were observed in healthy vaccinated donors experiencing breakthrough infections with SARS-CoV-2. Moreover, hybrid immunity was characterized by elevated expression of IFN-γ, which was linked with clonotype specificity in the CD8+ T cell lineage. Collectively, these findings identify a molecular hallmark of hybrid immunity and suggest that vaccination after infection is associated with cumulative immunological benefits over time, potentially conferring enhanced protection against subsequent episodes of COVID-19.

[The morbidity after sepsis motivates person-centred clinical follow-up]. / Morbiditet efter sepsis motiv för personlig uppföljning.

The documented morbidity problems after sepsis motivated inclusion of routine clinical follow-up at 2-6 weeks after sepsis care in the national patient-centred clinical pathway for sepsis in Sweden. This routine has been evaluated in a pilot study, in which a nurse at a department of infectious diseases performed a structured telephone follow-up after sepsis care. The pilot study showed that the routine was resource demanding and illustrated that it is not optimal to use a uniform follow-up routine in a broad sepsis population. Thus, the clinical follow-up recommendations within the patient-centred clinical pathway for sepsis should be updated, adapted for broadly available health-care structures, and more person-centred.

In-hospital cardiac arrest due to sepsis - Aetiologies and outcomes in a Swedish cohort study.

Objectives: Awareness of causes of cardiac arrest is essential to prevent them. A recent review found that almost every sixth in-hospital cardiac arrest is caused by infection. Few studies have explored how infections cause cardiac arrest. Aim: To describe the features, mechanisms and outcome of sepsis-related cardiac arrests. Material and methods: All patients ≥18 years who suffered a cardiac arrest at Karolinska University Hospital between 2007 and 2022 with sepsis as the primary cause were included. Data were collected the Swedish Registry for Cardiopulmonary Resuscitation and medical records. The primary outcome was survival to discharge. Results: Out of 2,327 in-hospital cardiac arrests, 5% (n = 123) suffered it due to sepsis, and 17% (21) survived to hospital discharge. Two thirds of patients were admitted to the hospital due to sepsis and suffered their cardiac arrest after a median of four days. About half (n = 59) had deranged vital signs before the event. Most were witnessed in general wards. In all, 47% (n = 58) had asystole and 24% (n = 30) as the first heart rhythm. The respiratory tract was the most common source of infection. Most patients were undergoing antibiotic therapy and one third had a positive microbiological culture with mixed gram-positive bacteria or Escherichia coli in the urine. Conclusion: Our results suggest that sepsis is an uncommon and not increasing cause of in-hospital cardiac arrest and its outcome is in line with other non-shockable cardiac arrests. Deranged respiratory and/or circulatory vital signs precede the event.

Design of a national patient-centred clinical pathway for sepsis in Sweden.

BACKGROUND: The World Health Organization has adopted a resolution on sepsis and urged member states to develop national processes to improve sepsis care. In Sweden, sepsis was selected as one of the ten first diagnoses to be addressed, when the Swedish government in 2019 allocated funds for patient-centred clinical pathways in healthcare. A national multidisciplinary working group, including a patient representative, was appointed to develop the patient-centred clinical pathway for sepsis. METHODS: The working group mapped challenges and needs surrounding sepsis care and included a survey sent to all emergency departments (ED) in Sweden, and then designed a patient-centred clinical pathway for sepsis. RESULTS: The working group decided to focus on the following four areas: (1) sepsis alert for early detection and management optimisation for the most severely ill sepsis patients in the ED; (2) accurate sepsis diagnosis coding; (3) structured information to patients at discharge after sepsis care and (4) structured telephone follow-up after sepsis care. A health-economic analysis indicated that the implementation of the clinical pathway for sepsis will most likely not drive costs. An important aspect of the clinical pathway is implementing continuous monitoring of performance and process indicators. A national working group is currently building up such a system for monitoring, focusing on extraction of this information from the electronic health records systems. CONCLUSION: A national patient-centred clinical pathway for sepsis has been developed and is currently being implemented in Swedish healthcare. We believe that the clinical pathway and the accompanying monitoring will provide a more efficient and equal sepsis care and improved possibilities to monitor and further develop sepsis care in Sweden.

Plasma calprotectin as an indicator of need of transfer to intensive care in patients with suspected sepsis at the emergency department.

BACKGROUND: Deciding whether to transfer patients with sepsis from the emergency department (ED) to intensive care units (ICUs) is challenging. We hypothesised that the new biomarker plasma calprotectin (p-calprotectin) could be used to aid the selection of patients for intensive care transfer, since it has been shown to be a promising tool for the determination of sepsis severity in critical care. METHODS: This prospective study was performed on consecutive sepsis alert patients in the ED of Karolinska University Hospital Huddinge. The sepsis alert mandates clinical assessment and decisions regarding treatment, disposition, and level of care by physicians from the ED, the Department of Infectious Diseases, and the ICU. Blood sample analysis for C-reactive protein, procalcitonin, neutrophils, and lymphocytes was routinely performed. P-calprotectin was analysed from frozen plasma samples, using a specific turbidimetric assay. RESULTS: Three-hundred fifty-one patients who triggered the sepsis alert were available for the study. Among 319 patients who were considered to have an infection, 66 patients (26%) were immediately transferred to the ICU or high-dependency unit (HDU), and 253 patients (74%) were transferred to ordinary wards. Median p-calprotectin was 2.2 mg/L (IQR 1.2-3.9 mg/L) for all patients with infection, it was 3.3 (IQR 1.6-5.2) for those transferred to ICU/HDU and 2.1 (IQR 1.1-3.5) for those transferred to ward units (p = 0.0001). Receiver operating characteristic curve analysis for transfer to the ICU/HDU showed superiority for p-calprotectin compared with procalcitonin and neutrophil-lymphocyte ratio, regarding both all sepsis alert cases and the patients with infection (p < 0.001 for all comparisons). The best p-calprotectin cut-off, 4.0 mg/L, showed a sensitivity of 42.5% and specificity of 83% for transfer to the ICU/HDU among patients with infection. CONCLUSIONS: In sepsis alert patients, p-calprotectin was significantly elevated in patients who were subject to immediate ICU/HDU transfer after assessment by a multidisciplinary team. P-calprotectin was superior to traditional biomarkers in predicting the need for transfer to the ICU/HDU.

Targeted plasma proteomics reveals signatures discriminating COVID-19 from sepsis with pneumonia.

BACKGROUND: COVID-19 remains a major public health challenge, requiring the development of tools to improve diagnosis and inform therapeutic decisions. As dysregulated inflammation and coagulation responses have been implicated in the pathophysiology of COVID-19 and sepsis, we studied their plasma proteome profiles to delineate similarities from specific features. METHODS: We measured 276 plasma proteins involved in Inflammation, organ damage, immune response and coagulation in healthy controls, COVID-19 patients during acute and convalescence phase, and sepsis patients; the latter included (i) community-acquired pneumonia (CAP) caused by Influenza, (ii) bacterial CAP, (iii) non-pneumonia sepsis, and (iv) septic shock patients. RESULTS: We identified a core response to infection consisting of 42 proteins altered in both COVID-19 and sepsis, although higher levels of cytokine storm-associated proteins were evident in sepsis. Furthermore, microbiologic etiology and clinical endotypes were linked to unique signatures. Finally, through machine learning, we identified biomarkers, such as TRIM21, PTN and CASP8, that accurately differentiated COVID-19 from CAP-sepsis with higher accuracy than standard clinical markers. CONCLUSIONS: This study extends the understanding of host responses underlying sepsis and COVID-19, indicating varying disease mechanisms with unique signatures. These diagnostic and severity signatures are candidates for the development of personalized management of COVID-19 and sepsis.

[Four blood culture bottles from one venipuncture instead of divided into two: new Swedish national recommendation for blood culture]. / Ta fyra blododlingsflaskor i en och samma venpunktion.

Blood culture is the standard method for microbiological diagnostics in sepsis. In many countries, the traditional recommendation for blood culture has been collection of four blood culture bottles with two bottles from each of two venipunctures. New studies show that four blood culture bottles from the same venipuncture provides similar culture results and higher number of obtained blood culture bottles, than the traditional method. Thus, new national recommendations recommend collection of four blood culture bottles from the same venipuncture as the routine blood culture method in Sweden.

The Karolinska KI/K COVID-19 Immune Atlas: An open resource for immunological research and educational purposes.

The Karolinska KI/K COVID-19 Immune Atlas project was conceptualized in March 2020 as a part of the academic research response to the developing SARS-CoV-2 pandemic. The aim was to rapidly provide a curated dataset covering the acute immune response towards SARS-CoV-2 infection in humans, as it occurred during the first wave. The Immune Atlas was built as an open resource for broad research and educational purposes. It contains a presentation of the response evoked by different immune and inflammatory cells in defined naïve patient-groups as they presented with moderate and severe COVID-19 disease. The present Resource Article describes how the Karolinska KI/K COVID-19 Immune Atlas allow scientists, students, and other interested parties to freely explore the nature of the immune response towards human SARS-CoV-2 infection in an online setting.

Characterization of the Upper Respiratory Bacterial Microbiome in Critically Ill COVID-19 Patients.

The upper respiratory tract (URT) microbiome can contribute to the acquisition and severity of respiratory viral infections. The described associations between URT microbiota and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are limited at microbiota genus level and by the lack of functional interpretation. Our study, therefore, characterized the URT bacterial microbiome at species level and their encoded pathways in patients with COVID-19 and correlated these to clinical outcomes. Whole metagenome sequencing was performed on nasopharyngeal samples from hospitalized patients with critical COVID-19 (n = 37) and SARS-CoV-2-negative individuals (n = 20). Decreased bacterial diversity, a reduction in commensal bacteria, and high abundance of pathogenic bacteria were observed in patients compared to negative controls. Several bacterial species and metabolic pathways were associated with better respiratory status and lower inflammation. Strong correlations were found between species biomarkers and metabolic pathways associated with better clinical outcome, especially Moraxella lincolnii and pathways of vitamin K2 biosynthesis. Our study demonstrates correlations between the URT microbiome and COVID-19 patient outcomes; further studies are warranted to validate these findings and to explore the causal roles of the identified microbiome biomarkers in COVID-19 pathogenesis.

Pneumococcal urinary antigen testing for antimicrobial guidance in community-acquired pneumonia-A register-based cohort study.

OBJECTIVES: To evaluate the effect of pneumococcal urinary antigen test (UAT) usage on broad-spectrum antibiotic treatment in community-acquired pneumonia (CAP). METHODS: Patients admitted to 32 Swedish hospitals between 2011 and 2014 were retrospectively included from the Swedish National Quality Register of CAP. Using propensity score matched data, stratified by CRB-65 score, we studied the effect of performing UAT and of positive test results on treatment with broad-spectrum ß-lactam monotherapy (BSBM) and antibiotics with coverage for atypical bacteria compared to narrow-spectrum ß-lactam monotherapy (NSBM). RESULTS: UAT was performed for 4,995/14,590 (34.2%) patients, 603/4,995 (12.1%) of whom had positive test results. At day three, performing UAT was not associated with decreased use of BSBM (OR 1.07, 95% CI 0.94-1.23) but was associated with increased atypical coverage among patients with CRB-65 score 2 (OR 1.47, 95% CI 1.06-2.02). A positive UAT was associated with decreased BSBM use (OR 0.39, 95% CI 0.25-0.60) and decreased atypical coverage (OR 0.25, 95% CI 0.16-0.37), predominantly in non-severe CAP. At day one, performing UAT was associated with atypical coverage among patients with CRB-65 scores 2 (OR 2.60, 95% CI 1.69-3.98) and 3-4 (OR 3.69, 95% CI 1.55-8.79), and a positive test reduced the odds of BSBM treatment among CRB-65 score 3-4 patients (OR 3.49, 95% CI 1.02-12.0). CONCLUSIONS: Performing UAT had no overall effect on decreasing the use of BSBM treatment by day three of hospitalization, yet non-severely ill patients with positive UAT results were less likely to be treated with BSBM and antibiotics with atypical coverage.

Sustained elevation of soluble B- and T- lymphocyte attenuator predicts long-term mortality in patients with bacteremia and sepsis.

Soluble B and T lymphocyte attenuator (sBTLA) has been shown to be associated with severity and outcome, in critically ill septic patients. We aimed to assess the dynamic expression of sBTLA, as a prognostic biomarker of long-term mortality in patients with bloodstream infection (BSI) and sepsis, and to evaluate its association with biomarkers indicative of inflammation and immune dysregulation. Secondarily, sBTLA was evaluated in association with severity and bacterial etiology. Patients with BSI (n = 108) were prospectively included, and serially sampled from admission to day 28. Blood and plasma donors (n = 31), sampled twice 28 days apart, served as controls. sBTLA concentration in plasma was determined with enzyme-linked immunosorbent assay. Associations between sBTLA on day 1-2 and 7, and mortality at 90 days and 1 year, were determined with unadjusted, and adjusted Cox regression. Differences related to severity was assessed with linear regression. Mixed model was used to assess sBTLA dynamics over time, and sBTLA associations with bacterial etiology and other biomarkers. sBTLA on day 1-2 and 7 was associated with mortality, in particular failure to normalize sBTLA by day 7 was associated with an increased risk of death before day 90, adjusted HR 17 (95% CI 1.8-160), and one year, adjusted HR 15 (95% CI 2.8-76). sBTLA was positively associated with CRP, and negatively with lymphocyte count. sBTLA on day 1-2 was not linearly associated with baseline SOFA score increase. High SOFA (≥4) was however associated with higher mean sBTLA than SOFA ≤3. sBTLA was not associated with bacterial etiology. We show that sustained elevation of sBTLA one week after hospital admission is associated with late mortality in patients with BSI and sepsis, and that sBTLA concentration is associated with CRP and decreased lymphocyte count. This suggests that sBTLA might be an indicator of sustained immune-dysregulation, and a prognostic tool in sepsis.

Ventilator-Associated Lower Respiratory Tract Bacterial Infections in COVID-19 Compared With Non-COVID-19 Patients.

OBJECTIVES: Ventilator-associated lower respiratory tract infections (VA-LRTIs) are associated with prolonged length of stay and increased mortality. We aimed to investigate the occurrence of bacterial VA-LRTI among mechanically ventilated COVID-19 patients and compare these findings to non-COVID-19 cohorts throughout the first and second wave of the pandemic. DESIGN: Retrospective cohort study. SETTING: Karolinska University Hospital, Stockholm, Sweden. PATIENTS: All patients greater than or equal to 18 years treated with mechanical ventilation between January 1, 2011, and December 31, 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The cohort consisted of 20,223 ICU episodes (479 COVID-19), with a VA-LRTI incidence proportion of 30% (129/426) in COVID-19 and 18% (1,081/5,907) in non-COVID-19 among patients ventilated greater than or equal to 48 hours. The median length of ventilator treatment for COVID-19 patients was 10 days (interquartile range, 5-18 d), which was significantly longer than for all other investigated specific diagnoses. The VA-LRTI incidence rate per 1,000 ventilator days at risk was 31 (95% CI, 26-37) for COVID-19 and 34 (95% CI, 32-36) for non-COVID-19. With COVID-19 as reference, adjusted subdistribution hazard ratios for VA-LRTI was 0.29-0.50 (95% CI, < 1) for influenza, bacterial pneumonia, acute respiratory distress syndrome, and severe sepsis, but 1.38 (95% CI, 1.15-1.65) for specific noninfectious diagnoses. Compared with COVID-19 in the first wave of the pandemic, COVID-19 in the second wave had adjusted subdistribution hazard ratio of 1.85 (95% CI, 1.14-2.99). In early VA-LRTI Staphylococcus aureus was more common and Streptococcus pneumoniae, Haemophilus influenzae, and Escherichia coli less common in COVID-19 patients, while Serratia species was more often identified in late VA-LRTI. CONCLUSIONS: COVID-19 is associated with exceptionally long durations of mechanical ventilation treatment and high VA-LRTI occurrence proportions. The incidence rate of VA-LRTI was compared with the pooled non-COVID-19 cohort, however, not increased in COVID-19. Significant differences in the incidence of VA-LRTI occurred between the first and second wave of the COVID-19 pandemic.

Correlation of clinical sepsis definitions with microbiological characteristics in patients admitted through a sepsis alert system; a prospective cohort study.

BACKGROUND: Sepsis was recently redefined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. With this redefinition (Sepsis-3), clinical and microbiological characteristics of patients with sepsis may differ from the patients fulfilling the previous definition (Sepsis-2). PURPOSE: To describe differences in clinical and microbiological characteristics of sepsis episodes between Sepsis-3 and Sepsis-2. The secondary aim was to compare blood culture outcomes between episodes fulfilling Sepsis-3 and Sepsis-2 criteria, respectively. METHODS: A prospective study design was used to include patients presenting with clinically suspected sepsis in the emergency department. Six blood culture bottles were collected from each patient. Blood cultures were described as having clinically relevant growth, contaminant growth, or no growth. Clinical and laboratory data were collected from medical records and the laboratory information system. RESULTS: The analysis included 514 episodes. There were 357/514 (79.5%) Sepsis-3 and 411/514 (80.0%) Sepsis-2 episodes. In total, 341/514 (66.3%) episodes fulfilled both Sepsis-3 and Sepsis-2 criteria. Blood cultures were positive for clinically relevant growth in 130/357 (36.1%) and 145/411 (35.3%) episodes in Sepsis-3 and Sepsis-2, respectively. Other clinical and microbiological characteristics did not differ between Sepsis-3 and Sepsis-2. CONCLUSIONS: A high proportion of patients included through a sepsis alert system fulfilled both Sepsis-3 and Sepsis-2 criteria. The performance of blood cultures in detection of microorganisms was poor and were similar in Sepsis-3 and Sepsis-2 patients.

COVID-19-specific metabolic imprint yields insights into multiorgan system perturbations.

Corona disease 2019 (COVID-19) affects multiple organ systems. Recent studies have indicated perturbations in the circulating metabolome linked to COVID-19 severity. However, several questions pertain with respect to the metabolome in COVID-19. We performed an in-depth assessment of 1129 unique metabolites in 27 hospitalized COVID-19 patients and integrated results with large-scale proteomic and immunology data to capture multiorgan system perturbations. More than half of the detected metabolic alterations in COVID-19 were driven by patient-specific confounding factors ranging from comorbidities to xenobiotic substances. Systematically adjusting for this, a COVID-19-specific metabolic imprint was defined which, over time, underwent a switch in response to severe acute respiratory syndrome coronavirus-2 seroconversion. Integration of the COVID-19 metabolome with clinical, cellular, molecular, and immunological severity scales further revealed a network of metabolic trajectories aligned with multiple pathways for immune activation, and organ damage including neurological inflammation and damage. Altogether, this resource refines our understanding of the multiorgan system perturbations in severe COVID-19 patients.

Mortality in hospitalized COVID-19 patients was associated with the COVID-19 admission rate during the first year of the pandemic in Sweden.

INTRODUCTION: Studies from the first pandemic wave found associations between COVID-19 hospital load and mortality. Here, we aimed to study if mortality of hospitalized COVID-19 patients was associated with the COVID-19 admission rate during a full year of the pandemic in Sweden. METHOD: Observational review of all patients admitted to hospital with COVID-19 in Sweden between March 2020 and February 2021 (n = 42,017). Primary outcome was 60-day all-cause mortality related to number of COVID-19 hospital admissions per month/100,000 inhabitants. Poisson regression was used to estimate the relative risk for death by month of admission, adjusting for pre-existing factors. RESULTS: The overall mortality was 17.4%. Excluding March 2020, mortality was clearly correlated to the number of COVID-19 admissions per month (coefficient of correlation ρ=.96; p<.0001). After adjustment for pre-existing factors, the correlation remained significant (ρ=.75, p=.02). Patients admitted in December (high admission rate and high mortality) had more comorbidities and longer hospital stays, and patients treated in intensive care units (ICU) had longer pre-ICU hospital stays and worse respiratory status on ICU admission than those admitted in July to September (low admission rate and low mortality). CONCLUSION: Mortality in hospitalized COVID-19 patients was clearly associated with the COVID-19 admission rate. Admission of healthier patients between pandemic waves and delayed ICU care during wave peaks could contribute to this pattern. The study supports measures to flatten-the-curve to reduce the number of COVID-19 patients admitted to hospital.

Peripheral Oxygen Saturation Facilitates Assessment of Respiratory Dysfunction in the Sequential Organ Failure Assessment Score With Implications for the Sepsis-3 Criteria.

OBJECTIVES: Sequential Organ Failure Assessment score is the basis of the Sepsis-3 criteria and requires arterial blood gas analysis to assess respiratory function. Peripheral oxygen saturation is a noninvasive alternative but is not included in neither Sequential Organ Failure Assessment score nor Sepsis-3. We aimed to assess the association between worst peripheral oxygen saturation during onset of suspected infection and mortality. DESIGN: Cohort study of hospital admissions from a main cohort and emergency department visits from four external validation cohorts between year 2011 and 2018. Data were collected from electronic health records and prospectively by study investigators. SETTING: Eight academic and community hospitals in Sweden and Canada. PATIENTS: Adult patients with suspected infection episodes. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The main cohort included 19,396 episodes (median age, 67.0 [53.0-77.0]; 9,007 [46.4%] women; 1,044 [5.4%] died). The validation cohorts included 10,586 episodes (range of median age, 61.0-76.0; women 42.1-50.2%; mortality 2.3-13.3%). Peripheral oxygen saturation levels 96-95% were not significantly associated with increased mortality in the main or pooled validation cohorts. At peripheral oxygen saturation 94%, the adjusted odds ratio of death was 1.56 (95% CI, 1.10-2.23) in the main cohort and 1.36 (95% CI, 1.00-1.85) in the pooled validation cohorts and increased gradually below this level. Respiratory assessment using peripheral oxygen saturation 94-91% and less than 91% to generate 1 and 2 Sequential Organ Failure Assessment points, respectively, improved the discrimination of the Sequential Organ Failure Assessment score from area under the receiver operating characteristics 0.75 (95% CI, 0.74-0.77) to 0.78 (95% CI, 0.77-0.80; p < 0.001). Peripheral oxygen saturation/Fio2 ratio had slightly better predictive performance compared with peripheral oxygen saturation alone, but the clinical impact was minor. CONCLUSIONS: These findings provide evidence for assessing respiratory function with peripheral oxygen saturation in the Sequential Organ Failure Assessment score and the Sepsis-3 criteria. Our data support using peripheral oxygen saturation thresholds 94% and 90% to get 1 and 2 Sequential Organ Failure Assessment respiratory points, respectively. This has important implications primarily for emergency practice, rapid response teams, surveillance, research, and resource-limited settings.

[Insights from creating a covid-19 biobank in Sweden]. / Så skapades covid-19-biobanken.

Biobanks function as important repositories for biological samples collected in health care. As such, they play an important role in enabling important medical research over time. In response to the covid-19 outbreak in Stockholm, Sweden, a group of specialists in intensive care, infectious diseases, and clinical microbiology, as well as scientists with experience in immunology and viral diseases, rapidly gathered. The group discussed how to cope with the prevailing situation, both from a clinical and a research-oriented perspective. Among strategies decided was an attempt to rapidly organize a biological sample collection organized in a biobank for immediate but also long-term research purposes. Given the pandemic conditions with a new virus, the biobank project and associated immediate immunological research tasks turned out to be challenging. In the following months, many lessons were learned from the systematic collection of clinical samples and associated immunological research. Many insights were gained of value for future pandemic preparedness.