RESUMEN
SARS-CoV-2-specific memory T cells will likely prove critical for long-term immune protection against COVID-19. Here, we systematically mapped the functional and phenotypic landscape of SARS-CoV-2-specific T cell responses in unexposed individuals, exposed family members, and individuals with acute or convalescent COVID-19. Acute-phase SARS-CoV-2-specific T cells displayed a highly activated cytotoxic phenotype that correlated with various clinical markers of disease severity, whereas convalescent-phase SARS-CoV-2-specific T cells were polyfunctional and displayed a stem-like memory phenotype. Importantly, SARS-CoV-2-specific T cells were detectable in antibody-seronegative exposed family members and convalescent individuals with a history of asymptomatic and mild COVID-19. Our collective dataset shows that SARS-CoV-2 elicits broadly directed and functionally replete memory T cell responses, suggesting that natural exposure or infection may prevent recurrent episodes of severe COVID-19.
Asunto(s)
Convalecencia , Infecciones por Coronavirus/inmunología , Neumonía Viral/inmunología , Linfocitos T/inmunología , Adulto , Anticuerpos Antivirales/inmunología , Infecciones Asintomáticas , Betacoronavirus/inmunología , COVID-19 , Infecciones por Coronavirus/patología , Femenino , Humanos , Memoria Inmunológica , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/patología , SARS-CoV-2RESUMEN
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.
Asunto(s)
COVID-19 , Células T Invariantes Asociadas a Mucosa , Humanos , Antígenos HLA-DR , InflamaciónRESUMEN
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.
Asunto(s)
Autoanticuerpos , COVID-19 , Interferón Tipo I , SARS-CoV-2 , Humanos , COVID-19/inmunología , Interferón Tipo I/inmunología , Autoanticuerpos/sangre , Autoanticuerpos/inmunología , SARS-CoV-2/inmunología , Masculino , Femenino , Persona de Mediana Edad , Inmunidad Celular , Adulto , Anciano , Inmunidad Adaptativa/inmunología , Linfocitos T/inmunología , Índice de Severidad de la EnfermedadRESUMEN
PURPOSE: To study the association between the use of drugs for hypertension or heart failure, particularly diuretics, and risk of death in COVID-19. METHODS: We conducted a cohort study, based on record linked individual-based data from national registers, of all Swedish inhabitants 50 years and older (n = 3,909,321) at the start of the first SARS-CoV-2 wave in Sweden. The association between use of angiotensin-converting enzyme inhibitors (ACEI), angiotensin II receptor blockers (ARB), thiazides, loop diuretics, aldosterone antagonists, beta blocking agents and calcium channel blockers at the index date 6 March 2020, and death in COVID-19 during 7 March to 31 July 2020, was analysed using Cox-proportional hazards regression, adjusted for a wide range of possible confounders. RESULTS: Use of loop diuretics was associated with higher risk [adjusted hazard ratio (HR) 1.26; 95% confidence interval (95% CI) 1.17-1.35] and thiazides with reduced risk (0.78; 0.69-0.88) of death in COVID-19. In addition, lower risk was observed for ACEI and higher risk for beta-blocking agents, although both associations were weak. For ARB, aldosterone antagonists and calcium channel blockers no significant associations were found. CONCLUSION: In this nationwide cohort of nearly 4 million persons 50 years and older, the use of loop diuretics was associated with increased risk of death in COVID-19 during the first SARS-CoV-2 wave in Sweden. This contrasted to the decreased risk observed for thiazides. As treatment with loop diuretics is common, particularly in the elderly, the group most affected by severe COVID-19, this finding merit further investigation.
RESUMEN
Dendritic cells (DCs) and monocytes are crucial mediators of innate and adaptive immune responses during viral infection, but misdirected responses by these cells may contribute to immunopathology. Here, we performed high-dimensional flow cytometry-analysis focusing on mononuclear phagocyte (MNP) lineages in SARS-CoV-2-infected patients with moderate and severe COVID-19. We provide a deep and comprehensive map of the MNP landscape in COVID-19. A redistribution of monocyte subsets toward intermediate monocytes and a general decrease in circulating DCs was observed in response to infection. Severe disease coincided with the appearance of monocytic myeloid-derived suppressor cell-like cells and a higher frequency of pre-DC2. Furthermore, phenotypic alterations in MNPs, and their late precursors, were cell-lineage-specific and associated either with the general response against SARS-CoV-2 or COVID-19 severity. This included an interferon-imprint in DC1s observed in all patients and a decreased expression of the coinhibitory molecule CD200R in pre-DCs, DC2s, and DC3 subsets of severely sick patients. Finally, unsupervised analysis revealed that the MNP profile, alone, pointed to a cluster of COVID-19 nonsurvivors. This study provides a reference for the MNP response to SARS-CoV-2 infection and unravels mononuclear phagocyte dysregulations associated with severe COVID-19.
Asunto(s)
COVID-19/inmunología , Sistema Mononuclear Fagocítico/inmunología , SARS-CoV-2/inmunología , Adulto , COVID-19/epidemiología , COVID-19/metabolismo , COVID-19/virología , Citocinas/inmunología , Células Dendríticas/inmunología , Femenino , Humanos , Interferones/inmunología , Masculino , Persona de Mediana Edad , Monocitos/inmunología , Sistema Mononuclear Fagocítico/metabolismo , Índice de Severidad de la Enfermedad , SueciaRESUMEN
Since the outset of the COVID-19 pandemic, increasing evidence suggests that the innate immune responses play an important role in the disease development. A dysregulated inflammatory state has been proposed as a key driver of clinical complications in COVID-19, with a potential detrimental role of granulocytes. However, a comprehensive phenotypic description of circulating granulocytes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients is lacking. In this study, we used high-dimensional flow cytometry for granulocyte immunophenotyping in peripheral blood collected from COVID-19 patients during acute and convalescent phases. Severe COVID-19 was associated with increased levels of both mature and immature neutrophils, and decreased counts of eosinophils and basophils. Distinct immunotypes were evident in COVID-19 patients, with altered expression of several receptors involved in activation, adhesion, and migration of granulocytes (e.g., CD62L, CD11a/b, CD69, CD63, CXCR4). Paired sampling revealed recovery and phenotypic restoration of the granulocytic signature in the convalescent phase. The identified granulocyte immunotypes correlated with distinct sets of soluble inflammatory markers, supporting pathophysiologic relevance. Furthermore, clinical features, including multiorgan dysfunction and respiratory function, could be predicted using combined laboratory measurements and immunophenotyping. This study provides a comprehensive granulocyte characterization in COVID-19 and reveals specific immunotypes with potential predictive value for key clinical features associated with COVID-19.
Asunto(s)
COVID-19/inmunología , Granulocitos/inmunología , COVID-19/sangre , COVID-19/diagnóstico , COVID-19/fisiopatología , Granulocitos/citología , Humanos , Inmunidad Innata , Inmunofenotipificación , Recuento de Leucocitos , Pulmón/fisiopatología , Modelos Biológicos , Puntuaciones en la Disfunción de Órganos , SARS-CoV-2 , Índice de Severidad de la EnfermedadRESUMEN
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.
Asunto(s)
COVID-19/inmunología , COVID-19/metabolismo , Metaboloma/inmunología , SARS-CoV-2 , Adolescente , Adulto , Anciano , COVID-19/complicaciones , Estudios de Casos y Controles , Enfermedades del Sistema Nervioso Central/etiología , Enfermedades del Sistema Nervioso Central/inmunología , Enfermedades del Sistema Nervioso Central/metabolismo , Estudios de Cohortes , Femenino , Humanos , Masculino , Metabolómica , Persona de Mediana Edad , Especificidad de Órganos , Pandemias , Fenotipo , Proteómica , Índice de Severidad de la Enfermedad , Adulto JovenRESUMEN
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.
Asunto(s)
COVID-19 , Infecciones Comunitarias Adquiridas , Neumonía , Sepsis , Humanos , COVID-19/complicaciones , Proteómica , Inflamación/complicaciones , BiomarcadoresRESUMEN
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.
Asunto(s)
Polipéptido alfa Relacionado con Calcitonina , Sepsis , Humanos , Estudios Prospectivos , Complejo de Antígeno L1 de Leucocito , Sepsis/diagnóstico , Sepsis/terapia , Cuidados Críticos , Unidades de Cuidados Intensivos , Servicio de Urgencia en Hospital , BiomarcadoresRESUMEN
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.
Asunto(s)
Unidades de Cuidados Intensivos , Puntuaciones en la Disfunción de Órganos , Consumo de Oxígeno/fisiología , Saturación de Oxígeno/fisiología , Sepsis/sangre , Sepsis/mortalidad , Anciano , Estudios de Cohortes , Femenino , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Estudios Retrospectivos , Síndrome de Respuesta Inflamatoria SistémicaRESUMEN
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.
Asunto(s)
COVID-19 , Neumonía Asociada al Ventilador , Infecciones del Sistema Respiratorio , Infecciones Estafilocócicas , COVID-19/epidemiología , COVID-19/terapia , Humanos , Pandemias , Neumonía Asociada al Ventilador/epidemiología , Sistema Respiratorio , Infecciones del Sistema Respiratorio/epidemiología , Estudios Retrospectivos , Infecciones Estafilocócicas/epidemiología , Ventiladores MecánicosRESUMEN
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.
RESUMEN
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.
Asunto(s)
Enfermedades Transmisibles , Servicio de Urgencia en Hospital/estadística & datos numéricos , Hospitalización/estadística & datos numéricos , Sepsis/mortalidad , Anciano , Anciano de 80 o más Años , Femenino , Mortalidad Hospitalaria , Humanos , Infecciones/mortalidad , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sepsis/diagnóstico , Sepsis/microbiologíaRESUMEN
BACKGROUND: Information on characteristics and outcomes of intensive care unit (ICU) patients with COVID-19 remains limited. We examined characteristics, clinical course and early outcomes of patients with COVID-19 admitted to ICU. METHODS: We included all 260 patients with COVID-19 admitted to nine ICUs at the Karolinska University Hospital (Stockholm, Sweden) between 9 March and 20 April 2020. Primary outcome was in-hospital mortality among patients with definite outcomes (discharged from ICU or death), as of 30 April 2020 (study end point). Secondary outcomes included ICU length of stay, the proportion of patients receiving mechanical ventilation and renal replacement therapy, and hospital discharge destination. RESULTS: Of 260 ICU patients with COVID-19, 208 (80.0%) were men, the median age was 59 (IQR 51-65) years, 154 (59.2%) had at least one comorbidity, and the median duration of symptoms preceding ICU admission was 11 (IQR 8-14) days. Sixty-two (23.8%) patients remained in ICU at study end point. Among the 198 patients with definite outcomes, ICU length of stay was 12 (IQR, 6-18) days, 163 (82.3%) received mechanical ventilation, 28 (14.1%) received renal replacement therapy, 60 (30.3%) died, 62 (31.3%) were discharged home, 47 (23.7%) were discharged to ward, and 29 (14.6%) were discharged to another health care facility. On multivariable logistic regression analysis, older age and admission from the emergency department was associated with higher mortality. CONCLUSION: This study presents detailed data on clinical characteristics and early outcomes of consecutive patients with COVID-19 admitted to ICU in a large tertiary hospital in Sweden.
Asunto(s)
COVID-19/terapia , Cuidados Críticos/estadística & datos numéricos , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , COVID-19/mortalidad , Comorbilidad , Determinación de Punto Final , Femenino , Mortalidad Hospitalaria , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Alta del Paciente , Pacientes , Terapia de Reemplazo Renal , Respiración Artificial/estadística & datos numéricos , Estudios Retrospectivos , Suecia , Centros de Atención Terciaria , Resultado del TratamientoRESUMEN
Blood culture (BC) often fails to detect bloodstream microorganisms in sepsis. However, molecular diagnostics hold great potential. The molecular method PCR/electrospray ionization-mass spectrometry (PCR/ESI-MS) can detect DNA from hundreds of different microorganisms in whole blood. The aim of the present study was to evaluate the performance of this method in a multicenter study including 16 teaching hospitals in the United States (n = 13) and Europe (n = 3). First, on testing of 2,754 contrived whole blood samples, with or without spiked microorganisms, PCR/ESI-MS produced 99.1% true-positive and 97.2% true-negative results. Second, among 1,460 patients with suspected sepsis (sepsis-2 definition), BC and PCR/ESI-MS on whole blood were positive in 14.6% and 25.6% of cases, respectively, with the following result combinations: BC positive and PCR/ESI-MS negative, 4.3%; BC positive and PCR/ESI-MS positive, 10.3%; BC negative and PCR/ESI-MS positive, 15.3%; and BC negative and PCR/ESI-MS negative, 70.1%. Compared with BC, PCR/ESI-MS showed the following sensitivities (coagulase-negative staphylococci not included): Gram-positive bacteria, 58%; Gram-negative bacteria, 78%; and Candida species, 83%. The specificities were >94% for all individual species. Patients who had received prior antimicrobial medications (n = 603) had significantly higher PCR/ESI-MS positivity rates than patients without prior antimicrobial treatment-31% versus 22% (P < 0.0001)-with pronounced differences for Gram-negative bacteria and Candida species. In conclusion, PCR/ESI-MS showed excellent performance on contrived samples. On clinical samples, it showed high specificities, moderately high sensitivities for Gram-negative bacteria and Candida species, and elevated positivity rates during antimicrobial treatment. These promising results encourage further development of molecular diagnostics to be used with whole blood for detection of bloodstream microorganisms in sepsis.
Asunto(s)
Sepsis , Espectrometría de Masa por Ionización de Electrospray , Cultivo de Sangre , Europa (Continente) , Humanos , Reacción en Cadena de la Polimerasa , Sepsis/diagnósticoRESUMEN
The severity of bloodstream infections (BSI) depends on pathogen, source, and host factors. Secretory leukocyte protease inhibitor (SLPI) counteracts tissue damage, balances inflammation, and is increased in pneumonia and sepsis. We aimed to evaluate whether SLPI production differs depending on etiology, disease severity, and sex in BSI and to correlate SLPI with markers of inflammation and immunosuppression. Of the adult patients with BSI, 109 were included and sampled repeatedly, from hospital admission through day 28. Controls (blood donors) were sampled twice. SLPI in plasma was measured with enzyme-linked immunosorbent assay (ELISA) technique. Streptococcus pneumoniae and Staphylococcus aureus etiology were associated with higher SLPI than Escherichia coli on days 1-2 and 3. On day 1-2, subjects with sepsis had higher SLPI concentrations than those with non-septic BSI. Pneumonia was associated with higher SLPI than a non-pulmonary source of infection. SLPI co-varied with inflammatory markers. SLPI concentrations did not differ with regard to sex in the full cohort, but men with pneumonia had higher SLPI than women on day 1-2. S. pneumoniae and S. aureus BSI were associated with higher SLPI, when compared to E. coli. Severity and pneumonia, as well as male sex in the pneumonia sub-cohort, were factors independently associated with higher SLPI.
Asunto(s)
Bacteriemia/microbiología , Infecciones por Escherichia coli/diagnóstico , Infecciones Neumocócicas/diagnóstico , Inhibidor Secretorio de Peptidasas Leucocitarias/sangre , Infecciones Estafilocócicas/diagnóstico , Anciano , Anciano de 80 o más Años , Bacteriemia/diagnóstico , Biomarcadores/sangre , Escherichia coli , Femenino , Humanos , Inflamación , Masculino , Persona de Mediana Edad , Neumonía Bacteriana/diagnóstico , Neumonía Bacteriana/microbiología , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Factores Sexuales , Staphylococcus aureus , Streptococcus pneumoniaeRESUMEN
The inflammasome is a multiprotein complex that mediates caspase-1 activation with subsequent maturation of the proinflammatory cytokines IL-1ß and IL-18. The NLRP3 inflammasome is known to be activated by Staphylococcus aureus, one of the leading causes of bacteremia worldwide. Inflammasome activation and regulation in response to bacterial infection have been found to be of importance for a balanced host immune response. However, inflammasome signaling in vivo in humans initiated by S. aureus is currently sparsely studied. This study therefore aimed to investigate NLRP3 inflammasome activity in 20 patients with S. aureus bacteremia (SAB), by repeated measurement during the first week of bacteremia, compared with controls. Caspase-1 activity was measured in monocytes and neutrophils by flow cytometry detecting FLICA (fluorescent-labeled inhibitor of caspase-1), while IL-1ß and IL-18 was measured by Luminex and ELISA, respectively. As a measure of inflammasome priming, messenger RNA (mRNA) expression of NLRP3, CASP1 (procaspase-1), and IL1B (pro-IL-1ß) was analyzed by quantitative PCR. We found induced caspase-1 activity in innate immune cells with subsequent release of IL-18 in patients during the acute phase of bacteremia, indicating activation of the inflammasome. There was substantial interindividual variation in caspase-1 activity between patients with SAB. We also found an altered inflammasome priming with low mRNA levels of NLRP3 accompanied by elevated mRNA levels of IL1B. This increased knowledge of the individual host immune response in SAB could provide support in the effort to optimize management and treatment of each individual patient.
Asunto(s)
Caspasa 1/sangre , Inflamasomas/metabolismo , Interleucina-1beta/sangre , Proteína con Dominio Pirina 3 de la Familia NLR/sangre , Infecciones Estafilocócicas/inmunología , Staphylococcus aureus/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Bacteriemia , Femenino , Humanos , Interleucina-18 , Masculino , Persona de Mediana EdadRESUMEN
Although there are several US Food and Drug Administration (FDA)-approved/cleared molecular microbiology diagnostics for direct analysis of patient samples, all are single target or panel-based tests. There is no FDA-approved/cleared diagnostic for broad microbial detection. Polymerase chain reaction (PCR)/electrospray ionization-mass spectrometry (PCR/ESI-MS), commercialized as the IRIDICA system (Abbott) and formerly PLEX-ID, had been under development for over a decade and had become CE-marked and commercially available in Europe in 2014. Capable of detecting a large number of microorganisms, it was under review at the FDA when, in April 2017, Abbott discontinued it. This turn of events represents not only the loss of a potential diagnostic tool for infectious diseases but may be a harbinger of similar situations with other emerging and expensive microbial diagnostics, especially genomic tests.
Asunto(s)
Enfermedades Transmisibles/diagnóstico , Reacción en Cadena de la Polimerasa , Espectrometría de Masa por Ionización de Electrospray , Bacteriemia/diagnóstico , Humanos , Técnicas de Diagnóstico Molecular/normas , Sepsis/diagnóstico , Estados Unidos , United States Food and Drug AdministrationRESUMEN
To improve management of Staphylococcus aureus bacteremia (SAB), better understanding of host-pathogen interactions is needed. In vitro studies have shown that S. aureus bacteria induce dose-dependent immunosuppression that is evidenced by reduced expression of major histocompatibility complex (MHC) class II on antigen presenting cells. Thus, the aim of this study was to determine whether expression of the MHC class II-related genes HLA-DRA and CD74 is more greatly reduced in complicated SAB, with its probable higher loads of S. aureus, than in uncomplicated SAB. Adult patients with SAB were prospectively included and blood samples taken on the day of confirmation of SAB (Day 1) and on Days 2, 3, 5 and 7. HLA-DRA and CD74 mRNA expression was determined by quantitative reverse transcription PCR. Sepsis was defined according to the Sepsis-3 classification and SAB was categorized as complicated in patients with deep-seated infection and/or hematogenous seeding. Twenty patients with SAB were enrolled and samples obtained on all assessment days. HLA-DRA and CD74 expression did not differ significantly between patients with SAB and sepsis (n = 13) and those without sepsis (n = 7) on any assessment day. However, patients with complicated SAB (n = 14) had significantly weaker HLA-DRA expression on all five assessment days than patients with uncomplicated SAB (n = 6). Additionally, they tended to have weaker CD74 expressions. Neutrophil, monocyte and leukocyte counts did not differ significantly between complicated and uncomplicated SAB. In conclusion, patients with complicated SAB show weaker HLA-DRA expression than those with uncomplicated SAB during the first week of bacteremia.