Usefulness of real-time RT-PCR to understand the kinetics of SARS-CoV-2 in blood: A prospective study.

BACKGROUND: SARS-CoV-2 viral load and kinetics assessed in serial blood samples from hospitalised COVID-19 patients by RT-PCR are poorly understood. METHODS: We conducted an observational, prospective case series study in hospitalised COVID-19 patients. Clinical outcome data (Intensive Care Unit admission and mortality) were collected from all patients until discharge. Viremia was determined longitudinally during hospitalisation, in plasma and serum samples collected sequentially, using two commercial and standardised RT-PCR techniques approved for use in diagnosis of SARS-CoV-2. Viral load (copies/mL and log10) was determined with quantitative TaqPath™COVID-19 test. Persistent viremia (PV) was defined as two or more consecutive quantifiable viral loads detected in blood samples (plasma/serum) during hospitalisation. RESULTS: SARS-CoV-2 viremia was studied in 57 hospitalised COVID-19 patients. PV was detected in 16 (28%) patients. All of them, except for one who rapidly progressed to death, cleared viremia during hospitalisation. Poor clinical outcome occurred in 62.5% of patients with PV, while none of the negative patients or those with sporadic viremia presented this outcome (p < 0.0001). Viral load was significantly higher in patients with PV than in those with Sporadic Viremia (p < 0.05). Patients presented PV for a short period of time: median time from admission was 5 days (Range = 2-12) and 4.5 days (Range = 2-8) for plasma and serum samples, respectively. Similar results were obtained with all RT-PCR assays for both types of samples. CONCLUSIONS: Detection of persistent SARS-CoV-2 viremia, by real time RT-PCR, expressed as viral load over time, could allow identifying hospitalised COVID-19 patients at risk of poor clinical outcome.

Evaluation of two RT-PCR techniques for SARS-CoV-2 RNA detection in serum for microbiological diagnosis.

Presence of SARS-CoV-2 RNA in serum (viremia) of COVID-19 patients has been related to poor prognosis and death. The aim of this study was to evaluate both the ability to detect viremia in COVID-19 patients of two commercial reverse real-time-PCR (rRT-PCR) tests, Cobas® and TaqPath™, comparing them with a gold standard method, and their implementation in microbiology laboratories. This retrospective cohort study included 303 adult patients (203 diagnosed with COVID-19 and 100 non-COVID-19 patients) admitted to a tertiary hospital, with at least one serum sample collected within the first 48 h from admission. A total of 365 serum samples were included: 100 from non-COVID patients (pre-pandemic and pandemic control groups) and 265 from COVID-19 patients. Serum samples were considered positive when at least one target was detected. All patients in control groups showed negative viremia. Cobas® and TaqPath™ tests showed specificity and Positive Predictive Value over 96%. Nevertheless, sensitivity (53.72 and 73.63, respectively) and Negative Predictive Value (64.78 and 75) were lower. Viremia difference between ICU and non-ICU patients was significant (p ≤ 0.001) for both techniques. Consequently, SARS-CoV-2 viremia detection by both rRT-PCR tests should be considered a good tool to stratify COVID-19 patients and could be implemented in microbiology laboratories.

IL-6 serum levels predict severity and response to tocilizumab in COVID-19: An observational study.

BACKGROUND: Patients with coronavirus disaese 2019 (COVID-19) can develop a cytokine release syndrome that eventually leads to acute respiratory distress syndrome requiring invasive mechanical ventilation (IMV). Because IL-6 is a relevant cytokine in acute respiratory distress syndrome, the blockade of its receptor with tocilizumab (TCZ) could reduce mortality and/or morbidity in severe COVID-19. OBJECTIVE: We sought to determine whether baseline IL-6 serum levels can predict the need for IMV and the response to TCZ. METHODS: A retrospective observational study was performed in hospitalized patients diagnosed with COVID-19. Clinical information and laboratory findings, including IL-6 levels, were collected approximately 3 and 9 days after admission to be matched with preadministration and postadministration of TCZ. Multivariable logistic and linear regressions and survival analysis were performed depending on outcomes: need for IMV, evolution of arterial oxygen tension/fraction of inspired oxygen ratio, or mortality. RESULTS: One hundred forty-six patients were studied, predominantly males (66%); median age was 63 years. Forty-four patients (30%) required IMV, and 58 patients (40%) received treatment with TCZ. IL-6 levels greater than 30 pg/mL was the best predictor for IMV (odds ratio, 7.1; P < .001). Early administration of TCZ was associated with improvement in oxygenation (arterial oxygen tension/fraction of inspired oxygen ratio) in patients with high IL-6 (P = .048). Patients with high IL-6 not treated with TCZ showed high mortality (hazard ratio, 4.6; P = .003), as well as those with low IL-6 treated with TCZ (hazard ratio, 3.6; P = .016). No relevant serious adverse events were observed in TCZ-treated patients. CONCLUSIONS: Baseline IL-6 greater than 30 pg/mL predicts IMV requirement in patients with COVID-19 and contributes to establish an adequate indication for TCZ administration.

Estudio de una cohorte de paciente con fibrosis quística y Scedosporium spp / Study of a Cohort of Patients With Cystic Fibrosis and Isolation of Scedosporium spp

Introducción: En los últimos años se observa un aumento de la prevalencia de colonización e infección por Scedosporium spp. en pacientes con fibrosis quística (FQ). En el presente estudio se registra la frecuencia de aislamiento de Scedosporium spp. en una Unidad de FQ de adultos, analizándose las características de los pacientes y los factores predisponentes. Métodos: Se realizó un estudio observacional retrospectivo en 87 pacientes adultos con FQ en los que se valoró la presencia de cultivo positivo para Scedosporium spp. durante 5 años (enero de 2012-julio de 2017). Se recogieron las siguientes variables clínicas: edad, sexo, índice de masa corporal, genotipo, presencia de insuficiencia pancreática, colonizaciones bacterianas, función pulmonar, complicaciones, exacerbaciones y tratamiento, así como puntuación Bhalla modificada de la última tomografía computarizada axial de alta resolución. Los resultados se analizaron con el paquete estadístico IBM SPSS Statistics Version 22.0. Resultados: En un 25,3% de los pacientes se aisló Scedosporium spp. En el análisis bivariante se observó en estos enfermos más frecuencia de Pseudomonas aeruginosa, peor puntuación en la clasificación de Bhalla (destacando los ítems presencia de bronquiectasias, tapones mucosos y generaciones bronquiales), un descenso leve en la capacidad de difusión pulmonar (DLCO) y que recibían con más frecuencia antibioterapia inhalada. En el análisis multivariante de regresión logística únicamente el ítem generaciones bronquiales fue significativo. Conclusiones: Scedosporium spp. debe considerarse un patógeno oportunista emergente en pacientes con FQ del que se desconoce su implicación clínica, factores de riesgo o necesidad de tratamiento

Introduction: In recent years an increase in the prevalence of colonization and infection by Scedosporium spp. in patients with cystic fibrosis (CF) has been observed. In this article, we study the frequency of isolation of Scedosporium spp. in an adult CF Unit, analyzing characteristics of the patients and predisposing factors. Methods: A retrospective observational study was conducted in 87 adult CF patients in whom the presence of positive culture for Scedosporium spp. was tested for a 5-year period (January 2012-July 2017). We recorded the following clinical variables: age, sex, body mass index, genotype, presence of pancreatic insufficiency, bacterial colonization, lung function, other complications, exacerbations and treatment, and the modified Bhalla score from the last high-resolution computed tomography. Results were analyzed with IBM SPSS Statistics Version 22.0 software. Results: Scedosporium spp. was isolated in 25.3% of patients. In the bivariate analysis, these patients showed a higher rate of Pseudomonas aeruginosa infection, worse score in the Bhalla classification (highlighting the following items: bronchiectasis, mucus plugs and bronchial generations), a slight decrease in the lung diffusion capacity and more frequently received inhaled antibiotics. In the logistic regression multivariate analysis, only the bronchial generations item was significant. Conclusion: Scedosporium spp. must be considered an emerging opportunistic pathogen in patients with CF whose clinical involvement, risk factors or need for treatment is unknown

Study of a Cohort of Patients With Cystic Fibrosis and Isolation of Scedosporium spp. / Estudio de una cohorte de paciente con fibrosis quística y Scedosporium spp.

INTRODUCTION: In recent years an increase in the prevalence of colonization and infection by Scedosporium spp. in patients with cystic fibrosis (CF) has been observed. In this article, we study the frequency of isolation of Scedosporium spp. in an adult CF Unit, analyzing characteristics of the patients and predisposing factors. METHODS: A retrospective observational study was conducted in 87 adult CF patients in whom the presence of positive culture for Scedosporium spp. was tested for a 5-year period (January 2012-July 2017). We recorded the following clinical variables: age, sex, body mass index, genotype, presence of pancreatic insufficiency, bacterial colonization, lung function, other complications, exacerbations and treatment, and the modified Bhalla score from the last high-resolution computed tomography. Results were analyzed with IBM SPSS Statistics Version 22.0 software. RESULTS: Scedosporium spp. was isolated in 25.3% of patients. In the bivariate analysis, these patients showed a higher rate of Pseudomonas aeruginosa infection, worse score in the Bhalla classification (highlighting the following items: bronchiectasis, mucus plugs and bronchial generations), a slight decrease in the lung diffusion capacity and more frequently received inhaled antibiotics. In the logistic regression multivariate analysis, only the bronchial generations item was significant. CONCLUSION: Scedosporium spp. must be considered an emerging opportunistic pathogen in patients with CF whose clinical involvement, risk factors or need for treatment is unknown.