CCQM-P199b: Interlaboratory comparability study of SARS-CoV-2 RNA copy number quantification (preprint)

Nucleic acid amplification tests including reverse transcription-quantitative PCR (RT-qPCR) are used to detect RNA from Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of the Coronavirus disease 2019 (COVID-19) pandemic. Standardized measurements of RNA can facilitate comparable performance of laboratory tests in the absence of existing reference measurement systems early on in a pandemic. Interlaboratory study CCQM-P199b 'SARS-CoV-2 RNA copy number quantification' was designed to test the fitness-for-purpose of developed candidate reference measurement procedures (RMPs) for SARS-CoV-2 genomic targets in purified RNA materials, and was conducted under the auspices of the Consultative Committee for Amount of Substance: Metrology in Chemistry and Biology (CCQM) to evaluate the measurement comparability of national metrology institutes (NMIs) and designated institutes (DIs), thereby supporting international standardization. Twenty-one laboratories participated in CCQM-P199b and were requested to report the RNA copy number concentration, expressed in number of copies per microliter, of the SARS-CoV-2 nucleocapsid (N) gene partial region (NC_045512.2: 28274-29239) and envelope (E) gene (NC_045512.2: 26245-26472) (optional measurement) in samples consisting of in vitro transcribed RNA or purified RNA from lentiviral constructs. Materials were provided in two categories: lower concentration (approximately 10 x 1 - 10 x 4/uL in aqueous solution containing human RNA background) and high concentration (approximately 10 x 9/uL in aqueous solution without any other RNA background). For the measurement of N gene concentration in the lower concentration study materials, the majority of laboratories (n = 17) used one-step reverse transcription-digital PCR (RT-dPCR), with three laboratories applying two-step RT-dPCR and one laboratory RT-qPCR. Sixteen laboratories submitted results for E gene concentration. Reproducibility (% CV or equivalent) for RT-dPCR ranged from 19 % to 31 %. Measurements of the high concentration study material by orthogonal methods (isotope dilution-mass spectrometry and single molecule flow cytometry) and a gravimetrically linked lower concentration material were in a good agreement, suggesting a lack of overall bias in RT-dPCR measurements. However methodological factors such as primer and probe (assay) sequences, RT-dPCR reagents and dPCR partition volume were found to be potential sources of interlaboratory variation which need to be controlled when applying this technique. This study demonstrates that the accuracy of RT-dPCR is fit-for-purpose as a RMP for viral RNA target quantification in purified RNA materials and highlights where metrological approaches such as the use of in vitro transcribed controls, orthogonal methods and measurement uncertainty evaluation can support standardization of molecular methods.

Mental health of female sex workers in the COVID-19 pandemic: stressors and coping strategies. / Saúde mental de trabalhadoras sexuais na pandemia da COVID-19: agentes estressores e estratégias de coping.

The objective was to analyze the coping strategies adopted by female sex workers in the face of stressors resulting from the COVID-19 pandemic. Qualitative study supported by Systems and Coping theories. An in-depth interview was carried out with 30 sex workers from the Alto Sertão Produtivo Baiano between September and October 2020. The narratives were submitted to the resources of hermeneutics-dialectic to organize the categories. Four categories make reference to the system's stressors: negative feelings of fear, anxiety and difficulties in sleeping with the uncertainties in the face of the pandemic; concern about personal and family support; irritability in the face of conflicts; anxieties and insecurities with working conditions. Five categories allude to coping: strategies focused on the problem (pandemic); reframing and regulation of emotions; spirituality and religiosity; support networks and social support; use of medications. Stressors arise as a result of sexual service experiences combined with the pandemic situation with reduced customers and income, leading to the development of negative feelings and emotions. However, coping strategies are diverse and they women made effort to deal with problems and to balance their mental health.

Objetivou-se analisar as estratégias de coping adotadas por trabalhadoras sexuais frente aos agentes estressores decorrentes da pandemia da COVID-19. Estudo qualitativo, apoiado nas teorias do Sistemas e Coping. Realizou-se entrevista em profundidade com 30 trabalhadoras sexuais, do Alto Sertão Produtivo Baiano, entre os meses de setembro e outubro de 2020. As narrativas foram submetidas aos recursos da hermenêutica-dialética para organização das categorias. Quatro categorias remetem aos agentes estressores do sistema: sentimentos negativos de medo, ansiedade e dificuldades de dormir com as incertezas diante da pandemia; preocupação com o sustento dos familiares; irritabilidade diante de conflitos; angústias e inseguranças com as condições de trabalho. Cinco categorias fazem alusão ao coping: focam no problema (pandemia); ressignificação e regulação de emoções; espiritualidade e religiosidade; redes de apoio e suporte social; uso de substâncias e medicamentos. Os estressores surgem em decorrência das vivências do serviço sexual aliadas a situação pandêmica com redução de clientes e renda, desenvolvendo sentimentos e emoções negativas. Todavia, as estratégias de coping são diversas e tentativas de lidar com os problemas e equilibrar a saúde mental.

Impact of prone positioning on patients with COVID-19 and ARDS on invasive mechanical ventilation: a multicenter cohort study.

OBJECTIVE: To identify factors that lead to a positive oxygenation response and predictive factors of mortality after prone positioning. METHODS: This was a retrospective, multicenter, cohort study involving seven hospitals in Brazil. Inclusion criteria were being > 18 years of age with a suspected or confirmed diagnosis of COVID-19, being on invasive mechanical ventilation, having a PaO2/FIO2 ratio < 150 mmHg, and being submitted to prone positioning. After the first prone positioning session, a 20 mmHg improvement in the PaO2/FIO2 ratio was defined as a positive response. RESULTS: The study involved 574 patients, 412 (72%) of whom responded positively to the first prone positioning session. Multiple logistic regression showed that responders had lower Simplified Acute Physiology Score III (SAPS III)/SOFA scores and lower D-dimer levels (p = 0.01; p = 0.04; and p = 0.04, respectively). It was suggested that initial SAPS III and initial PaO2/FIO2 were predictors of oxygenation response. The mortality rate was 69.3%. Increased risk of mortality was associated with age (OR = 1.04 [95 CI: 1.01-1.06]), time to first prone positioning session (OR = 1.18 [95 CI: 1.06-1.31]), number of sessions (OR = 1.31 [95% CI: 1.00-1.72]), proportion of pulmonary impairment (OR = 1.55 [95% CI: 1.02-2.35]), and immunosuppression (OR = 3.83 [95% CI: 1.35-10.86]). CONCLUSIONS: Our results show that most patients in our sample had a positive oxygenation response after the first prone positioning session. However, the mortality rate was high, probably due to the health status and the number of comorbidities of the patients, as well as the severity of their disease. Our results also suggest that SAPS III and the initial PaO2/FIO2 predict the oxygenation response; in addition, age, time to first prone positioning, number of sessions, pulmonary impairment, and immunosuppression can predict mortality.

Effect of immunonutrition on serum levels of C-reactive protein and lymphocytes in patients with COVID-19: a randomized, controlled, double-blind clinical trial.

INTRODUCTION: Introduction: patients with COVID-19 undergo changes in leukocyte count, respiratory disorders, and an increase in inflammatory substances. To improve the inflammatory condition, some nutrients can be used, including arginine, omega-3 fatty acids and nucleotides. This study aims to evaluate how oral immunonutrient supplements affects serum C-reactive protein (CRP) levels and lymphocyte count in patients with COVID-19. Methods: in this double-blind clinical trial, we randomized 43 adult patients with COVID-19 to receive a standard high-protein normocaloric supplement (control) or an immunonutrient-enriched supplement (experiment) for 7 days. The primary outcome was to evaluate changes in total lymphocyte count and serum level of CRP. The assessment of risk and nutritional status of these patients was also performed. Results: forty-three patients with mean age of 41.5 (± 1.8) years were followed up, 39.5 % of them women. The mean body mass index was 27.6 (± 0.8) kg/m² and 58.1 % had low nutritional risk. In the experiment group, there was a CRP reduction of 23.6 (± 7.5) mg/L, while in the control branch the decrease was 14.8 (± 12.1) mg/L (p = 0.002). There was an increase in lymphocytes in the experiment group (+367.5 ± 401.8 cells/mm³) and a reduction in the control group (-282.8 ± 327.8 cells/mm³), although there was no statistical significance (p = 0.369). Relative risk (RR) of treatment in reducing CRP by 30 % or more was 4.45 (p < 0.001; 95 % CI, 1.79-11.07). RR in increasing lymphocyte count by 30 % or more was 1.28 (p = 0.327; 95 % CI, 0.67-2.45). Conclusion: we conclude that immunonutrient supplements seem to reduce CRP levels more than standard high-protein normocaloric supplements.

INTRODUCCIÓN: Introducción: los pacientes con COVID-19 sufren cambios en el recuento de leucocitos, trastornos respiratorios y aumento de sustancias inflamatorias. Para mejorar la condición inflamatoria se pueden usar algunos nutrientes, como la arginina, los ácidos grasos omega-3 y los nucleótidos. Este estudio tiene como objetivo evaluar cómo los suplementos de inmunonutrientes orales afectan a los niveles séricos de proteína C-reactiva (PCR) y al recuento de linfocitos en pacientes con COVID-19. Métodos: en este ensayo clínico doble ciego, aleatorizamos a 43 pacientes adultos con COVID-19 para recibir un suplemento normocalórico estándar alto en proteínas (control) o un suplemento enriquecido con inmunonutrientes (experimento) durante 7 días. El resultado primario fue evaluar los cambios en el recuento total de linfocitos y el nivel sérico de PCR. También se realizó la evaluación del riesgo y el estado nutricional de estos pacientes. Resultados: cuarenta y tres pacientes con edad media de 41,5 (± 1,8) años fueron seguidos, el 39,5 % de ellos mujeres. El índice de masa corporal medio fue de 27,6 (± 0,8) kg/m² y el 58,1 % tenían bajo riesgo nutricional. En el grupo experimental hubo una reducción de la PCR de 23,6 (± 7,5) mg/L, mientras que en la rama de control la disminución fue de 14,8 (± 12,1) mg/L (p = 0,002). Hubo un aumento de linfocitos en el grupo experimental (+367,5 ± 401,8 células/mm³) y una reducción en el grupo de control (-282,8 ± 327,8 células/mm³), aunque no hubo significación estadística (p = 0,369). El riesgo relativo (RR) del tratamiento para reducir la PCR en un 30 % o más fue de 4,45 (p < 0,001; IC 95 %: 1,79-11,07). El RR en el aumento del recuento de linfocitos en un 30 % o más fue de 1,28 (p = 0,327; IC 95 %: 0,67-2,45). Conclusión: se concluye que los suplementos de inmunonutrientes parecen reducir los niveles de PCR más que los suplementos normocalóricos estándar altos en proteína.

SARS-CoV-2 specific memory T lymphocytes from COVID-19 convalescent donors: identification, biobanking and large scale production for Adoptive Cell Therapy (preprint)

SARS-CoV-2 is causing a second outbreak so the hope for its complete eradication is far from happening. In the absence of effective vaccines, it is mandatory to find effective treatments with low adverse effects able to treat hospitalized patients with COVID-19 disease. In this work, we determined the existence of SARS-CoV-2 specific T cells within the CD45RA- T memory cells from the blood of convalescent donors. Memory T cells can respond quickly to the infection and provide long-term immune protection to reduce the severity of the COVID-19 symptoms. Also, CD45RA- memory T cells confer protection from other pathogens the donors encountered in their life. This is vital to clear other secondary infections usually developed in hospitalized COVID-19 patients. SARS-CoV-2 specific memory T cells were found within all the CD45RA- subsets CD3+, CD4+, CD8+, and in the central memory and effector memory subpopulations. The procedure to obtain the cells is feasible, easy to implement for small scale manufacture, quick and cost-effective involving minimal manipulation, and without GMP condition requirements. This biobank of specific SARS-CoV-2 memory T cells would be immediately available off-the-shelf to treat moderate/severe cases of COVID-19 increasing the therapeutic options available for these patients.