Extracellular Vesicles from Human Plasma Show a Distinctive Proteome and miRNome Profile in Patients with Severe Cutaneous Adverse Reactions.

Cutaneous drug-induced reactions are immune-mediated responses that can lead to life-threatening diseases such as drug reaction with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome, and toxic epidermal necrolysis, collectively known as severe cutaneous adverse reactions (SCARs). Unfortunately, they cannot be predicted during drug development, and, at present, a prognostic biomarker is not available nor are validated in vitro assays for diagnosis. Thus, by using proteomic and microarray miRNA analysis, the cargo of extracellular vesicles obtained from SCARs patients was analyzed and correlated with the severity of the reaction. Confirmatory assays using Western blot and qRT-PCR were performed to validate findings, and bioinformatic tools were used to establish the correlation between protein and miRNAs expression between groups. The proteomic analysis showed an increase in the amount of pro-inflammatory proteins, von Willebrand factor, and C-reactive protein and a decrease in anti-inflammatory and protective proteins in the SCARs group compared with the control group. Additionally, histone protein H2A was enriched in DRESS patients. APO1 and SERPINA4 proteins, highly increased in the control group but absent in the SCARs group, are the target of several overexpressed miRNAs, suggesting that the regulation of these proteins might involve gene silencing and protein repressing mechanisms in the severe patients. According with previous reports showing its presence in plasma and T-cells, microRNA miR-18 was upregulated in extracellular vesicles obtained from the most severe patients. Determination of the unique cargo associated with different disease conditions will help to understand the pathophysiology of these complex reactions and might help to develop novel biomarkers for life-threatening iatrogenic cutaneous disease.

Genotyping of the Major SARS-CoV-2 Clade by Short-Amplicon High-Resolution Melting (SA-HRM) Analysis.

The genome of the SARS-CoV-2 virus, the causal agent of the COVID-19 pandemic, has diverged due to multiple mutations since its emergence as a human pathogen in December 2019. Some mutations have defined several SARS-CoV-2 clades that seem to behave differently in terms of regional distribution and other biological features. Next-generation sequencing (NGS) approaches are used to classify the sequence variants in viruses from individual human patients. However, the cost and relative scarcity of NGS equipment and expertise in developing countries prevent studies aimed to associate specific clades and variants to clinical features and outcomes in such territories. As of March 2021, the GR clade and its derivatives, including the B.1.1.7 and B.1.1.28 variants, predominate worldwide. We implemented the post-PCR small-amplicon high-resolution melting analysis to genotype SARS-CoV-2 viruses isolated from the saliva of individual patients. This procedure was able to clearly distinguish two groups of samples of SARS-CoV-2-positive samples predicted, according to their melting profiles, to contain GR and non-GR viruses. This grouping of the samples was validated by means of amplification-refractory mutation system (ARMS) assay as well as Sanger sequencing.

Saliva as a promising biofluid for SARS-CoV-2 detection during the early stages of infection.

Background: Diagnostic testing for coronavirus disease (COVID)-19 is performed using nasopharyngeal swabs. This type of sampling is uncomfortable for the patient, dangerous for health workers, and its high demand has led to a global shortage of swabs. One of the alternative specimens is saliva. However, the optimal conditions for the test have not been established. Methods: Reverse transcription-polymerase chain reaction was used to detect the viral genome in saliva samples kept at room temperature, in the fridge or frozen for 2 days. In addition, the influence of brushing teeth and feeding on the detection of the virus in saliva was addressed. Finally, the efficiency of saliva in revealing the presence of the virus during the hospitalization period was determined in children. Results: The viral genome was consistently detected regardless of the storage conditions of saliva samples. Brushing teeth and feeding did not influence the sensitivity of the test. In hospitalized children, positive results were obtained only during the early days. Conclusions: These results support the idea of the use of saliva as an alternative specimen for diagnostic testing for COVID-19. The viral genome is stable and endures perturbations in the oral cavity. However, clearance of the virus from the mouth during the infection may limit the use of the test only to the early stages of the disease.

Introducción: El diagnóstico de COVID-19 (enfermedad por coronavirus 2019) se realiza con un hisopado nasofaríngeo. El procedimiento de toma de muestra es molesto para el paciente y peligroso para el personal de salud, y la alta demanda de análisis ha conducido a la escasez de hisopos. Una alternativa es el uso de saliva, pero las condiciones óptimas para realizar el estudio no han sido establecidas. Métodos: Se usó la reacción en cadena de la polimerasa con transcriptasa reversa para detectar el genoma viral en muestras de saliva mantenidas a temperatura ambiente, en refrigeración o congeladas. Además, se evaluó la influencia del aseo bucal y de la ingesta de alimento en la detección del virus. Finalmente, se determinó el desempeño de la saliva para reportar la presencia del virus durante el periodo de hospitalización en niños. Resultados: El genoma viral fue estable durante 2 días a las diferentes temperaturas ensayadas. El aseo bucal y la ingesta de alimento no influyeron en la detección del virus. En los niños hospitalizados solo se obtuvieron resultados positivos durante los primeros días. Conclusiones: Los resultados coinciden con la idea del uso de la saliva como biofluido alternativo para el diagnóstico de COVID-19. El genoma viral es estable y no se ve afectado por perturbaciones en la cavidad oral; sin embargo, la dinámica de la infección puede provocar que el ensayo solo sea útil durante las primeras etapas de la enfermedad.

Saliva as a promising biofluid for SARS-CoV-2 detection during the early stages of infection / La saliva como biofluido promisorio para la detección del SARS-CoV-2 durante las primeras etapas de la infección

Abstract Background: Diagnostic testing for coronavirus disease (COVID)-19 is performed using nasopharyngeal swabs. This type of sampling is uncomfortable for the patient, dangerous for health workers, and its high demand has led to a global shortage of swabs. One of the alternative specimens is saliva. However, the optimal conditions for the test have not been established. Methods: Reverse transcription-polymerase chain reaction was used to detect the viral genome in saliva samples kept at room temperature, in the fridge or frozen for 2 days. In addition, the influence of brushing teeth and feeding on the detection of the virus in saliva was addressed. Finally, the efficiency of saliva in revealing the presence of the virus during the hospitalization period was determined in children. Results: The viral genome was consistently detected regardless of the storage conditions of saliva samples. Brushing teeth and feeding did not influence the sensitivity of the test. In hospitalized children, positive results were obtained only during the early days. Conclusions: These results support the idea of the use of saliva as an alternative specimen for diagnostic testing for COVID-19. The viral genome is stable and endures perturbations in the oral cavity. However, clearance of the virus from the mouth during the infection may limit the use of the test only to the early stages of the disease.

Resumen Introducción: El diagnóstico de COVID-19 (enfermedad por coronavirus 2019) se realiza con un hisopado nasofaríngeo. El procedimiento de toma de muestra es molesto para el paciente y peligroso para el personal de salud, y la alta demanda de análisis ha conducido a la escasez de hisopos. Una alternativa es el uso de saliva, pero las condiciones óptimas para realizar el estudio no han sido establecidas. Métodos: Se usó la reacción en cadena de la polimerasa con transcriptasa reversa para detectar el genoma viral en muestras de saliva mantenidas a temperatura ambiente, en refrigeración o congeladas. Además, se evaluó la influencia del aseo bucal y de la ingesta de alimento en la detección del virus. Finalmente, se determinó el desempeño de la saliva para reportar la presencia del virus durante el periodo de hospitalización en niños. Resultados: El genoma viral fue estable durante 2 días a las diferentes temperaturas ensayadas. El aseo bucal y la ingesta de alimento no influyeron en la detección del virus. En los niños hospitalizados solo se obtuvieron resultados positivos durante los primeros días. Conclusiones: Los resultados coinciden con la idea del uso de la saliva como biofluido alternativo para el diagnóstico de COVID-19. El genoma viral es estable y no se ve afectado por perturbaciones en la cavidad oral; sin embargo, la dinámica de la infección puede provocar que el ensayo solo sea útil durante las primeras etapas de la enfermedad.