Impact of Fast SARS-CoV-2 Molecular Point-Of-Care Testing on Patients' Length of Stay in an Emergency Department.

The ID NOW COVID-19 system (IDNOW) is a point-of-care test (POCT) providing results within 15 min. We evaluated the impact of IDNOW use on patient length of stay (LOS) in an emergency department (ED). In the ED of Saint-Louis Hospital, Paris, France, adult patients requiring a rapid diagnosis of SARS-CoV-2 were tested with Cepheid Xpert Xpress SARS-CoV-2 or FilmArray respiratory panel RP2 in the virology laboratory between 18 October and 3 November 2020 (period 1) and with IDNOW between 4 November and 30 November 2020 (period 2). A total of 676 patients participated in the study, 337 during period 1 and 339 during period 2. The median LOS in ED was significantly higher in period 1 than in period 2 (276 versus 208 min, P < 0.0001). More patients spent less than 4 h in the ED in period 2 (61.3%) than in period 1 (38.3%) (P < 0.0001). By univariate analysis, factors associated with ED LOS were hypertension, anosmia/ageusia, number of patients per day, and ID NOW implementation in period 2. By multivariate analysis, the period of testing remained significantly associated with ED LOS. Rapid molecular SARS-CoV-2 POCT was associated with a reduced LOS for patients admitted to an ED. IMPORTANCE During COVID-19 pandemic upsurges, emergency departments had to deal with a massive flow of incoming patients. The need for COVID-19 infection status determination before medical ward admission worsened ED overcrowding. The development of molecular point-of-care testing gave new opportunities for getting faster results of SARS-CoV-2 genome detection 24 h a day. In our study, we show, with a multivariate analysis, that the use of the POCT COVID-19 IDNOW reduced the ED length of stay by 1 h. The rate of patients who waited less than 4 h in the ED increased significantly. Our study highlights the benefit of COVID-19 molecular POCT for preventing ED overcrowding and facilitating bed allocation and SARS-CoV-2-infected patient isolation.

Poussée sévère de DITRA causée par le SARS-CoV-2

Introduction Le DITRA, déficit de l’antagoniste du récepteur de l’interleukine trente-six (IL36RA), est un syndrome monogénique auto-inflammatoire rare résultant de l’interaction de mutations autosomiques récessives ou double hétérozygotes composites du gène IL36RN codant pour l’IL-36RA, avec des facteurs déclenchants tels que l’infection et la grossesse. Matériel et méthodes Un patient de 16 ans souffrant de DITRA (mutation c.4G>T) à début précoce se présentait pour une poussée de psoriasis pustuleux généralisé (PPG) couvrant 60 % de la surface corporelle (GPPPGA=3/5 ;GPPASI=45,2/72), survenant 2jours après l’apparition des premiers symptômes de COVID-19: céphalalgie fébrile, asthénie, anosmie. Il était en rémission clinique complète depuis des mois après l’arrêt de l’adalimumab, initié suite aux échecs de l’acitrétine et de la ciclosporine. On notait une hyperleucocytose sanguine à neutrophiles (17610/mm3), une CRP normale. La PCR multiplex nasopharyngée confirmait l’atteinte exclusive par un SARS-CoV-2. À j32, la sérologie COVID-19 était fortement positive (indice 5,79) associée à une forte augmentation de la signature transcriptomique sanguine neutrophilique mais pas chez la sœur légèrement atteinte et non infectée. L’expression de l’ARNm des gènes de signature de l’interféron (ISG) était normale dans les 2 cas. La poussée de PPG s’est amendée à 2 mois de la réintroduction de l’adalimumab, sans rechute. Discussion Le DITRA est caractérisé par des poussées aiguës de PPG parfois mortelles, associées à une anomalie d’expression ou fonction de l’IL36RA. Des signatures transcriptomiques neutrophilique et de l’IFN de type 1 ont été décrites, mais inconstantes pour cette dernière. Il s’agit du 1er cas de poussée de DITRA induite par le SARS-CoV-2, confirmant l’impact des déclencheurs infectieux, en particulier des infections respiratoires virales (IRV), sur le profil évolutif de ce syndrome auto-inflammatoire. Les interactions moléculaires et cellulaires reliant l’inflammation bronchique induite par le SARS-CoV-2 et l’inflammation cutanée/systémique dans le PPG, restent inconnues. La forte signature neutrophilique est associée à une augmentation de l’IL-36 et des chimiokines attirant/activant les neutrophiles (CXCL-1, CXCL-2, CXCL-8,…). L’IFN-I joue un rôle déterminant dans une réponse immunitaire efficace contre le SARS-CoV-2 mais n’était pas augmenté contrairement à d’autres PPG, démontrant l’existence de voies d’inflammation alternatives pour le déclenchement des poussées. Le clivage catalytique par l’élastase de la forme immature et inactive de l’IL-36RA pour une fonction optimale de l’antagoniste est obligatoire pour prévenir l’inflammation neutrophilique cutanée aiguë après des événements déclencheurs. Le rôle de la voie IL-36 dans l’inflammation bronchique et ce cas ouvrent la voie à des études mécanistiques visant à déchiffrer les liens moléculaires et cellulaires entre les IRV et les poussées de psoriasis.

Evaluation of a saliva molecular point of care for the detection of SARS-CoV-2 in ambulatory care.

Rapid identification of SARS-CoV-2-infected individuals is a cornerstone for the control of virus spread. The sensitivity of SARS-CoV-2 RNA detection by RT-PCR is similar in saliva and nasopharyngeal swabs. Rapid molecular point-of-care tests in saliva could facilitate, broaden and speed up the diagnosis. We conducted a prospective study in two community COVID-19 screening centers to evaluate the performances of a CE-marked RT-LAMP assay (EasyCoV) designed for the detection of SARS-CoV2 RNA from fresh saliva samples, compared to nasopharyngeal RT-PCR, to saliva RT-PCR and to nasopharyngeal antigen testing. Overall, 117 of the 1718 participants (7%) tested positive with nasopharyngeal RT-PCR. Compared to nasopharyngeal RT-PCR, the sensitivity and specificity of the RT-LAMP assay in saliva were 34% and 97%, respectively. The Ct values of nasopharyngeal RT-PCR were significantly lower in the 40 true positive subjects with saliva RT-LAMP (Ct 25.9) than in the 48 false negative subjects with saliva RT-LAMP (Ct 28.4) (p = 0.028). Considering six alternate criteria for reference tests, including saliva RT-PCR and nasopharyngeal antigen, the sensitivity of saliva RT-LAMP ranged between 27 and 44%. The detection of SARS-CoV-2 in crude saliva samples with an RT-LAMP assay had a lower sensitivity than nasopharyngeal RT-PCR, saliva RT-PCR and nasopharyngeal antigen testing.Registration number: NCT04578509.

Immune checkpoint inhibitors increase T cell immunity during SARS-CoV-2 infection.

The COVID-19 pandemic has spread worldwide, yet the role of antiviral T cell immunity during infection and the contribution of immune checkpoints remain unclear. By prospectively following a cohort of 292 patients with melanoma, half of which treated with immune checkpoint inhibitors (ICIs), we identified 15 patients with acute or convalescent COVID-19 and investigated their transcriptomic, proteomic, and cellular profiles. We found that ICI treatment was not associated with severe COVID-19 and did not alter the induction of inflammatory and type I interferon responses. In-depth phenotyping demonstrated expansion of CD8 effector memory T cells, enhanced T cell activation, and impaired plasmablast induction in ICI-treated COVID-19 patients. The evaluation of specific adaptive immunity in convalescent patients showed higher spike (S), nucleoprotein (N), and membrane (M) antigen-specific T cell responses and similar induction of spike-specific antibody responses. Our findings provide evidence that ICI during COVID-19 enhanced T cell immunity without exacerbating inflammation.

Accuracy of saliva and nasopharyngeal sampling for detection of SARS-CoV-2 in community screening: a multicentric cohort study.

Nasopharyngeal sampling for nucleic acid amplification testing (NAAT) is the standard diagnostic test of coronavirus disease 2019. Our objectives were to assess, in real-life conditions, the diagnostic accuracy of a nasopharyngeal point-of-care antigen (Ag) test and of saliva NAAT for detection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in ambulatory care. This was a prospective cohort study from 19 October through 18 December 2020 in two community COVID-19 screening centers in Paris, France. Two nasopharyngeal swabs and one saliva sample were simultaneously collected. Diagnostic accuracies of nasopharyngeal Ag testing and of three saliva NAAT methods were assessed as compared to nasopharyngeal NAAT. A total of 1452 ambulatory children and adults were included. Overall, 129/1443 (9%) participants tested positive on nasopharyngeal NAAT (102/564 [18%] in symptomatic and 27/879 [3%] in asymptomatic participants). Sensitivity was 94%, 23%, 96%, and 94% for the three different protocols of saliva NAAT and for the nasopharyngeal Ag test, respectively. Estimates of specificity were above 95% for all methods. Diagnostic accuracy was similar in symptomatic and asymptomatic individuals. Diagnostic accuracy of nasopharyngeal Ag testing and of saliva NAAT is similar to that of nasopharyngeal NAAT, subject to compliance with specific protocols for saliva. Registration number: NCT04578509.

Performance of 30 commercial SARS-CoV-2 serology assays in testing symptomatic COVID-19 patients.

We report evaluation of 30 assays' (17 rapid tests (RDTs) and 13 automated/manual ELISA/CLIA assay (IAs)) clinical performances with 2594 sera collected from symptomatic patients with positive SARS-CoV-2 rRT-PCR on a respiratory sample, and 1996 pre-epidemic serum samples expected to be negative. Only 4 RDT and 3 IAs fitted both specificity (> 98%) and sensitivity (> 90%) criteria according to French recommendations. Serology may offer valuable information during COVID-19 pandemic, but inconsistent performances observed among the 30 commercial assays evaluated, which underlines the importance of independent evaluation before clinical implementation.

Multicenter comparison of the Cobas 6800 system with the RealStar RT-PCR kit for the detection of SARS-CoV-2.

BACKGROUND: RT-PCR testing is crucial in the diagnostic of SARS-CoV-2 infection. The use of reliable and comparable PCR assays is a cornerstone to allow use of different PCR assays depending on the local equipment. In this work, we provide a comparison of the Cobas® (Roche) and the RealStar® assay (Altona). METHODS: Assessment of the two assays was performed prospectively in three reference Parisians hospitals, using 170 clinical samples. They were tested with the Cobas® assay, selected to obtain a distribution of cycle threshold (Ct) as large as possible, and tested with the RealStar assay with three largely available extraction platforms: QIAsymphony (Qiagen), MagNAPure (Roche) and NucliSENS-easyMag (BioMérieux). RESULTS: Overall, the agreement (positive for at least one gene) was 76 %. This rate differed considerably depending on the Cobas Ct values for gene E: below 35 (n = 91), the concordance was 99 %. Regarding the positive Ct values, linear regression analysis showed a coefficient of determination (R2) of 0.88 and the Deming regression line revealed a strong correlation with a slope of 1.023 and an intercept of -3.9. Bland-Altman analysis showed that the mean difference (Cobas® minus RealStar®) was + 3.3 Ct, with a SD of + 2.3 Ct. CONCLUSIONS: In this comparison, both RealStar® and Cobas® assays provided comparable qualitative results and a high correlation when both tests were positive. Discrepancies exist after 35 Ct and varied depending on the extraction system used for the RealStar® assay, probably due to a low viral load close to the detection limit of both assays.