High capacity clinical SARS-CoV-2 molecular testing using combinatorial pooling.

BACKGROUND: The SARS-CoV-2 pandemic led to unprecedented testing demands, causing major testing delays globally. One strategy used for increasing testing capacity was pooled-testing, using a two-stage technique first introduced during WWII. However, such traditional pooled testing was used in practice only when positivity rates were below 2%. METHODS: Here we report the development, validation and clinical application of P-BEST - a single-stage pooled-testing strategy that was approved for clinical use in Israel. RESULTS: P-BEST is clinically validated using 3636 side-by-side tests and is able to correctly detect all positive samples and accurately estimate their Ct value. Following regulatory approval by the Israeli Ministry of Health, P-BEST was used in 2021 to clinically test 837,138 samples using 270,095 PCR tests - a 3.1fold reduction in the number of tests. This period includes the Alpha and Delta waves, when positivity rates exceeded 10%, rendering traditional pooling non-practical. We also describe a tablet-based solution that allows performing manual single-stage pooling in settings where liquid dispensing robots are not available. CONCLUSIONS: Our data provides a proof-of-concept for large-scale clinical implementation of single-stage pooled-testing for continuous surveillance of multiple pathogens with reduced test costs, and as an important tool for increasing testing efficiency during pandemic outbreaks.

Testing samples for SARS-CoV-2 is usually done on one sample at a time. However, the unprecedented demand for testing during the COVID-19 pandemic led to the adoption of pooled testing strategies, where samples are combined before being tested. This strategy requires two rounds: first, each pool of samples is tested, and then a second testing round is performed on individual samples from positive pools. We developed and implemented a pooling method for SARS-CoV-2 that requires a single round of testing, thus enabling the shorter turnaround times required during a pandemic. The method was approved for clinical use in Israel and was used to successfully test 837,138 clinical samples using fewer than a third of the tests usually required. Our study provides a blueprint for rapid implementation of efficient high-throughput testing in future pandemics.

Comparative Safety and Efficacy of Left Atrial Appendage Occlusion with the Watchman Device and Amplatzer Cardiac Plug: Results of the Russian National Registry.

PURPOSE: This multicenter, prospective registry evaluated the comparative safety and efficacy of left atrial appendage occlusion (LAAO) using the Watchman device (WD) and the Amplatzer Cardiac Plug (ACP) in patients with nonvalvular atrial fibrillation (NVAF) in real-world clinical practice in Russia. METHODS: The study included data from 200 consecutive NVAF patients (66.8 ± 7.8 years, 44.5% female, median CHA2DS2VASc 4, median HAS-BLED 3) who had undergone LAAO implantation using WD (n = 108) or ACP (n = 92) from September 2015 to December 2017 in 5 medical centers in Russia. The primary safety endpoint was the procedure-related major adverse events, and the primary efficacy endpoint was the composite of thromboembolic events, device thrombosis, hemorrhagic events, and unexplained death during the 12-month follow-up. RESULTS: Successful LAAO was performed in all 92 (100%) patients with ACP and 105 (97.2%) with WD (p = 0.053). At 12 months, primary safety endpoint occurred in 6.5% of patients in the ACP group with no events in the WD group (6.5% vs. 0%, p = 0.008). During the 12-month follow-up, the primary efficacy endpoint has occurred in 8.3% of patients in the WD group (n = 9) and 1.1% of patients in the ACP group (n = 1) (p = 0.016). CONCLUSIONS: In this multicenter prospective registry, LAA closure with the WD was associated with significantly higher thromboembolic events rate in NVAF patients. Patients, receiving the ACP, had more procedure-related major adverse events. However, further multicenter studies are necessary to evaluate these findings.

Prognostic relevance of miR-124-3p and its target TP53INP1 in pediatric ependymoma.

Ependymoma is a malignant pediatric brain tumor, often incurable under the current treatment regimen. We aimed to evaluate the expression of microRNAs (miRs) in pediatric ependymoma tumors in an attempt to identify prognostic molecular markers which would lead to potential therapeutic targets. Following miR-array expression analysis, we focused on 9 miRs that correlated with relapse which were further validated by quantitative real-time PCR (qRT-PCR) in a cohort of 67 patients. Western blotting and immunohistochemistry were used to measure target protein expression in 20 and 34 tumor samples, respectively. High expression of miR-124-3p significantly correlated with the lower progression-free survival (PFS) of 16% compared to 67% in those expressing low levels (P = .002). Interestingly, in the group of patients with local disease (n = 56) expression levels of this miR distinguished 2 subgroups with a significantly different outcome (P = .001). miR-124-3p was identified as an independent prognostic factor of relapse in the multivariate analysis performed in the whole cohort and in the group with localized disease. In the localized group, a patient expressing high levels of miR-124-3p had a 4.1-fold increased risk for relapse (P = .005). We demonstrated the direct binding of miR-124-3p to its target TP53INP1. Negative TP53INP1 protein levels correlated with a poor outcome (P = .034). We propose miR-124-3p and TP53INP1 as new biomarkers for prognostic stratification that may be possible therapeutic targets for ependymoma.