October 23, 2020 | IL-6 emerges as a promising biomarker, new antibody tests, and Monell Chemical Sciences Center reports loss of smell more prevalent than thought. Plus: new tests from Oxford Nanopore, Genalyte and optical technologies detect the virus.
Research Updates
The correlation between elevated interleukin 6 (IL‐6) concentrations and the risk of respiratory failure in COVID‐19 patients, makes IL-6 a promising biomarker of advanced disease. Researchers at McMaster University and SQI Diagnostics have created a surface coating that repels every component of blood and other complex fluids such as urine, but is dotted with microscopic islands of molecules that attract IL-6, making it possible to detect and measure IL-6 with unprecedented accuracy and sensitivity, at concentrations as low as 0.5 picograms per mL—or one half of one trillionth of a gram per mL—making it far more sensitive than existing technology. They published the technology in Small and are working to adapt it to the Toronto company's existing testing platforms in the hope of moving it into clinical use as soon as possible. DOI: 10.1002/smll.202003844
Scientists at The Ohio State University have developed a new lab testing procedure for the detection of antibodies against SARS-CoV-2 that gives results more quickly than existing assays and specifically identifies so-called "neutralizing" antibodies - those that protect by blocking infection of cells. The new assay is based on an HIV-1 lentiviral vector and was used to evaluate SARS-CoV-2 antibodies in serum from individuals with a broad range of COVID-19 symptoms, including intensive care unit (ICU) patients, health care workers (HCWs), and convalescent plasma donors. The highest neutralizing antibody titers were observed among ICU patients, followed by general hospitalized patients, HCWs and convalescent plasma donors. The study highlights a wide phenotypic variation in human antibody responses against SARS-CoV-2, and demonstrates the efficacy of a novel lentivirus pseudotype assay for high-throughput serological surveys of neutralizing antibody titers in large cohorts. It was published in JCI Insight. DOI: 10.1172/jci.insight.143213
Monell Chemical Senses Center researchers scanned the published literature on COVID-19 and SARS-CoV-2 infections looking for data on loss of smell among patients. They identified 34 articles quantifying anosmia as a symptom of COVID-19 (6 tested with objective methods, 28 with subjective), collected from cases identified from January 16 to April 30, 2020. The pooled prevalence estimate of smell loss was 77% when assessed through objective measurements and 44% with subjective measurements. The researchers conclude that there is a much higher prevalence of olfactory loss in COVID-19 than previously believed. DOI: 10.1093/chemse/bjaa064
Industry Updates
Genalyte’s SARS-CoV-2 Multi-Antigen Serology Panel has received Emergency Use Authorization (EUA) from the FDA. The panel tests for the detection of IgG and IgM antibodies the body produces in response to the novel coronavirus (SARS-CoV-2). Genalyte’s multi-antigen serology panel and its FDA-cleared Maverick Diagnostic System will further expand nationwide antibody testing, by providing a high-quality and rapid testing solution that delivers central, lab-quality results in 20 minutes at point-of-care locations. The SARS-CoV-2 Multi-Antigen Serology Panel is poised to become an increasingly important tool as serology-based antibody testing expands in the fight against COVID-19. Press release.
Oxford Nanopore has released LamPORE, a rapid, scalable, accurate test, for the detection of the SARS-CoV-2 virus that causes COVID-19. LamPORE is designed to be performed on a desktop device, GridION, or a palm-sized device, MinION Mk1C. Following an application to the UK’s MHRA, the LamPORE assay is now CE marked for in vitro diagnostic use for the detection of the SARS-CoV-2 virus, using the GridION device. Further regulatory approvals are being pursued in other countries, including Emergency Use Authorization in the United States, and with our partner G42 in the United Arab Emirates. A recent publication showed that in a study of more than 500 samples, LamPORE showed a sensitivity of 99.1% [96.9-99.9] and specificity of 99.6% [98.0-100]. LamPORE is currently being rolled out globally, with initial use in the UK, Germany, Switzerland and United Arab Emirates. Press release.
A multidisciplinary team of scientists from the University of Malaga are developing a point-of-care detection system based on photonic sensors. The research team already has a real prototype of a sensing system based on photonic chips, and a measuring device, which is capable of detecting proteins in very low concentrations—inflammation and antibody biomarkers present in patients that are allergic to antibiotics. The project aims to adapt the system for the detection of SARS-CoV-2 and its antibodies, as well as optimize and reduce the price of the measuring device. To this end, they are going to work on two lines: keep improving the optical sensitivity of the sensor and develop chemical protocols so that only a specific protein that expresses SARS-CoV-2, or the antibodies to such protein, as appropriate, adhere to the surface of the waveguides. Press release (in Spanish).
Scientists at the University of Technology Sydney (UTS) have used novel optical technology to design a highly sensitive saliva test for the SARS-CoV-2 virus antigens, or viral protein fragments. The test can deliver a positive result in under 15 minutes. The rapid antigen test collects saliva in a cartridge placed in an existing hand-held device, first developed by West Australian company Alcolizer for illicit drug testing. Customized iStrip technology measures the viral load in the saliva sample, even at very low levels, and displays the result on the instrument's small screen. This device has GPS location technology and integration to cloud reporting tools to assist with contact tracing. Press release.