Breakthroughs promise faster, better COVID testing
October 1, 2020
COVID testing using a smartphone
Researchers are reporting they may be able to test for COVID-19 in just 30 minutes with the use of a smartphone. As COVID-19 continues to spread, bottlenecks in supplies and laboratory personnel have led to long waiting times for COVID testing results in some areas. In a new study, University of Illinois, Urbana-Champaign researchers have demonstrated a prototype of a rapid COVID-19 molecular test and a simple-to-use, portable instrument for reading the results with a smartphone in 30 minutes. If it pans out, there would be no need to send samples to a lab.
“If such a device and test were available, we could test for COVID-19 at public events, auditoriums, large gatherings and potentially even at home for self-testing. The results could be sent back to the appropriate public health system for coordination,” said Rashid Bashir, who is a professor of bioengineering and the dean of the Grainger College of Engineering at the University of Illinois.
Typical tests for SARS-CoV-2, the virus that causes COVID-19, take a sample from a patient with a long nasopharyngeal swab. The swab is then put into a substance called viral transport media, and sent to a lab for a multistep process of extracting, isolating and multiplying the telltale RNA inside the virus. This RNA multiplication process, called RT-PCR, requires several temperature fluctuation cycles, specialized equipment and trained personnel.
The Illinois team used a simpler process to analyze the viral transport media, called LAMP, which bypasses the RNA extraction and purification steps.
“LAMP only needs one temperature, 65 Celsius, so it is much easier to control,” said study investigator Anurup Ganguli, who is also with the University of Illinois. “Also, LAMP works more robustly than PCR, especially when there are contaminants in the test sample. We can just briefly heat the sample, break open the virus and detect the genetic sequence that specifically identifies SARS-CoV-2.”
The researchers compared the LAMP assay with PCR, first using synthetic nasal fluid spiked with the virus and then with clinical samples. They found the results were in agreement with PCR results, and they documented the accuracy of the LAMP test. The researchers now are exploring whether the assay would work with saliva samples to eliminate the need for nasopharyngeal swabs.
Predicting the severity of COVID infection
Some very good news to report on combating COVID-19: Researchers now have identified six molecules that can be used as biomarkers to predict how severely ill a person will become once they become infected. A team from Lawson Health Research Institute and Western University in Canada has made significant steps forward in understanding COVID-19 and also identified a new mechanism causing blood clots in COVID-19 patients.
“We’ve begun answering some of the biggest COVID-19 questions asked by clinicians and health researchers,” said Dr. Douglas Fraser, who is the lead researcher from Lawson and Western’s Schulich School of Medicine & Dentistry, and Critical Care Physician at LHSC, Ontario, Canada. “While the findings need to be validated with larger groups of patients, they could have important implications for treating and studying this disease.”
With no proven therapies, many COVID-19 patients admitted to intensive care units (ICUs) do not survive.
“When a patient is admitted to ICU, we normally wait to see if they are going to get worse before we consider any risky interventions. To improve outcomes, we not only need new therapies but also a way to predict prognosis or which patients are going to get worse,” said Dr. Fraser.
The researchers identified six molecules of importance (CLM-1, IL12RB1, CD83, FAM3B, IGFR1R and OPTC). They found that these molecules were elevated in COVID-19 patients who would become even more severely ill. They found that when measured on a COVID-19 patient’s first day of ICU admission, the molecules could be used to predict which patients will survive following standard ICU treatment.
“While further research is needed, we’re confident in these biomarkers and suspect these patterns may be present even before ICU admission, such as when a patient first presents to the emergency department,” said Dr. Fraser.
The team measured 1,161 plasma proteins from the blood of 30 participants (10 COVID-19 patients, 10 patients with other infections admitted to the ICU, and 10 healthy control participants). Blood was drawn on specific days of ICU admission, processed in a lab and then analyzed using statistical methods and artificial intelligence.
These findings could be very important and lead to new ways of predicting a patient’s disease severity. It could allow for medical teams to have important conversations with family members, setting goals of care based on the patient’s health and personal wishes. Medical teams could use the knowledge to mobilize resources more quickly. If they know a patient is at higher risk of death, they may consider intervening sooner despite associated risks. The team also hopes the findings can be used to better design COVID-19 clinical trials by grouping patients based on their risk. This could allow for stronger results when examining potential treatments for the disease.
A major complication occurring in most critically ill COVID-19 patients is clotting in the lung’s small blood vessels, which leads to low oxygen levels in the body.
“The reason for this clotting has been unclear. Most suspect the clotting mechanisms in our blood are put into overdrive and so many clinicians have been treating with anticoagulant therapies like the drug heparin,” said Dr. Fraser. “But we’ve uncovered an entirely different mechanism.”
The team analyzed the blood samples from 30 participants, and found evidence that the inner linings of small blood vessels are becoming damaged and inflamed, making them a welcoming environment for platelets (small blood cells) to stick. They discovered that COVID-19 patients had elevated levels of three molecules (hyaluronic acid, syndecan-1 and P-selectin).
The team suggests that two therapies may hold promise for treating blood clots in COVID-19 patients: platelet inhibitors to stop platelets from sticking and molecules to protect and restore the inner lining of blood vessels.
“By exploring these therapies as potential alternatives to anticoagulant therapies, we may be able to improve patient outcomes,” said Dr. Fraser. “Through our combined findings, we hope to provide tools to predict which patients will become the most severely ill and treatments for both hyper inflammation and blood clots.”