As the novel coronavirus continues to spread around the globe, a more accurate test that can detect the virus much earlier than other tests has been adapted and validated by Michigan State University researchers and could be available by the end of April. The U.S. Food and Drug Administration has been asked to grant emergency use authorization for the test.
The new testing method is 500 times more sensitive than the standard coronavirus test, said Jack Lipton chair of the College of Human Medicine’s Department of Translational Neuroscience, whose team validated the process. That is important, he said, because it reduces the number of false negative test results that incorrectly diagnose people as free of the disease, allowing them to infect others.
Another positive differentiator is that this test does not use the reagents others do which is slowing down the manufacturing of current tests.
The standard test returns an estimated 20% to 30% false negative results in patients who have not yet exhibited symptoms due to a low viral load — that is the amount of the virus in a test sample.
Bio-Rad Laboratories, the company that developed and is the manufacturer of a machine called the Droplet Digital PCR, which MSU’s researchers used in validating their new testing method, is asking the FDA to grant emergency use authorization for the test. A company official said the application process should be completed in April, allowing labs across the country to begin offering this test immediately.
MSU’s research is “very compelling,” said Carolyn Reifsnyder, director of global marketing for Bio-Rad’s Digital Biology Group. “What’s more compelling,” she said, “is what Jack (Lipton) and his team did using creative ways to solve a problem.”
The new test is based on information that was posted on the web site medRxiv.org by researchers in China. Joseph Patterson, a research assistant professor in the Department of Translational Neuroscience, approached Lipton, confident that the MSU team could adapt the test based on the study from China.
“I said, ‘Let’s do it,’” Lipton recalled. “We used the method that came out of China and adapted it to see if it would work for us, and it works.”
Using the Droplet Digital PCR, the researchers tested genetic material in the laboratory before testing samples from human volunteers. The machine amplifies the genetic material in a small sample and then calculates how much of the virus is in a patient’s body.
After receiving expedited approval from MSU’s Institutional Review Board, researchers tested university faculty and staff who volunteered, including one who previously had tested positive for COVID-19, the respiratory disease caused by the novel coronavirus.
“We could see the subject’s viral load was off the chart,” Lipton said, adding that the staff member is recovering. A subsequent retest using the new method showed that the staff member’s viral load had dropped significantly.
“There are a lot of questions that can be answered to help us understand this disease and the recovery process,” Lipton said.
The researchers used different chemical reagents than those that have been in short supply for the standard test, Lipton said.
MSU’s Department of Translational Neuroscience is not a clinical health provider and, therefore, is not authorized to offer the test to patients. Reifsnyder, however, said that the Droplet Digital PCR machines are in laboratories all over the country.
The MSU researchers have made their findings available to other researchers with the goal of making the process widely available soon, Lipton said. Other research teams already are using the new method to reexamine previous samples that came back negative under the standard test.
“The more testing anyone can do in this crisis when lives are on the line, the better,” Lipton said, adding that his team was more than willing to share its findings. “If we can use our skill sets to help other people, this is what we can do,” he said. “It’s just the right thing to do.”
His study team includes Patterson, Caryl Sortwell, Allyson Cole-Strauss and John Beck.
The MSU test method was based on a study published on medRxiv.org titled, “ddPCR: A more sensitive and accurate tool for SARS-CoV-2 detection in low viral load specimens,” by Wuhan University researchers Tao Suo, Xinjin Liu, Ming Guo, Jiangpeng Feng, Wenjia Hu, Yang Yang, Qiuhan Zhang, Xin Wang, Muhanmmad Sajid, Dong Guo, Zhixiang Huang, Liping Deng, Tielong Chen, Fang Liu, Ke Xu, Yuan Liu, Qi Zhang, Yingle Liu, Yong Xiong, Guozhong Guo, Yu Chen and Ke Lan.
