New coronavirus test could be ‘game-changing’

Matt Woodley

6/04/2020 5:08:51 PM

The point-of-care test aims to rapidly determine a person’s immunity to coronavirus and how at-risk they are of contracting severe disease.

The coronavirus.
Monash University has developed markers to track memory B lymphocyte cells formed after coronavirus infection.

Developed by Monash University scientists, the new test is based on recently developed technology used to assess a patient’s immunity to allergens and influenza.
The researchers will begin receiving cell samples next week from colleagues in Melbourne and three areas with high numbers of coronavirus cases – Italy, China and New York.
Associate Professor Mark Morgan, Chair of the RACGP Expert Committee – Quality Care (REC–QC), told newsGP while it is still not known whether infection causes protective immunity, if effective the new test could be useful in a general practice setting.
‘If GPs were able to identify patients who have protective immunity – either from infection or from future immunisation – this would be game-changing,’ he said.
‘Identifying those patients who are at risk of deterioration would be very helpful for GPs who could then proactively follow up at-risk patients more closely. Rural and remote GPs could also have advanced notice of which patients might need emergency transfer.
‘However, any new piece of testing technology needs to have clear descriptions of the ways it is intended to be used. We don’t want to have a repeat of the current misuse [of] point-of-care serology testing.’
The Public Health Laboratory Network has cautioned that there are ‘significant limitations’ to the use of point-of-care serology tests and are not recommended as first line tests for the diagnosis of acute viral infection as the ‘quality and clinical utility of these emerging tests, in the majority of cases, is uncertain’.
Western Australia has also banned the use of point-of-care serology tests for acute detection and diagnostic purposes after Chief Health Officer Dr Andrew Robertson deemed them ‘an unacceptable risk’.
However, their use as a screening tool for people post-infection and for research public health screening purposes is not prohibited.
Aside from identifying immune and at-risk patients, Monash researchers said it could be used to identify immune healthcare workers and allow them to safely work on the frontline.
Associate Professor Menno van Zelm, who is leading the development of the test together with Professor Robyn O’Hehir, said it is vital that coronavirus testing technology continues to evolve.
‘It is important that we now move from needing a test that simply tells whether someone is infected – which is the priority now – to needing a test that can determine who is infectious, who is immune, who is going to get a serious case of the disease and who will only develop a mild case of upper airway infection,’ Associate Professor van Zelm said. 
‘This and other tests like it will provide us with a more nuanced approach to managing the disease.’
The new technology analyses ‘memory B lymphocytes’ – immune system cells that make antibodies to combat invading pathogens such as viruses. These memory cells are able to ‘remember’ the same pathogen for faster antibody production in future infections.
The Monash team has developed markers for those memory B cells formed after coronavirus infection. By binding these markers to a fluorescent label they can use commonly available equipment called a Fluorescence Activated Cell Sorter to determine the number of memory B cells present in a coronavirus patient, enabling the assessment of their immune status.
They will also be looking at memory B cells taken at various stages, and severity, of coronavirus infection to look for different markers on these B cells that may become predictors of those who will get a mild version of the disease, and conversely those who may need care in ICU.
According to the researchers, if there is evidence of a large population of memory B cells specific to a pathogen then it is likely that person has been previously infected and will remain immune to the disease.
Such a test may also allow Australia to create so-called ‘immunity passports’, which could be issued to people who have already contracted the disease to increase the workforce in healthcare and other crucial sectors.
Professor Nigel McMillan, the director of infectious diseases and immunology at the Menzies Health Institute, told The Age such an initiative could be invaluable.
‘They could be a very useful resource,’ he said.
‘It would be very individualised for each person as to what they could do, but the most useful group is medical workers. We know from overseas that a significant portion of health workers may become infected at some point, so we could use that to our advantage.’
Professor McMillan also said immune health workers could reduce the demand for personal protective equipment, and volunteer for jobs such as swab testing of suspected coronavirus cases.
The RACGP has more information on coronavirus available on its website.
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Dr Dilip Singh Chauhan   7/04/2020 8:42:56 AM

PS exercise was my 1st prescription