“Unlike other serological tests to determine the presence of antibodies in the blood, this test does not require laboratory analysis and can be used at a healthcare centre or an elderly nursing home, for example. A few drops of blood are placed on a test strip and the results are presented in a display within 15 minutes”, says Magnus Rasmussen, Professor and specialist in infectious disease at Skåne University Hospital, who led the study together with Yang De Marinis, Associate Professor at the Department of Clinical Sciences, Lund University.
Currently, patients with COVID-19 are usually diagnosed through a nasal or throat swab that shows any trace of the viral RNA in a laboratory PCR analysis. The PCR method is technically demanding and relatively expensive. As an important complementary test, an antibody test shows whether a person previously had the infection.
Among existing antibody tests, the new COVID-19 antibody test developed at Lund University has a robust performance with a sensitivity of 92% and specificity of 97%. The test is CE-marked and registered at the Swedish Medical Products Agency, and marketed through ZetaGene Ltd., a Swedish registered company.
“The antibody test could greatly contribute to mapping the spread of COVID-19 in society and preventing future virus outbreaks”, says Yang De Marinis.
The COVID-19 antibody test measures the presence of two types of antibodies that develop in response to a SARS-CoV-2 virus infection:
- IgM antibodies that respond to the initiation of the infection and
- IgG antibodies that are formed at a later stage.
Both antibodies play important roles in immunity. Specifically, this new COVID-19 antibody test detects both IgM and IgG antibodies targeting the receptor-binding domain of viral spike protein which binds to receptors on human cells for viral entry. The test is therefore highly sensitive and specific, with minimal risk of false negative results or false positive results.
In the study, the researchers examined the relationship between the presence of different antibodies, the time of infection onset and the severity of COVID-19. The results show an increase in antibody response during the course of COVID-19 illness, and that the IgM antibodies appear to remain longer in the blood of patients who have been seriously ill and needed hospital care.
The researchers also analysed various forms of blood: whole blood, serum and plasma taken from a vein in the elbow crease. Results suggest that the test is more sensitive to detecting antibodies in serum or plasma compared to whole blood.
Two new follow-up studies have been initiated to screen hospital and university staff by the COVID-19 antibody test.
“There has been much focus on healthcare staff and the possible risks they are exposed to at work. However, there are also indications showing that hospital staff are most often infected outside the hospital or in hospitals by asymptomatic colleagues, rather than by patients. But we don’t want just to assume this, we want to find out through our studies. Furthermore, we will map the prevalence of previous COVID-19 infection in various departments at the hospital and university”, says Magnus Rasmussen.
The first part is about to be finalized, where staff at the Division of Infectious Diseases at Skåne University Hospital are tested for COVID-19 antibodies.
“We aim to test the entire staff at the division, including doctors, nurses, assistant nurses and the cleaning staff. This will be followed by a larger screening on around 600 health-care employees at Skåne University Hospital, and employees at non-medicine related departments at Lund University. Our studies also include PCR test results and a detailed questionnaire for risk exposure analysis. These studies will provide important information on how we may best protect our staff and avoid transmission”, concludes Magnus Rasmussen.
The clinical validation study of the test was accepted for publication in June 2020 in scientific journal Infection Ecology and Epidemiology.
Serology assessment of antibody response to SARS-CoV-2 in patients with COVID-19 by rapid IgM/IgG antibody test
Pre-print is available at medRxiv: https://doi.org/10.1101/2020.08.05.20168815
About the study:
The published study includes 45 patients with confirmed COVID-19 with mild or severe symptoms at various disease stages, and 69 blood samples from control individuals without COVID-19.
About CE marking:
The antibody test (ZetaGene COVID-19 Rapid IgM IgG Test) used in the studies is CE-marked, which indicates that the device is fit for its intended purpose stated, meets legislation relating to safety, and can be freely marketed in the European Union. The test is a registered product at the Swedish Medical Products Agency (Läkemedelsverket). For more information, visit: www.zetagene.com.
Declaration of affiliations:
The test was developed by ZetaGene Ltd., a company that develops diagnostic tools for the healthcare industry based on micro-fluid technology. ZetaGene Ltd. was founded by Yang De Marinis, Associate Professor at Lund University, with the help of Lund University Innovation. ZetaGene is looking for potential partners and investors to implement the COVID-19 antibody test on a large scale in Sweden and other EU countries.
Yang De Marinis, Associate Professor at Lund University and founder of ZetaGene Ltd.
yang [dot] de_marinis [at] med [dot] lu [dot] se
+46 735 43 34 15
Magnus Rasmussen, Professor at Lund University and medical specialist at the Infection Clinic at Skåne University Hospital
magnus [dot] rasmussen [at] med [dot] lu [dot] se
+46 46 177047