Scientists do not yet know if SARS-CoV-2 – the virus that causes COVID-19 – can be transmitted by blood transfusion. But given the unknowns around this new pathogen, researchers at Colorado State University used existing technologies to show that exposing the coronavirus to riboflavin and ultraviolet light reduces pathogens in human plasma and whole-blood products.
Dr Izabela Ragan, post-doctoral fellow in the department of biomedical sciences at CSU, said the research team tackled one of the big questions about the novel coronavirus: If the pathogen can spread through blood or by donating blood, would it be possible to kill the virus?
"The research we conducted answers that question: yes, you can," said Ragan. "We eliminated a huge amount of virus and we could not detect the virus post-treatment." The research team used the Mirasol Pathogen Reduction Technology System to treat nine plasma and three whole-blood products for the study.
The technology – which is owned by medical device company Terumo BCT – was invented by Ray Goodrich, senior author of the study and executive director of the Infectious Disease Research Centre at CSU. He is also a professor in the department of microbiology, immunology and pathology.
Dr Heather Pidcoke, a co-author on the study and chief medical research officer at CSU, said the process used by the research team is quite simple. The blood product or plasma is placed in a specially designed storage bag, riboflavin solution is added, and the mixture is then exposed to UV light. The Mirasol PRT device gently shakes the bag to circulate the blood cells, so the cells come to the surface where they are exposed to the UV light.
The authors caution that this is not an experiment to try at home. The light does not penetrate the entire bag, so it's not the same as exposing body parts to UV light.
Goodrich said the research may help to avoid what happened in the 1980s, when HIV was transmitted through blood and blood products while scientists were still trying to isolate and identify what might be causing the spread of the virus. However, he noted that the Mirasol system is currently only approved for use outside of the US, mainly in Europe, the Middle East and Africa.
"Our research may help inform people outside the US who are using it," he said. "They may breathe a sigh of relief knowing that while we continue to study this, there is some potential mitigation in place just in case."
CSU researchers are currently studying whether SARS-CoV-2 is transmitted by blood. Ragan said they hope to answer that question very soon.
Ray Goodrich has consulted for Terumo BCT, Inc. He is an inventor of the Mirasol PRT technology and holds patents on the use of the technology for the treatment of blood products and in preparing vaccines. These patents are assigned to Colorado State University.
Abstract
Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has recently been identified as the causative agent for Coronavirus Disease 2019 (COVID-19). The ability of this agent to be transmitted by blood transfusion has not been documented, although viral RNA has been detected in serum. Exposure to treatment with riboflavin and ultraviolet light (R + UV) reduces blood-borne pathogens while maintaining blood product quality. Here, we report on the efficacy of R + UV in reducing SARS-CoV-2 infectivity when tested in human plasma and whole blood products.
Study design and methods: SARS-CoV-2 (isolate USA-WA1/2020) was used to inoculate plasma and whole blood units that then underwent treatment with riboflavin and UV light (Mirasol Pathogen Reduction Technology System, Terumo BCT, Lakewood, CO). The infectious titers of SARS-CoV-2 in the samples before and after R + UV treatment were determined by plaque assay on Vero E6 cells. Each plasma pool (n = 9) underwent R + UV treatment performed in triplicate using individual units of plasma and then repeated using individual whole blood donations (n = 3).
Results: Riboflavin and UV light reduced the infectious titer of SARS-CoV-2 below the limit of detection for plasma products at 60–100% of the recommended energy dose. At the UV light dose recommended by the manufacturer, the mean log reductions in the viral titers were ≥ 4.79 ± 0.15 Logs in plasma and 3.30 ± 0.26 in whole blood units.
Conclusion: Riboflavin and UV light effectively reduced the titer of SARS-CoV-2 to the limit of detection in human plasma and by 3.30 ± 0.26 on average in whole blood. Two clades of SARS-CoV-2 have been described and questions remain about whether exposure to one strain confers strong immunity to the other. Pathogen-reduced blood products may be a safer option for critically ill patients with COVID-19, particularly those in high-risk categories.
Authors
Izabela Ragan, Lindsay Hartson, Heather Pidcoke, Richard Bowen, Raymond Goodrich
[link url="https://source.colostate.edu/using-riboflavin-uv-light-in-specialized-device-reduces-sars-cov-2-pathogens-in-plasma-whole-blood/"]Colorado State University material[/link]
[link url="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233947"]PLOS One abstract[/link]