Blood Plasma of Covid Survivors ‘Helps Critically Ill Patients’
Giving hospitalized Covid patients blood plasma transfusions from virus survivors could still reduce their risk of dying, scientists now say.
Doctors had hoped that infusions of restorative plasma — a straw-colored liquid in the blood that contains antibodies — could help the infected recover.
But a series of studies showed that the treatment does not increase survival, leading the World Health Organization to recommend using it only for critically ill patients.
Now, researchers in New York have found that those treated with the therapy were 15 percent less likely to die within four weeks.
Patients most at risk for the coronavirus, such as those battling diabetes or heart disease, benefited even more from treatment, the team said.
The experts examined the results of eight existing studies, involving more than 2,000 Covid patients.
They argued that older studies were too small to notice the effect of the treatment, which has been used to treat infections for at least a century.
Professor Andrea Troxel, study leader and biostatistician at NYU Langone Health, said: ‘Our results show that, overall, patients hospitalized with Covid can derive modest benefit from restorative plasma.
‘Patients with coexisting disease were most likely to see improvement in convalescent plasma, probably because they have the most difficulty producing antibodies to fight their infection.
“The infused plasma increases their bodies’ ability to fight the virus, but only in the early stages of the disease and before the disease overwhelms their bodies.”
In the UK, trials of restorative plasma as a Covid treatment were suspended after scientists said the results did not show the therapy helped moderately ill people.
But the treatment is given to hospitalized patients in the US who have suppressed immune systems.
Restorative plasma (pictured) — the main component of blood that contains antibodies and other immune cells needed to fight the infection — taken from Covid survivors may reduce patients’ risk of death, NYU researchers say
WHAT IS CONVALESCENT PLASMA AND WHERE IS IT USED?
Restorative plasma has been used to treat infections for at least a century, dating back to the 1918 Spanish flu pandemic.
It was also tested during the 2009-2010 H1N1 flu pandemic, the 2003 SARS epidemic, and the 2012 MERS epidemic.
Recovering plasma was used as a last resort to improve the survival rate of patients with SARS whose condition continued to deteriorate.
It has been proven “effective and life-saving” against other infections, such as rabies and diphtheria, said Dr Mike Ryan of the World Health Organization.
“It’s a very important area to pursue,” said Dr. Ryan.
What is blood plasma?
Blood plasma is a straw-colored liquid that carries red and white blood cells and platelets (which cause blood clots) throughout the body.
It also contains antibodies to fight viruses, including Covid in those who have recovered from infection.
Doctors had hoped that the antibodies in the plasma would help Covid patients recover from the disease.
How does it work?
Blood banks accept plasma donations in the same way as whole blood donations; regular plasma is used every day in hospitals and emergency rooms.
If someone is only donating plasma, their blood is drawn through a tube, the plasma is separated and the rest is infused back into the donor’s body.
Then that plasma is tested and purified to make sure it doesn’t contain blood-borne viruses and is safe to use.
For Covid research, people who have recovered from the virus would donate.
NYU researchers examined data from eight different studies — completed in the US, Belgium, Brazil, India, Spain and the Netherlands — to assess how effective the treatment was.
The studies involved 2,341 people hospitalized with Covid, an average of 60 years of age, who received an injection of blood plasma.
Plasma is the largest component of blood, it makes up 55 percent, and contains antibodies.
The team found that those who received the treatment shortly after being hospitalized were 15 percent less likely to die within a month, compared with those who did not receive it or received a placebo transfusion.
The study, published JAMA network openedcontradicts previous findings that the therapy is ineffective or of limited value.
Imperial College London dropped their trial of the treatment last year after data from nearly 1,000 patients showed ‘no evidence’ that restorative plasma increased survival.
And researchers at the University of Oxford followed suit last year after an analysis of 1,800 deaths among 10,400 patients showed it made “no significant difference.”
Subsequently, the WHO advised doctors to limit treatment to only severe and critical patients as part of clinical trials.
The agency, which examined 16 studies involving more than 16,000 patients, concluded that the treatment does not improve survival or reduce the risk of a patient needing a ventilator. It is also expensive and time consuming to manage.
However, it said critically ill patients may benefit, so clinical trials of the treatment should continue.
But Professor Troxel said pooling the results of multiple studies shows the benefits of the treatment because the others were too small to demonstrate the impact on subgroups of patients.
Study researcher Dr Mila Ortigoza said convalescent plasma collected from previously infected and subsequently vaccinated donors would contain high levels of antibodies that could protect against future mutations of the virus.
So restorative plasma may provide faster and more robust treatment against Covid’s variants than other therapies that “become less effective over time and must undergo a redesign process to address a new variant, such as monoclonal antibody treatments” , she said.
Co-investigator Professor Eve Petkova, a population health expert at the university, said the team is using the findings to create a scoring system to make it easier for clinicians to calculate who will benefit most from treatment. .