COVID-19: no sufficient evidence for plasma therapy
In many clinics COVID be treated 19 patients with the blood plasma of convalescent Corona-treated patients and in-patients. However, according to a new investigation, sufficient evidence is lacking for this treatment so far.
Despite intensive research in numerous scientific institutions around the world, there is still no effective therapy against the Coronavirus disease (COVID-19). Therefore, it is used in some cases in the blood plasma of people who have already survived a SARS-CoV-2 infection. This treatment helps but really?
Antibodies in the blood plasma of Convalescent
According to a recent communication of the research network Cochrane people who have recovered from COVID-19 have, in their blood plasma of antibodies against the Coronavirus SARS-CoV-2, which play an important role in the acquired immunity against the disease.
For this reason, the Plasma could be from a blood donation of convalescent patients and patients in which such antibodies contains, possibly for the treatment of acute COVID-19-Sick used.
The information that you can use it either directly in the cell-free blood plasma (“convalescent Plasma”) or recovers from such a plasma donation, a so-called Hyper-immune serum with a very high concentration of antibodies.
This principle of plasma therapy was already at the end of the 19th century. Century by the German immunologist Emil von Behring discovered and has since been successful against a number of infectious diseases.
These treatments (administered by a drip or an injection) are generally well tolerated, but can cause unwanted effects.
Only a few studies completed
The authors of this “Cochrane Rapid Review” wanted to find out whether such a Plasma treatment with Plasma, respectively antibodies from convalescent COVID-19-patients and in -patients is an effective treatment for people with COVID-19, and in how far you unwanted side-effects.
For this, the experts looked for systematically important medical databases for clinical studies for the treatment with convalescent Plasma or hyperimmune serum for patients with COVID-19.
As the communication explains the process of Cochrane Rapid Reviews such as this are created in an accelerated procedure, to ensure in the case of particularly urgent questions in the best possible Balance between speed and methodological accuracy.
However, the extensive search yielded only eight completed studies (all so-called case series) with a total of 32 Participants. The significance was not only limited because of the small number of Participants greatly.
As part of were divided taking in none of these studies randomly into different treatment groups such randomized trials generally provide the most trustworthy evidence.
In addition, the case series did not include a comparison group of individuals who were treated without convalescent Plasma, it was not, therefore, controlled studies. And finally, Participants received in addition to plasma therapy, various other treatments, which complicates the comparison of the results of the study in addition.
No reputable statements possible
For these reasons, the author had to trust the evidence would, in accordance with the established evaluation scheme, “GRADE” consistently as “very low” scale.
This means that on the Basis of previously completed studies as yet no reputable statements on the effectiveness and risks of plasma therapy against COVID-19 to make.
Even if all of the study participants can be survived, however, often only a short Follow-up and 15 were able to leave you even the clinic, so this at first glance to be a positive result, in the view of the authors as well with the natural course of the disease or other treatments, explain how the use of convalescent Plasma.
“In summary, the information from the Stand at the end of April 2020, the available studies mean that we are still very unsure as to whether the use of convalescent Plasma of patients with COVID-helps 19, and how safe is this therapy,” says co-author Nicole Skoetz, the Director of the University hospital of Cologne for the Review competent Cochrane network, “Cochrane Cancer”.
“Despite an extensive search, we were able to include only evidence of a very low trustworthiness from small, uncontrolled studies in which the participants received in addition to Plasma, there are several other treatments. In addition, these studies used inconsistent endpoints, which complicates the comparison of the results,“ explains the expert.
“For all these reasons, we are not able to distinguish currently whether the recovery of a patient was due to treatment or the natural course of the disease.”
The effectiveness is not refuted
This lack of good evidence does not mean, though, that the effectiveness of a Plasma treatment for COVID-19 would be refuted.
And according to Vanessa Piechotta, research assistant in Skoetz‘ Cologne working group, and further a co-author of the review, there is good reason to hope that the great knowledge could fill the gaps soon.
“The research in this area is in full swing. We have identified around 50 ongoing studies, of which 22 randomized studies with high validity are,“ says the researcher.
“16 of these studies should still be in the course of this year. Therefore, we will update our review as a so-called ‘Living Systematic Review’ on a monthly basis, so that it reflects the latest available evidence.” (ad)