Largest study in Europe of convalescent plasma found that its use did not produce benefits against COVID-19

the convalescent plasma has become one of the most widely used treatments for COVID-19, while vaccines that today prevent the disease, at least in its most severe forms, were in development.

Even today is still used worldwide in the absence of effective treatment and as a safe alternative -for its successful history in MERS-CoV, Ebola and the H1N1 influenza epidemic-.

Plasma from cured patients It is a transparent and somewhat yellowish liquid that makes up more than half of the total volume of blood and is obtained by apheresis, a procedure that involves the use of a machine., which separates cells using disposable and single-use equipment that separates the different components of the blood: red blood cells, platelets and plasma. The latter is separated into a volume to be defined for each donor. It is performed by puncturing a vein in the arm through which blood is drawn in and the rest of the red blood cells and platelets are returned simultaneously from another vein. The volume of plasma extracted will be replaced by a physiological solution of equivalent volume.

The United States Food and Drug Administration (FDA) has issued a emergency use authorization (UNITED STATES) for experimental convalescent plasma as a treatment for COVID-19 in hospitalized patients as part of the agency’s ongoing efforts to fight COVID-19.

But despite its massive use, different scientific studies on recovering plasma have not shown a clear benefit for the massive cure of patients. This is the case of a recent survey carried out in 177 hospitals in the United Kingdom and published in the specialist medical journal The Lancet

“In hospitalized patients with COVID-19, high titer convalescent plasma did not improve survival or other predefined clinical outcomess ”, was the conclusion of the experts who signed the document.

Between May 28, 2020 and January 15, 2021, 11,558 (71%) of the 16,287 patients included in the RECOVERY study they were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. The study found no significant difference in 28-day mortality between the two groups evaluated: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group. died within 28 days. Remember that RECOVERY is an adaptive, randomized, individually controlled, open-label platform trial to assess the effects of various potential treatments in hospitalized patients with COVID-19, such as convalescent plasma, dexamethasone, hydroxychloroquine, lopinavir-ritonavir, azithromycin and tocilizumab.

“The 28-day mortality rate was similar in all pre-specified patient subgroups, including patients with no detectable antibodies to SARS-CoV-2 at randomization. Assignment to convalescent plasma had no significant effect on the proportion of patients discharged within 28 days (3832 [66%] patients in the convalescent plasma groupvs 3822 [66%] patients in the usual care group. Among those who did not receive invasive mechanical ventilation at randomization, there were no significant differences in the proportion of patients who met the combined endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5,493 patients in the convalescent plasma group in front of 1568 [29] %]out of 5,448 patients in the usual care group, ”the experts said.

This open, randomized, controlled (Randomized Evaluation of COVID-19 Therapy) platform trial continues to assess a number of possible treatments in COVID-19 hospital patients in the UK. Eligible and consenting patients were randomized to receive usual care alone (usual care group) or usual care plus high titer convalescent plasma (convalescent plasma group).

“Convalescent plasma has been used for over 100 years as a passive immunotherapy for influenza pneumonia and more recently for SARS-CoV. Although observational studies have suggested that convalescent plasma may reduce mortality in severe viral respiratory infections, evidence from randomized trials remains scarce and inconclusive, ”they said in the study.

And they concluded: “Efficacy of convalescent plasma as a treatment for hospitalized patients with COVID-19 is uncertain“.

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