A study recently published in The New England Journal of Medicine found that administering plasma from COVID-19 convalescents with neutralizing antibody titers ≥1:160 to patients with acute respiratory distress syndrome (ARDS) caused by COVID-19 , within 5 days of starting invasive mechanical ventilation significantly reduced mortality.
Doctors from the Therapeutic Clinic of the School of Medicine of the National and Kapodistrian University of Athens summarize the main points of the study by Benoît Misset and colleagues.
In this particular clinical study conducted in Belgium, 475 adult patients with ARDS caused by COVID-19 who were placed on invasive mechanical ventilation (intubation) within the previous 5 days were randomized to receive either convalescent plasma (237 subjects) or usual supportive care (238 subjects) in 17 clinics between September 10, 2020, and March 9, 2022. Of the participating patients, 342 (72%) were randomized less than 48 hours after initiation of invasive mechanical airway support. Most patients had either moderate (57.7%) or severe (32.4%) ARDS at study entry. Glucocorticoids (cortisone) were administered to the majority (98.1%) of patients.
In the group of patients receiving convalescent plasma, 82.3% received plasma with a neutralizing antibody titer of at least 1:320, while the remaining 17.7% of patients received plasma with a neutralizing titer of 1:160 due to limited plasma availability.
At day 28 from study entry, the mortality rate was 35.4% in the group receiving convalescent plasma compared with 45.0% in the group receiving usual care, the difference being statistically significant. Further analysis showed that the benefit of convalescent plasma administration was mainly observed in patients randomized less than 48 hours after initiation of mechanical respiratory support (mortality 32.7%).
The rate of serious adverse events did not differ significantly between the two groups and were attributed to either COVID-19 or multiple organ failure unrelated to plasma administration.
However, the authors note that as the majority of patients were enrolled during periods when SARS-CoV-2 Alpha, Delta and Omicron variants (B.1.1.529) were predominant in Belgium, the results need to be confirmed in patients with ARDS affected by newer variants of the virus.
It is worth noting that during the initial phase of the COVID-19 pandemic, a multicenter phase 2 study led by Professor Thanos Dimopoulos was carried out in our country in hospitalized patients with severe COVID-19 disease. And in this study, patients receiving convalescent plasma had an increased chance of survival, while administration of plasma with a high titer of neutralizing antibodies was independently associated with a significant reduction in the risk of death (https://pubmed.ncbi.nlm.nih.gov/33920489 /).