Blood plasma safe to treat severely ill coronavirus patients, finds study on 5,000 hospitalized adults
Of those who received convalescent plasma transfusions for the study, fewer than one percent experienced adverse events
Blood plasma from recovered coronavirus patients appears to be safe to use on Covid-19 patients, according to the most comprehensive study in the US. The results are a promising development in the fight against the novel coronavirus, for which there is no treatment or vaccine currently.
The research team analyzed key safety metrics after the transfusion of convalescent plasma in 5,000 hospitalized adults with severe or life-threatening Covid-19. This is part of the US Food and Drug Administration or FDA’s national Expanded Access Program (EAP) for Covid-19. The early findings from the study suggest that experimental convalescent plasma is safe in treating severely ill patients. The transfusions resulted in few serious side-effects and the death rate was not excessive, according to the research team. It includes experts from Mayo Clinic, Michigan State University, and Johns Hopkins Bloomberg School of Public Health.
“This is just the beginning of the reporting process. We are optimistic but must remain objective as we assess increasing amounts of patient data," Dr Michael Joyner, head of the EAP at Mayo Clinic, said in a statement.
Known as convalescent plasma therapy, it uses donated blood plasma from patients who have recovered from the infection. This is because people who have recovered from the new coronavirus have antibodies in their plasma made by the immune system that can attack the virus. This antibody-rich plasma is transfused into someone infected with the virus in the hopes that antibodies from the recovered person can help the person who is sick by killing the virus the next time it attacks.
At this time, convalescent plasma is the only antibody-based therapy available for Covid-19. It is currently being evaluated in the US as a treatment for patients with serious or immediately life-threatening Covid-19 infections, or those considered to be at high risk of progression to severe or life-threatening disease. In the US, a person may qualify to donate plasma for coronavirus patients if they are at least 17 years old and weigh 110 lbs. The individuals must be in good health and have a prior, verified diagnosis of Covid-19, but are now symptom-free and fully recovered from the disease.
The report assessed the first seven days following transfusion of patients hospitalized with coronavirus. The research protocol defines severe or life-threatening as dyspnea, decreased blood oxygen saturation, respiratory failure, septic shock, and multiple organ dysfunction or failure. 66% of the patients were in an ICU, and nearly 20% carried the diagnosis of multi-organ dysfunction or failure.
“From April 3 to May 11, 2020, a total of 14,288 patients with severe or life-threatening Covid-19 or who were judged by a healthcare provider to be at high risk of progression to severe or life-threatening Covid-19 were enrolled in the EAP. In that time, a total of 8,932 enrolled patients received a C-19 convalescent plasma transfusion. Data from the first 5,000 transfused patients were included in this report,” say researchers. Around 10,422 coronavirus patients have now received the treatment at facilities across the country, according to data till May 14.
“At the time of enrollment, 4,051 (81%) patients had severe or life-threatening coronavirus and 949 (19%) were judged to have a high risk of progressing to severe or life-threatening Covid-19. Before the convalescent plasma transfusion, 3,316 patients were admitted to the ICU,” says the analysis.
Patients received plasma between April 3 and May 3. After transfusion of convalescent plasma, the researchers found that serious adverse events occurred in fewer than 1% of the treated patients. The mortality rate seven days after treatment was 14.9%, shows analysis. The researchers note that while the study was not designed to evaluate the efficacy of convalescent plasma, a seven-day incidence of mortality of 14.9% in this number of patients indicates “no signal of toxicity beyond what is expected from plasma use in severely ill patients.”
“Within four hours of completion of the Covid-19 convalescent plasma transfusion (inclusive of the plasma transfusion), 36 serious adverse events (SAEs) were reported (less than 1% of all transfusions). However, only 2 (of 36) SAEs were judged as definitely related to the convalescent plasma transfusion by the treating physician,” the findings state.
Over the first seven days after the transfusion, a total of 602 mortalities were observed. Of the 3,316 patients admitted to the ICU, 456 died. Further, of the 1,682 hospitalized patients not admitted to the ICU, 146 died. “Given the deadly nature of Covid-19 and the large population of critically ill patients included in these analyses, the mortality rate does not appear excessive. These early indicators suggest that transfusion of convalescent plasma is safe in hospitalized patients with Covid-19,” the researchers conclude.
According to the experts, these emerging data provide early safety indicators of convalescent plasma for Covid-19 treatment and suggest research should shift focus toward determining the efficacy of convalescent plasma. The researchers also caution that this is a first safety report and does not provide any findings on the effectiveness of convalescent plasma in the treatment of Covid-19. The team’s next steps are to collect and review more safety data and continue studies to determine the efficacy of the intervention.