Use of convalescent donor plasma to treat patients with severe SARS-CoV-2 infection (COVID-19)

The SARS-CoV-2 virus pandemic affects the whole world and has now reached Brazil. The magnitude and consequences of the COVID-19 epidemic in the country are still unknown. In this study, we will assess the impact of COVID-19 convalescent plasma transfusion in patients with severe clinical presentation of this disease. The clinical picture of SARS-CoV-2 infection is heterogeneous, with a mild and oligosymptomatic clinical presentation, or even asymptomatic, in most cases, but a portion of patients has a severe evolution, with respiratory failure, responsible for most deaths. To date, there is no specific therapy for COVID-19. A potentially promising alternative is the infusion of preformed antibodies, coming from convalescent individuals of COVID-19. This form of therapy, through the infusion of serum or plasma, is the only way to confer immediate immunity, until the affected organism itself has time to mount its own immune response (adaptive immunity). The first reports of this treatment modality date back almost a century, to treat diseases such as polio, measles, mumps and influenza. More recently, in 2009 and 2010, convalescent serum was used to treat patients with severe H1N1 influenza, in which the group of transfused patients (n = 20) was shown to have a lower mortality rate than that observed in the group not transfused (n = 73) (20.0% vs 54.8%; P = 0.01). In addition, the group of transfused patients had a viral load and levels of inflammatory cytokines (IL-6, TNF ±) on days 3, 5 and 7 significantly lower than those observed in the group of non-transfused patients (P <0.05). The first coronavirus epidemic (SARS-CoV), which also originated in China, in 2002 and 2003, provided information regarding the feasibility of using convalescent plasma, in which antibodies neutralizing the virus were identified. The second coronavirus epidemic occurred in the Middle East, in 2012, and then in South Korea. In both epidemics, the mortality rate was very high. Eighty patients with severe acute respiratory syndrome caused by coronavirus were treated with convalescent plasma, with a more favorable clinical outcome in transfused patients. Plasma was obtained from convalescents from the seventh day of their recovery, so that they contained high antibody titers. A recent meta-analysis suggested that convalescent plasma transfusion reduced mortality in groups of patients with severe acute respiratory syndrome caused by viral, coronavirus and Influenza virus. The authors identified 32 studies, mostly of low methodological quality and with a high risk of bias. The hypothesis is that transfusion of plasma from convalescent donor of COVID-19 could result in a more favorable clinical evolution and increase the survival rate of individuals with severe involvement by the disease. Forty patients with the severe form of COVID-19 will be treated with convalescent plasma, whose outcomes will be compared with a control group consisting of 80 patients with the same disease, with similar characteristics and clinical severity. Each patient will receive an approximate dose of 10 mL / kg / day of convalescent plasma (600 mL / day for adults), for 3 consecutive days. The main objective is to compare the survival curve between the two groups until the 30th and then until the 60th day of randomization in a group of patients with COVID-19 treated with convalescent plasma from this infection with that observed in a group of patients undergoing conventional (supportive) treatment. The most important secondary objectives are to assess viral load, the influence of age on the survival rate and the occurrence of possible adverse reactions to plasma transfusion in both groups.