The heavy acute respiratory syndrome caused by a coronavirus-2 (SARS-CoV-2) is the reason of a pandemic of a koronavirusny disease 2019 (COVID-19). Now various therapeutic methods including antimalarial drugs, antiviral drugs, antibiotics and vaccines are studied.
Meanwhile the present pandemic drew attention to old therapeutic methods for treatment of infectious diseases. Rekonvalestsentny plasma (a blood plasma of the recovered patients) represents one of treatment options in the current situation as it was successfully used at other outbreaks of coronaviruses. Nevertheless, it is necessary to conduct randomized controlled studies to confirm usefulness of this intervention, including the hospitalized patients with easy symptoms and patients in ORIT.
Rekonvalestsentny plasma is received with use of an aferez at living patients with the previous infections caused by the interesting pathogens against which antibodies are developed. A main objective of such therapy is neutralization of a pathogen and its destruction. Considering fast process of receiving, rekonvalestsentny plasma was considered as the emergency intervention at several pandemics, including the Spaniard, SARS-CoV, a virus of fever of the Western Neil and Ebola virus. Purpose of rekonvalestsentny plasma at an early stage after emergence of symptoms showed decline in mortality in comparison with placebo or lack of therapy at heavy acute respiratory infections of a virus etiology, such as flu and SARS-CoV, however the similar answer at a disease Ebola was not observed.
During an aferez, in addition to neutralized antibodies, receive other proteins, such as antiinflammatory cytokines, coagulation factors, natural antibodies, defensins, pentraksina and other proteins from donors. In this sense transfusion of rekonvalestsentny plasma can provide to the infected patients additional benefits, such as immunomodulation by means of weakening of heavy inflammatory reaction. In cases of COVID-19 excessive activation of the immune system which can be followed by the system hyper inflammation or "a tsitokinovy storm" caused by IL-1β, IL-2, IL-6, IL-17, IL-8, FNO and CCL2 is observed. This inflammatory reaction can lead to the heavy injury of lungs involving fibrosis and decrease in pulmonary capacity.
Safety of use of rekonvalestsentny plasma is one more task historically relevant in epidemics. Now there are proofs of safety of rekonvalestsentny plasma in emergency situations, in particular, in the A (H1N1), SARS-CoV and MERS-CoV flu epidemics of a research did not find any side effects connected with administration of rekonvalestsentny plasma. In case of fever Ebola administration of rekonvalestsentny plasma was connected with easy side reactions, such as nausea, erythema of skin and fever. For COVID19 reports showed that administration of rekonvalestsentny plasma is safe, and it was not connected with serious side effects. Thus, thanks to shipping and potential efficiency of rekonvalestsentny plasma, it is a good candidate for assessment as therapeutic approach of fight against the current pandemic. Donors of plasma have to undergo standard inspection before donorship to provide compliance to existing rules concerning plasma donorship. As production of rekonvalestsentny plasma demands the high quality standards, this plasma should not contain any infections therefore it is necessary to carry out tests for the human immunodeficiency virus (HIV), hepatitis B, hepatitis C, syphilis, T-cellular lymphotropic virus of the person 1 and 2 and on Trypanosoma cruzi (at residence in the endemic area). Other protocols assume an inactivation of pathogens Riboflavinum or Psoralenum in combination with impact of ultra-violet radiation for increase in safety of rekonvalestsentny plasma.
Aferez is the recommended procedure for receiving plasma. This procedure is based on continuous centrifugation of blood of the donor to provide selective collecting plasma. The efficiency of this technique is from 400 to 800 ml after a single donor aferez. This amount of plasma can be kept 200 or 250 ml in gemakona and to be frozen within 24 hours after collecting for the subsequent transfusion.
There is no standard dose at transfusion of rekonvalestsentny plasma. In various researches for coronaviruses administration of rekonvalestsentny plasma varied from 200 to 500 ml in schemes with single and double introduction. Now the dose of 3 ml/kg within two days is recommended.
Thus, at observance of all rules of a fence and transfusion and also high-quality inspection of the donor, rekonvalestsentny plasma is safe and potentially effective strategy in fight against new and already known pathogens, especially when the effect of antiviral drugs and vaccines is not proved.