We also need to know these background knowledge in the treatment of fever with plasma

The convalescent plasma therapy is a kind of passive immunotherapy, which collects the blood rich in antibody from the recovered patients and infuses it to other patients after treatment As a protein produced by immune cells in vivo, antibody can specifically recognize and help the body clear pathogens After the pathogen is cleared, the antibody will exist in human body for a certain time Therefore, theoretically, it is possible to get these antibodies from the blood of the convalescent and inject them into the severe and critical patients to help them overcome the virus The novel coronavirus pneumonia plasma product is a plasma containing highly effective new crown virus specific antibodies donated by the rehabilitative person It is prepared by virus inactivation and neutralizing antibodies against the new crown virus and detected by multiple pathogenic microorganisms, and is used for the treatment of severe cases of new crown pneumonia In the novel coronavirus pneumonia diagnosis and treatment plan (revised version fifth), it is mentioned that "convalescent plasma therapy can be used in conditional conditions" What should be paid attention to in convalescent plasma therapy? Compared with novel coronavirus, the preparation of plasma is more complicated than that of drugs and vaccines It needs to collect blood from the recovered patients, screen pathogens and ensure that no new coronavirus is found in the blood, and then infuse the patients However, there are some risks in importing complex plasma into human body, such as the occurrence of allergies, the spread of pathogens such as HIV and malaria in window period, and some uncertain problems In addition, the antibody levels in blood of different donors are very different, so it is difficult to standardize Therefore, the quality assurance system must be applied in the whole process from collection, preparation, storage to inspection and application of the recovered plasma, which conforms to the pharmaceutical production quality management specifications Participants must be strictly trained Plasma donors need to undergo strict evaluation to ensure that their physical condition is restored well Plasma donation will not cause damage to their bodies They also need to donate plasma voluntarily and ensure the traceability of plasma The history of convalescent plasma therapy is as early as the end of the 19th century Researchers have found that it is effective in the treatment of diphtheria and tetanus In the first half of the 20th century, it was widely used in the treatment of various diseases, such as measles, mumps, pneumonia, shock, severe trauma and other severe infections Although the development of antibiotics, antiviral drugs and vaccines has gradually eliminated them, the "recovery plasma therapy" still plays an important role at a critical moment In the human fight against SARS, H1N1, H5N1 and Ebola, plasma therapy has appeared A systematic analysis of 32 studies on convalescent plasma therapy for SARS or influenza found that convalescent plasma therapy can reduce mortality and the earlier treatment, the better Other studies have shown that plasma therapy in convalescent period may reduce the mortality of patients with severe influenza A and SARS virus infection In June 2003, Chinese medical journal published a paper "the characteristics of the onset and clinical diagnosis and treatment of the first batch of SARS patients in Beijing" The corresponding author is Wang Fusheng, academician of 302 Hospital of PLA This project was supported by the major scientific and technological emergency research program of SARS prevention and control in the whole army In this paper, a 74 year old SARS patient in Beijing was treated with convalescent plasma It is reported that in addition to the comprehensive treatment measures, the patient was also given 50 ml of convalescent plasma once on the 17th day of the onset of the disease, and then the patient recovered and discharged on the 21st day The preliminary results showed that the course of this case was shortened obviously, and the plasma therapy had a certain therapeutic effect But at the same time, the paper points out that the plasma treatment needs strict quality control requirements: including the need to determine the recovery period of patients to meet the requirements of blood donation, and the extracted plasma needs to be strictly checked by relevant etiological tests (such as HIV, HBV, HCV and other viruses), before it can be reinfusion to SARS patients It can be seen that the indications of plasma therapy should be very strict, only for those patients with rapid progress, old age or severe patients with basic diseases At the same time, the paper also points out that whether the plasma treatment in the recovery period of SARS can quickly reduce the viral load in patients and to what extent it can reduce or improve the pathological changes in patients' lungs need to be studied In 2006, a meta-analysis of 1703 patients indicated that in H5N1, convalescent plasma therapy may be an effective, timely and widely available treatment method, which should be studied in clinical trials In the treatment of H1N1, a 2011 study showed that the use of convalescent plasma treatment can reduce the respiratory virus load, reduce the cytokine response in serum and mortality In 2015, a meta-analysis of 32 studies on the treatment of SARS and influenza with convalescent plasma also suggested that convalescent plasma might reduce mortality and be safe However, the convalescent plasma therapy is not a panacea, its effectiveness and safety need to be analyzed according to the specific disease A study published in the New England Journal of medicine in 2016 found that the survival rate of patients with Ebola virus infection did not improve after receiving 500 ml of convalescent plasma treatment, but its effect may be affected by the lower titer of plasma antibody, and whether the plasma treatment with higher titer antibody is effective remains to be studied A randomized, double-blind, phase 3 clinical study published in the lancet respiratory diseases in 2019 showed that high titer anti influenza immune plasma had no significant benefit compared with non immune plasma (titer ≤ 1:10) in the treatment of severe influenza (BIOON Com)