Handbook of COVID-19 Prevention and Treatment-- Convalescent Plasma Therapy for COVID-19 Patients

Handbook of COVID-19 Prevention and Treatment-- Convalescent Plasma Therapy for COVID-19 Patients

  • 2020-03-25

XI. Convalescent Plasma Therapy for COVID-19 Patients

Since Behring and Kitasato reported the therapeutic effects of diphtheria antitoxin plasma in

1 B91, plasma therapy has become an important means of pathogen immunotherapy for acute
infectious diseases. The disease progression is rapid for severe and critically ill patients of an
emerging infectious disease. In the early phase, the pathogens damage the target organs
directly and then lead to severe immuno-pathological damage. The passive immune
antibodies can effectively and directly neutralize the pathogens, which reduces the damage
of the target organs and then block the subsequent immune-pathological damages. During
multiple global pandemic outbreaks, WHO also emphasized that "convalescent plasma therapy
is one of the most recommended potential therapies, and it has been used during other
epidemic outbreaks". Since the outbreak of COVID-19, the initial mortality rate was rather
high due to the lack of specific and effective treatments. As mortality rate is an important
metric that the public concerns, clinic treatments which can reduce the fatality rate of critical
cases effectively are key to avoid public panic. As a provincial-level hospital in Zhejiang
province, we have been responsible to treat the patients from Hangzhou and the critically ill
patients of the province. There are abundant potential convalescent plasma donors and
critically ill patients who need convalescent plasma treatment in our hospital.

Plasma collection
In addition to the common requirements of blood donation and procedures, the following details
should be noted.
1.1 Donors
At least two weeks after recovery and being discharged (the nucleic acid test of the sample taken from
the lower respiratory tract remains negative~14 days). 18,; Age,; 55. The body weight>50 kg (for
male) or > 45 kg (for female). At least one week since last glucocorticoid usage. More than two weeks
since last blood donation.
1.2 Collection Method
Plasmapheresis, 200-400 ml each time (based on medical consultation).
1.3 Post-Collection Testing
In addition to the general quality test and the test of blood-borne disease, the blood samples need to
be tested for:
(1) Nucleic acid testing for SARS-CoV-2;
(2) 160-fold dilution for the qualitative test of SARS-CoV-2 specific lgG and lgM detection; or 320-fold
dilution for the qualitative test of whole antibody detection. If possible, keep> 3 ml plasma for the
viral neutralization experiments.
The following should be noted. During the comparison of virus neutralization titer and luminescent
lgG antibody quantitative detection, we found that the present SARS-CoV-2 specific lgG antibody
detection does not fully demonstrate the actual virus neutralization capability of the plasma.
Therefore, we suggested the virus neutralization test as the first choice, or test the overall antibody
level with the 320-fold dilution of the plasma.

 Clinical Use of the Convalescent Plasma

2.1 Indication
(1) Severe or critically ill COVID-19 patients tested positive in respiratory tract test;
(2) The COVID-19 patients who are not severe or critically ill, but in a state of immunity suppression;
or have low CT values in the virus nucleic acid testing but with a rapid disease progression in the lungs.
Note: In principle, the convalescent plasma should not be used on COVID-19 patients with disease
course exceeding three weeks. But in clinical applications, we found that the convalescent plasma
therapy is effective for patients with a disease course exceeding three weeks and whose virus nucleic
acid tests continuously to show positive from respiratory tracts specimen. It can speed up virus
clearance, increase the numbers of the plasma lymphocytes and NK cells, reduce the level of plasma
lactic acid, and improve renal functions.
2.2 Contraindication
(1) Allergy history of plasma, sodium citrate and methylene blue;
(2) For patients with history of autoimmune system diseases or selective lgA deficiency,
the application of convalescent plasma should be evaluated cautiously by clinicians.
2.3 Infusion plan In general, the dosage of convalescent plasma therapy is ~400 ml for
one infusion, or~ 200 ml per infusion for multiple infusions.

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