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The pandemic of Coronavirus Disease 2019 (COVID-19) in 2020 has posed a great challenge to global public health resources. Since there are no specific antiviral drugs at present, convalescent plasma (CP) from patients who have recovered from COVID-19 is one of the specific biologic therapies being considered to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Preliminary studies have shown that the CP containing high titer neutralizing antibody against SARS-CoV-2 is safe and promising in blocking viral replication and improving patients'clinical symptoms. In this article, we briefly summarize the application of CP in treatment of COVID-19, and explores possible action mechanism, relevant clinical research and possible influencing factors of clinical effect, which may be helpful to the rational application of CP in treatment of COVID-19. Copyright © 2021 Changchun Institute of Biological Products. All rights reserved.
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Objective To establish a sample panel for detection of severe acute respiratory symptom coronavirus 2 (SARS-CoV-2) antigen and apply to the development and quality evaluation of SARS-CoV-2 antigen colloidal gold test cassettes. Methods A sample panel for detection of SARS-CoV-2 antigen was established using 12 kinds of bulks of inactivated non-SARS-CoV-2 vaccine as negative controls, while two batches (Bl and B2) of bulks of inactivated SARS-CoV-2 vaccine (Bl, B2) and one batch (SI) of inactivated SARS-CoV-2 culture as positive controls. Bl was used as a positive control to evaluate the colloidal gold test cassettes from four manufacturers (A, B, C and D), and to monitor the development process of cassette from manufacturer A to improve its sensitivity. The negative sample panel was used to evaluate the specificity of colloidal gold test cassettes from five manufacturers (A, C, E, F and G), while positive sample panel (B2, SI and recombinant N protein) to evaluate the sensitivity. Inactivated SARS-CoV-2 culture SI was deter-mined with the commercial SARS-CoV-2 nucleic acid detection kit, and the result was compared with that by the colloidal gold test cassette from manufacturer A. Results N protein was determined as the main epitope of SARS-CoV-2 antigen by evaluation with positive control. The colloidal gold test cassettes from manufacturer A showed a sensitivity of 1 : 2 x 103to B1. The colloidal gold test cassettes from five manufacturers showed no cross reactions with inactivated non-SARS-CoV-2 vaccines, indicating a high specificity. The sensitivity of colloidal gold test cassette from manufacturer A was 106to B2 and 1 : 2 x 107to S1. However, the sensitivities of colloidal gold test cassettes from manufacturers E, F and were more than 1 : 103to B2 and 1 : 104- 1 : 105to SI, and that from manufacturer C was 1 : 104to B2 and 1 : 106to SI. The sensitivity of colloidal gold test cassette from manufacturer A was 100 pg/mL, while those from the other four manufacturers were 10 pg/mL, to recombinant N protein. The sensitivity of commercial nucleic acid detection kit to SI was 1 : 107, which was equal to that of colloidal gold test cassette from manufacturer A (1 : 2 x 107). Conclusion A sample panel for detection of SARS-CoV-2 antigen was successfully established, which showed high specificity and sensitivity, and might be used for the development and quality evaluation of SARS-CoV-2 antigen colloidal gold test cassettes. Copyright © 2022 Changchun Institute of Biological Products. All rights reserved.
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Objective To explore the application and safety of apheresis technology in collection of Coronavirus Disease 2019 (COVID-19) convalescent plasma (CP), and to analyze the quality characteristics of the plasma. Methods The general data of COVID-19 convalescent plasma (CP) donors, including gender, age, date of discharge or release from medical isolation, were collected based on informed consent. After physical examination, the CP was collected by apheresis technology with plasma separator, inactivated with methylene blue, and determined for severe acute respiratory symptom Coronavirus 2 (SARS-CoV-2) nucleic acid and specific antibody (RBD-IgG) against SARS-CoV-2. Results The collection process went well, and no serious adverse events related to plasma collection were reported during or after the collection. The average age of COVID-19 CP donors was 38 years (n = 933). The distributions of blood groups A, B, AB and 0 in RhD (+) COVID-19 CP were 33. 4%, 29. 2%, 10% and 27. 2% respectively. The plasma donation date was 18 d from the discharge date in average. All the test results of SARS-CoV-2 nucleic acid in CP were negative, while the proportion of plasma samples at SARS-CoV-2 antibody titer of more than 1: 160 was 92. 60%. Conclusion Apheresis technology was safe and reliable. The COVID-19 CP contained high titer antibody. Large-scale collection and preparation of inactivated plasma against SARS-CoV-2 played an important role in the treatment of COVID-19.
ABSTRACT
The pandemic of Coronavirus Disease 2019 (COVID-19) in 2020 has posed a great challenge to global public health resources. Since there are no specific antiviral drugs at present, convalescent plasma (CP) from patients who have recovered from COVID-19 is one of the specific biologic therapies being considered to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Preliminary studies have shown that the CP containing high titer neu¬tralizing antibody against SARS-CoV-2 is safe and promising in blocking viral replication and improving patients'clinical symptoms. In this article, we briefly summarize the application of CP in treatment of COVID-19, and explores possible action mechanism, relevant clinical research and possible influencing factors of clinical effect, which may be helpful to the rational application of CP in treatment of COVID-19.
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Objective: To compare the correlation between the results of SARS-CoV-2 neutralizing antibody colloidal gold test cards prepared by two different principles and the SARS-CoV-2 pseudovirus neutralization experiment, and to evaluate the feasibility of the neutralizing antibody colloidal gold test card for the SARS-CoV-2 neutralizing antibody detection in different populations. Methods: Two kinds of SARS-CoV-2 neutralizing antibody colloidal gold test cards using double antigen sandwich method (manufacturer A) and competitive blocking method (manufacturers B) were used to detect the samples with SARS-CoV-2 neutralizing antibody titers. Detection sensitivity and the correlation between the two methods and the neutralization experiment were compared. The intravenous human immunoglobulin and specific immunoglobulin prepared before the outbreak of COVID-19 epidemic were detected to investigate the specificity of the eligible test card. In order to determine whether there is a hook effect, individual immunized plasma samples of high ELISA titers were tested with series of dilutions and original dilution. Single post-immunized plasma samples were detected with different ELISA titers, the positive rates were determined and the color changes were observed. Single post-immunized plasma samples were screened in the low-dilution area of ELISA according to chromaticity of 120NT50 and 300NT50 on the colorimetric card to prepare pooled plasma. The results were compared with the currently used indirect ELISA method. Results: The detection limits of manufacturers A and B for the first-generation NIBSC international standard 20/136 (anti-SARS-CoV-2 human immunoglobulin international standard) were 0.612 5 and 5 IU•mL-1, respectively. The results of different titers of pooled plasma (both of post-immunization with SARS-CoV-2 vaccine and COVID-19 convalescence plasma) have a good correlation with the neutralizing antibody titer. The post-immunization plasma with high ELISA dilutions (above 10 000) did not show hook effect. The positive rate of individual plasma of different ELISA dilution levels reached 100% when the dilution was above 160, and the uniformity of the chromaticity was higher when the dilution level was above 640. The overall chromaticity became darker as the ELISA dilution increased. The chromaticities of Ppool 120NT50 and Ppool 300NT50 screened according to the colorimetric chart were close to the neutralizing antibody titers. Conclusion: The correlation between the results of the manufacturer A neutralizing antibody test card using the dual antigen sandwich method to detect SARS-CoV-2 neutralizing antibody in convalescent plasma and post-immunization plasma and the titer of the pseudovirus neutralization experiment is better than that of the manufacturer B product using the competitive inhibition method and indirect ELISA. And the color brightness of the detection line is positively correlated with the level of neutralizing antibody, which can be used for preliminary screening of neutralizing antibody in different populations.
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Objective: To systematically analyze the 670 convalescent plasma (CP) samples from patients with coro-navirus disease 2019 (COVID-19). Methods: The plasma samples were analyzed and evaluated for routine test items including hepatitis B virus surface antigen (HBsAg), hepatitis C virus (HCV) antibody, human immunodeficiency virus (HIV)-l/HI V-2 antibody, Treponema pallidum (TP) and alanine aminotransferase (ALT) as well as blood group, nucleic acid of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), IgG antibody, methylene blue residue and sterility. Results: A total of 121 substandard plasma samples were detected from 670 convalescent plasma samples, of which substandard IgG antibody titer accounted for the highest proportion of 7. 91%. In the turn of proportions, the blood groups were A (32. 52%), B (29. 94%), 0 (28. 886%) and AB (8. 66%). Ml the test results of nucleic acids of SARS-CoV-2 were negative. A total of 485 samples were from Wuhan, of which the highest proportion (21. 95%) were from the donors at ages of > 30 ∼ 35 years, including 264 males and 221 females. Of the high titer plasma, those at titers of not less than 1: 640 accounted for the highest proportion (77. 43%). Most of the IgG titers in plasma of common patients were not less than 1: 640 > 10 - 20 d, while were less than 1: 160 3 ∼ 10 d, after hospitalization. However, 35 plasma samples were negative for IgG antibody (at titers of less than 1: 80), in 9 of which other pathogens were detected. Conclusion: Unqualified IgG titer was the main reason for unqualified CP. The proportion of CP of group O was lower than that of the group in healthy population. The highest proportion of plasma donors in Wuhan was in the populations at ages of > 30 ∼ 35 years, which was higher in males than in females. Satisfactory immune responses were induced in most of patients in convalescence period, which removed the virus in vivo effectively. High antibody titers were induced > 10 ~ 20 d after hospitalization, making the common cases were not easy to change into severe ones. It was speculated that patients negative for IgG antibody might be infected with other pathogens. © 2020 Changchun Institute of Biological Products. All rights reserved.
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Correction to: European Review for Medical and Pharmacological Sciences 2020; 24 (22): 11939-11944-DOI: 10.26355/eurrev_202011_23854-PMID: 33275267, published online 30 November, 2020. The authors state that "Figures 3 and 4 were used twice due to a careless mistake during the preparation of Figures". There are amendments to this paper. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/23854.
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Objective: To establish a detection method for the methylene blue residues in inactivated plasma against SARS-CoV-2, and to apply the method to inactivated plasma of different dosages. Methods: Methylene blue in plasma was absorbed using solid phase extraction cartridge, and the absorbance at 654 nm was measured by UV-2550 spectrophotometer. The absorbance of the eluate extract from standard control plasma and virus inactivated plasma by solid phase was measured, and the methylene blue residue in the test plasma was calculated based on the ratio of the absorbance. Then, linearity-range, precision, accuracy and quantitative limit of the method are validated based on 11 batches of inactivated plasma in specifications of 50, 75 and 100 mL. Results: The detection method of methylene blue residue, was established within the linear range of 0.01~0.05 μmol•L-1. The verification standards are as follows: R value is 0.994 4;precision is 7% and accuracy is between 102%~110%;and the quantitative limit is 0.013 μmol•L-1;the quantitative detection CV is less than 5%, all of which are in conformity with requirements of Pharmacopoeia of PRC (Edition 2015). The levels of methylene blue residue in inactivated plasma of each specification were within the detection range of the developed method, and the residue levels were much lower than that in standard(≤0.30 μmol•L-1). Conclusion: The method can be successfully applied for the detection of methylene blue residues in the inactivated plasma against SARS-COV-2 of different specifications.
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OBJECTIVE: Coronavirus disease 2019 (COVID-19) has become a worldwide public health emergency; unfortunately, there is currently no treatment for improving outcomes or reducing viral-clearance times in infected patients. The aim of the present study was to evaluate the efficacy of interferon (IFN) with or without lopinavir and ritonavir as antiviral therapeutic option for treating COVID-19 infection. PATIENTS AND METHODS: The present study enrolled 148 patients that received either standard care, treatment with IFN alfa-2b, or IFN alfa-2b combined with lopinavir plus ritonavir. Viral testing was performed using Reverse-Transcription Polymerase Chain Reaction (RT-PCR). RESULTS: There was no significant difference in the viral-clearance time at 28 days after treatment between patients receiving standard care and those receiving anti-viral treatments. However, the average viral-clearance time of patients receiving standard care (14 days) was shorter than that for patients receiving IFN alfa-2b or IFN alfa-2b combined with lopinavir plus ritonavir (15.5 or 17.5 days) (p<0.05). Patients treated with IFN alfa-2b within five days or IFN alfa-2b combined with lopinavir plus ritonavir after three days of symptoms exhibited shorter viral-clearance times than the other groups (p<0.05). Moreover, viral-clearance times were significantly longer in patients receiving standard care or anti-viral treatment 5 days after symptoms appeared than those of patients who received these treatments within five days of symptom onset (p<0.05). CONCLUSIONS: Early symptomatic treatment is most critical for maximizing amelioration of COVID-19 infection. Anti-viral treatment might have complicated effect on viral-clearance.