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Introduction: During the first year of coronavirus disease (COVID)-19 outbreak, kidney transplant programs were suspended in several countries in the World. Republic of Belarus did not suspend organ transplant program carefully weighed the risks and benefits of pursuing or postponing kidney transplantation. In cooperation with national-level efforts, our transplant program adopted universal donor and recipient screening using reverse transcriptase polymerase chain reaction for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) with or without chest CT scans before kidney transplantation. Thus, national kidney transplant activities in Republic of Belarus remained stable for both living and deceased donor transplantation compared with the same period during the previous year. The objective was to study the safety of kidney transplantation, the incidence of COVID-19 disease in kidney transplant patients and medical care providing for transplanted patients during this pandemic period. Method(s): A retrospective review of all patients who had received a kidney transplant at State Institution "Minsk Scientific and Practical Center for Surgery, Transplantology and Hematology" in Minsk, Republic of Belarus was performed from January 2020 to November 2022. Result(s): Dynamics of kidney transplantations number, clinical data of recipients during 3 years Covid-19 pandemic compared with the previous year are presented in table 1. The rate of infection in early postoperative period was low: 1,1% (2020), 0,5% (2021) and 0% (November 2022). In case of SARS-CoV2 infection modifications of immunosuppression (IS) therapy were based on the clinical conditions. For asymptomatic patients "wait and see approach" was mostly used;a suspension of antimetabolites drugs was adopted in the majority of patients with symptomatic COVID-19 infections. For CNIs, withdrawal was the preferred choice in severely symptomatic patients. A discontinuation of all IS drugs was used only in severely symptomatic COVID-19 patients on invasive mechanical ventilation. Since 2022 we started to use remdesivir in recipients with symptomatic course of disease with positive results. [Formula presented] From the middle of 2021 we commenced specific vaccination among transplanted patients. Most widely available vaccines in Belarus were CoronaVac (Sinovac Life Sciences, Beijing, China) and Gam-COVID-Vac (Gamaleya Research Institute of Epidemiology and Microbiology, Russia). There were no revealed any adverse effects of vaccination among our group. Conclusion(s): In our experience, the current kidney transplant program seems viable and safe, even during periods of health emergencies. No conflict of interestCopyright © 2023
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Introduction. Immunocompromised individuals, such as kidney and liver recipients, are at high risk for a severe course of COVID-19, which explains the special interest in this category of patients in conditions of high incidence of this infection and mass vaccination with available vaccines. Purpose. To study the characteristics of humoral post-infection and post-vaccination immunity to SARS-CoV-2 in kidney and liver recipients based on qualitative and quantitative serotesting. Materials and methods. The study of characteristics of post-infection immunity was carried out in the group of immunocompromised individuals (n=213) including kidney (n=177) and liver (n=26) recipients with PCR confirmed COVID-19, while the study of post-vaccination immunity was carried out in the group of kidney (n=56) and liver (n=12) recipients immunized with Sputnik V (Russia) or Vero Cell (China). In comparative studies, a simple randomized sample was used of immunocompetent patients who recovered from COVID-19 (n=163), corresponding in age and gender to that of the recipients examined, as well as a convenient sample of immunocompetent individuals vaccinated with Sputnik V (n=257) and Vero Cell (n=160). Serotesting for the detection of IgG to S and N proteins of SARS-CoV-2 was carried out by ELISA. Reliable intervals for proportions were calculated using the Wald method. The significance of the detected differences was assessed by the χ2 (chi-square) method. Results. The paper presents data on comparative serological testing of kidney and liver recipients recovered from COVID-19. The detection rate of post-infectious IgG to N and S proteins of SARS-CoV-2 was found to be 88.1% in the group of kidney recipients, 91.3% in the group of liver recipients, and 91.7% in the group of immunocompetent individuals. At the same time, the proportion of N protein seropositive subjects in all groups of observation was lower in comparison with that to S protein, with a significant difference in the group of kidney recipients (59.9% and 86.4%, respectively, p<0.001). The overall dynamics of the decrease in proportion of seropositive individuals during the observation period up to 12 months from the onset of clinical manifestations of infection in both groups of recipients and in the group of immunocompetent individuals had common patterns, however, seroprevalence rates for IgG to N protein significantly differed over time (9–12 months from the onset of the disease) and were much higher in the group of immunocompetent individuals (p<0.001). Despite the presence of general patterns of post-infection antibody response formation, seroprevalence rates to SARS-CoV-2 and the duration of post-infection antibody persistence were slightly lower in the group of kidney recipients than in the group of liver recipients and in immunocompetent individuals. The immunological efficacy of vaccination (the proportion of individuals with post-vaccination antibodies) in the group of kidney recipients was significantly lower (p<0.001) than in the group of immunocompetent patients after both Sputnik V (68.0% and 98.8%, respectively) and Vero Cell (58.1% and 95.0%, respectively) immunization. In liver transplant recipients, there were no significant differences with immunocompetent individuals in terms of post-vaccination response. Conclusion. The data obtained indicate certain differences in characteristics of post-infection and post-vaccination antibody response due to patients' immune status. © 2022, Professionalnye Izdaniya. All rights reserved.
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BACKGROUND: This paper presents the results of studying the characteristics of the antibody response in kidney recipients who are at high risk of severe COVID-19. METHOD: The study of features of the formation of post-infectious anti-SARS-CoV-2 IgG was carried out in the group of kidney recipients (n = 171) with PCR confirmed diagnosis of COVID-19. Studies of the characteristics of post-vaccination immunity were carried out in a group of vaccinated recipients (n = 49) with Sputnik V (Russia) or Vero Cell (China). ELISA was used to detect IgG to S and N proteins of the SARS-CoV-2. Comparative studies used a simple randomized selection of immunocompetent COVID-19 patients (n = 163). Statistical data processing was carried out using the χ2 andWald's methods. RESULTS: It was found that 30 days after the onset of clinical symptoms of COVID- 19 in kidney recipients, IgG to S and/or N proteins of SARS-CoV-2 were detected in 89.5% (83.9%-93.3%) of them. The detection rate of IgG to the S protein was higher than that to the N protein [87.7% (81.9%-91.9%) and 62.0% (54.5%-68.9%), respectively). At the same time, the seroprevalence to the pathogen varied by age: in the 18-34-year-old group it was 77.7% (59.9%-88.9%), in the 50-64-year-old group it was 96.7% (88.2%-99.8%) and in the group >64 years old it was 80.0% (66.8%-89.0%). This trend of antibody production in older recipients correlated with the highest frequency of registration in them of moderate and severe forms [66.7% (56.4%-75.6%)]. Differences due to the severity of the disease were noted both in the frequency of detectable antibodies [80.3% (69.5%-88.0%) in recipients with a mild form of COVID-19 and 96.0% in recipients with a severe form of infection (P < .001)] and in the intensity of the formed anti-SARS-CoV-2 immunity. Thus, high values of PC (positivity coefficient) (>12) to S protein were recorded in 52.7% (39.8%-65.3%) and 63.2% (53.1%-72.2%) patients with mild and severe forms of COVID-19, respectively, which indicated a direct dependence of the production of antiviral antibodies on the severity of the infection. It was found that in 62.6% (55.1%-69.5%) of recovered recipients anti-SARS-CoV-2 IgG persisted for a period of 3 months from the onset of infection. In a significant proportion of recipients [42.8% (35.5%-50.2%)], antibodies were detected for up to 15 months. In general, the post-infectious antibody response in kidney recipients and immunocompetent patients had similar patterns of development. Despite the general mechanism of antibody production, in immunocompetent patients, the frequency of detection of antiviral antibodies (to N protein: 82.9% and to S protein: 91.2%), tension indicators. (high values of PC to N protein: 51.0% and to S protein: 75.5%) and the duration of retention (in 50.3% at 15 months of monitoring) were slightly higher than the same parameters in recipients with COVID-19. In kidney recipients after immunization with Sputnik V and Vero Cell (n = 34), a rather low detection rate of antiviral IgG [52.9% (36.7%-68.6%) compared with a similar parameter (P < .001) in vaccinated immunocompetent individuals [96.8% (94.8%-98.1%)] was found. The seroprevalence in the group of recipients with hybrid immunity (after illness and vaccination, n = 15) was 86.7% (60.9%-97.5%). In a comparative analysis of the intensity of post-vaccination immunity, high values of PC to S protein (>12) were recorded in 44.0% (26.7%-62.9%) of recipients vaccinated with Sputnik V and 50.0% (31.4%-68.6%) of recipients vaccinated with Vero Cell. The inverse relationship was observed in immunocompetent individuals: 64.7% (58.1%- 70.7%) for Sputnik V and 44.2% (36.8%-51.8%] for Vero Cell. CONCLUSION: The patterns of antibody response to the causative agent in recipients with COVID-19 are comparable to those in immunocompetent patients, while for vaccinated recipients, a low frequency of detection of antiviral antibodies was shown, which indicates the need to continue research on the humoral immunity in people with vulnerable immunity in order to select the best t ctics for COVID-19 immunization.
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Introduction. The coronavirus infection COVID-19 has been one of the main challenges for humanity in recent decades. The study of the possibility and development of technologies of using SARS-CoV-2 coronavirus macromolecules for the creation of diagnostic tools and vaccines on their basis is one of the priority areas of research today. Purpose. To obtain the complete SARS-CoV-2 nucleoprotein and polypeptides based on it, followed by the study of their antigenic properties and the possibility of using them as an antigenic component for serological kits for diagnostics of COVID-19. Materials and methods. The research design included the following: searching for antigenic determinants using the “Predicted antigenic peptides” service, obtaining the complete nucleoprotein of the SARS-CoV-2 coronavirus and its fragments using modern biotechnological methods, and testing their antigenic activity with ELISA. The source of the N gene was the genomic RNA of the SARS-CoV-2 coronavirus, isolated from a sample of the nasopharyngeal aspirate of a patient with COVID-19. The strains-producers of the target polypeptides were obtained on the base of the bacterial protein-synthesizing system Escherichia coli BL21 (DE3). The approbation of their antigenic activity was carried out using the blood sera, in which the presence or absence of antiviral antibodies was confirmed with the sets of reagents of “Diagnostic Systems” (Russia). Results. Analysis of the amino acid sequence, based on the primary structure of the protein, revealed 16 antigenic epitopes located in the N-protein. Nucleotide sequences corresponding to polypeptides with the antigenicity index of at least 1.0 units and characterized by a high degree of amino acid differences / substitutions, were expressed in E. coli cells. The antigenic activity of the recombinant polypeptides was tested by the efficiency of binding of candidate proteins and a sample of the known negative and positive (not containing and containing M and G antibodies to SARS-CoV-2 coronavirus, respectively) blood serum. In the study of 100% of the known positive samples in ELISA based on the created recombinant polypeptides, a positive result was obtained;and in the study of 100% of the known negative blood sera, a negative result was obtained. Conclusion. The obtained results indicate that the created polypeptides are promising as a base for the development of diagnostic kits for the detection of antiSARS-CoV-2 antibodies in the serum / plasma of patients with the ELISA method. © 2021, Professionalnye Izdaniya. All rights reserved.
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The presented work contains an analysis of seroprevalence, tension, and duration of post-vaccination immunity to the SARS-CoV-2 coronavirus in the residents of the Republic of Belarus after immunization with two vaccine preparations available in the country: Sputnik V and Vero Cell. It was found that seroconversion after the injection of the Vero Cell vaccine occurred significantly later than after the Sputnik V vaccine (p < 0.001). Nevertheless, two-stage immunization with the vaccines provided a sufficiently high efficiency of the inoculated antibodies to the S protein of the COVID-19 pathogen: the proportion of seropositive persons reached 99.19 [96.89;99.97] % for Sputnik V and 96.03 [90.81;98.53] % for Vero Cell. The efficiency of antibody formation after immunization with the Vero Cell vaccine was lower in older persons (in the group > 65 years). The proportion of individuals with the highest IgG score for the SARS-CoV-2 S protein was higher after the Sputnik V administration compared to that in response to the Vero Cell vaccine (p < 0.05), and gradually decreased over time. However, no significant decrease in the level of seropositive individuals after 90 days from the start of immunization with the both vaccine preparations was detected. In COVID-19 survivors immunized with the Sputnik V vaccine, the quantitative indicators of post-vaccination antibodies reached their peak values after 1 dose of the vaccine. The obtained results complement the accumulated world science and practical information on the problem of the post-vaccination immunity formation in the context of the use of different drugs against COVID-19.
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The presented work contains the analysis of a virus-specific antibody frequency in patients with COVID-19, the timing of their appearance and the kinetics of seroconversion. It was found that total antibodies to SARS-CoV-2 coronavirus were detected in 55.7 % and IgG - in 74.7 % of patients with laboratory-confirmed COVID-19 infection. Their frequency was significantly higher than that in patients of the other examined groups. During the first 6 days, the kinetics of seroconversion was characterized by the appearance of total antibodies and IgG in 10.5 and 5.3 % of patients with COVID-19, respectively. In most patients (71.4 %), seroconversion of IgM and IgG was registered from 7 to 11 days and 100 % of patients had total antibodies and IgG to SARS-CoV-2 after 22 days of disease. The presented results complement the data accumulated in different countries of the world regarding the formation of a humoral immune response in COVID-19. © 2020 Verlag Ferdinand Schoningh. All rights reserved.