The impact of different pathogen reduction technologies on total IgG and subclass profiles of COVID-19 convalescent plasma

Background: COVID-19 convalescent plasma (CCP) was shown to reduce disease progression if high-titre CCP is administered in early infection. CCP donors have a risk profile like first time donors, especially with respect to window-period viral transmissions. Pathogen reduction (PR) could mitigate that risk, but may have impact on quality and quantity of plasma proteins, including neutralizing antibodies. It has been shown that different IgG subclasses contribute differently to CCP neutralizing activity, raising the question of a potential impact of PR on different IgG subclasses. Aims: Side-by-side comparison of the impact of 3 commercially available PR technologies on total IgG and subclasses quantity and subclass distribution in CCP. Methods: 36 apheresis CCP donations collected with a MCS+ 9000 plasmapheresis device (Haemonetics S.A., Switzerland), or DigiPla 80 (Sichuan Nigale Biomed, China) plasmapheresis device (650-750 ml) were allocated to 3 study groups with 12 units respectively. The impact of amotosalen/UVA (AS)-treatment (INTERCEPT Blood System, Cerus) against Riboflavin UVB (RB) (Mirasol Pathogen Reduction System, Terumo BCT), AS against Methylene Blue (MB) (Theraflex MB, Macopharma) and RB against MB on the quantity and distribution of IgG and subclasses was assessed in a side-by-side comparison study with a nephelometric analyser (BN II System, Siemens Healthcare). PRtreatment was conducted immediately post collection. All samples for analysis were frozen within 6 h post collection and stored at -75°C until testing. All samples were analysed simultaneously with the same device, the same lot of reagents and the same operator. Results: IgG subclass distributions were not significantly changed post PR-treatment with all 3 technologies (p > 0.05). There was also no significant difference in the median loss of concentration for IgG1 and IgG2 between the three technologies (p > 0.05). The median loss (%) of IgG3 (2.1 and 2.6-fold compared to AS and MBtreatment respectively, p < 0.01) and IgG4 (1.6 and 5.9-fold compared to AS and MB-treatment respectively, p < 0.01) post RBtreatment was significantly higher. The median loss (%) of IgG4 post AS-treatment was significantly higher compared to MB-treatment (3.5-fold, p < 0.01). Summary/Conclusions: The 3 commercially available PR systems do not significantly change the IgG subclass distribution, but impact differently IgG3 and IgG4 post-treatment loss. It was reported that IgG1 and IgG3 play an important role in neutralization, which should be considered when planning PR-treatment for CCP. .

Blood transfusion in COVID-19 hospital

Background: The novel coronavirus disease 2019 (COVID-19) has caused a sudden and unexpected rise in hospitalizations and deaths around the world. Many hospitals have changed their daily work and become infectious. A reduction in blood collection of 10 to 50% has been reported. In Russia, in 2020, compared to 2019, blood collection decreased by 4%. Data on the use of blood products by patients with COVID-19 is very limited and highly variable. According to various sources, from 3.3 to 13.4% of patients with COVID-19 need a blood transfusion. In different hospitals transferred to the COVID-19 mode, blood transfusion changes in different ways: somewhere it increases, and somewhere it decreases. Aims: To identify the features of transfusion therapy in the COVID- 19 hospital of the Pirogov Center. Methods: We studied the structure of recipients and blood transfusions in the COVID-19 hospital and other departments of the Pirogov Center in 2020. We transfused leucodepleted red blood cells in PAGGS-M, leucodepleted amotosalen/UVA pathogen inactivated platelets in SSP+ and methylene blue/white light pathogen inactivated male plasma. No COVID-19 convalescent plasma has been transfused. Results: Among the 1141 patients of the COVID-19 hospital, 61 patients (5.3%) and among 37,136 patients in other departments, 710 (1.9%) patients received transfusions of blood components. During the operation of the COVID-19 hospital, the Pirogov Center's need for donor blood components was fully met. In the COVID-19 hospital compared to other departments: • the part of recipients of all blood components, red blood cells and plasma was higher (p < 0.01);• 4 units and 4-6 units of red blood cells were transfused more often (p < 0.01), more than 11 units of red blood cells were not transfused;• among recipients of red blood cells, the part of people over 60 years old is 42.4% higher than the same part among other patients (p < 0.01);• among plasma recipients, the part of persons under 45 years of age is significantly reduced (p < 0.05). Red blood cells transfusion helped to save most of the most severe patients: • over 70 years old, • anaemia on admission, • the period of D-dimer concentration over 1.5 mg/l-more than 20 days, • concomitant oncological diseases-in 20% of patients. Among patients with new coronavirus infection and no indication for red blood cell transfusion, haemoglobin concentration negatively correlates with age and D-dimer level. The absence of such connections in red blood cells recipients indicates the importance of other factors (oncological process, bleeding) in the development of anaemia that requires transfusion correction. Summary/Conclusions: The data on the needs of patients in the COVID-19 hospital for transfusion therapy can be used as a benchmark for the related work planning.

Inactivation of SARS-CoV-2 in All Blood Components Using Amotosalen/Ultraviolet A Light and Amustaline/Glutathione Pathogen Reduction Technologies.

No cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transfusion-transmitted infections (TTI) have been reported. The detection of viral RNA in peripheral blood from infected patients and blood components from infected asymptomatic blood donors is, however, concerning. This study investigated the efficacy of the amotosalen/UVA light (A/UVA) and amustaline (S-303)/glutathione (GSH) pathogen reduction technologies (PRT) to inactivate SARS-CoV-2 in plasma and platelet concentrates (PC), or red blood cells (RBC), respectively. Plasma, PC prepared in platelet additive solution (PC-PAS) or 100% plasma (PC-100), and RBC prepared in AS-1 additive solution were spiked with SARS-CoV-2 and PR treated. Infectious viral titers were determined by plaque assay and log reduction factors (LRF) were determined by comparing titers before and after treatment. PR treatment of SARS-CoV-2-contaminated blood components resulted in inactivation of the infectious virus to the limit of detection with A/UVA LRF of >3.3 for plasma, >3.2 for PC-PAS-plasma, and >3.5 for PC-plasma and S-303/GSH LRF > 4.2 for RBC. These data confirm the susceptibility of coronaviruses, including SARS-CoV-2 to A/UVA treatment. This study demonstrates the effectiveness of the S-303/GSH treatment to inactivate SARS-CoV-2, and that PRT can reduce the risk of SARS-CoV-2 TTI in all blood components.

Efficient inactivation of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in human apheresis platelet concentrates with amotosalen and ultraviolet A light.

OBJECTIVES: The detection of SARS-CoV-2 RNA in blood and platelet concentrates from asymptomatic donors, and the detection of viral particles on the surface and inside platelets during in vitro experiments, raised concerns over the potential risk for transfusion-transmitted-infection (TTI). The objective of this study was to assess the efficacy of the amotosalen/UVA pathogen reduction technology for SARS-CoV-2 in human platelet concentrates to mitigate such potential risk. MATERIAL AND METHODS: Five apheresis platelet units in 100% plasma were spiked with a clinical SARS-CoV-2 isolate followed by treatment with amotosalen/UVA (INTERCEPT Blood System), pre- and posttreatment samples were collected as well as untreated positive and negative controls. The infectious viral titer was assessed by plaque assay and the genomic titer by quantitative RT-PCR. To exclude the presence of infectious particles post-pathogen reduction treatment below the limit of detection, three consecutive rounds of passaging on permissive cell lines were conducted. RESULTS: SARS-CoV-2 in platelet concentrates was inactivated with amotosalen/UVA below the limit of detection with a mean log reduction of>3.31±0.23. During three consecutive rounds of passaging, no viral replication was detected. Pathogen reduction treatment also inhibited nucleic acid detection with a log reduction of>4.46±0.51 PFU equivalents. CONCLUSION: SARS-CoV-2 was efficiently inactivated in platelet concentrates by amotosalen/UVA treatment. These results are in line with previous inactivation data for SARS-CoV-2 in plasma as well as MERS-CoV and SARS-CoV-1 in platelets and plasma, demonstrating efficient inactivation of human coronaviruses.

Amotosalen and ultraviolet A light treatment efficiently inactivates severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human plasma.

BACKGROUND AND OBJECTIVES: During the ongoing pandemic of COVID-19, SARS-CoV-2 RNA was detected in plasma and platelet products from asymptomatic blood donors, raising concerns about potential risk of transfusion transmission, also in the context of the current therapeutic approach utilizing plasma from convalescent donors. The objective of this study was to assess the efficacy of amotosalen/UVA light treatment to inactivate SARS-CoV-2 in human plasma to reduce the risk of potential transmission through blood transfusion. METHODS: Pools of three whole-blood-derived human plasma units (630-650 ml) were inoculated with a clinical SARS-CoV-2 isolate. Spiked units were treated with amotosalen/UVA light (INTERCEPT Blood System™) to inactivate SARS-CoV-2. Infectious titres and genomic viral load were assessed by plaque assay and real-time quantitative PCR. Inactivated samples were subject to three successive passages on permissive tissue culture to exclude the presence of replication-competent viral particles. RESULTS: Inactivation of infectious viral particles in spiked plasma units below the limit of detection was achieved by amotosalen/UVA light treatment with a mean log reduction of >3·32 ± 0·2. Passaging of inactivated samples on permissive tissue showed no viral replication even after 9 days of incubation and three passages, confirming complete inactivation. The treatment also inhibited NAT detection by nucleic acid modification with a mean log reduction of 2·92 ± 0·87 PFU genomic equivalents. CONCLUSION: Amotosalen/UVA light treatment of SARS-CoV-2 spiked human plasma units efficiently and completely inactivated >3·32 ± 0·2 log of SARS-CoV-2 infectivity, showing that such treatment could minimize the risk of transfusion-related SARS-CoV-2 transmission.

Impact of pathogen reduction methods on immunological properties of the COVID-19 convalescent plasma.

BACKGROUND AND OBJECTIVES: COVID-19 convalescent plasma is an experimental treatment against SARS-CoV-2. The aim of this study is to assess the impact of different pathogen reduction methods on the levels and virus neutralizing activity of the specific antibodies against SARS-CoV2 in convalescent plasma. MATERIALS AND METHODS: A total of 140 plasma doses collected by plasmapheresis from COVID-19 convalescent donors were subjected to pathogen reduction by three methods: methylene blue (M)/visible light, riboflavin (R)/UVB and amotosalen (A)/UVA. To conduct a paired comparison, individual plasma doses were divided into 2 samples that were subjected to one of these methods. The titres of SARS-CoV2 neutralizing antibodies (NtAbs) and levels of specific immunoglobulins to RBD, S- and N-proteins of SARS-CoV-2 were measured before and after pathogen reduction. RESULTS: The methods reduced NtAbs titres differently: among units with the initial titre 80 or above, 81% of units remained unchanged and 19% decreased by one step after methylene blue; 60% were unchanged and 40% decreased by one step after amotosalen; after riboflavin 43% were unchanged and 50% (7%, respectively) had a one-step (two-step, respectively) decrease. Paired two-sample comparisons (M vs. A, M vs. R and A vs. R) revealed that the largest statistically significant decrease in quantity and activity of the specific antibodies resulted from the riboflavin treatment. CONCLUSION: Pathogen reduction with methylene blue or with amotosalen provides the greater likelihood of preserving the immunological properties of the COVID-19 convalescent plasma compared to riboflavin.