Analysis of the IgG subclass profile and IgG sum-total discrepancy in COVID-19 convalescent plasma donors: A single-centre prospective cohort study.

INTRODUCTION: Although IgG1 and IgG3 have been shown to be the dominant subclasses in the acute phase of SARS-CoV-2 infection, little is known about the distribution of IgG subclasses during the recovery phase of COVID-19. The aim of the study was to analyze the profile of IgG subclasses in COVID-19 convalescent plasma donors. METHODS: A total of 36 convalescent plasma donors were included in the analysis. IgG and IgG subclass levels were measured using a nephelometric assay in plasma samples obtained directly from the plasma container. RESULTS: Although there was no significant difference in the concentration of IgG subclasses between the study and control groups, the contribution of IgG1 to the total IgG pool between the study and control groups was statistically significant (p = 0.0478). In addition, there was a discrepancy between the total IgG and IgG sum values in the study group, exceeding 15 % in 19,4 % of samples (n = 7), while in the control group no samples with a sum/ total IgG difference > 15 % were observed. CONCLUSIONS: The selective affinity of the IgG1 subclass for the polyclonal anti-IgG reagent may interfere with the determination of total IgG and should be considered when interpreting the results of enzyme immunoassays DATA AVAILABILITY: The data that support the findings of this study are available on request from the corresponding author.

The Impact of Pathogen Reduction on Total IgG and IgG Subclass Profiles of Convalescent Plasma.

Introduction: In case of newly emerging pathogens, convalescent plasma (CP) is often the only early available treatment option. It has been shown that different IgG subclasses contribute differently to CP neutralizing activity. As CP donors often have a risk profile like first-time donors, especially with respect to window-period viral transmission, pathogen reduction (PR) could mitigate that risk. The aim of our study, especially in the light of potential future pandemics, was to evaluate the impact of commercially available PR technologies on total IgG and IgG subclasses quantity and distribution in CP using COVID-19 CP (CCP) as surrogate for CP in a side-by-side comparison approach. Methods: 36 apheresis CCP donations were allocated to three study groups and a side-by-side assessment of the potential impact of amotosalen (AS)/UVA treatment compared to a riboflavin (RB)/UVB treatment, AS against methylene blue (MB) treatment, and RB against MB treatment on the quantity of IgG and IgG subclasses with a nephelometric analyzer was performed. Results: IgG subclass distributions were not significantly changed post PR treatment with all three technologies. There was also no significant difference in the median loss of concentration for IgG1 and IgG2 between the three technologies. We recognized a non-significant trend of a higher IgG4 median loss post RB treatment compared to post AS and MB treatment, respectively. Conclusion: Although the three commercially available PR systems do not significantly alter the distribution of IgG subclasses, we detected a non-significant trend of higher IgG4 loss after RB treatment. The potential impact of that finding needs further investigation.

Maintaining plasma quality and safety in the state of ongoing epidemic - The role of pathogen reduction.

In the field of transfusion medicine, many pathogen reduction techniques (PRTs) are currently available, including those based on photochemical (PI) and photodynamic inactivation (PDI). This is particularly important in the face of emerging viral pathogens that may pose a threat to blood recipients, as in the case of the COVID-19 pandemic. However, PRTs have some limitations, primarily related to their adverse effects on coagulation factors, which should be considered before their intended use. A comprehensive search of PubMed, Wiley Online Library and Science Direct databases was conducted to identify original papers. As a result, ten studies evaluating fresh plasma and frozen-thawed plasma treated with different PI/ PDI methods and evaluating concentrations of coagulation factors and natural anticoagulants both before and after photochemical treatment were included in the review. The use of PI and PDI is associated with a significant decrease in the activity of all analysed coagulation factors, while the recovery of natural anticoagulants remains at a satisfactory level, variable for individual inactivation methods. In addition, the published evidence reviewed above does not unequivocally favour the implementation of PI/PDI either before freezing or after thawing as plasma products obtained with these two approaches seem to satisfy the existing quality criteria. Based on current evidence, if implemented responsibly and in accordance with the current guidelines, both PI and PDI can ensure satisfactory plasma quality and improve its safety.

No increase in anti-A isohemagglutinin titer after SARS-CoV-2 infection: A retrospective cohort analysis of group O apheresis platelet donors.

The risk of a hemolytic reaction during the transfusion of ABO non-identical PC is determined by the presence of natural anti-A IgM antibodies, the titer of which may increase after infections. The aim of the study was to evaluate the titer of anti-A isohemagglutinins in platelet concentrate (PC) obtained by apheresis from group O donors who experienced SARS-CoV-2 infection, and to compare the titer before and after infection. A retrospective single-center analysis of 21 PC donors with a previous COVID-19 history was performed. The results showed neither a statistically important increase in the anti-A IgM antibody titers nor a significant correlation between the anti-A IgM antibody level and anti-SARS-CoV-2S1 antibody titer in the donors with an asymptomatic or mild COVID-19. Further population-based studies on anti-A titers are necessary for a comprehensive assessment of this phenomenon.

High-frequency (13.56-MHz) and ultrahigh-frequency (915-MHz) radio identification systems do not affect platelet activation and functions.

BACKGROUND: In radiofrequency identification (RFID) systems used in labeling of blood components, blood cells are subjected to the direct influence of electromagnetic waves throughout the storage period. The aim of this study was to prove the safety of storage of platelet concentrates (PCs) in containers labeled with RFID tags. STUDY DESIGN AND METHODS: Ten pooled PCs obtained from 12 buffy coats each suspended in additive solution were divided into three separate containers that were assigned to three groups: control, PCs labeled with ultrahigh frequency (UHF) range tags and exposed to 915-MHz radio waves, and PCs labeled with high-frequency (HF) range tags and exposed to 13.56-MHz radio waves. PCs were stored at 20 to 24°C for 7 days. In vitro tests of platelet (PLT) function were performed on the first, fifth, and seventh days of storage. RESULTS: There were no significant differences in pH; hypotonic shock resistance; surface expression of CD62P, CD42a, or CD63; release of PLT-derived microparticles; PLT aggregation; and number of PLTs between PCs stored at a constant exposure to radio waves of two different frequencies and the control group on the first, fifth, and seventh days of storage. CONCLUSION: The results of the study indicate no impact of electromagnetic radiation generated in HF and UHF RFID systems and constant contact with the tags on the quality of stored PCs.

Ozonation of Whole Blood Results in an Increased Release of Microparticles from Blood Cells.

Autohemotherapy with ozonated blood is used in the treatment of a broad spectrum of clinical disorders. Ozone demonstrates strong oxidizing properties and causes damage to cell membranes. The impact of whole-blood ozonation on the release of microparticles from blood and endothelial cells and the concentration of selected markers in the hemostatic system (APTT, PT, D-dimer, fibrinogen) were investigated. Venous blood, obtained from 19 healthy men, was split into four equal parts and treated with air, 15 µg/mL ozone, or 30 µg/mL ozone, or left untreated. The number and types of microparticles released were determined using flow cytometry on the basis of surface antigen expression: erythrocyte-derived microparticles (CD235+), platelet-derived microparticles (CD42+), leukocyte-derived microparticles (CD45+), and endothelial-derived microparticles (CD144+). The study is the first to demonstrate that ozone induces a statistically significant increase in the number of microparticles derived from blood and endothelial cells. Although statistically significant, the changes in some coagulation factors were somewhat mild and did not exceed normal values.

A 63-Year-Old Woman with SARS-CoV-2 Infection, Who Developed Severe COVID-19 Pneumonia and Was Supported with Convalescent Plasma Therapy.

BACKGROUND There is no evidence-based treatment for coronavirus disease 2019 (COVID-19). We report the case of a 63-year-old woman with SARS-CoV-2 infection who developed severe COVID-19 pneumonia and was treated with convalescent plasma. CASE REPORT A 63-year-old woman who presented with severe and prolonged course of COVID-19 disease (fever up to 39.4°C, persistent cough, and dyspnea) received a convalescent plasma transfusion, which led to complete recovery. The diagnosis was confirmed by RT-PCR testing using the CFX96 Real-Time System (Bio-Rad, USA) from nasopharyngeal swabs. In laboratory tests, an increase in acute-phase parameters was observed. Chest computed tomography (CT) showed abnormalities typical for COVID-19. On days 9 and 11 of the disease, she received the convalescent plasma prepared from a single plasmapheresis donation from a male donor. This male donor was qualified as a convalescent plasma donor according to Polish guidelines, which are compliant with European guidelines. He donated plasma at the Regional Centre for Transfusion Medicine in Bialystok, Poland. The therapy with convalescent plasma led to clinical improvement and normalization of inflammatory parameters. CONCLUSIONS This report presents a case of severe COVID-19 pneumonia in a 63-year-old woman who was given supportive treatment with convalescent plasma. Ongoing clinical trials will determine whether convalescent plasma therapy is an effective treatment for SARS-CoV-2 infection.

[Tissue factor (TF) and inhibitor (TFPI) concentrations in patients with urinary tract tumors and haematological malignancies]. / Stezenie czynnika tkankowego i jego inhibitora u chorych na guzy ukladu moczowego i choroby rozrostowe ukladu krwiotwórczego.

The aim of study was to evaluate TF activity and TFPI concentration in patients with haematological malignancies and urinary tract tumors. TFPI concentration and activity and TF concentration were measured in 20 patients suffering from acute myeloblastic leukaemia (AML), 21 patients with chronic myelogenous leukaemia (CML), 17 patients with chronic lymphatic leukaemia (CLL), 16 patients with multiple myeloma (MM) and 65 healthy adults. TFPI and TF concentrations were measured also in patients with renal cell carcinoma (n = 12) and bladder cancer (n = 17) and patients with benign prostatic hyperplasia (BPH) (n = 15). Patients with AML, CML, CLL, and cancer revealed elevated TFPI concentrations. Patients with AML, CML, CLL, MM showed decreased TFPI activity. However TFPI concentration correlated inversely with TFPI activity only in the AML group. No significant changes were observed in TF concentrations in all investigated groups.