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.

Efficacy of intravitreal injections of melphalan in the treatment of retinoblastoma vitreous seeding.

BACKGROUND: The introduction of intravitreal injections of melphalan (IVIM) has significantly improved the efficacy of retinoblastoma treatment and the prognosis for eye preservation. OBJECTIVES: To evaluate the results of using IVIM to treat retinoblastoma vitreous seeding. MATERIAL AND METHODS: This was a clinical, retrospective, single-center study. Twenty-six children (27 eyes) who met all of the following inclusion criteria qualified for the study: 1) active vitreous seeding at the time of retinoblastoma diagnosis; 2) IVIM performed between 1 January 2017 and 30 September 2020; and 3) a minimum follow-up period of 12 months since the last IVIM. Doses of 20-40 µg melphalan per injection were used. RESULTS: The eye observation period from the last IVIM to the last ophthalmic examination averaged 32.41 months (median 30.00; range 13.00-56.00). Success (no active tumors in the vitreous body) was achieved in 24 eyes (88.9%), and a doubtful result (recurrence in the retina with a difficult-to-determine etiology) in 2 eyes (7.4%). In 1 eye (3.7%), despite treatment, active tumors were still present in the vitreous body. Out of all 27 eyes, 4 eyeballs were removed, but the direct cause of enucleation was not vitreous seeding. There were no complications in the form of intraocular inflammation, extraocular retinoblastoma or distant metastases. There was 1 case of anterior uveitis and 1 case of cataract. CONCLUSIONS: The IVIM is a highly effective and safe form of treatment for retinoblastoma vitreous seeding.

Investigation of anthropogenic gadolinium in tap water of polish cities: Gdansk, Kraków, Warszawa, and Wroclaw.

In urban areas where tap water is often produced by a purification of water supplied from a river bank filtration, a significant fraction of gadolinium (Gd) total pool is of an anthropogenic origin. It happens because Gd-based contrast agents used in Magnetic Resonance Imaging (MRI) are not removed during wastewater treatment and they are discharged to the environment and returned to the water cycle. Despite the growing number of MRI examinations worldwide, little is known about the anthropogenic Gd in Polish surface water as well as drinking water. The aim of this pilot study was to gain information about the occurrence of emergent pollution as Gd in potable water available for inhabitants of Polish municipal areas. Tap water samples from Gdansk, Kraków, Wroclaw and Warszawa were analyzed by an inductively coupled plasma quadrupole mass spectrometry after their preconcentration by a seaFAST-pico chromatographic system. In this study, the sum of REE was in the range registered in the drinking waters of European urban regions (usually below 100 ng/L). The highest values of the sum of REE total concentrations were observed in the tap water samples collected in Warszawa (37.7 ng/L) and Wroclaw (35.9 ng/L and 32.9 ng/L), where water supplies originate from the Wisla River and Olawa River, respectively. The highest total Gd concentration was observed in the tap water of Warszawa city where the anthropogenic Gd fraction represented about 90% of the total Gd. The lowest values of the sum REE were registered in tap waters of Gdansk (sum of REE below 2.2 ng/L) with up to 17% of the anthropogenic Gd. Thus, our study showed the occurrence of the anthropogenic Gd in all analyzed tap waters.

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.

[Quality of buffy-coat-derived platelet concentrates prepared using automated system terumo automated centrifuge and separator integration (TACSI)]. / Ocena jakosci koncentratów plytek krwi otrzymanych z utyciem automatycznego systemu Terumo automated centrifuge and separator integration (TACSI).

UNLABELLED: Platelet recovery, and viability, and function is strongly dependent on the method of the preparation of platelet concentrate (PC). The glucose consumption, decrease of pH, release of alpha granules during storage in platelet concentrate impair their clinical effectiveness. THE AIM OF STUDY: To compare of the quality of buffy-coat-derieved platelet concentrates prepared using automatic system terumo automated centrifuge and separator integration (TACSI) and stored over 7 days. MATERIAL AND METHODS: PCs were prepared from buffy coats using manual method (group I), or automatic system TACSI (group II). Fifteen PCs prepared from the 5 buffy coats each were stored over 7 days in 22-24 degrees C and tested. Samples were taken from the PCs container on days 1 and 7. The following laboratory tests were performed: number of platelets, platelets derived microparticles, CD62P expression, platelet adhesion, pH, glucose, lactate dehydrogenase activity. RESULTS: We have observed higher expression of CD62P in PCs prepared using manual method compared to the PCs produced automatically Platelet recovery was significantly higher in PCs prepared using automatic systems compare to manual method. CONCLUSION: Compared to manual methods, automatic system for preparation of buffy coats, is more efficient and enable production of platelets concentrates of higher quality.

Mapping of the Covid-19 Vaccine Uptake Determinants From Mining Twitter Data.

Opinion polls on vaccine uptake clearly show that Covid-19 vaccine hesitancy is increasing worldwide. Thus, reaching herd immunity not only depends on the efficacy of the vaccine itself, but also on overcoming this hesitancy of uptake in the population. In this study, we revealed the determinants regarding vaccination directly from people's opinions on Twitter, based on the framework of the 6As taxonomy. Covid-19 vaccine acceptance depends mostly on the characteristics of new vaccines (i.e. their safety, side effects, effectiveness, etc.), and the national vaccination strategy (i.e. immunization schedules, quantities of vaccination points and their localization, etc.), which should focus on increasing citizens' awareness, among various other factors. The results of this study point to areas for potentially improving mass campaigns of Covid-19 immunization to increase vaccine uptake and its coverage and also provide insight into possible directions of future research.

Remodeling of Retinal Microcirculation Is Associated With Subclinical Arterial Injury in Hypertensive Children.

[Figure: see text].

Coexistence of bilateral macular edema and pale optic disc in the patient with Cohen syndrome.

BACKGROUND: Cohen syndrome (Q87.8;ORPHA:193; OMIM#216550) is an autosomal recessive inherited genetic disorder caused by mutation in the VPS13B/COH1 gene. It is characterized by variable clinical symptoms such as deformity of the head, face, hands and feet, eye abnormalities, abdominal obesity, neutropenia and nonprogressive intellectual disability. The typical lesions in the eyeball in Cohen syndrome include high myopia, retinal dystrophy, strabismus, maculopathy and lens subluxation. The present study describes the coexistence of bilateral macular edema with pale optic disc in a patient with a homozygous deletion in the VPS13B/COH1 gene. MATERIAL AND METHODS: A 6-year-old Caucasian girl with facial dysmorphism, microcephaly, prominent upper incisors, narrow hands with slender fingers, congenital heart defect and ophthalmic symptoms was subjected to genetic testing. The genetic evaluation revealed a homozygous deletion on the long arm of chromosome 8 encompassing 20-25 exons of the VPS13 gene, as confirmed by Cohen syndrome. She underwent a full ophthalmological examination with the assessment of slit lamp examination of anterior segment and fundoscopy, refraction error, biometry, central corneal thickness and additionally electroretinography, optical coherence tomography and fundus photography. RESULTS: In the ophthalmologic examination, the girl had bilateral astigmatism accompanied by myopia and a marked reduction in central corneal thickness. Fundus examination showed pale optic nerve discs and "salt and pepper" retinopathy. Bilateral cystic macular edema was revealed in handheld optical coherence tomography. Electroretinography showed a reduced response amplitude of cones and rods. CONCLUSION: In a patient with high myopia, macular edema, pale optic disc and facial dysmorphism, Cohen syndrome should be considered in the differential diagnosis. The severity of individual clinical features in patients with Cohen syndrome varies. It can be assumed that the type of mutation affects the occurrence and severity of individual symptoms.