Medicinal IgG products (2020) show high infectivity neutralizing activity against seasonal influenza virus strains selected for future vaccines (2020-22)

Immunoglobulin (Ig)G medicinal products manufactured in 2020 were tested for infectivity neutralization and hemagglutination inhibition against World Health Organization-selected influenza strains included in worldwide vaccines 2020–2022. The IgG batches (from US plasma) showed potent activity. Intravenous immunoglobulin could potentially add to therapies for serious influenza cases in immunocompromised patients. Further study is warranted.

Effective presence of antibodies against common human coronavirus in IgG immunoglobulin medicinal products.: Antibodies to common coronaviruses in IgG medicinal products

BACKGROUND

In these studies, immunoglobulin (IgG) products (IV, IM, SC) prepared from geographically diverse plasma pools were tested for activity against common human coronaviruses (HCoV). Products from plasma obtained from Germany, Czech Republic, Slovak Republic, USA, and Spain were tested for antibodies to common HCoV: 229E, OC43, NL63, and HKU1. Since these products are manufactured from pooled plasma from thousands of donors, the antibodies therein are representative of HCoV exposure in the population at large.

METHODS

IgG products were tested for antibodies to four common HCoV by ELISA. Neutralization assays were conducted using HCoV-229E cultured onto MRC5 cells.

RESULTS

The ELISA assays showed that when expressed as specific activity (anti-HCoV activity/mg IgG) similar activity against the four common HCoV was seen across the IgG products regardless of concentration or geographic origin. Highest anti-HCoV activity was seen against HCoV-229E, followed by HCoV-OC43, and then HCoV-NL63 and HCoV-HKU1. The neutralization assays showed similar potency for two preparations of IgG prepared by different processes.

CONCLUSIONS

This is the first demonstration of antibodies to common HCoV in IgG products. These results may explain the cross-reactivity seen with pre-pandemic IgG products and SARS-CoV-2 and contribute to the variability in disease course in different patients.

Anti-SARS-CoV-2 hyperimmune globulin demonstrates potent neutralization and antibody-dependent cellular cytotoxicity and phagocytosis through N and S proteins

Background

Although coronavirus disease 2019 (COVID-19) vaccinations have provided a significant reduction in infections, effective COVID-19 treatments remain an urgent need.

Methods

Functional characterization of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) hyperimmune immunoglobulin (hIG) from human convalescent plasma was performed by different virus neutralization methodologies (plaque reduction, virus-induced cytotoxicity, median tissue culture infectious dose [TCID₅₀] reduction, and immunofluorimetry) at different laboratories using geographically different SARS-CoV-2 isolates (USA [1], Italy [1], and Spain [2]; 2 containing the D614G mutation). Neutralization capacity against the original Wuhan SARS-CoV-2 strain and variants (D614G mutant, B.1.1.7, P.1, and B.1.351) was evaluated using a pseudovirus expressing the corresponding spike (S) protein. Antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) was also evaluated.

Results

All SARS-CoV-2 isolates were potently neutralized by hIG as shown by all 4 methodologies. Wild-type SARS-CoV-2 and variants were effectively neutralized using the pseudovirus. The hIG (IgG type) induced ADCC and ADCP against SARS-CoV-2 N and S proteins but not E protein. Very low concentrations (25–100 µg IgG/mL) were required. A potent effect was triggered by antibodies in hIG solutions against the SARS-CoV-2 S and N proteins.

Conclusions

Beyond neutralization, IgG Fc-dependent pathways may play a role in combatting SARS-CoV-2 infections using COVID-19 hIG. This could be especially relevant for the treatment of more neutralization-resistant SARS-CoV-2 variants.

Cross-neutralization activity against SARS-CoV-2 is present in currently available intravenous immunoglobulins

Background: Cross-reactivity against human coronaviruses with Flebogamma® DIF and Gamunex®-C, two available intravenous immunoglobulins (IVIG), has been reported. In this study, these IVIG were tested for neutralization activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), SARS-CoV and Middle East respiratory syndrome CoV (MERS-CoV). Materials & methods: Neutralization capacity of lots of IVIG manufactured prior to COVID-19 pandemic was assessed against these viruses in cell culture. Infectivity neutralization was quantified by percent reduction in plaque-forming units and/or cytopathic/cytotoxic methods. Results: All IVIG preparations showed neutralization of SARS-CoV-2 isolates. All IVIG lots produced neutralization of SARS-CoV. No IVIG preparation showed significant neutralizing activity against MERS-CoV. Conclusion: The tested IVIG contain antibodies with significant in vitro cross-neutralization capacity against SARS-CoV-2 and SARS-CoV, but not MERS-CoV. These preparations are currently under evaluation as potential therapies for COVID-19.

Human mesenchymal stem cells maintain their phenotype, multipotentiality, and genetic stability when cultured using a defined xeno-free human plasma fraction

Background

Mesenchymal stem cells (MSCs) show promising characteristics for their use in advanced therapy medicinal products. However, there are some unresolved concerns, such as the use of animal components for their expansion.

In this study we assessed the suitability of a xeno-free supplement for cell culture (SCC) derived from human plasma, to culture and expand human MSCs (hMSCs) from different origins. Characteristics of viable cultured hMSCs such as genetic stability, phenotype and multipotentiality were qualitatively evaluated.

Methods

hMSCs from adipose tissue (AT), bone marrow (BM) and umbilical cord (UC) and supplier sources (commercial/non-commercial) were used. After hMSCs expansion in a xeno-free medium, classical hMSCs markers were studied by immunocytochemistry, and genetic stability was tested by classic karyotyping. The capacity of hMSCs to differentiate into adipogenic, osteogenic, and chondrogenic cells in differentiation media was assessed using different staining. Different lots of SCC were used to assure consistency between batches.

Results

All hMSCs tested maintained their morphology and adherence to plastic during their expansion, and preserved their genetic stability, phenotype and differentiation potential. No differences were observed when using different lots of SCC. Moreover, the proliferation rate, evaluated as population doubling time (PDT) of commercial BM and AT hMSCs, was higher in the xeno-free medium than in the control media provided by the suppliers of the cells (PDT of 4.6 for BM-hMSC and 6.4 for AT-hMSC in xeno-free medium, and 7.0 and 14.7 respectively in the commercial media). UC-hMSCs PDT was similar in all the media tested. When using non-commercial BM-hMSCs, PDT was lower in the xeno-free medium, but reverted to the control level with the addition of growth factors.

Conclusions

SCC-containing medium can be a feasible xeno-free alternative to expand hMSCs for advanced therapies.

Non isotopic automatable molecular procedures for the detection of enteroviruses

Five microwell non isotopic hybridization assays, based on colorimetric immunoenzymatic reading, were developed and evaluated for the rapid and automatable detection of enteroviruses. Virus nucleic acids and/or capture probes were covalently bound to microtiter wells, and digoxigenin-11-dUTP was used as label for the detection of hybridized material. Among these procedures, a reverse transcriptase polymerase chain reaction (RT-PCR) hybridization assay was the most sensitive, enabling the detection of 10 MPNCU of poliovirus, and offering detection specificity for other enteroviruses, such as coxsackieviruses and echoviruses. The second most sensitive method was a complementary hybridization assay, simultaneously using three detection probes, one from the 5' end and two from the 3' end of poliovirus genome, offering a sensitivity for poliovirus detection of 5 x 10(3) MPNCU.

[Pseudosarcomatous tumor of the bladder]

Pseudosarcomatous tumour of the bladder is a benign neoforming process of uncommon occurrence, consisting in a fibroblastic proliferation originated in the vesical wall and the perivesical fat, with unknown etiology, that given its cellular pleomorphism and the infiltrative nature of the injury can be incorrectly diagnosed as a sarcoma. This paper presents one case of pseudosarcomatous tumour of the bladder in a 9 year-old child, with no history of local traumatism or previous surgery, consisting in a tumoration affecting the vesical wall associated with a significant perivesical fibrosis with extension towards the area of the iliac veasels. Microscopically, the injury shows proliferation of spindle cells, arranged in a myxoid stroma with a prominent vascular net. No cytologic atypia is demonstrated or increase in the number of mitosis. The immunohistochemical study shows features of myofibroblasts in the proliferant cell. A review of the literature is made on 40 cases of inflammatory pseudosarcoma, evaluating the clinical characteristics, morphologic findings and treatment involved, as well as the postoperative evolution of the patient.

Adsorption-elution with negatively and positively-charged glass powder for the concentration of hepatitis A virus from water

Two methods based on virus adsorption and elution from glass powder were developed for the concentration of hepatitis A virus (HAV) from large volumes of water. The cytopathogenic pHM-175 strain of HAV was used to test these procedures in tap water, fresh water, sea water and raw sewage. HAV was quantitated by a plaque assay in the FRhK-4 cell line. HAV was concentrated by glass powder adsorption-elution from 20-liter samples with satisfactory efficiencies in all types of water: 100% for tap water, 80% for freshwater, 75% for sea water and 61% for sewage. The charge of glass powder was modified by polyethylenimine treatment to avoid the need to pretreat the sample. Concentration efficiencies of HAV in 20-1 samples through adsorption to and elution from positively-charged glass powder were 100% for tap water, 94% for sea water, and 61% for fresh water and sewage. Both methods were used for the detection of wild-type HAV in raw sewage. Wild-type HAV in concentrated sewage samples was detected by molecular hybridization with a digoxigenin-labelled cDNA probe.

The effect of estrogens on serum ferritin levels in duck

Serum and tissue ferritin content is measured in duck by a RIA method before and after treatment with estrogens, as well as serum ferritin in laying and non-laying hen. Both serum ferritin and tissue ferritin decrease after treatment with estrogens, while serum iron increases. A relationship between serum ferritin and iron stores in duck is shown.

A radioimmunoassay for duck serum ferritin

Development and optimization of a radioimmunoassay for duck serum ferritin described. 125I-labelled ferritin and rabbit anti-ferritin antibody are used together with goat anti-rabbit gamma globulin as separating agent for the bound and free fractions. The assay has a working range of up to 500 micrograms of ferritin per litre and a sample requirement of 50 microliter of serum. The assay requires a 24 h period and has a sensitivity of 10 micrograms of ferritin per litre.

Isolation and purification of duck liver ferritin

A rapid method of purifying duck liver ferritin using high speed centrifugation and chromatography on Sephadex G-200 and Sepharose 6B is described. Protein and iron concentration for each step of purification is given. This method yields 0.12 mg of pure ferritin per gram of wet tissue.

[Epilepsy after febrile seizures. Predisposing factors and role of phenobarbital in its prophylaxis (author's transl)]

Authors studied two different groups of patients. One of them with febrile seizures and the other febrile seizures associated to epilepsy, in order to find risk factors for the presentation of this one. They conclude that epilepsy has a presentation rate of 9,6% in patients with previous febrile seizures, having the highest risk when they show previous familial seizures, neonatal pathology and altered EEG after the first febrile convulsion. They study the role of phenobarbital taken after febrile seizures, as prophylaxis. No effect was observed in the prevention of following epilepsy.