Content and specificity of the Anti-SARS-CoV-2 antibodies in solutions for immunoglobulin replacement therapy

BACKGROUND

Specific antibodies are important for post-vaccination and post-infection immune responses against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The role of antibodies in preventing and treating Coronavirus disease 2019 (COVID-19) in high-risk populations has been highlighted through the use of virus-specific monoclonal antibodies, which has raised the question of immunoglobulin replacement therapy (IRT) used in immunocompromised patients.

METHODS

Virus-specific anti-receptor-binding domain (RBD) and anti-nucleocapsid protein (NCAP) antibodies (assessed using a chemiluminescence assay and virus-neutralizing antibodies (virus neutralization test against Delta and Omicron variants)) were analyzed in 20 batches of 10 % (100 mg/mL) immunoglobulin solutions for intravenous IRT from two commercially available producers between January 2022 and March 2023 for clinical use.

RESULTS

Anti-RBD and anti-NCAP antibodies were detected in all 20 batches of assessed IRT solutions (mean concentrations of 2817 IU/mL and 2380 IU/mL, respectively). Notably, the concentration of the virus-specific antibodies increased continuously during the follow-up period (from 822.5 IU/mL to 4066.4 IU/mL and 102 IU/mL to 3455.9 IU/mL). These antibodies demonstrated high virus-neutralizing activity against the Delta variant (mean titers of 436 and 325) but were limited to the Omicron variant (mean titers 78 and 70). The differences observed between the two brands were not statistically significant.

CONCLUSION

IRT solutions contain high concentrations of anti-SARS-CoV-2 specific antibodies, which may prevent COVID-19; however, the efficacy can be influenced by variable virus-neutralizing activities against different viral strains. Therefore, appropriate IRT should be combined with other approaches, such as vaccination or pre- and post-exposure prophylaxis. Passively transmitted specific antibodies may also lead to false-positive serological test results.

Clinical Outcomes, Immunogenicity, and Safety of BNT162b2 Vaccine in Primary Antibody Deficiency

BACKGROUND

Common variable immunodeficiency (CVID) is characterized by an impaired postvaccination response, high susceptibility to respiratory tract infections, and a broad spectrum of noninfectious complications. Thus, patients with CVID may be at high risk for COVID-19, and vaccination's role in prevention is questionable.

OBJECTIVE

We evaluated the clinical outcomes, safety, and dynamics of humoral and T-cell immune responses induced by the mRNA vaccine BNT162b2 in CVID.

METHODS

This prospective observational cohort study focused on the clinical outcomes (proportion of infected patients and disease severity), safety (incidences of adverse events and changes in laboratory parameters), and dynamics of humoral (specific postvaccination and virus-neutralizing antibody assessment) and T-cell immune responses (anti-SARS-CoV-2-specific T-cell detection) in 21 patients with CVID after a two-dose administration of BNT162b2. The patients were observed for 6 months.

RESULTS

Humoral response was observed in 52% of patients (11 of 21) at month 1 after vaccination but continuously decreased to 33.3% at month 6 (five of 15). Nevertheless, they had a remarkably lower anti-SARS-CoV-2 neutralizing antibody titer compared with healthy controls. The T-cell response was measurable in 46% of patients with CVID (six of 13) at month 1 and persisted over the study period. Mild infection occurred in three patients within the follow-up period (14.3%). The vaccine also exhibited a favorable safety profile.

CONCLUSIONS

The BNT162b2 vaccine elicited a measurable antibody response in a high proportion of patients, but it was limited by low titer of virus-neutralizing antibodies and rapid waning of anti-receptor-binding domain SARS-CoV-2-specific antibodies. T-cell response was detected in one-third of patients and remained stable within the follow-up period. Vaccination has favorable safety and clinical-related outcomes in preventing severe COVID-19.

Effectiveness and Durability of mRNA Vaccine-Induced SARS-CoV-2-Specific Humoral and Cellular Immunity in Severe Asthma Patients on Biological Therapy

Coronavirus disease 2019 (COVID-19) vaccines effectively elicit humoral and cellular immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in healthy populations. This immunity decreases several months after vaccination. However, the efficacy of vaccine-induced immunity and its durability in patients with severe asthma on biological therapy are unknown. In this study, we evaluated the effectiveness and durability of mRNA vaccine-induced SARS-CoV-2-specific humoral and cellular immunity in severe asthma patients on biological therapy. The study included 34 patients with severe asthma treated with anti-IgE (omalizumab, n=17), anti-IL5 (mepolizumab, n=13; reslizumab, n=3), or anti-IL5R (benralizumab, n=1) biological therapy. All patients were vaccinated with two doses of the BNT162b2 mRNA vaccine with a 6-week interval between the doses. We found that this COVID-19 vaccination regimen elicited SARS-CoV-2-specific humoral and cellular immunity, which had significantly declined 6 months after receipt of the second dose of the vaccine. The type of biological treatment did not affect vaccine-elicited immunity. However, patient age negatively impacted the vaccine-induced humoral response. On the other hand, no such age-related impact on vaccine-elicited cellular immunity was observed. Our findings show that treatment of patients with severe asthma with biological therapy does not compromise the effectiveness or durability of COVID-19 vaccine-induced immunity.

SARS-CoV-2 spike glycoprotein-reactive T cells can be readily expanded from COVID-19 vaccinated donors

Introduction

The COVID‐19 vaccine was designed to provide protection against infection by the severe respiratory coronavirus 2 (SARS‐CoV‐2) and coronavirus disease 2019 (COVID‐19). However, the vaccine's efficacy can be compromised in patients with immunodeficiencies or the vaccine‐induced immunoprotection suppressed by other comorbidity treatments, such as chemotherapy or immunotherapy. To enhance the protective role of the COVID‐19 vaccine, we have investigated a combination of the COVID‐19 vaccination with ex vivo enrichment and large‐scale expansion of SARS‐CoV‐2 spike glycoprotein‐reactive CD4⁺ and CD8⁺ T cells.

Methods

SARS‐CoV‐2‐unexposed donors were vaccinated with two doses of the BNT162b2 SARS‐CoV‐2 vaccine. The peripheral blood mononuclear cells of the vaccinated donors were cell culture‐enriched with T cells reactive to peptides derived from SARS‐CoV‐2 spike glycoprotein. The enriched cell cultures were large‐scale expanded using the rapid expansion protocol (REP) and the peptide‐reactive T cells were evaluated.

Results

We show that vaccination with the SARS‐CoV‐2 spike glycoprotein‐based mRNA COVID‐19 vaccine‐induced humoral response against SARS‐CoV‐2 spike glycoprotein in all tested healthy SARS‐CoV‐2‐unexposed donors. This humoral response was found to correlate with the ability of the donors' PBMCs to become enriched with SARS‐CoV‐2 spike glycoprotein‐reactive CD4⁺ and CD8⁺ T cells. Using an 11‐day REP, the enriched cell cultures were expanded nearly 1000‐fold, and the proportions of the SARS‐CoV‐2 spike glycoprotein‐reactive T cells increased.

Conclusion

These findings show for the first time that the combination of the COVID‐19 vaccination and ex vivo T cell large‐scale expansion of SARS‐CoV‐2‐reactive T cells could be a powerful tool for developing T cell‐based adoptive cellular immunotherapy of COVID‐19.

Immunogenicity of BNT162b2 mRNA COVID-19 vaccine and SARS-CoV-2 infection in lung transplant recipients

The immunogenicity of the novel mRNA COVID-19 vaccine in immunocompromised lung transplant recipients is still unknown. We compared the antibody response after the first and second doses of the BNT162b2 mRNA COVID-19 vaccine (Pfizer-BioNTech) with the response after natural SARS-CoV-2 infection in lung transplant recipients. None of the vaccinees tested after two doses of the mRNA BNT162b2 vaccine developed anti-SARS-CoV-2 IgG, while 85% patients presented an antibody response after SARS-CoV-2 infection. The absence of antibody response to vaccination led us to investigate the cellular response in a subset of patients. We detected SARS-CoV-2 specific T-cells in 4 out of 12 tested patients. Some patients therefore might have clinical benefit from the vaccine despite an absent antibody response. These results contrast with the excellent antibody response in immunocompetent individuals observed in mRNA BNT162b2 trials and indicate an urgent need to identify the best vaccine type and scheme for immunocompromised transplanted patients.

Reliability of Autoantibodies Against a Tissue Transglutaminase Neo-Epitope for the Diagnosis of Pediatric Celiac Disease

BACKGROUND

This study aimed to assess the declared benefits of the new test using antibodies against tissue transglutaminase in complex with gliadin representing a neo-epitope in the IgA and IgG class of immunoglobulins compared with currently used tissue transglutaminase antibodies in the IgA class of immunoglobulins among children.

METHODS

In the cross-sectional study (P1 study, n = 406) and two small-size prospective observational studies (P2 study, n = 59 and P3 study, n = 12), serum samples from all children were simultaneously tested for endomysial antibodies, IgA tissue transglutaminase antibodies, and antibodies against tissue transglutaminase in complex with gliadin in the IgA and IgG class of immunoglobulins. The exact McNemar test, Wilcoxon test, and Spearman's correlation coefficient were used to analyze the data.

RESULTS

We found a significant asymmetry of the tissue transglutaminase antibodies test compared with the antibodies against tissue transglutaminase neo-epitope test (P1). More patients (1.5%) had tissue transglutaminase an¬tibodies positive and antibodies against tissue transglutaminase neo-epitope negative results, whereas no patients had tissue transglutaminase antibodies negative and antibodies against tissue transglutaminase neo-epitope positive results. Of 59 children with tissue transglutaminase antibodies and/or endomysial antibodies positive results (P2), one (1.7%) did not have celiac disease. In agreement with the P1 study, four patients (6.8%) with confirmed celiac disease were tissue transglutaminase antibodies positive and antibodies against tissue transglutaminase neo-epitope negative. In this group, the sensitivity of the antibodies against tissue transglutaminase neo-epitope test for diagnosis of celiac disease was 91.4% (95% confidence interval, 81.0 - 97.1%). Among children diagnosed with functional gastrointestinal disorder (P3), all had negative serological test results, and none was diagnosed with celiac disease.

CONCLUSIONS

The results do not indicate that antibodies against tissue transglutaminase neo-epitope test would be an unambiguously better test than the currently used tissue transglutaminase antibodies.

Phase I/II clinical trial of dendritic-cell based immunotherapy (DCVAC/PCa) combined with chemotherapy in patients with metastatic, castration-resistant prostate cancer

PURPOSE

We conducted an open-label, single-arm Phase I/II clinical trial in metastatic CRPC (mCRPC) patients eligible for docetaxel combined with treatment with autologous mature dendritic cells (DCs) pulsed with killed LNCaP prostate cancer cells (DCVAC/PCa). The primary and secondary endpoints were safety and immune responses, respectively. Overall survival (OS), followed as a part of the safety evaluation, was compared to the predicted OS according to the Halabi and MSKCC nomograms.

EXPERIMENTAL DESIGN

Twenty-five patients with progressive mCRPC were enrolled. Treatment comprised of initial 7 days administration of metronomic cyclophosphamide 50 mg p.o. DCVAC/PCa treatment consisted of a median twelve doses of 1 × 107 dendritic cells per dose injected s.c. (Aldara creme was applied at the site of injection) during a one-year period. The initial 2 doses of DCVAC/PCa were administered at a 2-week interval, followed by the administration of docetaxel (75 mg/m2) and prednisone (5 mg twice daily) given every 3 weeks until toxicity or intolerance was observed. The DCVAC/PCa was then injected every 6 weeks up to the maximum number of doses manufactured from one leukapheresis.

RESULTS

No serious DCVAC/PCa-related adverse events have been reported. The median OS was 19 months, whereas the predicted median OS was 11.8 months with the Halabi nomogram and 13 months with the MSKCC nomogram. Kaplan-Meier analyses showed that patients had a lower risk of death compared with both MSKCC (Hazard Ratio 0.26, 95% CI: 0.13-0.51) and Halabi (Hazard Ratio 0.33, 95% CI: 0.17-0.63) predictions. We observed a significant decrease in Tregs in the peripheral blood. The long-term administration of DCVAC/PCa led to the induction and maintenance of PSA specific T cells. We did not identify any immunological parameter that significantly correlated with better OS.

CONCLUSIONS

In patients with mCRPC, the combined chemoimmunotherapy with DCVAC/PCa and docetaxel was safe and resulted in longer than expected survival. Concomitant chemotherapy did not preclude the induction of specific anti-tumor cytotoxic T cells.

Symptom positivity is essential for omitting biopsy in children with suspected celiac disease according to the new ESPGHAN guidelines

The aim of this study was to assess the accuracy of serological tests in combination with clinical symptoms for diagnosing celiac disease (CD) according to the new proposed European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) criteria. We retrospectively assessed children and adolescents aged 16 months -19 years who were examined for suspicion of CD (n = 345). Evaluation of clinical symptoms and the presence of tissue transglutaminase (anti-TG-IgA) and endomysial antibodies (EMA-IgA) as well as intestinal biopsies was performed in all patients. Human leukocyte antigens (HLAs) were not included. Among 345 biopsied children, 213 (62 %) children had anti-TG titers >10 times the upper limit of normal (ULN) and positive EMA antibodies. Ninety-nine (29 %) children also had symptoms suggestive of CD in addition to EMA positivity and elevated titers of anti-TG >10 times the ULN. In patients who were asymptomatic, but positive for EMA, and had anti-TG antibodies >10 times the ULN, the specificity of tests for Marsh 2-3 was only 85 %, while in symptomatic patients with the same antibodies levels, the specificity was 99 %. Conclusion: Our results reveal that intestinal biopsies could be omitted in 28 % of patients when the new ESPGHAN guidelines are applied. Due to high accuracy of serological tests in combination with clinical symptoms for diagnosis of CD, the new guideline seems to be applicable even without the use of HLA testing.

[Immunomodulatory effect of Consupren Sol. Spofa (cyclosporin A). Preclinical study]

Consupren Spofa was demonstrated in our tests to be a distinguished immunomudulating agent. The preparation did not show any direct lymphotoxicity or myelotoxicity but it markedly influenced maturation of T lymphocytes in the thymus. When testing the functional activity of the immunity system in vivo, the inhibitory effect of Consupren Spofa was manifested only when administering a relatively larger dose of the drug with an antigenic stimulus or shortly after it, i.e., in the period of early activating processes. The use of a suitable time and dosage regimen is therefore decisive to induce an inhibitory effect. On the basis of comparative experiments it can be stated that Consupren Spofa is minimally as much effective as, or in some experiments even more effective than Sandimmun Sandoz.

[Thymosin fraction 5. Preclinical study]

Thymosin fraction 5 from the Research Institute for Pharmacy and Biochemistry possessed the immunomodulatory activity in performed tests. The activity is manifested mostly by the induction of the maturation and the differentiation of T cell precursors, which are released from thymus to secondary lymphoid organs. Thymosin fraction 5 causes the expression of the surface membrane markers Thy-1.2, Lyt-2 and L3T4 on the immature T lymphocytes as well. The induced cells are immunocompetent and able to exert the complete functional activity. In the intact mice thymosin fraction 5 had not pronounced effect on the functional potency of mature immunocompetent cells, but in MTA influenced mice its stimulatory effect on the proliferative response to mitogens and on the antibody production against the T-dependent antigen was demonstrated. Thymosin fraction 5 influenced positively not only the components of the specific immunity, but also the functional activity of peritoneal macrophages. The toxicity of thymosin fraction 5 was in the battery of tests in vitro and in vivo very low and therefore it can be considered to be harmless for the clinical practice.

The possibilities of predicting allergic effects of new antirheumatics

The new antirheumatic drugs Benzofenac and Flobufen were assessed for their possible influence on various immunological parameters. They were shown to enhance passive cutaneous anaphylaxis (PCA) to ovalbumin in rats and to suppress the numbers of helper and suppressor T-lymphocytes in mice. The effect of Benzofenac in the latter system was found to be more pronounced. The drugs had no effects in any of the other test systems, including the development of delayed hypersensitivity, mitogen-induced lymphocyte proliferation in vitro and the production of antisera (as tested by PCA).