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.

Assessment of lymphocyte proliferation for diagnostic purpose: Comparison of CFSE staining, Ki-67 expression and 3H-thymidine incorporation.

The capability of lymphocytes to respond to antigenic or mitogenic stimulation is an important feature in the diagnosis of various immunodeficiencies and immune disorders. We used large cohorts of both immune compromised patients and healthy controls to measure lymphocyte proliferations by means of three methods: CFSE staining, Ki-67 expression and 3H-thymidine incorporation. The advantages and disadvantages of each method was then evaluated for use in routine clinical diagnostic. The statistical analysis was performed between the outcomes and the correlation between all three methods was computed. CFSE and Ki-67 assay correlated well with the r=0.767, correlation between Ki-67 expression and 3H-thymidine incorporation was 0.546 and correlation between CFSE staining and 3H-thymidine incorporation was 0.337. The differences between these three methods concerning complexity, sensitivity and reliability as well as the financial aspects are discussed hereafter. CFSE and its analogues provide the cheapest and reasonable choice for measuring lymphocyte proliferation, while Ki-67 represents a more expensive, but more sensitive and robust method. The original 3H-thymidine assay does not bring any advantages and cannot compare to the competition presented by modern flow cytometric methods available today.

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.

Clinical relevance of regulatory T cells monitoring in the peripheral blood of ovarian cancer patients.

BACKGROUND: Tregs play a suppressive role in the control of antitumour immunity. In this study we evaluated the relevance of prospective monitoring of peripheral blood regulatory T cells (Tregs) as a potential prognostic marker of future outcome of epithelial ovarian cancer in patients with or without a metronomic chemotherapy. METHODS: 46 patients diagnosed with the ovarian cancer were enrolled in the study and divided into groups according to the stage of the disease, outcome of the surgery and treatment received. Proportions of Tregs in the peripheral blood samples were evaluated using flow cytometry. RESULTS: We show that the early stage of the disease and absence of the tumor residuum after radical surgery are the most important factors predicting a favourable clinical outcome in the ovarian cancer. We did not show any significant effect of consolidation chemotherapy with metronomic doses of etoposide or cyclophosphamide on the peripheral blood Tregs and on the clinical outcome. The slope of the Tregs trend line was a significant predictor of an early relapse, even after controlling for stage and tumor residuum after the surgical debulking by using the Cox proportional hazard model. CONCLUSIONS: This study shows that the faster kinetics of Tregs increase in the peripheral blood, expressed as the slope of the Tregs trend line, is a significant predictor of ovarian cancer early relapse hazard. However, due to its relatively low specificity, the informative value of regular monitoring of Tregs kinetics in the peripheral blood for the subsequent clinical outcome is limited.

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.

Regulatory T cells, dendritic cells and neutrophils in patients with renal cell carcinoma.

We evaluated dendritic cells (DC), regulatory T lymphocytes (Treg) and neutrophils in 37 patients with newly diagnosed renal cell carcinoma (RCC) in the tumor and peripheral blood (PB) and correlated these parameters with tumor staging (early-T1, 2, late-T3, 4 and metastatic disease). The number of myeloid and plasmacytoid DC in blood of RCC patients was higher than in healthy controls. The percentage of myeloid dendritic cells (mDC) from CD45+ cells in tumors was higher in comparison with peripheral blood irrespective of disease stage. Higher percentage of these cells expressed a maturation marker in the periphery in the early stage (CD83 expressing cells). The number of plasmacytoid dendritic cells (pDC) in PB was similar in both early and late stage groups, but the early group displayed a significantly higher percentage of pDC in tumor cell suspension. Neutrophil counts in the peripheral blood of RCC patients were higher than in healthy controls, but the counts in both tumor stage groups were similar. The proportion of neutrophils from CD45+ cells was higher in late stage tumors. Higher percentage of Treg from CD4+ cells was detected in renal carcinoma tissue in comparison to PB with no difference between stages of the disease. Our results reflect the complex interplay between various cells of the immune system and the tumor microenvironment. Activation of dendritic cell subpopulations at early stages of the disease course is counterbalanced by the early appearance of T regulatory cells both in the periphery and tumor tissue. Later stages are characterized by the accumulation of neutrophils in the tumor. Appropriate timing of anticancer strategies, especially immunotherapy, should take these dynamics of the immune response in RCC patients into account.