Evaluation Of Humoral Response Research Articles

Interactions of humoral immune response indicators and parameters of systemic inflammatory response in patients with post-COVID-19 syndrome

Objective. To assess the state of the systemic inflammatory response and humoral immune response in middle-aged patients came through COVID-19 infection in mild and moderate severity. Materials and methods. A cohort single-center study involving 83 patients came through COVID-19 infection in mild and moderate severity (women - 69.9% (58 patients), men - 30.1% (25 patients); median age 53 years [49; 56] was conducted over the period 2022-2023. All patients underwent clinical examination, evaluation of humoral response with determination of IgG and IgM antibodies to SARS-CoV-2 virus, as well as concentration of interleukins: interleukin-1β, interleukin-4, interleukin-6, interleukin-8, interleukin-10, high-sensitivity C-reactive protein, tumour necrosis factor α, transforming growth factor β1 and procalcitonin concentrations. Patients were divided into three groups: 1-3 months; 3-6 months; and 6 months to 1 year after COVID-19 infection. Results. Within a year the percentage of IgM-positive patients in all patient groups was about a quarter (25 %, 21 % and 25 % respectively). While remaining within the reference values for the whole group, procalcitonin and interleukin-10 levels in the selected cohort exceeded those of the test-negative cohort (p = 0.0053 and p = 0.0044, respectively), which we considered as persistent chronic compensated inflammation. Conclusion. A quarter of patients who came through COVID-19 infection in mild and moderate severity have persistently positive IgM levels for a year, combined with proinflammatory status according to systemic inflammatory response parameters.

Evaluation of Humoral Response following SARS-CoV-2 mRNA-Based Vaccination in Liver Transplant Recipients Receiving Tailored Immunosuppressive Therapy.

Background: The role of tailored immunosuppression (IS) in the development of the humoral response (HR) to SARS-CoV-2 mRNA-based vaccination in liver transplant (LT) recipients is unknown. Methods: This is a single-centre prospective study of patients who underwent LT between January 2015 and December 2021 and who have received three doses of mRNA-based SARS-CoV-2 vaccination. Patients undergoing Tacrolimus-based immunosuppression (TAC-IS) were compared with those undergoing Everolimus-based immunosuppression (EVR-IS). Patients receiving the TAC-EVR combination were divided into two groups based on trough TAC concentrations, i.e., above or below 5 ng/mL. HR (analysed with ECLIA) was assessed at 30 to 135 days after vaccination. The primary outcome was the presence of a positive antibody titre (≥0.8 U/mL). Secondary outcomes were the presence of a highly protective antibody titre (≥142 U/mL), median antibody titre, and incidence of COVID-19. Results: Sixty-one participants were included. Twenty-four (40%) were receiving TAC-IS and thirty-seven (60%) were receiving EVR-IS. At the median follow-up of 116 (range: 89-154) days, there were no significant differences in positive antibody titre (95.8% vs. 94.6%; p = 0.8269), highly-protective antibody titre (83.3% vs. 81.1%; p = 0.8231), median antibody titre (2410 [IQ range 350-2500] vs. 1670 [IQ range 380-2500]; p = 0.9450), and COVID-19 incidence (0% vs. 5.4%; p = 0.5148). High serum creatinine and low estimated glomerular filtration rate were risk factors for a weak or absent HR. Conclusions: Three doses of mRNA-based SARS-CoV-2 vaccination yielded a highly protective HR in LT recipients. The use of TAC or EVR-based IS does not appear to influence HR or antibody titre, while renal disease is a risk factor for a weak or null HR.

Differences in Humoral and Cellular Response to COVID-19 Vaccine Against Different Variants over Time in Chronic Lymphocytic Leukemia

Background Patients with chronic lymphocytic leukemia (CLL) are at an increased risk of adverse clinical outcomes following COVID-19 infection, due to impaired humoral and cellular response to infection and vaccination. Most of the data available focus on humoral responses to SARS-CoV-2 vaccination or T cell responses following 2-dose vaccine series. However, the effect of emerging variants of concern (VoC) on T cell recognition in this population has not been previously reported. Aim of the study To evaluate functional humoral response and functional SARS-CoV-2 spike-specific T cell response in CLL patients after the second, the third dose, and 12-months since the first dose. To determine the effect of treatment on immune outcomes. To investigate T cell response to Omicron (BA.2) and ancestral strains, and the impact of Omicron-defining mutations on total spike-specific functional response. Methods CLL patients from Mayo Clinic, Rochester who submitted a blood sample soon after the second and the third dose, and 12-months after the first dose of an mRNA-based vaccination were included. The samples collected following a documented SARS-CoV-2 infection were excluded. Spike-specific T cell responses were quantified using IFN-γ ELISpot assay (R&D Systems). PBMCs were stimulated with a peptide pool spanning the complete sequence of ancestral SARS-CoV-2 spike and two 68-peptide pools: the BA.2 mutation pool selectively covering the mutated spike regions, and reference pool containing the wild-type sequences for the same regions (Peptivator pools, Miltenyi Biotec). The results were considered positive if at least two of the following three were met: average spot count > 5 SFUs/2x10^5; mean spot count >3-fold higher than in negative control; and statistically significant difference (paired t-test<0.5) between Ag-specific and negative control wells.For evaluation of humoral response, we utilized an assay measuring antibody capable of blocking spike receptor binding domain (RBD)-ACE2 (cPASS GenScript). Statistical analysis was performed using t-test and Mann-Whitney test for continuous variables; Chi-square (or Fisher's Exact test) was used for comparing categorical variables. The Mayo Clinic IRB approved the study. Results Thirty patients with CLL were included in the study. Eight patients received a fourth vaccine dose before the 12-months blood draw. The rate of positivity for receptor blocking activity was significantly higher in the untreated group after the 2ndand 3rd dose (0% vs. 75%, 38.5% vs. 93.3%, p>0.05). This difference was not observed for the cellular response to spike-specific ancestral in all the three timepoints. At 12 months 54.16 % of the patients had positive IFN-γ ELISpot response, with no significant difference between treated and untreated (58.3% vs. 50%, p=1.0), and patients with and without a fourth dose (62.5% vs. 50%, p=0.67). Among treated CLL patients, seven (70%) and five (41.6%) patients without neutralizing antibodies had detectable cellular response after the 2nd and 3rd dose, respectively. On average, less than 25% of the total spike-specific T cell reactivity was directed against the epitopes in the regions mutated in BA.2 subvariant. Moreover, we did not detect statistically significant differences in IFN-γspot counts between the mutational and reference 68-peptide pools at any timepoint (median spots T1: 1.62 vs. 2.33, p=0.4; T2: 5 vs. 4.33, p=0.31; T3: 5 vs. 6, p=0.49). Conclusion Treatment status impacts humoral, but no cellular response to SARS-CoV-2 vaccination CLL patients. However, the overall rate of positive cellular response one year after the first dose is low. This, combined with no boosting of cellular response upon the 4th dose, reflects an impaired response even after additional doses. Suboptimal cellular immunity may put CLL patients at higher risk of severe COVID-infection. We did not observe significant difference in the cellular response between ancestral and Omicron BA.2 strains, and only the smaller fraction of T cell response was directed against regions harboring BA.2-specific mutations. These findings confirm the greater observed cross-reactivity to VoC with cellular compared to humoral immune responses. They also suggest significant cellular immunity may remain in the face of Omicron circulation, at least among patients who have response to the vaccine. Given the small sample size, our findings need to be confirmed. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

MO975: Immunogenicity to A Third Dose of the Mrna-1273 Vaccine in Kidney Transplant Recipients

BACKGROUNDHumoral response after two doses of mRNA-based SARS-CoV-2 vaccines is weak in kidney transplant recipients (KTRs) [1]. Of concern, even a third dose of the mRNA-1273 vaccine induced a suboptimal humoral response in a cohort of KTRs who did not respond after two doses [2]. However, the assessment also of the T-cell immune response of mRNA vaccines in KTRs is limited in the literature [3]. Herein, we report the evaluation of humoral response induced after a third dose of the mRNA-1273 vaccine in a cohort of KTRs and T-cell immune responses in not responders to the third dose.METHODSObservational cohort data were collected from KTRs actively followed up in our outpatient clinic, with no history of COVID-19 infection, who received a third mRNA-1273 vaccine dose, 6 months after the second dose, as per suggested local policy.The primary endpoint was the humoral response provided at least 4 weeks after the third dose compared with the humoral response after the second dose.Anti-S1-RBD IgG antibodies were determined using a fluoroimmunoenzymatic method (Thermo Fisher Scientific), and the quantitative result expressed in BAU/mL (reference interval: <28 Negative; 28–40 Borderline; >40 Positive; linear range between 0.7 and >1632 according to the manufacturer). In seronegative and borderline KTRs after the third dose, an INFγ-release assay (IGRA) [Euroimmun, Lubeck, Germany] was used to detect T-cell immune responses. A patient result was considered negative, borderline and positive when IFNγ values were respectively <100, 100–200 and >200 mIU/mL.RESULTSSixty KTRs received a third dose of the mRNA-1273 vaccine. Overall, we obtained the antibody titre in 57 KTRs at a median of 23 days (IQR: 22–31) after the second dose and 23 days (IQR: 21–26) after the third dose.After the second dose, positive antibody titres were detectable in 28 KTRs (49%), and 2 KTRs (4%) had a borderline positivity. While after third dose, positive and borderline antibody responses were observed in 40 (70%) and 4 (7%) KTRs, respectively.Among all 57 KTRs, the median anti-S1-RBD IgG titre significantly increased after the third dose ( 448 versus 39 BAU/mL; P = 0.0018; Mann–Whitney test). While in 28 KTRs already seropositive after the second dose, the median antibody titre increased from 556 to >1632 BAU/mL (P = 0.0285; Mann–Whitney test). Figure 1 shows the kinetics of anti-S1-RBD IgG titres after the second and the third dose for all the 57 KTRs.Among 17 KTRs with negative and borderline humoral responses after the third dose, IFNγ values were positive and borderline in only 1 (6%) and 1 (6%) KTRs, respectively. The median IFNγ value was 22 mIU/mL (IQR: 0–1014).The 34 KTRs receiving mycophenolate mofetil (MMF) were less likely to develop adequate immune responses than the 23 KTRs not receiving MMF; 12 KTRs (35%) receiving MMF had no antibody and IFNγ positive response after the third dose in comparison to 4 KTRs (17%) not receiving MMF, and the median anti-S1-RBD IgG titre beyond the two groups after the third dose was statistically different (205 versus > 1632; P = 0.0046; Mann–Whitney test).CONCLUSIONSIn this study, the third dose of the mRNA-1273 vaccine increases the rate of positive antibody responses in non-responders KTRs after the second dose, and improves the magnitude of these responses in already seropositive KTRs. However, a fraction of KTRs still lacks protective antibody titres and T-cell responses after a third dose, with mycophenolate mofetil to be associated with poor immune responses. Alternative vaccination protocols are needed to protect this high-risk group.

Response to vaccination against SARS‐CoV‐2 in 168 patients with Waldenström macroglobulinaemia: A French Innovative Leukaemia Organization study

Response to vaccination against <scp>SARS‐CoV</scp>‐2 in 168 patients with Waldenström macroglobulinaemia: A French Innovative Leukaemia Organization study

Dioctadecyldimethylammonium bromide (DODAB-BF) as a new adjuvant for maternal-fetal immunization in mice against Neisseria meningitidis: evaluation of humoral response.

Neisseria meningitidis bacterium is a Gram-negative diplococcus. Among their serogroups, the B is one of the main causes of invasive meningococcal disease. Newborns and children are particularly susceptible to this infection because of their immune systems that are still maturing and relatively inexperienced. Thus, further studies on the use of maternal immunization for protection against this disease are needed. The purpose of this study was to evaluate the potential immunogenic antigens from the outer membrane of N. meningitidis serogroup B in outbred mice and the influence of maternal immunization in the offspring, and analyze the adjuvant effect of bilayer fragments of dioctadecyldimethylamonium bromide (DODAB-BF) and hydroxide aluminium (alum) in enhancing antibodies production and transference to offspring. IgG and IgG1, IgG2a and IgG2b subclasses of antibodies in serum from immunized mice and controls were quantified and compared. Immunization by subcutaneous and intramuscular routes exhibited evidence of IgG, and both adjuvants promoted the production of IgG1 and IgG2b that were transferred to the offspring. These antibodies also showed specificity with the outer membrane vesicles from homologous strain and were capable to cross react with different strains. The use of DODAB-BF seems to enhance immune response on mothers and offspring and may have immunological advantages.

Evaluation of humoral response and protective efficacy of two inactivated vaccines against bluetongue virus after vaccination of goats

Bluetongue serotype 8 has become a major animal health issue in the European Union and the European member States have agreed on a vaccination strategy, which involves only inactivated vaccines. In this study, the efficacy of two inactivated vaccines against bluetongue virus serotype 8 (BTV-8) used in Europe since 2008, BTVPUR ALSAP ® 8 (MERIAL) and BOVILIS ® BTV8 (Intervet/SP-AH), was evaluated in goats immunized and challenged with BTV-8 field isolates under experimental conditions. Serological, virological and clinical examinations were conducted before and after challenge. Three groups of 10 goats each (groups A, B and C) were randomly constituted and 2 groups (A and C) were subcutaneously vaccinated twice with one dose of the two commercial vaccines BTVPUR ALSAP 8 (group A) or BOVILIS BTV8 (group C) respectively. Animals of the groups A, C and B (B: controls) were challenged with a virulent inoculum containing BTV-8. During the experiment, it was found out that the BTV-8 challenge inoculum was contaminated with another BTV serotype. However, results demonstrated that vaccination of goats with two injections of BTVPUR ALSAP 8 or BOVILIS BTV8 provided a significant clinical protection against a BTV-8 challenge and completely prevented BTV-8 viraemia in all vaccinated animals. Qualitative data showed no difference in the kinetics and levels of the humoral response induced by these two inactivated vaccines.

Evaluation of humoral response and protective efficacy of three inactivated vaccines against bluetongue virus serotype 8 one year after vaccination of sheep and cattle

The long-term efficacy of three commercially available inactivated vaccines against bluetongue virus serotype 8 (BTV-8) (BLUEVAC ® 8, Zulvac ® 8, and BTVPUR ® AlSap 8) was evaluated in a seroprevalence study and challenge experiments. Seroprevalences 1 year after vaccination ranged from 75% to 100%. In two infection experiments, groups of vaccinated sheep and cattle selected either randomly or for low antibody levels were challenged with a European BTV-8 strain 12 months after vaccination. With two exceptions, all animals, including those with low antibody levels prior to challenge, were protected from viral replication and clinical disease even at low initial antibody levels. Vaccination of susceptible ruminants in yearly intervals is thus considered an adequate scheme for BTV-8 control in Europe.

A preliminary assessment of relative sensitivities to foreign red blood cell challenges in the northern bobwhite for potential evaluation of immunotoxicity

Many environmental toxins have been shown to suppress the immune system across taxa. The foreign red blood cell (RBC) challenge is an important part of a complement of tests used to assess immunocompetence in the laboratory because it can assess an individual’s humoral response without impacting its health. This challenge is used commonly across species and measures antibody titers in response to an intraperitoneal, intravenous, or subcutaneous injection of foreign RBCs. Determination of the best appropriate foreign RBC challenge is therefore important when designing tests for evaluation of humoral responses. The northern bobwhite (Colinus virginianus) is a commonly used species for avian toxicity tests, however little is known about the relative sensitivities of its humoral responses to foreign erythrocytes. In this pilot study, we exposed adult quail to intravenous injections of 5% solutions of sheep, rat, rabbit, bovine, or chicken erythrocytes and performed antibody titers [hemagglutination assay for total immunoglobulin (Ig), IgG, and IgM] for primary and secondary responses. Although the bobwhites appeared to respond strongly to rat RBCs, high variability in responses were observed among individuals. Chicken RBCs elicited the poorest responses for both primary and secondary challenges. Sheep and bovine RBCs were adequate antigens for this test in bobwhites. We found that rabbit erythrocytes elicited the strongest responses with the least amount of variability between individuals. Rabbit RBCs, therefore, appear to be the ideal antigen for this test of the humoral response in this species.

Humoral and Cellular Response of Pheasants Vaccinated against Newcastle Disease and Haemorrhagic Enteritis

The purpose of the experiment was to define whether and to what extent can prophylactic vaccinations against Newcastle disease (ND) and haemorrhagic enteritis (HE) affect the humoral and cellular response in pheasants. The evaluation of humoral response was performed on a basis of agglutinin titre after administered antigen and the cellular immunity index was the delayed type hypersensitivity (DTH) reaction. The pheasants were prophylactically vaccinated against Newcastle Disease (ND) on the 1st, 28th and 56th day of life. Moreover, on the 49th day of life, part of the birds was given in the drinking water a vaccine containing the HEV (Haemorrhagic Enteritis Virus). Fourteen days after the HEV vaccination, the birds were intravenously given 0.5 ml of the 10% SRBC (sheep red blood cells) suspension. Simultaneously with the SRBC administration the delayed hypersensitivity test was performed by intradermal administration of phytohaemagglutinin (PHA). It was shown that in pheasants vaccinated with NDV and additionally with HEV, the specific agglutinin anti-SRBC titre was significantly (p &lt; 0.05) lower than in birds vaccinated against ND only. It also appeared that, the antibodies resistant to 2-mercaptoethanol were 43% of the total pool of specific anti-SRBC antibodies in the NDV vaccinated birds, whereas in birds vaccinated also with HEV they were 75%. No significant differences were found in the DTH test. Only in the HEV vaccinated pheasants the tendency to increase the wing index value was noted. The results confirm the observations concerning immunosuppressive effects of simultaneous vaccinations. They also indicate that overloading the pheasants with many antigens (ND and HEV vaccination) may weaken the humoral response to administered SRBC.

Peptide synthesis containing a B-cell and a T-cell epitope on dextran beads and evaluation of humoral response against bead-peptide construct

Cross-linked dextran beads were chemically modified with Fmoc-βAla to give an amino functionalized support suitable for solid-phase peptide synthesis. On this support, a peptide compriising B-cell and T-cell epitopes in tandem was synthesized manually by Fmoc procedure monitoring the coupling reaction by bromophenol blue procedure and standard Kaiser test. The quality of peptide synthesis was verified by RP-HPLC and mass spectrometry. The size and morphologic characteristics of dextran beads were conserved after peptide synthesis. Furthermore, we analyzed immunogenicity in mice of the T-B peptide on dextran beads compared with T-B peptide immunogenicity when administered in CFA/IFA. In both cases, titers were high and there was not a significant difference in antibody titers between groups (p<0.05). But in contrast CFA they are biocompatible and did not induce any adverse reaction at the site of injection. This experiment suggests that the peptides synthesis on dextran beads can be used to raise the immunogenicity of synthetic peptide in vaccines or therapeutics.

Evaluation of humoral response with ragweed antigen in pregnant rats.

No difference was observed between the homocytotropic (IgE) antibody titers in the sera of pregnant and non-pregnant rats immunized with DWSR, suggesting that there is no evidence of immunosuppressive factor in humoral response during pregnancy.