Association Between Low Anti-spike Antibody Levels After the Third Dose of SARS-CoV-2 Vaccination and Hospitalization due to Symptomatic Breakthrough Infection in Kidney Transplant Recipients.

Background: Whether anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody levels post-third coronavirus disease (COVID-19) vaccination correlate with worse outcomes due to breakthrough infection is unclear. We evaluated the association between anti-SARS-CoV-2 antibody levels and symptomatic breakthrough infection or hospitalization during the Omicron surge in kidney transplant recipients. Methods: In total, 287 kidney transplant recipients expected to receive a third vaccination were enrolled between November 2021 and February 2022. The Abbott SARS-CoV-2 IgG II Quant test (Abbott, Chicago, IL, USA) was performed within three weeks before and four weeks after the third vaccination. The incidence of symptomatic breakthrough infection and hospitalization from two weeks to four months post-third vaccination was recorded. Results: After the third vaccination, the seropositive rate and median antibody titer of the 287 patients increased from 57.1% to 82.2% and from 71.7 (interquartile range [IQR] 7.2-402.8) to 1,612.1 (IQR 153.9-5,489.1) AU/mL, respectively. Sixty-four (22.3%) patients had symptomatic breakthrough infections, of whom 12 required hospitalization. Lower anti-receptor-binding domain (RBD) IgG levels (<400 AU/mL) post-third vaccination were a risk factor for symptomatic breakthrough infection (hazard ratio [HR]=3.46, P<0.001). Anti-RBD IgG levels <200 AU/mL were a critical risk factor for hospitalization (HR=36.4, P=0.007). Conclusions: Low anti-spike IgG levels after third vaccination in kidney transplant recipients were associated with symptomatic breakthrough infection and, particularly, with hospitalization during the Omicron surge. These data can be used to identify patients requiring additional protective measures, such as passive immunization using monoclonal antibodies.

Humoral Response of Different Types of SARS-CoV-2 Vaccines in Patients with Autoimmune Rheumatic Diseases: Experiences from a Serbian Cohort.

BACKGROUND: Data are scarce on the immunogenicity of coronavirus disease 2019 vaccines in patients with autoimmune rheumatic diseases (ARD). OBJECTIVES: To measure the immunoglobulin G (IgG) response after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunization and to evaluate clinical characteristics associated with seropositivity. METHODS: Samples were collected after the second and third doses of the three different types of vaccines in ARD patients. Seroconversion rates and IgG antibody S1/S2 titers were measured. RESULTS: The type of ARD diagnosis and previous treatment had no significant impact on the serum IgG antibody levels measured after the second (P = 0.489 and P = 0.330, respectively) and boost dose (P = 0.441 and P = 0.446, respectively). What made a significant difference regarding serum IgG antibody levels after the second dose was the type of SARS-CoV-2 vaccine. The difference was highly statistically significant for all vaccine types (P = 0.001 with the highest odds ratio for the mRNA vaccine). After the boost with the mRNA vaccine, all patients achieved a high level of serum IgG antibody levels (t = 10.31, P = 0.001). No ARD patients experienced serious post-vaccinal reactions. Eight patients developed COVID-19 before the boost dose. CONCLUSIONS: In ARDs patients, the highest level of serum IgG antibody against S1/S2 proteins was achieved with the mRNA vaccine, irrespective of the therapy applied or the type of the disease. We recommend a booster dose with mRNA vaccine in all ARDs for the highest SARS-CoV-2 protection without serious post-vaccinal reactions observed.

Associations of Adherence to the 2018 World Cancer Research Fund and the American Institute for Cancer Research Dietary Recommendations with Gut Microbiota and Inflammation Levels.

BACKGROUND: Whether the World Cancer Research Fund and the American Institute for Cancer Research (WCRF/AICR) dietary recommendations affect the gut microbiota and inflammatory status remains unclear. We examined the association of dietary adherence scores to the WCRF/AICR with gut microbiota and inflammation in a cross-sectional setting. METHODS: The WCRF/AICR diet adherence scores were calculated for 151 participants (adenoma 97, non-adenoma 54) from 7-day dietary records. The gut microbiota was analyzed by 16S rRNA gene sequencing of fecal samples. The levels of inflammatory biomarkers in both blood (i.e., IL-6, IL-8, IgA, IgM, and IgG) and fecal samples (i.e., FCP) were evaluated in 97 colorectal adenoma patients who had blood samples available. Multivariable linear regression analyses were conducted to examine the association of individual and total dietary adherence scores with gut microbiota and inflammatory biomarker levels. RESULTS: Participants with higher adherence had lower relative abundance of Proteobacteria (ß = -0.041, 95%CI: -0.073, -0.009), Enterobacteriaceae (ß = -0.035, 95%CI: -0.067, -0.003), and unidentified Enterobacteriaceae at the genus level (ß = -0.029, 95%CI: -0.055, -0.003) compared to those with lower adherence. Plant-based food intake was positively correlated with increased abundance of Phascolarctobacterium (ß = 0.013, 95%CI: 0.001, 0.026). Restricting fast food was linked to high abundance of Bacteroidaceae (ß = 0.149, 95%CI: 0.040, 0.257) and Bacteroides (ß = 0.149, 95%CI: 0.040, 0.257). Limiting sugary drinks was associated with reduced abundance of Lachnospiraceae (ß = -0.155, 95%CI: -0.292, -0.018). Plant-based food intake (ß = -0.251, 95%CI: -0.450, -0.052) and restriction of fast food (ß = -0.226, 95%CI: -0.443, -0.008) were associated with reduced IGG levels in men. Alcohol restriction was linked to lower IL-6 (ß = -7.095, 95%CI: -11.286, -2.903) and IL-8 (ß = -7.965, 95%CI: -14.700, -1.230) levels in women, but with higher IL-6 (ß = 0.918, 95%CI: 0.161, 1.675) levels in men. CONCLUSIONS: Our findings support the association of adherence to the WCRF/AICR diet with gut microbiota and inflammation. These results need to be validated in additional prospective or interventional studies.

Update on respiratory lesions in patients with IgG4-related autoimmune pancreatitis.

We previously reported respiratory involvement in 25 patients with autoimmune pancreatitis, a pancreatic manifestation of IgG4-related disease that responds well to glucocorticoid treatment. However, whether all respiratory lesions in patients with autoimmune pancreatitis have genuine respiratory involvement is unclear. This study aimed to update respiratory lesions' clinical and radiological characteristics in patients with autoimmune pancreatitis. We retrospectively reviewed the clinical and radiological data of 74 consecutive patients diagnosed with autoimmune pancreatitis at Shinshu University Hospital and treated with glucocorticoid. Clinical features and chest high-resolution computed tomography findings before and after therapy were reviewed. Fifty-one patients (68.9%) had respiratory lesions. In 65 of the 74 patients, chest high-resolution computed tomography results were evaluated before and after treatment. Patients with IgG4-related disease and respiratory lesions showed significantly higher serum IgG4 levels and hypocomplementemia than those without respiratory lesions; they also had more affected organs. While most abnormal thoracic findings improved, 4 cases of 7 with reticular opacities and all 11 cases with emphysema did not improve. Therefore, these lesions with poor response to glucocorticoid treatment should not be considered due to respiratory involvement of autoimmune pancreatitis based on the current classification criteria for IgG4-related disease. Patients with autoimmune pancreatitis and respiratory lesions exhibited higher disease activity than those without. Most chest high-resolution computed tomography lesions were responsive to glucocorticoid treatment, whereas reticular opacities and emphysema were poorly responsive.

Serial 68Ga-FAPI PET/CT After Treatment of Immunoglobulin G4-Related Pancreatitis and Retroperitoneal Fibrosis.

ABSTRACT: Immunoglobulin G4 (IgG4)-related disease is a fibroinflammatory condition involving diverse organs. We report a case of IgG4-related pancreatitis and retroperitoneal fibrosis with serial 68Ga-FAPI PET/CT scans after treatment. A 64-year-old man presented with left flank and epigastric pain. Laboratory, abdominal CT, and 68Ga-FAPI PET/CT findings were suggestive of IgG4-related pancreatitis and retroperitoneal fibrosis. Histology of the pancreas confirmed IgG4-related pancreatitis. The follow-up PET/CT scans after treatment with steroid therapy showed regression of 68Ga-FAPI uptake in the pancreas and periureteral soft tissue. The changes on 68Ga-FAPI PET/CT scans were much more prominent compared with the CT scans.

Association of SH2 domain-containing protein 1A, immunoglobulins and T lymphocyte subsets with Epstein- Barr virus infections.

BACKGROUND: We aimed to analyze the levels and associations of SH2 domain-containing protein 1A (SH2D1A), immunoglobulins and T lymphocyte (TL) subsets in children with Epstein-Barr virus (EBV) infections. METHODS: Sixty children with EBV infections admitted from January 2019 to January 2022 were selected, including 29 cases of infectious mononucleosis (IM group) and 31 cases of chronic active EBV infections (CAEBV group). Another 42 healthy children undergoing physical examination in the same period were selected as a control group. Their changes in SH2D1A, immunoglobulins and TL subsets (CD3+, CD4+ and CD8+) were compared. RESULTS: The levels of CD3+, CD4+ and CD8+ in the IM group were higher than those of the control group (P < 0.05), while they were lower in the CAEBV group than those of the control and IM groups (P < 0.05). The levels of SH2D1A, signaling lymphocyte activation molecule (SLAM) and SLAM-associated protein (SAP) were significantly higher in the IM group than those in the control and CAEBV groups (P < 0.05). The CAEBV group had decreased protein expressions of SLAM and SAP compared with those of the IM group. SH2D1A was positively correlated with immunoglobulin A, immunoglobulin G and TL subsets (CD3+, CD4+ and CD8+) (P < 0.05). CONCLUSIONS: Detecting SH2D1A, immunoglobulins and TLs contributes to the diagnosis and differentiation of IM and CAEBV.

Coexistence of IgLON5-IgG and SOX1-IgG in a Patient with Progressive Brainstem Dysfunction.

PURPOSE: The coexistence of IgLON5-IgG and SOX1-IgG is rare. Previous reports have shown that patients with IgLON5-IgG spectrum disease present with sleep disorders, bulbar involvement, and autonomic abnormality, while SOX1-IgG positive patients present with peripheral nervous system symptoms such as the Lambert-Eaton Myasthenic Syndrome (LEMS). CASE REPORT: We report a patient who presented with progressive ophthalmoplegia, ptosis, oropharyngeal dysphagia, gait instability, and sleep disorders. The paraneoplastic antibody screening tested doublepositive for IgLON5-IgG and SOX1-IgG. However, there was no clinical sign of LEMS in this patient. After extensive cancer screening, only lung nodules with hilar adenopathy were noted. CONCLUSION: The coexistence of IgLON5-IgG with onconeuronal SOX1-IgG would suggest an underlying immune-mediated paraneoplastic process rather than secondary autoimmunity because of neurodegeneration. This is the first IgLON5-IgG case reported in Thailand, with a case of doublepositive IgLON5-IgG and SOX1-IgG as well. Keyword: IgLON5-IgG, SOX1-IgG, Paraneoplastic process, case report.

Development of a cost-effective quantitative in-house ELISA assay for screening anti-S1 IgG antibodies targeting SARS-CoV-2.

The RBD, S, and N proteins, the three main antigens of the SARS-CoV-2 virus, activate the host immune system and cause the formation of IgM and IgG antibodies. While IgM indicates an early, acute infection stage, IgG shows a past infection or persistent sickness. This study used an indirect ELISA assay that targets the S1 subunit of the SARS-CoV-2 S protein to create an in-house, qualitative serological test specific to COVID-19. A total of 60 serum samples were examined using ELISA for anti-SARS-CoV-2 IgG, and 50 of those results were positive. An additional 20 samples were taken from cases that occurred before the pandemic. For the in-house ELISA assay, a plasmid containing the gene coding for the S1 subunit was transformed into E. coli DH5ɑ bacterial cells and the protein was synthesized and purified. The purified protein was utilized to coat the ELISA plate, which was subsequently used to assess the levels of IgG among individuals with SARS-CoV-2 infection. The study found a significant association (p-value=0.01) between the in-house and the commercial anti-S1 subunit IgG antibodies kits. The in-house ELISA responded well, with a sensitivity and specificity of 75.0% and 88.89%, respectively. Furthermore, a library of SARS-CoV-2 recombinant S1 subunits was created by competent bacteria and may be employed for various tasks, such as creating diagnostic tools and scientific investigation. Overall, the in-house anti-SARS-CoV-2 human IgG-ELISA proved to be sensitive and specific for identifying IgG antibodies in patients exposed to SARS-CoV-2.

[The role of food allergy as a provoking factor of migraine]. / Rol' pishchevoi allergii kak provotsiruyushchego faktora migreni.

OBJECTIVE: To assess the effect of food allergies on the course of migraine. MATERIAL AND METHODS: Seventy patients with migraine, aged 21-56 years old, were examined using headache diary, MIDAS and VAS, studies of specific antibodies of the IgG4 class (delayed type food allergy) by immuno-enzyme analysis (ELISA), microbiological examination of a smear from the mucous membrane of the posterior wall of the oropharynx with mass spectrometry of microbial markers (MSMM) with the identification of 57 microorganisms. RESULTS: We found an increase in specific IgG4 for a number of food allergens in most patients with migraine, of which 48.5% had a pronounced increase in IgG4 (>150 kEd/l) for at least one allergen (cow's milk - 13% patients, wheat flour - 5%, egg white - 47% or yolk - 26%, quail egg - 15%, sweet pepper - 6%), in 29% of people to several food allergens at once (all of them had chicken egg protein as one of the allergens). There was the association of IgG4 titers to wheat allergen with the severity of headache according to VAS (r-S=0.7; p=0.0046) in patients with the most severe, chronic migraine (17 people) and with an imbalance of the oropharyngeal microbiota, namely, concentration of pathological viruses Herpes spp. (rs=0.29; p=0.02), Epstein-Barr (rs=0.46; p=0.0002) and microscopic fungi (rs=0.39; p=0.0016), detected in these patients. CONCLUSION: We show for the first time the relationship between delayed-type food allergy and redistribution in the microbiome of the oropharynx of patients with migraine and once again confirm the role of delayed-type food allergy as a clinically significant factor influencing the course of migraine (its intensity and chronicity).

Relapse rate and predictors of relapse after cessation of glucocorticoid maintenance therapy in type 1 autoimmune pancreatitis: a multicenter retrospective study.

BACKGROUND: Type 1 autoimmune pancreatitis responds well to glucocorticoid therapy with a high remission rate. Moreover, glucocorticoid maintenance therapy can help prevent relapse. However, the relapse rate following cessation of long-term glucocorticoid therapy is unknown. The aim of this study was to clarify the relapse rate and predictors of relapse following long-term glucocorticoid therapy cessation. METHODS: We analyzed 94 patients who achieved remission after undergoing glucocorticoid therapy, discontinued treatment after at least 6 months of maintenance therapy, and were subsequently followed up for at least 6 months. The patients were divided into three groups based on treatment duration (< 18, 18-36, and ≥ 36 months), and their relapse rates were compared. Univariate and multivariate analyses of clinical factors were conducted to identify relapse predictors. RESULTS: After discontinuing glucocorticoid therapy, relapse was observed in 43 (45.7%) patients, with cumulative relapse rates of 28.2% at 1 year, 42.1% at 3 years, 47.0% at 5 years, and a plateau of 77.6% at 9 years. Of the 43 patients who relapsed, 25 (58.1%) relapsed within 1 year after after cessation of glucocorticoid therapy. Relapse and cumulative relapse rates did not differ significantly according to treatment duration. In the multivariate analysis, an elevated serum IgG4 level at the time of glucocorticoid cessation was found to be an independent predictor of relapse (hazard ratio, 4.511; p < 0.001). CONCLUSIONS: A high relapse rate occurred after cessation of glucocorticoid maintenance therapy, regardless of the duration of maintenance therapy, especially within the first year after cessation. However, the normalization of long-term serum IgG4 levels may be a factor in considering cessation.

Bartonella infections are prevalent in rodents despite efficient immune responses.

BACKGROUND: Pathogens face strong selection from host immune responses, yet many host populations support pervasive pathogen populations. We investigated this puzzle in a model system of Bartonella and rodents from Israel's northwestern Negev Desert. We chose to study this system because, in this region, 75-100% of rodents are infected with Bartonella at any given time, despite an efficient immunological response. In this region, Bartonella species circulate in three rodent species, and we tested the hypothesis that at least one of these hosts exhibits a waning immune response to Bartonella, which allows reinfections. METHODS: We inoculated captive animals of all three rodent species with the same Bartonella strain, and we quantified the bacterial dynamics and Bartonella-specific immunoglobulin G antibody kinetics over a period of 139 days after the primary inoculation, and then for 60 days following reinoculation with the same strain. RESULTS: Contrary to our hypothesis, we found a strong, long-lasting immunoglobulin G antibody response, with protective immunological memory in all three rodent species. That response prevented reinfection upon exposure of the rodents to the same Bartonella strain. CONCLUSIONS: This study constitutes an initial step toward understanding how the interplay between traits of Bartonella and their hosts influences the epidemiological dynamics of these pathogens in nature.

Studying temporal titre evolution of commercial SARS-CoV-2 assays reveals significant shortcomings of using BAU standardization for comparison.

BACKGROUND: Measuring specific anti-SARS-CoV-2 antibodies has become one of the main epidemiological tools to survey the ongoing SARS-CoV-2 pandemic, but also vaccination response. The WHO made available a set of well-characterized samples derived from recovered individuals to allow normalization between different quantitative anti-Spike assays to defined Binding Antibody Units (BAU). METHODS: To assess sero-responses longitudinally, a cohort of ninety-nine SARS-CoV-2 RT-PCR positive subjects was followed up together with forty-five vaccinees without previous infection but with two vaccinations. Sero-responses were evaluated using a total of six different assays: four measuring anti-Spike proteins (converted to BAU), one measuring anti-Nucleocapsid proteins and one SARS-CoV-2 surrogate virus neutralization. Both cohorts were evaluated using the Euroimmun Anti-SARS-CoV-2-ELISA anti-S1 IgG and the Roche Elecsys Anti-SARS-CoV-2 anti-S1 assay. RESULTS: In SARS-CoV-2-convalesce subjects, the BAU-sero-responses of Euroimmun Anti-SARS-CoV-2-ELISA anti-S1 IgG and Roche Elecsys Anti-SARS-CoV-2 anti-S1 peaked both at 47 (43-51) days, the first assay followed by a slow decay thereafter (> 208 days), while the second assay not presenting any decay within one year. Both assay values in BAUs are only equivalent a few months after infection, elsewhere correction factors up to 10 are necessary. In contrast, in infection-naive vaccinees the assays perform similarly. CONCLUSION: The results of our study suggest that the establishment of a protective correlate or vaccination booster recommendation based on different assays, although BAU-standardised, is still challenging. At the moment the characteristics of the available assays used are not related, and the BAU-standardisation is unable to correct for that.

High-Throughput IgG Reformatting and Expression Using Hybrid Secretion Signals and InTag Positive Selection Technology.

We have previously published protocols for high-throughput IgG reformatting and expression, that enable rapid reformatting of phage-displayed antibody Fab fragments into a single dual expression vector for full IgG expression in Expi293F cells (Chen et al. Nucleic Acids Res 42:e26, 2014; Chen et al. Methods in Molecular Biology, vol 1701, 2018). However, when working with phage clones from a naïve library containing highly diverse N-terminal sequences, where the 5' PCR primers bind, the PCR step can become cumbersome. To overcome this limitation, we have investigated and found that the C-terminal 7 amino acid residues of the human antibody VH1 secretion signal can be replaced with those from ompA or pelB bacterial signals to form hybrid signal sequences that can drive strong IgG expression in Expi293F cells. The use of such hybrid signals allows any Fab fragment in the library to be amplified and cloned into the IgG expression vector using only a single 5' PCR primer targeting the bacterial secretion signal of the light or heavy chain, thus dramatically simplifying the IgG reformatting workflow.

COVID-19 Serological Study in Non-infected Vaccinated Subjects: Differences among Age, Sex, and Vaccine Brand.

OBJECTIVE: To evaluate IgG antibody levels against SARS-CoV-2 in non-infected vaccinated subjects among vaccine brand, sex, and age. METHODS: Abbott's AdviseDx SARS-CoV-2 IgG II immunoassay was used to measure IgG levels within 6-9 months after the second dose vaccination; level >50 AU/mL was classified as a positive test. RESULTS: Data of 183 non-infected vaccinated subjects was analyzed according to the vaccine brand, time after second vaccination, sex, and age. Bivariate analysis showed that receiving the Moderna brand vaccine, being female, and younger were associated with higher antibody levels, p<.001. Conversely, no differences were observed between the IgG antibody levels against SARS-CoV-2 and time after second vaccination (6-7 months as compared to 8-9 months), p=.49. CONCLUSION: After six to nine months post-vaccination, receiving the Moderna vaccine, being female, and being younger were significantly associated to higher IgG antibody levels to SARS-CoV-2 in non-infected vaccinated subjects.

Duration of humoral immunity from smallpox vaccination and its cross-reaction with Mpox virus.

The ongoing pandemic caused by mpox virus (MPXV) has become an international public health emergency that poses a significant threat to global health. The vaccinia virus Tiantan strain (VTT) was used to vaccinate against smallpox in China 42 years ago. It is urgent to assess the level of immunity to smallpox in individuals vaccinated 43 or more years ago and evaluate their immunological susceptibility to MPXV. Here, we recruited 294 volunteers and detected the level of residual humoral immunity, including the vaccinia-specific IgG level and neutralizing antibody titer, and the cross-antibodies of MPXV A29L, B6R, A35R, and M1R. Our results showed that the humoral immunity from the smallpox vaccine in the population still remains, and VTT-specific NAb levels wane with age. The majority of the population pre-1981 who should be immunized with VTT still maintains certain levels of MPXV-specific antibodies, in particular, targeting A35R and B6R antigens. Furthermore, we separately analyzed the correlations between the OD450 values of VTT-specific IgG and A35R-specific IgG, B6R-specific IgG, and A29L-specific IgG with plasma samples diluted 1:40, showing a linear correlation (p < 0.0001). Our findings suggest that most Chinese populations still maintain VTT-specific IgG antibodies for 42 or more years after smallpox vaccination and could provide some level of protection against MPXV.

The impact of immunoglobulin G N-glycosylation level on COVID-19 outcome: evidence from a Mendelian randomization study.

Background: The coronavirus disease 2019 (COVID-19) pandemic has exerted a profound influence on humans. Increasing evidence shows that immune response is crucial in influencing the risk of infection and disease severity. Observational studies suggest an association between COVID-19 and immunoglobulin G (IgG) N-glycosylation traits, but the causal relevance of these traits in COVID-19 susceptibility and severity remains controversial. Methods: We conducted a two-sample Mendelian randomization (MR) analysis to explore the causal association between 77 IgG N-glycosylation traits and COVID-19 susceptibility, hospitalization, and severity using summary-level data from genome-wide association studies (GWAS) and applying multiple methods including inverse-variance weighting (IVW), MR Egger, and weighted median. We also used Cochran's Q statistic and leave-one-out analysis to detect heterogeneity across each single nucleotide polymorphism (SNP). Additionally, we used the MR-Egger intercept test, MR-PRESSO global test, and PhenoScanner tool to detect and remove SNPs with horizontal pleiotropy and to ensure the reliability of our results. Results: We found significant causal associations between genetically predicted IgG N-glycosylation traits and COVID-19 susceptibility, hospitalization, and severity. Specifically, we observed reduced risk of COVID-19 with the genetically predicted increased IgG N-glycan trait IGP45 (OR = 0.95, 95% CI = 0.92-0.98; FDR = 0.019). IGP22 and IGP30 were associated with a higher risk of COVID-19 hospitalization and severity. Two (IGP2 and IGP77) and five (IGP10, IGP14, IGP34, IGP36, and IGP50) IgG N-glycosylation traits were causally associated with a decreased risk of COVID-19 hospitalization and severity, respectively. Sensitivity analyses did not identify any horizontal pleiotropy. Conclusions: Our study provides evidence that genetically elevated IgG N-glycosylation traits may have a causal effect on diverse COVID-19 outcomes. Our findings have potential implications for developing targeted interventions to improve COVID-19 outcomes by modulating IgG N-glycosylation levels.

Dynamics of IgG antibody response against Plasmodium antigens among Nigerian infants and young children.

Background: Plasmodium falciparum malaria is a leading cause of child mortality in Nigeria. Neonates are born with maternal antibodies from placental transfer which may protect against malaria infection in the first months of life. The IgG dynamics of the transition from passively transferred antimalarial antibodies to actively acquired IgG from natural exposure have not been well elucidated. Methods: Blood samples collected during a 2018 Nigeria nationwide HIV/AIDS household survey were available for 9,443 children under 5 years of age, with a subset of infants under 2 months of age having maternal samples available (n=41). Samples were assayed for the P. falciparum HRP2 antigen and anti-malarial IgG antibodies. LOESS regression examined the dynamics in IgG response in the first 5 years of life. Correlation with maternal IgG levels was assessed for mother/child pairs. Results: Consistent decreases were observed in median IgG levels against all Plasmodium spp. antigen targets for the first months of life. At a population level, P. falciparum apical membrane antigen-1 (AMA1) and merozoite surface protein-1 19kD (PfMSP1) IgG decreased during the first 12 months of life before reaching a nadir, whereas IgGs to other targets only declined for the first 4 months of life. Seropositivity showed a similar decline with the lowest seropositivity against AMA1 and PfMSP1 at 10-12 months, though remaining above 50% during the first 2 years of life in higher transmission areas. No protective association was observed between IgG positivity and P. falciparum infection in infants. Maternal antibody levels showed a strong positive correlation with infant antibody levels for all P. falciparum antigens from birth to 2 months of age, but this correlation was lost by 6 months of age. Discussion: Maternally transferred anti-malarial IgG antibodies rapidly decline during the first 6 months of life, with variations among specific antigens and malaria transmission intensity. From 3-23 months of age, there was a wide range in IgG levels for the blood-stage antigens indicating high individual variation in antibody production as children are infected with malaria. Non-falciparum species-specific antigens showed similar patterns in waning immunity and correlation with paired mother's IgG levels compared to P. falciparum antigens.

Immuno-affinity chromatography for purification of IgG from hyper-immune sera raised against 146S fraction of Foot and Mouth Disease Virus for diagnostic purposes.

Immunoaffinity chromatography (IAC) is a fundamental isolation and purification tool which is incorporated in a substantial range of therapeutic and diagnostic applications. This study has reappraised the usefulness of immunoaffinity chromatography for the purification of polyclonal antibodies. Protein A based IAC is a convenient and reliable method for purification of IgG, from hyperimmunesera (HIS) raised in experimental animals such as rabbits, guinea pigs and mice to be utilized in pharmaceutics and diagnostics. The 146S fraction of Foot and Mouth Disease virus (FMDV) TCID50=10 5.6 was cultured on a baby hamster kidney cell line 21 (BHK-21), concentrated using salt precipitation method using PEG 6000, purified by size exclusion chromatography (SEC) using Sepharose-30 at 254nm absorbance. Purification of 146S FMDV was analyzed using 12% SDS-PAGE which provided two bands of light and heavy chains. The alum-based vaccine, consisting of ≥10µg of 146S FMDV, was applied in 10 male rabbits and 10 male guinea pigs and two animals of each group were taken as a negative control. The titer of serum was calculated using virus neutralization test. A Protein-A kit (Thermo scientific- 44667, 0528.2) was used to purify HIS raised against 146S FMDV and validated using 12% SDS PAGE in reducing condition. The data demonstrate that protein-A affinity chromatography is an efficient tool for the purification of antibodies from hyper-immune sera raised against 146S FMDV and can be used for the production of diagnostic kits e.g. Enzyme linked immuno-sorbent assay (ELISA) and radioimmunoassay.

Identification of novel first-trimester serum biomarkers for early prediction of preeclampsia.

BACKGROUND: Preeclampsia (PE) is a leading cause of maternal and perinatal mortality and morbidity worldwide, but effective early prediction remains a challenge due to the lack of reliable biomarkers. METHODS: Based on the extensive human biobank of our large-scale assisted reproductive cohort platform, the first-trimester serum levels of 48 cytokines, total immunoglobulins (Igs), anti-phosphatidylserine (aPS) antibodies, and several previously reported PE biomarkers [including placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and activin A] were measured in 34 women diagnosed with PE and 34 matched normotensive controls. RESULTS: The PE group has significantly higher first-trimester serum levels of interleukin (IL)-2Rα, IL-9, tumor necrosis factor-ß (TNF-ß), RANTES, hepatocyte growth factor (HGF), total IgM, and total IgG, and aPS IgG optical density (OD) value, as well as lower first-trimester serum levels of PlGF and total IgA and aPS-IgG immune complexes (IC) OD value than the control group. Combining top five first-trimester serum biomarkers (total IgM, total IgG, PlGF, aPS IgG, and total IgA) achieved superior predictive value [area under the curve (AUC) and 95% confidence interval (CI) 0.983 (0.952-1.000), with a sensitivity of 100% and a specificity of 94.1%] for PE development compared to PlGF and PlGF/sFlt-1 independently [AUC and 95% CI 0.825 (0.726-0.924) and 0.670 (0.539-0.800), respectively]. CONCLUSION: We identified novel first-trimester serum biomarkers and developed an effective first-trimester prediction model using immune-related factors and PlGF for PE, which could facilitate the development of early diagnostic strategies and provide immunological insight into the further mechanistic exploration of PE.