Antibody Profiles Research Articles

Long-term influenza antibodies profiles in previously vaccinated and non-vaccinated adults

ABSTRACT The aim of this work is to describe the dynamics of influenza antibodies after vaccination in adults. We conducted a case-cohort serological study in the automobile manufacturing plants of the Renault España S.A. group in Valladolid and Palencia (Spain), including 550 workers (66.9%) previously vaccinated against influenza (group V), and 272 (33.1%) never vaccinated (group NV). A pre-vaccination serum sample was collected, another after 30–40 days and another after 6 months. The dynamics of antibodies were analyzed. A lower seroprotection of NV before vaccination was observed, but an antibody response between 2 and 4 times higher than in V was assessed. After 6 months, antibodies declined in both groups until equalize. Antibodies titers decrease with age, and no differences were found among underlying pathologies. Adults never vaccinated against influenza had lower seroprotection than those previously vaccinated, but influenza vaccination produces a more intense serological response in them, acquiring significantly higher antibody titers than those previously vaccinated. The antibodies, although in lower titers, persist and equalize among both groups at least 6 months after vaccination, which allows the individual to be protected during the entire circulation of the influenza virus in the same season.

Machine Learning in Antibody Diagnostics for Inflammatory Bowel Disease Subtype Classification.

Antibody testing in inflammatory bowel disease (IBD) can add to diagnostic accuracy of the main subtypes Crohn's disease (CD) and ulcerative colitis (UC). Whether modern modeling techniques such as supervised and unsupervised machine learning are of value for finer distinction of subtypes such as IBD-unclassified (IBD-U) is not known. We determined the antibody profile of 100 adult IBD patients from the Swiss IBD cohort study with known subtype (50 CD, 50 UC) as well as of 76 IBD-U patients. We included ASCA IgG and IgA, p-ANCA, MPO- and PR3-ANCA, and xANCA measurements for computing different antibody panels as well as machine learning models. The AUC of an optimized antibody panel was 85% (95%CI, 78-92%) to distinguish CD from UC patients. The antibody profile of IBD-U patients was closely related to UC. No specific antibody profile was predictive for IBD-U nor for re-classification. The panel diagnostic was in favor of UC reclassification prediction with a correct assignment rate of 69.2-73.1% depending on the cut-off applied. Supervised machine learning could not distinguish between CD, UC, and IBD-U. More so, unsupervised machine learning suggested only two distinct clusters as a likely number of IBD subtypes. Antibodies in IBD are supportive in confirming clinical determined subtypes CD and UC but have limited capacity to predict IBD-U and reclassification during follow-up. In terms of antibody profiles, IBD-U is not a distinct subtype of IBD.

Signatures of AAV-2 immunity are enriched in children with severe acute hepatitis of unknown etiology.

Severe acute hepatitis of unknown etiology in children is under investigation in 35 countries. Although several potential etiologic agents have been investigated, a clear cause for the liver damage observed in these cases remains to be identified. Using VirScan, a high-throughput antibody profiling technology, we probed the antibody repertoires of nine cases of severe acute hepatitis of unknown etiology treated at Children's of Alabama and compared their antibody responses with 38 pediatric and 470 adult controls. We report increased adeno-associated dependoparvovirus A (AAV-A) breadth in cases relative to controls and adeno-associated virus 2 (AAV-2) peptide responses that were conserved in seven of nine cases but rarely observed in pediatric and adult controls. These findings suggest that AAV-2 is a likely etiologic agent of severe acute hepatitis of unknown etiology.

Photo-induced site-specific oxidative fragmentation of IgG1 mediated by iron(III)-containing histidine buffer: Mechanistic studies and excipient effects

Fragmentation may compromise the clinical efficacy and safety profile of monoclonal antibodies (mAbs). We recently reported that Fe(III)-containing histidine (His) buffer mediates site-specific mAb fragmentation within the Fc domain when exposed to visible light (Y. Zhang and C. Schöneich, Mol. Pharm. 2023, 20, 650–662). Here, we show that this fragmentation proceeds even more efficiently under near-UV light. Several formulation strategies were applied in an attempt to reduce the photo-induced fragmentation. In solution formulations, the fragmentation can be mitigated by reducing the concentration of His buffer, adding Fe(III)-chelating agents, and replacing His with other amino acids. Fragmentation can be almost completely inhibited by formulating the protein in the lyophilized state. Mechanistically, His plays a critical role in the fragmentation process, likely due to its affinity for Fe(II), driving a photo-redox reaction towards product formation.

Insights into the Binding Profile of Anti-chlorpyrifos Recombinant Antibodies: From Computational Simulation to Immunoassay Validation.

A novel virtual screening strategy was proposed for the profiling and discovery of active variable regions (VRs) that encode hapten-specific recombinant antibodies (rAbs). Chlorpyrifos, a hazardous organophosphorus pesticide, was selected as the target. First, a VR model-14G4 from anti-chlorpyrifos hybridoma was built via homology modeling. Its binding pattern toward seven organophosphorus analogues was assessed through virtual screening by performing molecular docking. Based on energy scoring, visual examination, and molecular interaction analysis, chlorpyrifos-methyl was also inferred as the high-affinity target for model-14G4 and was then confirmed via a non-competitive surface plasmon resonance (SPR) assay. Subsequently, we attempted to discover hapten-specific VRs by creating a collection of VR models for anonymous testing. Chlorpyrifos and model-14G4 were employed as the known hit and active VRs, respectively. After molecular docking, a novel anti-chlorpyrifos VR (model-1) was identified due to its satisfactory energy scoring and a similar binding pattern to the reference model-14G4. Expressed by HEK293(F) mammalian cells, the newly prepared full-length rAb-model-1 and rAb-14G4 exhibited high sensitivities for detecting chlorpyrifos by the indirect competitive enzyme-linked immunosorbent assay (ic-ELISA), with IC50 of 3.01 ng/mL and 42.82 ng/mL, respectively. They recognized chlorpyrifos-methyl with a cross-reactivity (CR) of 2.5-17.3%. Moreover, the binding properties of rAb-model-1 for recognizing chlorpyrifos and chlorpyrifos-methyl were confirmed via a non-competitive microscale thermophoresis (MST) method. Thus, the experimental results showed good agreement with computational outputs on antibody profiling. Furthermore, the recognition diversity of rAb-model-1 for chlorpyrifos and chlorpyrifos-methyl was studied via molecular dynamics simulation. Overall, the proposed study provides a versatile and economical strategy for antibody characterization and promotes the in vitro production of rAbs for pesticide monitoring.

Analysis of IgE antibody profiles to food and pollen plant allergens in children with birch allergy and oral allergic syndrome

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Unveiling a New Perspective on Distinguishing Omicron Breakthrough Cases and Postimmune COVID-19-Naive Individuals: Insights from Antibody Profiles.

In the situation of mass vaccination against COVID-19, few studies have reported on the early kinetics of specific antibodies (IgG/IgM/IgA) of vaccine breakthrough cases. There is still a lack of epidemiological evidence about the value of serological indicators in the auxiliary diagnosis of COVID-19 infection, especially when the nucleic acid results were undetectable. Omicron breakthrough cases post-inactivated vaccination (n = 456) and COVID-19-naive individuals with two doses of inactivated vaccination (n = 693) were enrolled. Blood samples were collected and tested for SARS-CoV-2 antibody levels based on the magnetic chemiluminescence enzyme immunoassay. Among Omicron breakthrough cases, the serum IgG antibody level was 36.34 Sample/CutOff (S/CO) (95% confidence interval [CI], 31.89 to 40.79) in the acute phase and 88.45 S/CO (95% CI, 82.79 to 94.12) in the recovery phase. Serum IgA can be detected in the first week post-symptom onset (PSO) and showed an almost linear increase within 5 weeks PSO. Compared with those of breakthrough cases, IgG and IgA titers of the postimmune group were much lower (4.70 S/CO and 0.46 S/CO, respectively). Multivariate regression showed that serum IgG and IgA levels in Omicron breakthrough cases were mainly affected by the weeks PSO (P < 0.001). Receiver operating characteristic ROC0 curve analysis showed that the area under the curve (AUC) was 0.744 and 0.806 when the cutoff values of IgA and IgG were 1 S/CO and 15 S/CO, respectively. Omicron breakthrough infection can lead to a further increase in IgG and IgA levels relative to those of the immunized population. When nucleic acid real-time PCR was negative, we would use the kinetics of IgG and IgA levels to distinguish the breakthrough cases from the immunized population. IMPORTANCE This study fills a gap in the epidemiological evidence by investigating the value of serological indicators, particularly IgG and IgA levels, in the auxiliary diagnosis of COVID-19 infections when nucleic acid results are undetectable. The findings reveal that among Omicron breakthrough cases, both IgG and IgA antibody levels exhibit significant changes. Serum IgG levels increase during the acute phase and rise further in the recovery phase. Serum IgA can be detected as early as the first week post-symptom onset (PSO), showing a consistent linear increase within 5 weeks PSO. Furthermore, receiver operating characteristic (ROC) curve analysis demonstrates the potential of IgG and IgA cutoff values as diagnostic markers. The study's conclusion underscores the importance of monitoring IgG and IgA kinetics in distinguishing Omicron breakthrough cases from vaccinated individuals. These findings contribute to the development of more accurate diagnostic approaches and help inform public health strategies during the ongoing COVID-19 pandemic.

Population immunity to pneumococcal serotypes in Kilifi, Kenya, before and 6 years after the introduction of PCV10 with a catch-up campaign: an observational study of cross-sectional serosurveys

In Kilifi (Kenya), a pneumococcal conjugate vaccine (PCV10) was introduced in 2011 in infants (aged <1 year, 3 + 0 schedule) with a catch-up campaign in children aged 1-4 years. We aimed to measure the effect of PCV10 on population immunity. In this observational study, repeated cross-sectional serosurveys were conducted in independent random samples of 500 children younger than 15 years every 2 years between 2009 and 2017. During these surveys, blood samples were collected by venesection. Concentrations of anti-capsular IgGs against vaccine serotypes (VTs) 1, 4, 5, 6B, 7F, 9V, 14, 18C, 19F, and 23F, and against serotypes 6A and 19A, were assayed by ELISA. We plotted the geometric mean concentrations (GMCs) by birth year to visualise age-specific antibody profiles. In infants, IgG concentrations of 0·35 μg/mL or higher were considered protective. Of 3673 volunteers approached, 2152 submitted samples for analysis across the five surveys. Vaccine introduction resulted in an increase in the proportion of young children with protective IgG concentrations, compared with before vaccine introduction (from 0-33% of infants with VT-specific levels over the correlate of protection in 2009, to 60-94% of infants in 2011). However, among those vaccinated in infancy, GMCs of all ten VTs had waned rapidly by the age of 1, but rose again later in childhood. GMCs among children aged 10-14 years were consistently high over time (eg, the range of GMCs across survey rounds were between 0·45 μg/mL and 1·00 μg/mL for VT 23F and between 2·00 μg/mL and 3·11 μg/mL for VT 19F). PCV10 in a 3 + 0 schedule elicited protective IgG levels during infancy, when disease risk is high. The high antibody levels in children aged 10-14 years might indicate continued exposure to vaccine serotypes due to residual carriage or to memory responses to cross-reactive antigens. Despite rapid waning of IgG after vaccination, disease incidence among young children in this setting remains low, suggesting that lower thresholds of antibody, or other markers of immunity (eg, memory B cells), may be needed to assess population protection among children who have aged past infancy. Gavi, the Vaccine Alliance; Wellcome Trust.

Some structural features of the peptide profile of myelin basic protein-hydrolyzing antibodies in schizophrenic patients.

The antibodies of schizophrenic patients that hydrolyze myelin basic protein (MBP) have been actively studied recently, but the mechanism of the catalytic properties of immunoglobulin molecules remains unknown. Determination of specific immunoglobulin sequences associated with the high activity of MBP proteolysis will help to understand the mechanisms of abzyme catalysis. In the course of comparative mass spectrometric analysis of IgG peptides from the blood serum of patients with acute schizophrenia and healthy people, 12 sequences were identified, which were found only in antibodies that hydrolyze MBP. These sequences belong to IgG heavy chains and κ- and λ-type light chains, with eight of them belonging to variable domains. The content of peptides from the variable regions of the light chains does not correlate with the proteolytic activity of IgG to MBP in patients with schizophrenia, whereas for two sequences from the variable regions of the heavy chains (FQ(+0.98)GWVTMTR and *LYLQMN(+0.98)SLR), an increase in activity with increasing their concentration. The results suggest that these sequences may be involved in one way or another in MBP hydrolysis.

COVID-19 vaccine induced poor neutralization titers for SARS-CoV-2 omicron variants in maternal and cord blood.

Maternally derived antibodies are crucial for neonatal immunity. Understanding the binding and cross-neutralization capacity of maternal and cord antibody responses to SARS-CoV-2 variants following COVID-19 vaccination in pregnancy can inform neonatal immunity. Here we characterized the binding and neutralizing antibody profile at delivery in 24 pregnant individuals following two doses of Moderna mRNA-1273 or Pfizer BNT162b2 vaccination. We analyzed for SARS-CoV-2 multivariant cross-neutralizing antibody levels for wildtype Wuhan, Delta, Omicron BA1, BA2, and BA4/BA5 variants. In addition, we evaluated the transplacental antibody transfer by profiling maternal and umbilical cord blood. Our results reveal that the current COVID-19 vaccination induced significantly higher RBD-specific binding IgG titers in cord blood compared to maternal blood for both the Wuhan and Omicron BA1 strain. Interestingly, the binding IgG antibody levels for the Omicron BA1 strain were significantly lower when compared to the Wuhan strain in both maternal and cord blood. In contrast to the binding, the Omicron BA1, BA2, and BA4/5 specific neutralizing antibody levels were significantly lower compared to the Wuhan and Delta variants. It is interesting to note that the BA4/5 neutralizing capacity was not detected in either maternal or cord blood. Our data suggest that the initial series of COVID-19 mRNA vaccines were immunogenic in pregnant women, and vaccine-elicited binding antibodies were detectable in cord blood at significantly higher levels for the Wuhan and Delta variants but not for the Omicron variants. Interestingly, the vaccination did not induce neutralizing antibodies for Omicron variants. These results provide novel insight into the impact of vaccination on maternal humoral immune response and transplacental antibody transfer for SARS-CoV-2 variants and support the need for bivalent boosters as new variants emerge.

A Study of Clinical Manifestations and their Association with Antinuclear Antibodies in Various Autoimmune Connective Tissue Disorders.

Autoimmune connective tissue diseases (AICTD) present with a myriad of clinical manifestations, including cutaneous. These disorders occur because of immune dysregulation that produces autoantibodies targeting connective tissue and internal organs. Screening these autoantibodies not only aids in the diagnosis but also in predicting specific organ involvement and the risk of complications related to the disease. This study was conducted (a) to study various cutaneous and systemic manifestations of AICTD, (b) to study the antinuclear antibody (ANA) profile and (c) to determine the association between systemic manifestations and antinuclear antibodies. Thirty cases of autoimmune connective tissue disease were recruited for the study. A physical examination, clinical profile and ANA profile were done. Nonscarring alopecia (83.3%) was the commonest cutaneous manifestation noted, followed by photosensitivity (73.3%). The most common system affected was musculoskeletal (67%), followed by renal (40%). Anti-dsDNA antibodies were significantly associated with musculoskeletal involvement (85%) with a P value of 0.038 and anti-Sm antibodies with neurological involvement (87%), followed by renal involvement (75%) with a P value of 0.018 and 0.001, respectively. Anti-SCL 70 antibodies were significantly associated with lung involvement (75%), with a P value of 0.009 and the presence of anti-SS-A antibodies with cardiovascular involvement (40%) with a P value of 0.014. Antinuclear antibodies are diagnostic as well as prognostic biomarkers for AICTD and contribute to precision medicine. These antibodies serve as markers to pursue involvement of organs, which in turn helps the treating physician to choose appropriate preventive measures.

Refractory Seizures with Encephalopathy May be Due to Hashimoto Encephalopathy

Background: Hashimoto's encephalopathy, also known as steroid-responsive encephalopathy associated with autoimmune thyroiditis, is a relatively uncommon neurological disorder, mostly in adults, with an extremely rare occurrence in children. Clinical Description: A 9-year-old girl presented with unprovoked seizures and encephalopathy. She had been diagnosed with hypothyroidism, at around 6 ½ years of age, though was noncompliant to therapy with levothyroxine. Management: The child was managed with intravenous (IV) antiepileptics and other supportive care. Seizures were refractory and with worsening sensorium, she required mechanical ventilation. The magnetic resonance imaging of the brain was unremarkable, as also the cerebrospinal analysis. Autoimmune encephalitis panel was negative. The electroencephalogram showed background activity of 10–11 Hz and few areas with generalized slow waves. As she was a known case of hypothyroidism without taking thyroid supplements for the past few months, thyroid profile was sent. Reports showed FT3-1.1 pg/dL, FT4-0.515 ng/dL, and thyroid-stimulating hormone (TSH) - 107.3 μIU/mL. Thyroid antibody profile revealed antithyroid peroxidase antibody &gt;500 IU/mL and antithyroglobulin antibody &gt;1000 IU/mL. Following this, an ultrasound of the neck was done which showed features of thyroiditis. Considering the possibility that the underlying thyroiditis could explain the obtunded state and refractory seizures, the patient was started on levothyroxine and IV methylprednisolone. The sensorium of the child improved dramatically, and she got extubated. There were no further seizures and her TSH level reduced gradually and eventually, she was discharged. Conclusions: In a child with altered sensorium and refractory seizures, Hashimoto encephalopathy is a diagnosis of exclusion and may be considered when most of the common causes of encephalopathy and seizures have been ruled out, especially in the setting of some clinical clues of hypothyroidism. The condition is often reversible with good response to steroid therapy.

Profile and clinical relevance of non-criteria antiphospholipid antibodies in patients diagnosed with or highly suspected of APS.

This study investigates the positivity and relevance of non-criteria aPLs with clinical phenotypes in patients highly suspected of or diagnosed with APS. Outpatient cases were included from a prospectively maintained database, and patients were grouped into APS (n = 168), seronegative APS (SNAPS, n = 9), those meeting the diagnostic criteria for clinical events without laboratory results (only-event, n = 15), those that had aPL positivity without clinical manifestations (asymptomatic APA, n = 39), and healthy controls (n = 88). Criteria aPL results and APS-related clinical features were extracted. Sixteen non-criteria aPLs were tested and analysed. LA, aCL and anti-β2 glycoprotein-I were positive in 84.5%, 61.3% and 74.4% of APS patients, and 61.5%, 59.0% and 74.4% of asymptomatic APA patients, respectively. In patients negative for criteria serological tests, 23 out of 24 were positive for at least one non-criteria aPL. Triple-positive patients also had significantly higher tests of some aPLs in comparison with other groups. Stroke was associated with anti-phosphatidyl-inositol (aPI) IgG and anti-phosphatidyl-glycerol (aPG) IgG. Late embryonic loss correlated with aPI IgM, and premature birth/eclampsia was associated with aPI IgG and aPG IgG. There were also positive associations between heart valve lesions and anti-phosphatidylserine-prothrombin (aPS/PT) IgM, APS nephropathy and anti-phosphatidyl-choline IgG or aPS/PT IgG, and livedo reticularis and anti-phosphatidyl-ethanolamine IgM. The prevalence of non-criteria aPLs differed from diagnostic biomarkers in patients diagnosed with or suspected of APS. Detection of aPLs provided additive value in the evaluation of APS-related clinical manifestations.

Viral co-infection, autoimmunity, and CSF HIV antibody profiles in HIV central nervous system escape

Antiretroviral therapy (ART) suppresses plasma and cerebrospinal fluid (CSF) HIV replication. Neurosymptomatic (NS) CSF escape is a rare exception in which CNS HIV replication occurs in the setting of neurologic impairment. The origins of NS escape are not fully understood. We performed a case-control study of asymptomatic (AS) escape and NS escape subjects with HIV-negative subjects as controls in which we investigated differential immunoreactivity to self-antigens in the CSF of NS escape by employing neuroanatomic CSF immunostaining and massively multiplexed self-antigen serology (PhIP-Seq). Additionally, we utilized pan-viral serology (VirScan) to deeply profile the CSF anti-viral antibody response and metagenomic next-generation sequencing (mNGS) for pathogen detection. We detected Epstein-Barr virus (EBV) DNA more frequently in the CSF of NS escape subjects than in AS escape subjects. Based on immunostaining and PhIP-Seq, there was evidence for increased immunoreactivity against self-antigens in NS escape CSF. Finally, VirScan revealed several immunodominant epitopes that map to the HIV envelope and gag proteins in the CSF of AS and NS escape subjects. Whether these additional inflammatory markers are byproducts of an HIV-driven process or whether they independently contribute to the neuropathogenesis of NS escape will require further study.

Clinical, neurophysiological and serological clues for the diagnosis of neuromyotonia and distinction from cramp-fasciculation syndrome

Neuromyotonia and cramp-fasciculation syndrome diagnosis currently relies on neurophysiological examination. In this study we investigated the clinical features and neural antibody profile of patients with neuromyotonia and cramp-fasciculation syndrome to assess the diagnostic value of serological testing. Available sera from adult patients with electromyography-defined neuromyotonia and cramp-fasciculation syndrome were tested for neural antibodies by indirect immunofluorescence on mouse brain sections and live cell-based assays. Forty patients were included, 14 with neuromyotonia and 26 with cramp-fasciculation syndrome. Neural antibodies were detected in 10/10 neuromyotonia sera, most commonly against contactin-associated protein 2 (7/10, 70%), and in 1/20 (5%) cramp-fasciculation syndrome sera. Clinical myokymia, hyperhidrosis, and paresthesia or neuropathic pain were more common in neuromyotonia and mostly associated with contactin-associated protein 2 antibodies. Central nervous system involvement was present in 4/14 (29%) neuromyotonia patients. A tumor was detected in 13/14 (93%) neuromyotonia patients (thymoma, 13), and in 4/26 (15%) with cramp-fasciculation syndrome (thymoma, 1; other neoplasms, 3). Twenty-one/27 (78%) patients achieved a significant improvement or complete remission. Our findings highlight clinical, neurophysiological and serological clues that can be useful in the diagnosis of neuromyotonia and cramp-fasciculation syndrome. Antibody testing is valuable for neuromyotonia diagnosis, while its usefulness in cramp-fasciculation syndrome confirmation is limited.

A Serological Analysis of the Humoral Immune Responses of Anti-RBD IgG, Anti-S1 IgG, and Anti-S2 IgG Levels Correlated to Anti-N IgG Positivity and Negativity in Sicilian Healthcare Workers (HCWs) with Third Doses of the mRNA-Based SARS-CoV-2 Vaccine: A Retrospective Cohort Study.

With SARS-CoV-2 antibody tests on the market, healthcare providers must be confident that they can use the results to provide actionable information to understand the characteristics and dynamics of the humoral response and antibodies (abs) in SARS-CoV-2-vaccinated patients. In this way, the study of the antibody responses of healthcare workers (HCWs), a population that is immunocompetent, adherent to vaccination, and continuously exposed to different virus variants, can help us understand immune protection and determine vaccine design goals. We retrospectively evaluated antibody responses via multiplex assays in a sample of 538 asymptomatic HCWs with a documented complete vaccination cycle of 3 doses of mRNA vaccination and no previous history of infection. Our sample was composed of 49.44% males and 50.56% females, with an age ranging from 21 to 71 years, and a mean age of 46.73 years. All of the HCWs' sera were collected from April to July 2022 at the Sant'Elia Hospital of Caltanissetta to investigate the immunologic responses against anti-RBD, anti-S1, anti-S2, and anti-N IgG abs. A significant difference in age between HCWs who were positive and negative for anti-N IgG was observed. For anti-S2 IgG, a significant difference between HCWs who were negative and positive compared to anti-N IgG was observed only for positive HCWs, with values including 10 (U/mL)-100 (U/mL); meanwhile, for anti-RBD IgG and anti-S1 IgG levels, there was only a significant difference observed for positive HCWs with diluted titers. For the negative values of anti-N IgG, among the titer dilution levels of anti-RBD, anti-S1, and anti-S2 IgG, the anti-S2 IgG levels were significantly lower than the anti-RBD and anti-S1 levels; in addition, the anti-S1 IgG levels were significantly lower than the anti-RBD IgG levels. For the anti-N IgG positive levels, only the anti-S2 IgG levels were significantly lower than the anti-RBD IgG and anti-S1 IgG levels. Finally, a logistic regression analysis showed that age and anti-S2 IgG were negative and positive predictors of anti-N IgG levels, respectively. The analysis between the vaccine type and mixed mRNA combination showed higher levels of antibodies in mixed vaccinated HCWs. This finding disappeared in the anti-N positive group. Most anti-N positive HCWs showed antibodies against the S2 domain and were young subjects. Therefore, the authors suggest that including the anti-SARS-CoV-2-S2 in antibody profiles can serve as a complementary testing approach to qRT-PCR for the early identification of asymptomatic infections in order to reduce the impact of potential new SARS-CoV-2 variants. Our serological investigation on the type of mRNA vaccine and mixed mRNA vaccines shows that future investigations on the serological responses in vaccinated asymptomatic patients exposed to previous infection or reinfection are warranted for updated vaccine boosters.

P-337 Does Endometriosis Have More Detrimental Effect on Ovarian Reserve in the Presence of Autoimmunity? A Prospective Observational Study

Abstract Study question Is the coexistence of autoimmunity more harmful to ovarian reserve in endometriosis patients? Summary answer The presence of autoimmunity does have additional harm to ovarian reserve in patients with endometriosis. What is known already It is known that endometriosis has a negative impact on ovarian reserve via different pathways. The presence of inflammation, increased reactive oxygen substances, and iron deposits in ovarian endometrioma have detrimental effects on the ovarian reserve. Although endometriosis was reported to have co-incidence with immunologic disorders up to 50%, there is not enough publication to assess the impact of autoimmunity on ovarian reserve in endometriosis. Study design, size, duration A prospective observational study including 100 women with endometriosis was performed between January 2022 and January 2023 in the endometriosis center of a tertiary university hospital. Participants/materials, setting, methods Patients who were diagnosed with endometriosis, under age 40, without confirmed systemic disease, enrolled in the study. All patients were assessed by physical examination and routine ultrasound check. Endometriosis diagnosis was based on that assessment or verified previous surgery. The blood samples were collected from all patients. Serum anti-mullerian hormone (AMH) and immunologic panel tests (anti-nuclear antibody profile, lupus anticoagulant antibody, thyroid antibodies) were analyzed. Main results and the role of chance A total of 99 patients were enrolled in the analysis (one patient was excluded because of missing parameters). Patients were divided into two groups depending on the presence of any autoimmune antibody. There were 58 patients with negative test (autoimmune (-) group) and 41 patients with at least one positive antibody (autoimmune (+) group). The demographic parameters, including age, fertility situation, abuse, pain scores, endometrioma diameter, and laterality, were similar between the groups. The anti-mullerian hormone levels were significantly lower in the autoimmune (+) group, (Respectively with interquartile ranges; 2.2 ng/ml (0.6-5.3) vs. 0.9 ng/ml (0.19-3.6), p = 0.01) When the results were adjusted according to the age and surgical history, the significant negative effect of autoimmunity on the ovarian reserve disappeared (p = 0.156). Limitations, reasons for caution The lack of sufficient studies in this area makes our results important. The small sample size and lack of subgroup analysis depending on different autoimmune diseases limit the study's strength. Wider implications of the findings This observational study revealed that almost half of the endometriosis patients have autoimmunity. However, the results supported the existing data; the impact of autoimmunity on ovarian reserve in endometriosis is a novel research field, and the present study suggests it should be further investigated in endometriosis patients. Trial registration number Not Applicable

Modeling the sequence dependence of differential antibody binding in the immune response to infectious disease.

Past studies have shown that incubation of human serum samples on high density peptide arrays followed by measurement of total antibody bound to each peptide sequence allows detection and discrimination of humoral immune responses to a variety of infectious diseases. This is true even though these arrays consist of peptides with near-random amino acid sequences that were not designed to mimic biological antigens. This "immunosignature" approach, is based on a statistical evaluation of the binding pattern for each sample but it ignores the information contained in the amino acid sequences that the antibodies are binding to. Here, similar array-based antibody profiles are instead used to train a neural network to model the sequence dependence of molecular recognition involved in the immune response of each sample. The binding profiles used resulted from incubating serum from 5 infectious disease cohorts (Hepatitis B and C, Dengue Fever, West Nile Virus and Chagas disease) and an uninfected cohort with 122,926 peptide sequences on an array. These sequences were selected quasi-randomly to represent an even but sparse sample of the entire possible combinatorial sequence space (~1012). This very sparse sampling of combinatorial sequence space was sufficient to capture a statistically accurate representation of the humoral immune response across the entire space. Processing array data using the neural network not only captures the disease-specific sequence-binding information but aggregates binding information with respect to sequence, removing sequence-independent noise and improving the accuracy of array-based classification of disease compared with the raw binding data. Because the neural network model is trained on all samples simultaneously, a highly condensed representation of the differential information between samples resides in the output layer of the model, and the column vectors from this layer can be used to represent each sample for classification or unsupervised clustering applications.

Idiopathic pulmonary hemosiderosis as an occupational disease: a clinical case

BACKGROUND. Idiopathic pulmonary hemosiderosis (IPH) in adults is a rare pathology of unknown etiology. We did not find information about IPH in adults with occupational hazards in the available literary sources, which makes this work relevant.&#x0D; OBJECTIVE. To analyze the peculiarities of the IPH course in a patient with 23 years’ experience as a gas-electric welder at factories by our own clinical observation.&#x0D; RESULTS AND DISCUSSION. Changes in the form of heterogeneous pneumatization of the lung parenchyma due to the increased interstitial component were determined on the computer tomography of the chest cavity (CT of the chest cavity) 1.5 years before the patient’s visit, but no additional examination was prescribed, and only the diagnosis “Chronic obstructive pulmonary disease” (COPD) was made. Negative dynamics due to the increase of miliary nodular dissemination of the lungs was revealed on the CT scan of the chest after 1.5 years. IPH was already detected pathohistologically after videothoracoscopy of the right lung with biopsy. Shortness of breath and cough increased in the patient, but apart from treatment aimed at COPD treating, no other therapy was prescribed (this therapy did not have a positive effect). The patient underwent a comprehensive immunological examination: the indicators of the anti-neutrophil cytoplasmic antibodies (ANCA) profile and the complex immunological blood test were within the normal range, which ruled out pulmonary vasculitis and an immune-mediated process. Considering the positive Quantiferon test, the patient was examined and the tuberculosis was excluded. Patient have not been suffered from hemoptysis and anemia from the moment of detection of the first changes on the CT scan of chest up to the present time. Due to treatment, the clinical and radiological stabilization of the process was determined after 4 months: the clinical symptoms of the disease decreased; small nodular shadows with areas of fibrosis, which are characteristic of the period of remission, were determined on the CT scan of the chest.&#x0D; CONCLUSIONS. IPH course features in a patient with a professional route are: a long period of development with COPD manifestations (without effect of therapy), absence of hemoptysis and anemia, normal indicators of the ANCA profile and complex immunological examination, a positive Quantiferon test. Corticosteroid therapy in high doses has a positive effect, which is manifested in the clinical and radiological stabilization of the process. The mechanism of IPH development may have been a toxic mechanism (23 years of work experience as a gas-electric welder at factories). Timely detection of IPH and timely prescribed corticosteroid therapy will prevent the progression of the process and the development of complications, as well as reduce mortality from this disease. Patients with IPH should be under dynamic observation due to timely evaluation of CT-dynamics of the process in the lungs and correction of the dose of corticosteroids.

Pregnancy outcomes in 1869 pregnancies in a large cohort from the Spanish Society of Rheumatology Lupus Register (RELESSER)

IntroductionObstetric complications are more common in women with systemic lupus erythematosus (SLE) than in the general population. ObjectiveTo assess pregnancy outcomes in women with SLE from the RELESSER cohort after 12 years of follow-up. MethodsA multicentre retrospective observational study was conducted. In addition to data from the RELESSER register, data were collected on obstetric/gynaecological variables and treatments received. The number of term pregnancies was compared between women with pregnancies before and after the diagnosis of SLE. Further, clinical and laboratory characteristics were compared between women with pregnancies before and after the diagnosis, on the one hand, and with and without complications during pregnancy, on the other. Bivariate and multivariate analyses were carried out to identify factors potentially associated with complications during pregnancy. ResultsA total of 809 women were included, with 1869 pregnancies, of which 1395 reached term. Women with pregnancies before the diagnosis of SLE had more pregnancies (2.37 vs 1.87) and a higher rate of term pregnancies (76.8% vs 69.8%, p < 0.001) compared to those with pregnancies after the diagnosis. Women with pregnancies before the diagnosis were diagnosed at an older age (43.4 vs 34.1 years) and had more comorbidities. No differences were observed between the groups with pregnancies before and after diagnosis in antibody profile, including anti-dsDNA, anti-Sm, anti-Ro, anti-La, lupus anticoagulant, anticardiolipin or anti-beta-2-glycoprotein. Overall, 114 out of the 809 women included in the study experienced complications during pregnancy, including miscarriage, preeclampsia/eclampsia, foetal death, and/or preterm birth. Women with complications had higher rates of antiphospholipid syndrome (40.5% vs 9.9%, p < 0.001) and higher rates of positivity for IgG anticardiolipin (33.9% vs 21.3%, p = 0.005), IgG anti-beta 2 glycoprotein (26.1% vs 14%, p = 0.007), and IgM anti-beta 2 glycoprotein (26.1% vs 16%, p = 0.032) antibodies, although no differences were found regarding lupus anticoagulant. Among the treatments received, only heparin was more commonly used by women with pregnancy complications. We did not find differences in corticosteroid or hydroxychloroquine use. ConclusionsThe likelihood of term pregnancy is higher before the diagnosis of SLE. In our cohort, positivity for anticardiolipin IgG and anti-beta-2- glycoprotein IgG/IgM, but not lupus anticoagulant, was associated with a higher risk of poorer pregnancy outcomes.