Elevated IgG Research Articles

Expert consensus on the diagnosis and treatment of immunoglobulin-G4 related ophthalmic disease (2024 edition)

Immunoglobulin-G4 related ophthalmic disease (IgG4-ROD) is an immune-mediated fibroin flammatory condition characterized by ocular mass lesions and elevated plasma IgG4 level. Since all the ocular tissues can be involved, and it can be accompanied by multiple organ and systemic diseases, the diagnosis and treatment require multidisciplinary collaboration. The Oculoplastic and Orbital Disease Group of Chinese Ophthalmological Society of Chinese Medical Association and the Chinese Rheumatology Association convened experts in ophthalmology, and rheumatology and immunology, and formulated "Expert consensus on the diagnosis and treatment of immunoglobulin-G4 related ophthalmic disease (2024 edition)" for the diagnosis and treatment of IgG4-ROD based on domestic and international studies and experience. The consensus mainly standardized the diagnostic criteria of IgG4-ROD from the aspects of ocular imaging, serum IgG4 level and ocular histopathology, and recommended the methods and indications of drug therapy (glucocorticoids, immunosuppressants and biologics) and surgical treatment.

Autoimmune and Neoplastic Outcomes After the mRNA Vaccination: The Role of T Regulatory Cell Responses

A plethora of autoimmune disease incidences occured after COVID-19 mRNA injections were rolled out. Aggressive cancer cases have occurred in the bodies of recipients at sites where the mRNA was injected and at distant metastatic sites. The mRNA vaccines cause thymic involution (shrinking) and dysregulation of the T regulatory (Treg) and T effector (Teff) homeostatic cell balance. Activated immune cells deliver spike protein to the thymic epithelial cells, damaging them. The Treg/Teff balance may determine the fate of autoimmunity and/or cancer and is different for patients with cancer versus those without any cancerous tissues. Repeated mRNA injections lead to empirical evidence of impaired immune functions (elevated IgG4, PD-L1), associated with increased autoimmunity and cancer risks, and decreased resistance to infections. In the with-cancer recipients, the mRNA vaccine may be associated with either autoimmunity or further progression of the cancer(s) depending on the immunotherapy treatment the patient receives. When an antigen stimulates the immune system, specific T regulatory (Treg) and T effector (Teff) subpopulations develop from naïve T cells. An imbalance between Treg and Teff cells can lead to either cancer or autoimmunity. Treg cells are beneficial in that they protect from autoimmunity. However, they suppress the immune response to tumors. In this review, we analyze Treg responses after SARS-CoV-2 mRNA vaccination and find distinct pathological responses under differing conditions. Injection with modified mRNA can lead to a delayed but highly active immune response, resulting in overactivation of the inflammasome. The mRNA “vaccine” induces a very strong IgG antibody response, while suppressing CD8+ T cell activation. Exosomes distribute the recombinant, synthetic spike protein and the mRNA encoding it throughout the organism. In cancer patients, disease progression depends on the starting point of the cancer patient at the time of injection and the type of cancer treatment underway. Migration of circulating dendritic cells and Treg cells back to the thymus, while they are carrying spike protein, damages the medullary thymic epithelial cells and accelerates thymic involution, a direct cause of inflammaging and immunosenescence. In summary, the Treg responses to mRNA injections and subsequent mRNA-encoded SARS-CoV-2 spike protein expression may disrupt immune capacities resulting in accelerated development of autoimmune disease and cancer. The processes discussed here are consistent with both epidemiological findings and case reports.

CpG-adjuvanted virus-like particle vaccine induces protective immunity against Leishmania donovani infection.

Visceral leishmaniasis (VL) poses a significant public health challenge due to the lack of an approved human vaccine. We attempted to enhance the efficacy of virus-like particle vaccines expressing the Leishmania donovani promastigote surface antigen (LdPSA-VLP) by adjuvanting with CpG oligodeoxynucleotide (CpG-ODN). Here, adjuvanted vaccine-induced immune responses and their efficacies in mice challenged with mCherry-expressing L. donovani promastigotes were evaluated. Adjuvanted LdPSA-VLP vaccination significantly elevated parasite-specific IgG, IgG1, IgG2a, and IgG2b serum antibody levels. Additionally, vaccinated mice exhibited enhanced germinal center B cells and splenic T cell activities, compared to unimmunized mice. Importantly, adjuvanted LdPSA-VLPs reduced the levels of inflammatory cytokines IFN-γ and IL-6 in visceral organs, leading to decreased total parasite burden and protection against L. donovani challenge. Our findings indicate that CpG-ODN enhanced the protection conferred by LdPSA-VLPs, offering a promising step toward effective VL vaccine development.

Effects of Bacterial Lysates on TLRs/NF-κB Pathway, Immune Function, and Prognosis in Children with Pulmonary Infection Caused by Streptococcus pneumoniae

Background: Bacterial lysates, as immunomodulators, may play a role in regulating the host immune response. Objectives: This study aimed to investigate the effects of bacterial lysates OM85-BV in treating pulmonary infections caused by Streptococcus pneumoniae in children. Methods: A total of 120 children with S. pneumoniae pulmonary infection were divided into two groups: The control group and the OM85-BV group, with a 1: 1 ratio. The control group received intravenous mezlocillin at 100 mL/kg/d, while the OM85-BV group, in addition to mezlocillin, received OM85-BV orally at 3.5 mg per dose. The improvement of clinical symptoms and pulmonary function indexes—including respiratory rate, tidal volume, volume to peak expiratory flow as a proportion of exhaled volume, and time to peak tidal expiratory flow as a proportion of expiratory time—were compared. Additionally, levels of C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), soluble interleukin-2 receptor (sIL-2R), T lymphocyte subsets, and immunoglobulins in serum were analyzed. Results: Compared to the control group, the OM85-BV group showed a significant decrease in respiratory rate and an increase in tidal volume, volume to peak expiratory flow, and time to peak tidal expiratory flow (P < 0.05 for all). The OM85-BV group also had significantly lower levels of serum inflammatory factors such as CRP, TNF-α, IL-6, and sIL-2R. In terms of immune function, the OM85-BV group showed increased levels of T lymphocyte subsets CD3+, CD4+, and CD4+/CD8+ ratios, with a decrease in CD8+, as well as elevated serum IgA and IgG levels. The total effective rate of treatment in the OM85-BV group was significantly higher than in the control group (P < 0.05). Conclusions: The addition of OM85-BV to the treatment of S. pneumoniae pulmonary infection in children significantly improves clinical symptoms, lung function, and immune function, while reducing the inflammatory response. OM85-BV appears to inhibit the activation of the toll-like receptors (TLRs) and nuclear factor kappa-B (NF-κB) pathway.

Study on the variation characteristics of serum lymphocyte subsets, immunoglobulins, and complement levels in patients with cheilitis

Objective: To analyze the variations of serum lymphocyte subsets, immunoglobulins, and complement levels in patients with cheilitis, and to explore the associations between the changes in serum immune levels and the onset of cheilitis. Methods: A retrospective analysis was conducted on 153 patients with cheilitis who visited the Department of Stomatology, The First Affiliated Hospital of Zhengzhou University from January 2017 to December 2023. They were compared with 50 healthy individuals who visited the physical examination department during the same period. The changes of serum lymphocyte subsets, immunoglobulins, and complement levels in patients with cheilitis were analyzed. Main detection indicators as the percentage of total T lymphocytes (T%), helper/inducer T lymphocytes (CD4+T%), absolute numbers of total T lymphocytes (T#), absolute numbers of helper/inducer T lymphocytes (CD4+T#), percentage of natural killer cells (NK%), absolute numbers of B lymphocytes (B#), immunoglobulins IgG, IgM and complement C3, C4 were included. Multivariate logistic regression was used to explore the relationship between serum lymphocyte subsets, immunoglobulins, complement levels and cheilitis. Subgroup analysis was further conducted on patients with cheilitis based on gender, age, cheilitis type and severity. Results: The levels of T% [69.54% (64.41%, 75.14%)], CD4+T% [(35.09±7.10)%], T# [1 328.00 (1 054.00, 1 560.50)], and CD4+T# [653.00 (505.00, 831.50)] in the cheilitis group were significantly lower than those in the control group respectively [72.33% (69.41%, 75.47%), (39.07±5.84)%, 1 483.50 (1 245.75, 1 805.25), 769.00 (687.25, 933.00), with the corresponding statistical test results of Z=-2.64, P=0.008; t=3.58, P<0.001; Z=-2.80, P=0.005; Z=-3.80, P<0.001]. The level of NK% [16.21% (12.16%, 21.29%)] was significantly higher in the cheilitis group compared to the control group [14.61% (10.97%, 17.87%)] (Z=-2.28, P=0.023). IgG [12.29 (10.77, 13.73) g/L] and IgM levels [1.18 (0.86, 1.58) g/L] were significantly higher in the cheilitis group than in the control group respectively [11.52 (10.16, 12.91) g/L, 0.99 (0.77, 1.26) g/L] (Z=-2.24, P=0.025; Z=-2.10, P=0.036), while complement C3 [(1.09±0.17) g/L] and C4 levels [0.23 (0.19, 0.28) g/L] were significantly lower in the cheilitis group compared to the control [(1.18±0.17) g/L, 0.31(0.24, 0.35) g/L] (t=3.10, P=0.002; Z=-4.79, P<0.001). Logistic regression analysis showed that elevated IgG (P=0.021), decreased C4 (P<0.001), decreased CD4+T% (P=0.003), and decreased T# (P=0.035) were independent influencing factors for the occurrence of cheilitis. The rate of abnormal lymphocyte immune analysis in the cheilitis group [68.0% (104/153)] was significantly higher than that in the control group [24.0% (12/50)] (χ2=29.76, P<0.001). The rate of abnormal immunoglobulin and complement detection in the cheilitis group [41.8% (64/153)] was significantly higher than that in the control group [4.0% (2/50)] (χ2=24.58, P<0.001). The rate of detection abnormalities in female patients with cheilitis [51.5% (53/103)] was significantly higher than in male ones [22.0% (11/50)] (χ2=12.00, P=0.001). Patients with granulomatous cheilitis had significantly lower levels of T# [1 136.50 (663.75, 1 310.50)] and B# [162.50 (104.00, 225.50)] compared to those with chronic cheilitis [1 366.00 (1 063.03, 1 602.00), 202.48 (148.00, 298.00)] (Z=-2.35, P=0.019; Z=-2.16, P=0.031). Conclusions: Patients with cheilitis exhibit a certain degree of imbalance on cellular immunity, humoral immunity, and innate immunity, which may be related to the onset of cheilitis.

High Prevalence of Anti-Prothrombin IgM and IgG Autoantibodies in Women With Unexplained Recurrent Pregnancy Loss.

To investigate the association between anti-prothrombin IgM and IgG antibodies and recurrent pregnancy loss (RPL) in a cohort of Lebanese women, and their impact on pregnancy outcomes. This was a retrospective case-control study involving 207 women with RPL and 179 age-matched multiparous controls. Quantitative sandwich ELISA assayed anti-prothrombin IgM and IgG antibodies. Univariate and multivariate logistic regression were employed to assess the risk imparted by anti-prothrombin antibodies, while ROC analysis was used to determine their sensitivity and specificity. Our study revealed that women with RPL had significantly higher serum levels of anti-prothrombin IgM and IgG than controls. Univariate regression analysis demonstrated that elevated anti-prothrombin IgM (OR = 1.13; 95% CI = 1.07, 1.19; P < 0.001) and IgG (OR = 1.05; 95% CI = 1.03, 1.08; P < 0.001) were associated with increased RPL risk. Multivariate analysis confirmed these findings, indicating that anti-prothrombin IgM (aOR = 1.13; 95% CI = 1.05, 1.20; P < 0.001) and IgG (aOR = 1.08; 95% CI = 1.05, 1.11; P < 0.001) are independent risk factors. ROC analysis yielded an AUC of 0.720 for IgM and 0.649 for IgG, underscoring their predictive value and offering hope for improved risk assessment and management of RPL. Elevated levels of anti-prothrombin IgM and IgG are significantly associated with RPL, suggesting an autoimmune component to pregnancy loss. These findings highlight the importance of screening for these antibodies in women with unexplained RPL to guide management and therapeutic strategies.

6797 Pituitary Apoplexy as initial Presentation of IgG4-Related hypophysitis

Abstract Disclosure: M. Alameri: None. A. Alnuaimi: None. Introduction: IgG4-related hypophysitis is a rare disease due to IgG4 lymphoplasmacytic infiltration of the pituitary gland. It can either be isolated or part of a multisystemic disease. We report a rare case of pituitary apoplexy as first manifestation of IgG4-RD. Case report: A 27-year-old previously healthy male presented to emergency department with severe headache, nausea, vomiting and visual impairment. CT brain showed a large sellar suprasellar mass of 3cm with thick rim enhancement. Blood test showed evidence of central adrenal insufficiency, central hypothyroidism and secondary hypogonadism. Patient was started on hormone replacement therapy for central adrenal insufficiency and central hypothyroidism. Pituitary magnetic resonance imaging (MRI) demonstrated a 3.1 x 2.4 x 2.4 cm well-defined large sellar suprasellar mass with thick rim enhancement with intrinsic heterogeneous T2 signal with hypointense T1 signal on fat-suppressed post contrast imaging consistent with necrotic haemorrhagic suggestive of pituitary apoplexy and background of hypophysitis. Upward displacement of optic chiasm was noted without involvement of cavernous sinus. The patient was initially treated with high-dose steroids aiming for reduction of the pituitary mass. However, eventually, he underwent transsphenoidal surgery due to alternated level of consciousness. Pituitary histopathology showed that vast majority of the tissue is necrotic. A small fragment of viable anterior pituitary tissue is present, which measures up to 5.5 mm in greatest dimension which exhibited marked chronic inflammation, predominantly comprised of small lymphocytes. Plasma cells were present and staining with IgG/IgG4 revealed two high-power fields with clusters of approximately 25 and 50 IgG4 positive plasma cells, respectively. Blood test showed elevated blood IgG4 levels of &amp;gt;2.60 g/L (normal reference range 0.03-2.01 g/L). Case was discussed at Endocrine MDT meeting which agreed that blood tests result along with histopathology findings were in keeping with IgG4-Related hypophysitis as per the Mayo Clinic, Leporati and Japan-Korea proposed criteria. Because blood IgG4 levels were elevated, a systemic evaluation was performed. No evidence of other systemic disease found. High dose steroid therapy was initiated, which reduced remnant inflammatory sellar changes. Discussion and conclusion: IgG4-related pituitary disease should be considered as differential diagnosis in unusual presentations of pituitary apoplexy in the context of sellar suprasellar hypophysitis. Presentation: 6/2/2024

7229 A Rare Case of Igg4 Hypophysitis Presenting as Hypogonadotropic Hypogonadism

Abstract Disclosure: C. Dimech: None. G. Jaiswal: None. Hypophysitis is a rare pituitary disorder including a broad range of inflammatory processes which affect the pituitary gland and infundibulum. Previously reported as 1 per 9 million individuals, the true incidence of hypophysitis per year is largely unknown due to the increase of novel etiologies such as immunoglobulin G4 (IgG4)- related disease. IgG4-related hypophysitis (IgG4-RH) was first clinically described in 2004 and later biopsy proven in 2007. The main clinical features are elevated serum IgG4 level and IgG4-positive lymphocyte infiltration of tissues on histopathology. IgG4-RH is reported to account for 1.3% of primary hypophysitis with 3.2:1 incidence ratio of men to women, in the 6th decade of life. Here we present a case of a 68-year-old Caucasian male who presented for evaluation of hypogonadotropic hypogonadism. As fasting morning testosterone levels were significantly low, MRI pituitary was completed which revealed a homogenously enhancing pituitary gland with thickened, nodular enhancement of the pituitary infundibulum. Subsequent lab work-up revealed normal function of remaining anterior pituitary without evidence of central vasopressin deficiency. Evaluation of underlying etiologies was unremarkable except for significantly elevated IgG4 levels (472mg/dL). Based on the significantly elevated IgG-4 levels (&amp;gt;135 mg/dl) and the radiographic findings of the pituitary infundibulum, the diagnosis of possible IgG4-RH was made. The patient was initiated on treatment with rituximab and glucocorticoid therapy with prednisone. Following 3 months of medical therapy, MRI pituitary showed resolution of stalk inflammation, confirming diagnosis of IgG4- RH. Presentation: 6/1/2024

Association of gut commensal translocation with autoantibody production in systemic lupus erythematosus

Abstract Objective Bacterial translocation across the gut barrier has been implicated in the pathogenesis of systemic lupus erythematosus (SLE), though underlying mechanisms remain unclear. This study aimed to investigate the role of translocated bacteria in the context of molecular mimicry by utilizing lupus model mice and blood samples from untreated SLE patients. Methods Bacterial translocation was evaluated using nonselective cultured mesenteric lymph nodes (MLNs) from B6SKG mice, a lupus model characterized by impaired TCR signalling and gut dysbiosis. The relationships of detected pathobionts with autoantibody production were examined using in vivo experiments, enzyme-linked immunosorbent assay, immunoblotting, and epitope mapping. Results Culture-based bacterial profiling in MLNs demonstrated that Lactobacillus murinus was enriched in B6SKG mice with elevated anti-dsDNA IgG levels. Subcutaneous injection of heat-killed L. murinus induced anti-dsDNA IgG production without altering T- or B cell subset composition. Immunoblotting and mass spectrometry analysis identified a peptide ATP-binding cassette (ABC) transporter as a molecular mimicry antigen, with its cross-reactivity in lupus mice confirmed by serological assays and in vivo immunization. The L. murinus ABC transporter exhibited surface epitopes that were cross-reactive with sera from lupus mice and patients. The ABC transporter from R. gnavus, known for its pathogenic role in lupus patients, had a similar epitope sequence to that of the L. murinus ABC transporter and reacted with lupus sera. Conclusion ABC transporters from gut bacteria can serve as cross-reactive antigens that may promote anti-dsDNA antibody production in genetically susceptible mice. These findings underscore the role of commensal-derived molecular mimicry and bacterial translocation in lupus pathogenesis.

DENV Peptides Delivered as Spherical Nucleic Acid Constructs Enhance Antigen Presentation and Immunogenicity in vitro and in vivo.

The global prevalence of Dengue virus (DENV) infection poses a significant health risk, urging the need for effective vaccinations. Peptide vaccines, known for their capacity to induce comprehensive immunity against multiple virus serotypes, offer promise due to their stability, safety, and design flexibility. Spherical nucleic acid (SNA), particularly those with gold nanoparticle cores, present an attractive avenue for enhancing peptide vaccine efficacy due to their modularity and immunomodulatory properties. The spherical nucleic acid-TBB (SNA-TBB), a novel nanovaccine construct, was fabricated through the co-functionalization process of SNA with epitope peptide, targeting all four serotypes of the DENV. This innovative approach aims to enhance immunogenicity and provide broad-spectrum protection against DENV infections. The physicochemical properties of SNA-TBB were characterized using dynamic light scattering, zeta potential measurement, and transmission electron microscopy. In vitro assessments included endocytosis studies, cytotoxicity evaluation, bone marrow-dendritic cells (BMDCs) maturation and activation analysis, cytokine detection, RNA sequencing, and transcript level analysis in BMDCs. In vivo immunization studies in mice involved evaluating IgG antibody titers, serum protection against DENV infection and safety assessment of nanovaccines. SNA-TBB demonstrated successful synthesis, enhanced endocytosis, and favorable physicochemical properties. In vitro assessments revealed no cytotoxicity and promoted BMDCs maturation. Cytokine analyses exhibited heightened IL-12p70, TNF-α, and IL-1β levels. Transcriptomic analysis highlighted genes linked to BMDCs maturation and immune responses. In vivo studies immunization with SNA-TBB resulted in elevated antigen-specific IgG antibody levels and conferred protection against DENV infection in neonatal mice. Evaluation of in vivo safety showed no signs of adverse effects in vital organs. The study demonstrates the successful development of SNA-TBB as a promising nanovaccine platform against DENV infection and highlights the potential of SNA-based peptide vaccines as a strategy for developing safe and effective antiviral immunotherapy.

Genetic variants associated with immune-mediated liver injury from checkpoint inhibitors.

The clinical features, liver histology, and genetic variants in 57 patients with moderate to severe immune-mediated liver injury from checkpoint inhibitors (ILICI) are presented. Between 2010 and 2022, 57 high-causality ILICI cases were enrolled in the Drug-Induced Liver Injury Network. HLA and selected candidate gene variants were tested for association with ILICI risk compared to the general population and other DILI controls. The 57 high-causality cases were attributed to pembrolizumab (16), ipilimumab (15), ipilimumab and nivolumab (13), and other immune checkpoint inhibitors (13) and occurred at a median of 72 days after the first infusion. Median age was 57.8 years, 66% male, and 89% were non-Hispanic Whites. At DILI onset, 53% had hepatocellular, 35% mixed, and 15% cholestatic, with younger patients more likely to have hepatocellular injury. The incidence of ANA, smooth muscle antibody, and elevated IgG levels was low (17%, 23%, and 0%), but corticosteroids were given to 86%. Microgranulomas and hepatic steatosis were seen in 54% and 46% of the 26 liver biopsies, respectively. The HLA alleles associated with autoimmune hepatitis were not over-represented, but 2 host immune response genes (EDIL3 and SAMA5A) and 3 other genes (GABRP, SMAD3, and SLCO1B1) were associated with ILICI (OR: 2.08-2.4, p<0.01). ILICI typically arises within 12 weeks of initiating immunotherapy and is self-limited in most cases. Genetic variants involved in host T-cell regulation and drug disposition were identified, implicating these pathways in the pathogenesis of ILICI. If validated, these findings could lead to improved diagnostic instruments and possible treatments for ILICI.

Clinical immunological characteristics of anti-interferon-γ autoantibodies syndrome: a 3 year prospective cohort study

ABSTRACT Anti-interferon-γ autoantibodies (AIGAs) syndrome is susceptible to disseminated opportunistic infections due to increased AIGAs, but its clinical immunological characteristics remain unrecognized. We conducted a prospective cohort study between January 2021 and December 2023, recruiting patients with opportunistic infections who were categorized into AIGAs-positive and AIGAs-negative groups. Clinical immunological data and outcomes were documented. A subset of AIGAs-positive patients received glucocorticoid treatment, and its effectiveness was evaluated. A total of 238 patients were enrolled, with 135 AIGAs-positive and 103 AIGAs-negative patients. AIGAs-positive patients showed higher rates of multiple pathogen dissemination, shorter progression-free survival (PFS), and increased exacerbation frequency. They also showed elevated erythrocyte sedimentation rate (ESR), globulin (GLB), immunoglobulin (Ig)G, IgE, and IgG4 levels. Among the 70 AIGAs-positive patients monitored for at least six months, three subtypes were identified: high AIGAs titer with immune damage, high AIGAs titer without immune damage, and low AIGAs titer without immune damage. Of the 55 patients followed for 1 year, decreasing AIGAs titer and immune indices (GLB, IgG, IgE, IgG4) were observed. Among the 31 patients with high AIGAs titer and immune damage treated with low-dose glucocorticoids at the stable phase, reductions were observed in immune indices and AIGAs titer in 67.74% of cases. In summary, AIGAs-positive patients exhibit infectious and immunological characteristics. Elevated AIGAs, IgG, IgG4, and IgE indicate abnormal immune damages. AIGAs titer generally decrease over time. Stable-phase AIGAs-positive patients can be categorized into three subtypes, with those having high AIGAs titer and increased immune indices potentially benefitting from glucocorticoid treatment.

Assessing IgG4-related ophthalmic disease and its mimics: a comparison of ACR/EULAR, organ-specific and revised comprehensive diagnostic criteria

AimsDiagnosis of IgG4-related ophthalmic disease (IgG4-ROD) rests on the correlation of clinical features, serological testing and histopathology, using internationally accepted diagnostic criteria for objective interpretation; however, several mimickers of IgG4-RD...

Cerebrospinal fluid characteristics of patients presenting for evaluation of pediatric acute-neuropsychiatric syndrome.

This study characterizes cerebral spinal fluid (CSF) indices including total protein, the albumin quotient, IgG index and oligoclonal bands in patients followed at a single center for pediatric acute-neuropsychiatric syndrome (PANS) and other psychiatric/behavioral deteriorations. In a retrospective chart review of 471 consecutive subjects evaluated for PANS at a single center, navigational keyword search of the electronic medical record was used to identify patients who underwent lumbar puncture (LP) as part of the evaluation of a severe or atypical psychiatric deterioration. Psychiatric symptom data was ascertained from parent questionnaires and clinical psychiatric evaluations. Inclusion criteria required that subjects presented with psychiatric deterioration at the time of first clinical visit and had a lumbar puncture completed as part of their evaluation. Subjects were categorized into three subgroups based on diagnosis: PANS (acute-onset of severe obsessive compulsive disorder (OCD) and/or eating restriction plus two other neuropsychiatric symptoms), autoimmune encephalitis (AE), and "other neuropsychiatric deterioration" (subacute onset of severe OCD, eating restriction, behavioral regression, psychosis, etc; not meeting criteria for PANS or AE). 71/471 (15.0 %) of patients underwent LP. At least one CSF abnormality was seen in 29% of patients with PANS, 45% of patients with "other neuropsychiatric deterioration", and 40% of patients who met criteria for autoimmune encephalitis. The most common findings included elevated CSF protein and/or albumin quotient. Elevated IgG index and IgG oligoclonal bands were rare in all three groups. Elevation of CSF protein and albumin quotient were found in pediatric patients undergoing LP for evaluation of severe psychiatric deteriorations (PANS, AE, and other neuropsychiatric deteriorations). Further studies are warranted to investigate blood brain barrier integrity at the onset of the neuropsychiatric deterioration and explore inflammatory mechanisms.

IgG4-Related Dacryoadenitis With Fibrous Mass in a 19-Month-Old Child: Case Report and Literature Review.

A 19-month-old boy presented with eyelid swelling, proptosis, and upgaze limitation in the OD. The radiological study showed a homogeneous mass enclosing the lacrimal gland. Near-total tumor excision revealed IgG4-related orbital disease. Eosinophilia, serum IgG4, and IgE elevations were detected without extraorbital involvement. The patient received oral prednisolone for 4 months postoperatively and remained relapse-free for 27 months. Among the 17 well-documented pediatric cases of IgG4-related orbital disease in the literature (including this case), 59% were female, and the median age was 10 years; 2 patients were under 2 years old. The disease was unilateral in 82% of the patients and caused a soft tissue mass in 88%, involving the lacrimal gland in 53%. Nine patients received immunosuppression only, 4 surgery and immunosuppression, and 2 only surgical excision. Treatment results were reported in 13 patients, and all were favorable. IgG4-related dacryoadenitis with a fibrous mass may occur in very young children, responding well to surgical excision and steroids. Although pediatric IgG4-related orbital disease is not well-characterized yet, it may manifest differently from its adult variant.

Acute presentation of autoimmune hepatitis -from acute hepatitis to ALF and ACLF.

Acute presentation of autoimmune hepatitis (AIH) occurs in 22-43% of all AIH cases, and is not a rare condition. Rather than constituting a single disease entity, it represents a clinical spectrum characterized by considerable variability in severity and the presence of preexisting chronic AIH. This spectrum ranges from acute AIH and acute severe AIH to AIH presenting as acute liver failure (ALF) or as acute-on-chronic liver failure (ACLF), contingent upon factors such as coagulopathy, hepatic encephalopathy, and underlying liver disease. Diagnosing acute presentation of AIH can be particularly challenging due to the frequent absence of classical serologic signatures such as autoantibodies and elevated IgG levels. Histopathological examination remains essential for diagnosis, typically necessitating percutaneous or transjugular liver biopsy. Corticosteroids (CS) are recommended for the management of acute AIH and acute severe AIH with coagulopathy. However, the therapeutic response to CS should be meticulously monitored. If a poor response is anticipated, liver transplantation (LT) should be promptly considered. For AIH presenting as ALF with encephalopathy or ACLF with advanced underlying liver disease, LT is generally advised. Nonetheless, there is potential for a trial of CS therapy in cases of ALF with low MELD scores or ACLF without encephalopathy. This review provides an overview of the latest findings concerning the definition, diagnosis, and management of acute presentation of AIH.

Only repeatedly elevated IgG4 levels in primary sclerosing cholangitis may distinguish a particular patient phenotype

BackgroundPrimary sclerosing cholangitis (PSC) is a chronic liver disease leading to inflammation with scaring and strictures of bile ducts, which can lead to liver cirrhosis. A subtype of PSC characterized by high serum IgG4 (sIgG4) levels has been reported to be associated with poor outcomes, but the exact role and the longitudinal development of sIgG4 levels in PSC progression remains to be clarified. The aim of this study was to investigate if subsequent analysis of sIgG4 levels allows the identification of the PSC phenotype with high sIgG4.MethodssIgG4 values were repeatedly analysed in a well-characterized European PSC cohort of 110 individuals. Biochemical parameters, clinical endpoints, death and liver transplantation were compared between PSC subgroups.Results12.7% (n = 14) of PSC patients showed increased sIgG4 levels (PSC-IgG4). The values normalized in 57.1% (n = 8; PSC-IgG4norm) during follow-up measurements, whereas the values remained permanently elevated in 42.9% (n = 6; PSC-IgG4const). Serum values of AP and γGT were significantly higher in PSC-IgG4const compared to PSC-IgG4norm at final blood sampling. Furthermore, mean age at PSC diagnosis was markedly lower in PSC-IgG4const compared to PSC-IgG4norm.ConclusionsThis is the first study analyzing longitudinal development of sIgG4 in PSC. Our data indicate that only sequential determination of sIgG4 levels allow to accurately distinguish between the PSC phenotype with high sIgG4 and PSC with low sIgG4.Graphical abstract

Abstract We076: Humoral profile of individuals with Chagas Cardiomyopathy

Chronic Chagas cardiomyopathy (CCC) is the most severe manifestation of Chagas disease and one of the main causes of cardiomyopathy in Latin America. The number of individuals infected with Trypanosoma cruzi (T. cruzi), the causative parasite of Chagas disease, exceeds 6 million, with an increasing presence in non-endemic regions such as Europe, Japan, Canada, and the USA. While approximately 70% of infected individuals remain asymptomatic and are categorized as indeterminate (IND), the remaining 30% develop cardiac manifestations several decades after the initial infection. Despite extensive efforts to elucidate the triggers and predictors underlying the progression from IND to CCC, the exact causative factors remain elusive. Hypotheses have been proposed that focus on the specific humoral response, including the production of antibodies that effectively neutralize the parasite or demonstrate cross-reactivity between parasite and cardiac proteins. Here, using PhIP-seq technology we comprehensively characterized the IgG profile of 897 T. cruzi seropositive individuals. We identified 628 epitopes with increased IgG reactivity in chronic T. cruzi seropositive individuals. Mucin TcMUCII, trans-sialidase, and MASP emerged as the primary classes of proteins showing elevated IgG response. Remarkably, the serum of CCC individuals showed robustly elevated reactivity against 84 epitopes compared to IND individuals, while IgG response against 23 epitopes was increased in the serum of IND individuals. Trans-sialidase and mucin-like glycoproteins were the main classes of proteins distinguishing these two groups. Among all epitopes with increased reactivity in the serum of CCC individuals compared to IND, 36 epitopes showed linear sequence similarity to 210 human proteins highly expressed in human heart. These included sarcomere structural proteins, suggesting potential cross-reactions between the antibodies targeting T. cruzi epitopes and proteins with key roles in cardiac function. Overall, our study describes the humoral landscape of Chagas disease, expanding the pool of potential candidates for future vaccine development or as targets for infection/trials efficiency monitoring. Additionally, we identified potential sources of antibody cross-reaction that may contribute to CCC progression, including epitopes sharing sequence similarities with key proteins involved in cardiac structure.

Crohn’s patients and healthy infants share immunodominant B cell response to commensal flagellin peptide epitopes

Inflammatory bowel disease (IBD) is a chronic manifestation of dysregulated immune response to the gut microbiota in genetically predisposed hosts. Nearly half of patients with Crohn's disease (CD) develop selective serum immunoglobulin (Ig)G response to flagellin proteins expressed by bacteria in the Lachnospiraceae family. This study aimed to identify the binding epitopes of these IgG antibodies and assess their relevance in CD and in homeostasis. Sera from an adult CD cohort, a treatment-naïve pediatric CD cohort, and 3 independent non-IBD infant cohorts were analyzed using novel techniques including a flagellin peptide microarray and a flagellin peptide cytometric bead array. A dominant B cell peptide epitope in patients with CD was identified, located in the highly conserved "hinge region" between the D0 and D1 domains at the amino-terminus of Lachnospiraceae flagellins. Elevated serum IgG reactivity to the hinge peptide was strongly associated with incidence of CD and the development of disease complications in children with CD up to 5 years in advance. Notably, high levels of serum IgG to the hinge epitope were also found in most infants from 3 different geographic regions (Uganda, Sweden, and the United States) at 1 year of age, which decrements rapidly afterward. These findings identified a distinct subset of patients with CD, united by a shared reactivity to a dominant commensal bacterial flagellin epitope, that may represent failure of a homeostatic response to the gut microbiota beginning in infancy.

Immunogenic and diagnostic potential of recombinant apical membrane antigen-1 from Plasmodium malariae

The apical membrane antigen-1 (AMA-1) is a crucial target for malaria management and prevention strategies. While the immunogenicity of AMA-1 has been extensively studied for Plasmodium falciparum and Plasmodium vivax, there is a notable scarcity of information for Plasmodium malariae. In this study, recombinant PmAMA-1 was expressed in Escherichia coli, and its integrity was confirmed via western blotting and indirect immunofluorescence assays. Immunization of BALB/c mice with rPmAMA-1 emulsified in Freund's adjuvant resulted in significantly elevated specific IgG antibodies, predominantly IgG1. The immune response exhibited Th1, Th2, and Th17 phenotypes, with a notable Th1 bias. Antisera from immunized mice effectively recognized native PmAMA-1 on P. malariae. These results suggest that PmAMA-1 is a promising target for both vaccine development and diagnostic applications for P. malariae infections, offering dual preventive and diagnostic benefits in malaria control.