Cell Antibodies Research Articles

Autoimmune Gastritis in Korean Patients with Gastric Tumors: Clinicopathologic Correlations and Diagnostic Histological Features.

Autoimmune gastritis (AIG) is a corpus-dominant atrophic gastritis in which patients are positive for antiparietal cell antibody (APCA) and/or anti-intrinsic factor antibody. The risk of developing gastric cancer in patients with AIG remains unclear, and reliable frequency data of AIG in patients with gastric cancer are lacking. We included 624 Korean patients with gastric tumors (612 gastric cancers and 12 neuroendocrine tumors) who had APCA results and were available for AIG evaluation. In patients with positive APCA results, endoscopy and histology findings were reviewed to diagnose AIG. Of the 624 patients, 37 (5.9%) tested positive for APCA, and ultimately, 11 (1.8%) met the diagnostic criteria for AIG (5 both endoscopy and histology findings, 4 endoscopy-only findings, 2 histology-only findings). The frequency of AIG in patients with gastric cancer was 1.3% (8/612), and that in patients with neuroendocrine tumors was 25.0% (3/12). Of the 11 patients with AIG, serum Helicobacter pylori antibody was positive in six patients (54.5%), all of whom had gastric cancer. Histologically, three patients showed pure AIG, four patients exhibited concurrent AIG and H. pylori gastritis, and the findings for four were indefinite for AIG. The pepsinogen (PG) I levels and PG I/II ratio were significantly lower in patients with gastric cancer with AIG than in patients with gastric cancer without AIG (p=0.042 and p=0.016, respectively). The frequency of AIG in gastric cancer patients was very low compared to that in patients with neuroendocrine tumors. Rather, concurrent AIG and H. pylori gastritis was common in patients with AIG with gastric cancer.

Effect of vaccination against Mycoplasma hyopneumoniae on divergent pig genetic groups

The bacterium Mycoplasma hyopneumoniae (Mhp) causes a chronic infectious respiratory disease in pigs, leading to important economic losses. This study aimed to compare the immune response of the local Piau breed and a commercial line to Mhp vaccination. For this, two phases were carried out. In the first, gene expression of toll-like receptors (TLR2, TLR4, TLR6, and TLR10) and cytokines (IL2, IL6, IL8, IL10, IL12, IL13, TNFα, and TGFβ) was assessed in porcine blood mononuclear cells (PBMC) from the two genetic groups before and after vaccination. In the second experiment, nitric oxide production, specific antibodies, and gene expression of toll-like receptors and cytokines were evaluated in bronchoalveolar lavage fluid (BALF) cells of vaccinated and unvaccinated pigs. After vaccination against Mhp, TLR2, TLR4, TLR6, TLR10, IL6, TNFα, and TGFβ expression levels were elevated in PBMC from commercial animals, and TLR6, TLR10, and TGFβ expression levels were elevated in PBMC from the Piau group. Vaccination also increased the production of Mhp-specific IgG antibodies in BALF cells in the Piau breed. Comparison of the two genetic groups revealed differences in TNFα and IL10 expression in BALF cells. These results show that Piau pigs have different immune responses to vaccination compared with commercial animals. It is worth noting that these genetic differences between both genetic groups may be related to phenotypic differences in Mhp resistance or susceptibility.

Unveiling the enigmatic roles of basophils in HIV infection: A narrative review.

The intricate interplay between the human immunodeficiency virus (HIV) and the immune system has long been a focal point in understanding disease progression. Among the myriad of immune cells, basophils, often overshadowed, have recently emerged as pivotal contributors to the complex immunological landscape of HIV infection. This paper aims to provide a succinct overview of the enigmatic roles of basophils in HIV pathogenesis, elucidating their multifaceted functions and implications. Basophils, conventionally perceived as minor players in immune responses, exhibit active participation in HIV infection. Their activation triggered by viral antigens, cytokines, and immune complexes orchestrates a cascade of immune events, influencing immune modulation, cytokine release, and the activation of adaptive immune cells. Furthermore, basophils function as antigen-presenting cells, potentially impacting viral dissemination and immune dysregulation. Additionally, basophils serve as crucial regulators in HIV infection through cytokine secretion, notably interleukin (IL)-4, IL-13, and IL-3, influencing immune cell differentiation, polarization, and antibody production. Their interactions with various immune cells intricately shape the immune response against HIV, impacting disease progression and immune equilibrium. Moreover, harnessing basophils as potential vaccine targets or immune modulators represents a compelling avenue for future research. In conclusion, the emerging understanding of basophils' multifaceted involvement in HIV infection challenges prior perceptions and underscores their significance in shaping immune responses and disease outcomes. This abstraction highlights the need for continued research to unlock the full potential of basophils, paving the way for novel strategies in combatting HIV/AIDS.

TM9SF1 expression correlates with autoimmune disease activity and regulates antibody production through mTOR-dependent autophagy

BackgroundTransmembrane 9 superfamily member 1 (TM9SF1) is involved in inflammation. Since both inflammatory and autoimmune diseases are linked to immune cells regulation, this study investigated the association between TM9SF1 expression and autoimmune disease activity. As B cell differentiation and autoantibody production exacerbate autoimmune disease, the signaling pathways involved in these processes were explored.MethodsTm9sf1−/− mouse rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) models were used to verify the relationship between gene expression and disease severity. Peripheral blood mononuclear cells (PBMCs) from 156 RA and 145 SLE patients were used to explore the relationship between TM9SF1 expression and disease activity. The effectiveness of TM9SF1 as a predictor of disease activity was assessed using multiple logistic regression and receiver operating characteristic (ROC) curves. The signaling pathways regulated by TM9SF1 in B cell maturation and antibody production were conducted by plasma cell induction experiment in vitro.ResultsThe Tm9sf1−/− RA and SLE model mice produced fewer autoantibodies and showed reduced disease severity relative to wild-type (WT) mice. TM9SF1 levels in PBMCs of patients were higher than those in healthy controls, and were reduced in patients with low disease activity relative to those with active RA and SLE. Furthermore, TM9SF1 levels were positively linked with autoantibody titers and pro-inflammatory cytokine levels in both diseases. ROC analyses indicated TM9SF1 outperformed several important clinical indicators in predicting disease activity (area under the curve (AUC) were 0.858 and 0.876 for RA and SLE, respectively). In vitro experiments demonstrated that Tm9sf1 knockout blocked differentiation of B cells into antibody-producing plasma cells by activating mTOR and inhibiting autophagy, and mTOR inhibitors such as rapamycin could reverse this effect.ConclusionsThe primary finding was the identification of the molecular mechanism underlying autophagy regulation in B cells, in which Tm9sf1 knockout was found to modulate mTOR-dependent autophagy to block B cell differentiation into antibody-secreting plasma cells. It was also found that TM9SF1 expression level in PBMCs was an accurate indicator of disease activity in patients with RA and SLE, suggesting its clinical potential for monitoring disease activity in these patients.

Circulating Autoantibodies in Adults with Hashimoto’s Thyroiditis: New Insights from a Single-Center, Cross-Sectional Study

Background: Hashimoto’s thyroiditis (HT) is a common autoimmune thyroid disorder characterized by elevated anti-thyroid peroxidase (A-TPO) antibodies. HT frequently coexists with other autoimmune conditions, which are marked by organ-specific and non-organ-specific autoantibodies, reflecting a deregulated immune response. However, the burden and clinical significance of these circulating autoantibodies in adult patients with HT remains unclear. Methods: A cross-sectional study was conducted at the University Hospital “R. Dulbecco” in Catanzaro, Italy, from November 2023 to May 2024, involving 200 euthyroid adults. The study population comprised 100 A-TPO-positive HT patients and 100 A-TPO-negative controls, matched for age and sex. Laboratory assessments included thyroid function tests and detection of autoantibodies [e.g., antinuclear antibodies (ANA), anti-parietal cell antibodies (APCA), and anti-neutrophil cytoplasmic antibodies (ANCA)]. Cytokine profiles were also measured using sensitive chemiluminescent multi-array technology. Results: HT patients were predominantly female (77.0%) with a median age of 56 years. Compared to controls, HT patients had higher median thyroid stimulating hormone (TSH) levels (2.215 vs. 1.705 μIU/mL, p = 0.025). Circulating autoantibodies were more prevalent in the HT group, with higher rates of APCA positivity (16.3% vs. 4.1%, p = 0.008) and atypical ANCA positivity (27.3% vs. 10.2%, p = 0.003). This suggests an increased risk for autoimmune gastritis and systemic inflammation. Additionally, HT patients with positive atypical ANCA showed elevated inflammatory cytokines, particularly interleukin-1 alpha (IL-1α), in female patients (p = 0.035). Conclusions: HT is significantly associated with a higher prevalence of circulating autoantibodies, such as APCA and atypical ANCA, which may indicate a heightened risk for autoimmune gastritis and broader autoimmune involvement. Detecting these autoantibodies in HT patients could serve as markers for more severe autoimmune dysfunction. These findings emphasize the need for proactive screening, especially in older patients and those with elevated A-TPO levels. Further research is essential to better understand the clinical implications and develop targeted management strategies for these patients.

Bispecific antibody (ABL602 2 + 1) induced bistable acute myeloid leukemia kinetics

ABL602 2 + 1, a bispecific antibody with two distinct domains binding to CLL-1 on leukemias and CD3 on T cells, exhibits superior T cell activation and tumour lysing activity. Treatment outcomes of bispecific antibody rely on acute myeloid leukemia cell replication and antibody induced tumour lysing, but their quantitative relationship was unknown. Mathematical models are employed to quantitatively investigate HL-60 cell kinetics determined by bispecific antibody and tumour burden. First, we analysed cytotoxicity assay data testing HL-60 cell against bispecific antibody and T cells, and found efficiency of bispecific antibody induced tumour lysing increases but saturates with increase of HL-60 cell, T cell and bispecific antibody concentration. As a result, their interaction leads to bistable HL-60 cell kinetics; namely, at a given bispecific antibody and T cell concentration interval, HL-60 cell kinetics with small tumour burdens are inhibited but refractory to large tumour burdens. T cell concentration is strong negatively correlated with HL-60 cell concentration. With bispecific antibody clearance, observed bistable HL-60 cell kinetics still exists. Our finding explains observed phenomenon that bispecific antibody was less efficacious at high tumour burden even with enough activated cytotoxic CD8 + T cells. Maintaining high antibody concentration and preventing T-cell exhaustion are equivalently important to sustain long-term control.

Proangiogenic effect of thyrotropin receptor stimulating antibody in human umbilical vein endothelial cells.

This study aims to investigate the role of TRAb in the angiogenesis associated with Graves' disease (GD) and to elucidate its underlying mechanisms. Human thyroid follicular epithelial cells (Nthy-ori 3-1) and human umbilical vein endothelial cells (HUVECs) were treated with the monoclonal thyroid-stimulating antibody M22 and thyroid-stimulating hormone (TSH) at various concentrations. Cell viability, migration, and tube formation were evaluated using CCK-8, wound healing, and tube formation assays, respectively. Protein expressions of TSHR receptor (TSHR) and phosphorylated AKT (p-AKT) in M22-induced HUVECs were quantified via Western blotting. Proteomic analysis was employed to identify changes in protein expression profiles and relevant signaling pathways in GD specimens. Immunofluorescence assays were conducted to detect and localize the expressions of CD34 and PROX1 in GD specimens and normal thyroid tissues. M22 stimulated the proliferation of Nthy-ori 3-1 cells and HUVECs in a dose-dependent manner, while TSH exhibited an inverted U-shaped dose-response effect. M22 also dose-dependently promoted angiogenesis, and more effectively induced tube formation in HUVECs compared to TSH, although the difference was not statistically significant. A total of 16 proteins were significantly upregulated and 24 were downregulated in M22-induced HUVECs. Notably, PROX1, the most significantly upregulated protein, is closely associated with angiogenesis. Immunofluorescence confirmed that PROX1 was significantly more expressed in thyroid tissues from GD patients compared to normal tissues adjacent to papillary thyroid cancer (PTC), and it co-localized with CD34. TRAb enhances angiogenesis and upregulates PROX1 expression in HUVECs, suggesting a novel possible mechanism for goiter formation in GD.

Advances in the study of artemisinin and its derivatives for the treatment of rheumatic skeletal disorders, autoimmune inflammatory diseases, and autoimmune disorders: a comprehensive review

Artemisinin and its derivatives are widely recognized as first-line treatments for malaria worldwide. Recent studies have demonstrated that artemisinin-based antimalarial drugs, such as artesunate, dihydroartemisinin, and artemether, not only possess excellent antimalarial properties but also exhibit antitumor, antifungal, and immunomodulatory effects. Researchers globally have synthesized artemisinin derivatives like SM735, SM905, and SM934, which offer advantages such as low toxicity, high bioavailability, and potential immunosuppressive properties. These compounds induce immunosuppression by inhibiting the activation of pathogenic T cells, suppressing B cell activation and antibody production, and enhancing the differentiation of regulatory T cells. This review summarized the mechanisms by which artemisinin and its analogs modulate excessive inflammation and immune responses in rheumatic and skeletal diseases, autoimmune inflammatory diseases, and autoimmune disorders, through pathways including TNF, Toll-like receptors, IL-6, RANKL, MAPK, PI3K/AKT/mTOR, JAK/STAT, and NRF2/GPX4. Notably, in the context of the NF-κB pathway, artemisinin not only inhibits NF-κB expression by disrupting upstream cascades and/or directly binding to NF-κB but also downregulates multiple downstream genes controlled by NF-κB, including inflammatory chemokines and their receptors. These downstream targets regulate various immune cell functions, apoptosis, proliferation, signal transduction, and antioxidant responses, ultimately intervening in systemic autoimmune diseases and autoimmune responses in organs such as the kidneys, nervous system, skin, liver, and biliary system by modulating immune dysregulation and inflammatory responses. Ongoing multicenter randomized clinical trials are investigating the effects of these compounds on rheumatic, inflammatory, and autoimmune diseases, with the aim of translating promising preclinical data into clinical applications.

MiR-375: it could be a general biomarker of metabolic changes and inflammation in type 1 diabetes patients and their siblings.

Type 1 diabetes (T1D) is a chronic autoimmune illness that results in loss of pancreatic beta cells and insulin insufficiency. MicroRNAs (miRNAs) are linked to immune system functions contributing to the pathophysiology of T1D, miRNA-375 is significantly expressed in the human pancreas and its circulatory levels might correspond to beta cell alterations. Pancreatic islet cell antibodies (ICA) and Glutamic acid decarboxylase antibodies (GADA) have roles in autoimmune pathogenesis and are predictive markers of T1D. The aim of this work was to detect serum level changes of miRNA-375, ICA, and GADA in T1D patients, and their siblings compared to healthy controls and correlate them with T1D biochemical parameters. The study included 66 T1D patients (32 males and 34 females; age range 3-18 years), 22 patients' siblings (13 males and 9 females; age range 4-17 years), and 23 healthy controls (7 males and 16 females; age range 4-17 years). MiRNA-375 levels were measured using quantitative reverse transcription polymerase chain reaction (RT-qPCR), while ICA and GADA levels were measured using enzyme-linked immunosorbent assay (ELISA). Data analysis was done utilizing SPSS-17 software. MiR-375 levels were downregulated in T1D patients and further decreased in their siblings when compared to healthy controls. Furthermore, miR-375 exhibited inverse correlations with HbA1c levels but no correlations with Total Insulin Dose, disease duration, or autoantibodies (GADA & ICA). Our study indicates that miR-375 is significantly downregulated in children with T1D and their siblings, suggesting its potential role as a biomarker for beta-cell function and glycemic control.

Generation of canine neutralizing antibodies against canine parvovirus by single B cell antibody technology.

Canine parvovirus (CPV) is a significant threat to canines and is widely distributed worldwide. While vaccination is currently the most effective preventive measure, existing vaccines are not able to offer comprehensive and dependable protection against CPV infection. Hence, there is a need to explore alternative or complementary strategies to tackle this problem. In this study, we present an approach for the efficient screening of canine antibodies targeting CPV using a single B cell antibody technique. We sorted single IgM- IgG+ CPV+ B cells from canine peripheral blood mononuclear cells using fluorescence-activated cell sorting (FACS) and obtained the variable region genes of heavy and light chains (VH and VL) by nested PCR amplification. Canine monoclonal antibodies were expressed in HEK293 cells, and a total of 60 antibodies were obtained, five of which demonstrated neutralizing activity against CPV. Those findings demonstrate the effectiveness of the method for obtaining canine monoclonal antibodies, which in turn aids in the identification and screening of neutralizing antibodies against various canine pathogens.

Sensory neurons regulate stimulus-dependent humoral immunity in mouse models of bacterial infection and asthma

Sensory neurons sense pathogenic infiltration to drive innate immune responses, but their role in humoral immunity is unclear. Here, using mouse models of Streptococcus pneumoniae infection and Alternaria alternata asthma, we show that sensory neurons are required for B cell recruitment and antibody production. In response to S. pneumoniae, sensory neuron depletion increases bacterial burden and reduces B cell numbers, IgG release, and neutrophil stimulation. Meanwhile, during A. alternata-induced airway inflammation, sensory neuron depletion decreases B cell population sizes, IgE levels, and asthmatic characteristics. Mechanistically, during bacterial infection, sensory neurons preferentially release vasoactive intestinal polypeptide (VIP). In response to asthma, sensory neurons release substance P. Administration of VIP into sensory neuron-depleted mice suppresses bacterial burden, while VIPR1 deficiency increases infection. Similarly, exogenous substance P delivery aggravates asthma in sensory neuron-depleted mice, while substance P deficiency ameliorates asthma. Our data, thus demonstrate that sensory neurons release select neuropeptides which target B cells dependent on the immunogen.

The function of serine/threonine-specific protein kinases in B cells.

The serine/threonine-specific protein kinases (STKs) are important for cell survival, proliferation, differentiation, and apoptosis. In B cells, these kinases play indispensable roles in regulating important cellular functions. Multiple studies on human and other animal cells have shown that multiple STKs are involved in different stages of B cell development and antibody production. However, how STKs affect B cell development and function is still not completely understood. Considering that B cells are clinically important in immunity and diseases, our understanding of STKs' roles in B cells is in great need of investigation with current technologies. Investigating serine/threonine kinases will not only deepen our insight into B cell-related disorders but also facilitate the identification of more effective drug targets for conditions like lymphoma and systemic lupus erythematosus.

B cell immune repertoire sequencing in tobacco cigarette smoking, vaping, and chronic obstructive pulmonary disease in the COPDGene cohort.

Cigarette smoking (CS) impairs B cell function and antibody production, increasing infection risk. The impact of e-cigarette use ('vaping') and combined CS and vaping ('dual-use') on B cell activity is unclear. To examine B cell receptor sequencing (BCR-seq) profiles associated with CS, vaping, dual-use, COPD-related outcomes, and demographic factors. BCR-seq was performed on blood RNA samples from 234 participants in the COPDGene study. We assessed multivariable associations of B cell function measures (immunoglobulin heavy chain (IGH) subclass expression and usage, class-switching, V-segment usage, and clonal expansion) with CS, vaping, dual-use, COPD severity, age, sex, and race. We adjusted for multiple comparisons using the Benjamini-Hochberg method, identifying significant associations at 5% FDR and suggestive associations at 10% FDR. Among 234 non-Hispanic white (NHW) and African American (AA) participants, CS and dual-use were significantly positively associated with increased secretory IgA production, with dual-use showing the strongest associations. Dual-use was positively associated with class switching and B cell clonal expansion, indicating increased B cell activation, with similar trends in those only smoking or only vaping. We observed significant associations between race and IgG antibody usage. AA participants had higher IgG subclass proportions and lower IgM usage compared to NHW participants. CS and vaping additively enhance B cell activation, most notably in dual-users. Self-reported race was strongly associated with IgG isotype usage. These findings highlight associations between B cell activation and antibody transcription, suggesting potential differences in immune and vaccine responses linked to CS, vaping, and race.

Development and Characterization of A Novel SpyTagged Modular Nanobody as A Detection Platform for CD22-Positive Cells.

CD22, as a surface protein of B cells, is used in the diagnosis and target-specific immunotherapy of B-cell malignancies. SpyTag and SpyCatcher, on the other hand, are two covalently coupled proteins capable of developing a bi- or multi-specific modular protein. The aim of this study was to develop FITC-conjugated SpyCatcher-SpyTagged anti-CD22 Nanobody (FITC-SpyC-SpyT-CD22Nb) to recognize CD22 on the surface of malignant B cells. In this experimental study, the SpyTag-CD22Nb construct was subcloned into a pET22 vector and expressed in E. coli BL21 (DE3). After purification using His-tag affinity chromatography, the size of the eluted protein was confirmed on a Western blot. In addition, the SpyCatcher protein, subcloned into pET28, was expressed in E. coli BL21 (DE3), purified by His-tag affinity chromatography and subjected to FITC labeling. FITC-SpyCatcher and SpyTag-CD22Nb were coupled in a 1:1 molar ratio. The specific binding of the produced FITC-SpyC-SpyT-CD22Nb was tested using CD22+ Raji and CD22- K562 cell lines and was evaluated by flow cytometry. SpyTag-CD22Nb and SpyCatcher were successfully expressed in E. coli BL21 (DE3). The 1:1 molar ratio of SpyTag-CD22Nb and FITC-SpyCatcher successfully formed FITC-SpyC-SpyT-CD22Nb at room temperature. The flow cytometry results showed that FITC-SpyC-SpyT-CD22Nb specifically binds to the CD22+ Raji cells, while there is no binding to the CD22- K562 control cells. The novel FITC-SpyC-SpyT-CD22Nb produced in the present study is capable of detecting the surficial expression of CD22. According to our findings, FITC-SpyC-SpyT-CD22Nb is applicable for specific targeting of CD22 in a therapeutic manner, i.e., chimeric antigen receptor (CAR)-T cell therapy and antibody drug conjugates (ADCs).

8813 Nivolumab-Induced Diabetes: A Hidden Danger

Abstract Disclosure: J. Case: None. R.V. Chemitiganti: None. D. Suravajjala: None. Immunomodulating therapy as utilized in chemotherapy for malignancy may lead to potential adverse events including immune-related adverse events(IRAEs). One such pathway by which this may occur is through alteration of the programmed cell death as affected by drugs such as nivolumab which inhibits appropriate matching of PD-1 and PD-L1 and may lead to a robust immune response with collateral damage to nontumor tissue. Multiple downstream effects may be seen leading to other pathologies including development of autoimmune diabetes as noted in the patient described herein. A 61 year old female presented to establish care for suspected type one diabetes mellitus. She had a history of renal cell cancer diagnosed about one year prior for which she was treated with nivolumab. She was found to have hyperglycemia on routine labwork with further labwork revealing inappropriately low c-peptide as measured at less than 0.10 ng/mL (0.8-3.85ng/mL) with a coincident glucose of 566mg/dL (74-106mg/dL). Further workup revealed no measurable presence of GAD65, antipancreatic islet cell or ZNT8 antibodies. Diagnosis was made of insulinopenic diabetes or otherwise autoimmune diabetes induced as an IRAE subsequent nivolumab use. She was subsequently started on a basal bolus regimen with insulin achieving blood glucose control. IRAEs are an unfortunate, albeit rare consequence of immune checkpoint inhibitors including nivolumab. Depending on the toxicity grade and prognosis the offending agent may be discontinued and steroids initiated to mitigate adverse effects. However sometimes the occurrence of an IRAE may go undetected until too late as noted in the above patient. Her presentation was atypical considering many present with DKA and as well IRAEs are less likely in monotherapy. Education of IRAEs as well as appropriate screening would aid in recognition of potential IRAEs at which time appropriate measures may be taken to alleviate collateral damage. Further elucidation of the mechanism by which this autoimmune response is activated against nontumor tissue may also lead to better understanding of autoimmune diabetes caused by other etiologies. Presentation: 6/2/2024

8145 Type 2 Diabetes In A Patient With IMAGe Syndrome

Abstract Disclosure: N. Mulpuri: None. S. Mirfakhraee: None. J. Abramowitz: None. Background: Individuals with mutations that lead to deficiency of POLE1 (a catalytic subunit of polymerase epsilon) may have clinical features of IMAGe syndrome (intrauterine growth restriction, metaphyseal dysplasia, adrenal hypoplasia congenital, and genitourinary anomalies) in addition to distinctive facial features and variable immunodeficiency. Of 15 reported cases in the literature, none were previously characterized with type 2 diabetes mellitus (T2DM). Clinical case: This is a 25-year-old woman with a history of IMAGe syndrome (confirmed mutation in the POLE gene). With regards to IMAGe syndrome history, during the prenatal period, she had growth restriction in the third trimester with delivery at 38 weeks. At 4 years-old, she presented with adrenal crisis and was started on glucocorticoid and mineralocorticoid therapy, now taking hydrocortisone 2.5mg three times daily (8.6 mg/m2/day) and fludrocortisone 0.05mg daily. Initial labs in the adult endocrine clinic were notable for serum glucose 339 mg/dL (65-99 mg/dL), undetectable estradiol (< 15 pg/ml) with FSH 6.8 mIU[JA1] /mL and LH 2.0 mIU/mL, TSH 1.25 mIU/L (0.40-4.50 mIU/dL), FT4 0.7 ng/dL (0.8-1.8 ng/dL). The patient denied any history of T2DM. She also denied polyuria, polydipsia, or weight loss. There was no stigmata of peripheral insulin resistance on exam. Subsequent labs included HbA1c 8.9%, fructosamine 417 mcmol/L (200-285 mcmol/L), insulin 18.4 mcIU/mL (2.6-24.9 mcIU/mL), and C-peptide 3.9 ng/dL (1.1-4.4 ng/dL) with serum glucose 164 mg/dL. Islet cell, insulin, and GAD-65 antibodies were undetectable. CT abdomen/pelvis did not show any pancreatic mass or anomalies. Initially, prandial insulin (lispro 3 units prior to each meal) was initiated given post-prandial hyperglycemia noted on continuous glucose monitoring. Low-dose levothyroxine, 25 mcg daily, was initiated given concern for secondary hypothyroidism, with subsequent normalization of serum thyroxine. HbA1c improved to 7.4% six months later. Ultimately, she transitioned to sitagliptin 25 mg daily and her latest HbA1c was 6.2% three years after initial diagnosis of T2DM. Conclusion: Of the 15 cases of IMAGe syndrome with mutations in POLE described in Logan et al, none were noted to have diabetes. The patient described above was diagnosed with new-onset diabetes at age 21, presumably T2DM in the context of undetectable antibodies and high-normal C-peptide. Interestingly, she did not have any typical stigmata of peripheral insulin resistance. Glucocorticoids used for the treatment of adrenal insufficiency in patients with IMAGe syndrome can contribute to development of T2DM. Patients with IMAGe syndrome on chronic glucocorticoids should be monitored for hyperglycemia and diabetes. Additionally, glucocorticoid doses should be optimized to balance mitigating side effects such as hyperglycemia and osteoporosis while preventing adrenal crisis. Presentation: 6/3/2024

8283 Diabetes Mellitus in Patients with Hemochromatosis- A Diagnostic and Therapeutic Challenge

Abstract Disclosure: U. Rafat: None. M. Siddiqui: None. J.L. Gilden: Other; Self; Novartis Pharmaceuticals. A. Moid: Other; Self; Novartis Pharmaceuticals. Background: Primary Hemochromatosis is a genetic condition most commonly due to two sets of mutations in the Human homeostatic iron regular Protein (HFE) gene. HFE modulates the expression of hepcidin, which regulates intestinal iron absorption, plasma iron concentration and distribution of iron in tissues. Hemochromatosis patients are at high risk for developing diabetes mellitus (DM) due to iron overload in the pancreas with damage to Beta cells and impaired insulin secretory capacity. Hemochromatosis is often called Bronze Diabetes due to brown discoloration of the skin from accumulation of iron, and is characterized by hepatic fibrosis, fatigue, arthralgias, cirrhosis, DM, arthropathy, pigmentation and cardiomyopathy. Case: We present a Caucasian male with homozygous hereditary hemochromatosis, diagnosed by liver biopsy at age 40 due to transaminitis and Ferritin level of 1500 ng/mL and Genetic testing- 2 copies of HFE gene pathogenic variant (C282Y). He was later diagnosed with DM age 51, started on Metformin and referred to Endocrine clinic with abdominal bloating, and polyarticular arthralgias. Physical exam=Vital Signs normal (WT. 231lbs, BMI 34), with splenomegaly, but normal musculoskeletal exam and skin without bronze discoloration. Both parents had T2DM. Lab- Hb a1c 8.7% (0.0-5.6), Iron saturation 71% (10-50), Ferritin 66.3 ng/mL (26-388), C-Peptide 3.30 ng/ml (0.81-3.85), with glucose level of 119 mg/dL, and negative IA-2 <5.4 U/mL, negative Islet cell antibody, GAD 65 <5 IU/mL (nl <5), Insulin Autoantibody <0.4 U/mL (nl <0.4), and Zinc Transporter 8 antibodies <10 U/mL (nl <15). Liver tests- AST 39 U/L(10-37), ALT 77 U/L (10-65), ALP 89 U/L (45-117), total bilirubin 1.1 mg/dL(0.2-1.2). Hormonal evaluation included TSH 1.2 uIU/mL (0.55-4.78), ACTH 19 pg/mL (0-47), AM Cortisol 16.28 ug/d (5.30-22.50) IGF1 158 ng/mL (50-317) FSH 9.6 mIU/mL(l.40-18.10), LH 5.09 mIU/mL (1.50-9.30), Prolactin 7.40 ng/mL(2.10-17.70), total testosterone 374 ng/dL(250-1100), free testosterone 66.2 pg/mL (35.0-155.0). Echocardiogram-left ventricular hypertrophy and thick right ventricular wall with concerns for iron overload. Hba1c improved to 6.6% on Metformin. Fructosamine 351umol/L (151-300). In the absence of advanced cardiac, hepatic and other organ involvement, and presence of elevated C-peptide and high BMI, this patient is being managed as T2DM, with low threshold to initiate insulin therapy considering possibility of concomitant Bronze DM. Conclusion: It is important to determine type of DM, so appropriate management options can be devised. While insulin is recommended for management in Bronze Diabetes, insulin sensitizers, such as metformin and/or GLP 1 agonists can be used in type 2 DM. One must also consider therapy based upon the risk of cancer and acute pancreatitis in the setting of pancreatic iron overload, when considering antihyperglycemic therapies. Presentation: 6/2/2024

7316 A Unique Presentation of Diabetes Mellitus in an 8-Year-Old Male Positive For 3 Different Mutations Related to MODY

Abstract Disclosure: R. Senguttuvan: None. A. Pamfil: None. Background: Maturity-Onset Diabetes of the Young (MODY) is the most common form of inherited non-autoimmune diabetes mellitus, characterized by autosomal dominant inheritance, young age at onset and beta cell dysfunction. There are at least 14 MODY mutations and we present a pediatric case not meeting criteria for type 1[T1DM] or type 2 diabetes mellitus[T2DM], who tested positive for mutations in 3 different genes known to cause MODY. Case: An 8-year-old male, born full term, 2776 grams and 48.3 cm, without history of neonatal hypoglycemia or hyperglycemia, was referred for new onset diabetes mellitus management. While undergoing evaluation for abdominal pain and constipation, he was found to have a fasting glucose of 126 mg/dL (7 mmol/L) and hemoglobin A1C of 6.5%. He endorsed polyuria, but no polydipsia. He had no clinical signs of insulin resistance (e.g., acanthosis nigricans) and a BMI of 23.65 kg/m2, at the 97th percentile. Family history is positive for diabetes mellitus requiring insulin, in father (diagnosed at 11 years) and paternal grandmother and T2DM in paternal aunt. Laboratory evaluation was negative for all 5 antibodies (GAD, IA-2, Anti-islet cell antibody, Zinc Transporter 8 and Insulin antibodies) and revealed an insulin level of 15.9 uIU/mL (RR: <2.0-13.0) and C peptide: 2.3 ng/mL (RR: 1.1-4.4). Lacking diagnostic criteria for T1DM or T2DM, genetic testing was performed. Patient tested heterozygous for mutations in 3 genes known to cause MODY: GCK [(c.350 G>T p. (G117V)], ABCC8 [(c.2270 C>G p.(T757R)], and HNF1B [(c.68A>G p.(K23R)], all variant of uncertain significance. Over an 8-month period, patient's weight decreased from 98 lbs. (44.9 kg) to 90 lbs. (41.1 kg) after meeting with our dietician and implementing healthy dietary changes, and his beta cell function markers improved from diagnosis: Fasting insulin (4.5 uIU/mL), C peptide (1.3 ng/mL), and glucose 119 mg/dL; Hemoglobin A1C remained relatively stable at 6.1%. A kidney ultrasound was normal. No medical intervention were started yet, and patient is being monitored clinically and biochemically every 3-4 months. Discussion: Clinical monitoring over time, genetic testing in the parents, are critical in this patient’s long-term treatment plan and prognosis. To our knowledge, this may be the first case of diabetes mellitus in a pediatric patient, positive for mutations in 3 different genes known to cause MODY. South Texas has one of the highest incidences of T2DM in the USA. In addition to screening for genetic forms of diabetes, in patients with negative T1DM antibodies and atypical phenotype for T2DM, we should consider genetic screening in mildly obese pediatric and young adult patients without significant acanthosis nigricans, who were already diagnosed as T2DM. Presentation: 6/1/2024

6745 Complete Remission of Type 1 Diabetes and the Honeymoon Phase: A Case Report

Abstract Disclosure: D. Krinsky: None. E. Brutsaert: None. J.A. Mullally: None. Introduction: Type 1 Diabetes (T1D) is a chronic autoimmune disease resulting in insulin deficiency from pancreatic beta-cell destruction. Recent evidence suggests that it can be a partially relapsing and remitting disease, with some patients with T1D being able to briefly discontinue insulin early in the disease course. This phenomenon has been referred to as the “honeymoon phase.” While this period tends to be short, on the order of weeks to months, we describe a unique case of a patient with T1D with a long remission, lasting about five years. Clinical Case A 21-year-old Mexican-American male (BMI 26) with past medical history of T1D presented with polyuria and a 50-pound unintentional weight loss over a 6-month period. He was first diagnosed with T1D at age 14 years when his Hemoglobin A1c (HbA1C) was 13.3% (normal range 4.0-5.6%) in the setting of hospitalization for diabetic ketoacidosis (DKA). All antibody testing done at that time was negative, but islet cell antibodies were later found to be positive. Insulin therapy was started, weaned, and then completely discontinued at age 16 when the patient’s HbA1c was normal at 5%. The patient had no symptoms of diabetes until 6 months prior to presenting, seven years after his original diagnosis. He was found to be in DKA with a HbA1c >14%. Additionally, insulin (< 3.0; normal range 6-27) and c-peptide (0.43; normal range 0.81-3.85) were low with an elevated glucose of 366. Insulin autoantibody, GAD-65 antibody, and islet cell antibody were negative. His DKA resolved and he was discharged on basal and nutritional insulin. Conclusion: The physiology of the honeymoon phase is not well understood and there is not a clear definition, although stimulated C-peptide levels, insulin requirements, and calculating insulin dose adjusted A1c (IDAA1c) have been commonly used. There is variability in reports of the prevalence of partial remission (PR), estimated to occur in 22-60% of patients, with an average duration of 9 months. Our case is unique in that the patient was diagnosed with T1D at the age of 14 years but was able to discontinue all insulin for five years. His presentation is consistent with a complete remission with insulin independence and normal glycemic control (HbA1C <6%) without the use of hypoglycemic agents. Complete remission has a prevalence of only 6.5%. Prior data has shown factors associated with diabetes remission include male sex, postpubescent age of diabetes onset, and fewer than two positive antibodies; factors seen with our patient. Our case highlights a very long remission of T1D, and a better understanding of the immunologic and metabolic factors at play in the honeymoon phase may pave the way for novel T1D prevention and treatment strategies. Presentation: 6/2/2024

6985 Intravenous Immunoglobulin induced Type 1 diabetes remission

Abstract Disclosure: N. Shahid: None. D. Newbern: None. Introduction: Intravenous immunoglobulin [IVIG] is an immunomodulatory agent used for treatment of autoimmune and inflammatory conditions. However, it is not indicated in patients with type 1 diabetes [T1D] as its efficacy has not been established. Clinical Case: A 9-year-old previously healthy boy presented to the Emergency Department with several days of unexplained bruising and mucosal bleeding with no prior history of trauma, bleeding disorders or other systemic symptoms. Physical examination showed generalized petechiae, ecchymosis and purpura. Vitals were normal including weight and BMI. Initial labs confirmed Immune thrombocytopenic purpura [ITP] as his platelets were less than 1K/µL with otherwise normal peripheral blood cell counts and smear. Concomitantly, labs showed significant hyperglycemia [260mg/dL] with glycosuria and trace ketonuria. Glycated hemoglobin [Hba1c] was elevated at 10.5% and ultimately Pancreatic autoantibodies [GAD65, Zinc transporter-8 and islet cell antibody] came back positive confirming T1D. Other autoimmune disorders such as adrenal insufficiency, thyroiditis, and celiac disease were ruled out. For the treatment of ITP, he the patient received 1 dose of IVIG 1g/kg and responded well with a rise in platelets to 6K/µL. The morning following the infusion, due to fasting hyperglycemia, the patient was started on basal-bolus insulin regimen. By 2nd day post IVIG, he had hypoglycemia, so insulin was discontinued with normalization of blood sugars. He is now 7 months post IVIG with no recurrent episodes of thrombocytopenia. He also remains off insulin with Hba1c in the 5.9-6.5% range. He eats a regular diet with avoidance of simple carbohydrates. He wears onwears a a continuous glucose monitor, which shows that blood sugars are in range 93% of the time He remains euglycemic overnight with transient self-resolving mild post-prandial hyperglycemia. Pancreatic autoantibodies have been reassessed and remain positive Conclusions: This case demonstrates that IVIG used for the treatment of ITP has induced a state of remission in our patient with newly diagnosed with T1D. IVIG is not a standard of treatment for T1D, however, when given for other autoantibody- or T-cell-mediated autoimmune conditions, it may reduce the insulin need in patients with known diabetes or induce remission in patients with newly diagnosed diabetes.