Immunoglobulin G4 Research Articles

High-Dimensional Cytometry Dissects Immunological Fingerprints of Idiopathic Inflammatory Myopathies.

Chronic inflammation of skeletal muscle is the common feature of idiopathic inflammatory myopathies (IIM). Given the rarity of the disease and potential difficulty of routinely obtaining target tissue, i.e., standardized skeletal muscle, our understanding of immune signatures of the IIM spectrum remains incomplete. Further insight into the immune topography of IIM is needed to determine specific treatment targets according to clinical and immunological phenotypes. Thus, we used high-dimensional flow cytometry to investigate the immune phenotypes of anti-synthetase syndrome (ASyS), dermatomyositis (DM) and inclusion-body myositis (IBM) patients as representative entities of the IIM spectrum and compared them to healthy controls. We studied the CD8, CD4 and B cell compartments in the blood aiming to provide a contemporary overview of the immune topography of the IIM spectrum. ASyS was characterized by altered CD4 composition and expanded T follicular helper cells supporting B cell-mediated autoimmunity. For DM, unsupervised clustering identified expansion of distinct B cell subtypes highly expressing immunoglobulin G4 (IgG4) and CD38. Lastly, terminally differentiated, cytotoxic CD8 T cells distinguish IBM from other IIM. Interestingly, these terminally differentiated CD8 T cells highly expressed the integrin CD18 mediating cellular adhesion and infiltration. The distinct immune cell topography of IIM might provide the framework for targeted treatment approaches potentially improving therapeutic outcomes.

Clinical Images: Dacryoadenitis in eosinophilic granulomatosis with polyangiitis mimicking immunoglobulin G4-related disease.

The patient, a 26-year-old woman, presented with a 2-week history of acute swelling in both lacrimal glands (A). She had recently developed uncontrolled asthma and nasal polyps. The laboratory test results were notable for an absolute eosinophil count of 5300 cells per μl (reference range 100-400 μl), exceeding 50% of circulating leukocytes. The antineutrophil cytoplasmic antibody test result was negative. Magnetic resonance imaging of the head confirmed swelling of the bilateral lacrimal glands (B, yellow arrowheads) and rhinosinusitis. A biopsy of her lacrimal gland revealed eosinophil-rich necrotizing granulomatous inflammation with vasculitis (C). Her serum immunoglobulin G4 (IgG4) level was slightly elevated (265 mg/dl, normal upper limit is 121 mg/dl), but IgG4 immunostaining of the biopsy specimen did not show a significant finding. A diagnosis of eosinophilic granulomatosis with polyangiitis (EGPA) was made. Treatment with 30 mg of prednisone was initiated, which was gradually tapered without glucocorticoid-sparing agents over 12 months. The swelling of her lacrimal glands resolved, and she was free of symptoms, including asthma and lacrimal gland swelling, at the 12-month follow-up. In summary, EGPA can present with lacrimal gland swelling and mimic IgG4-related Mikulicz disease (1, 2). A histopathological examination of the swollen lacrimal gland is the key to differentiating EGPA from IgG4-related Mikulicz disease in such cases. Disclosureform Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

A novel glucagon analog with an extended half-life, HM15136, normalizes glucose levels in rodent models of congenital hyperinsulinism

Congenital hyperinsulinism (CHI) is a rare genetic condition characterized by uncontrolled insulin secretion, resulting in hypoglycemia. Although glucagon has lately been regarded as a therapeutic option for CHI, its use is severely hampered by its poor solubility and stability at physiological pH, as well as its short duration of action. To address these constraints, we developed HM15136, a novel long-acting glucagon analog composed of a glucagon analog conjugated to the Fc fragment of human immunoglobulin G4 via a polyethylene glycol linker. In this study, we established that HM15136 was more soluble than natural glucagon (≥ 150 mg/mL vs 0.03 mg/mL). Next, we confirmed that HM15136 activated glucagon receptor in vitro and induced glycogenolysis and gluconeogenesis in rat primary hepatocytes. Pharmacokinetics (PK)/Pharmacodynamics (PD) analysis of HM15136 shows that HM15136 has a markedly longer half-life (36 h vs. < 5 min) and increased bioavailability (90%) compared to native glucagon in mice. Further, HM15136 could effectively reverse acute hypoglycemia induced by insulin challenge, and multiple doses of HM15136 could sustain increased blood glucose levels in CHI rats. In conclusion, our findings indicate that HM15136 promotes sustained elevation of blood glucose, demonstrating the potential for development as a once-weekly therapy for CHI.

Lacrimal Gland and Orbital Lesions in LatY136F Knock-in Mice, a Model for Human IgG4-Related Ophthalmic Disease

Purpose LatY136F knock-in mice were recently proposed as an animal model for immunoglobulin G4 (IgG4)-related disease. In this study, we investigated whether LatY136F knock-in mice exhibit ophthalmic lesions, specifically in the lacrimal and Harderian glands. Methods Lacrimal glands, Harderian glands, and adherent lymphoid follicle lesions were dissected from LatY136F knock-in mice and wild type (WT) C57BL/6 mice between 6 and 24 weeks of age. Tissues were stained with hematoxylin-eosin, immunoglobulin G (IgG), and anti-IgG1, a homologue of human IgG4, for histopathological analysis. Results In LatY136F knock-in mice, IgG1-positive cells infiltrated the space between the lacrimal gland acinar cells at 6, 9, 12, and 20 weeks or order, and the number of IgG1-positive cells did not differ significantly between these age groups. Infiltration of IgG1-positive inflammatory cell was also observed in the Harderian glands of LatY136F knock-in mice at all ages. The ratio of IgG1/IgG-positive cells averaged 80 and 67% in the lacrimal and Harderian glands, respectively. Dense IgG1-positive lesions were also seen in tissues adjacent to the lacrimal and Harderian glands in some LatY136F knock-in mice. In contrast, there were almost no IgG1-positive cell infiltrates in the lacrimal and Harderian glands of WT mice. Conclusion IgG1-positive cells infiltrate the lacrimal and Harderian glands of LatY136F knock-in mice, indicating that LatY136F knock-in mice could be a representative animal model for IgG4-related ophthalmic disease.

S1734 Etanercept: A Rare Cause of Drug-Induced Pancreatitis

Introduction: Despite causing as low as 0.1% of cases of acute pancreatitis (AP), drug-induced pancreatitis(DIP) is a growing and notable cause of AP. Prior data comes from case reports and series, with definitive studies and trials lacking. To definitively diagnose DIP, a latency period with reintroduction of the medication associated with a return of symptoms is required. This is often not feasible due to risk of disastrous complications. DIP presents an uncommon cause of AP, with no established diagnostic algorithm. Amongst these cases, etanercept-induced pancreatitis presents a rare subset rarely reported in the literature. Case Description/Methods: Our patient is a 65-year-old female with a history of rheumatoid arthritis (RA) who presented endorsing 3 days of epigastric abdominal pain. Labs indicated a normal liver function tests, calcium of 10.1mg/dl, lipase of 1012U/L, and triglycerides of 187 mg/dl. Abdominal imaging indicated hepatic steatosis, with no findings of AP nor notable biliary/gallbladder pathology. Patient was started on fluids with clinical improvement noted. Antinuclear antibody(ANA) and immunoglobulin G4(IgG4) would be negative. The patient was advised to stop etanercept therapy and follow up with gastroenterology and rheumatology outpatient. She has since been discharged and is doing well off etanercept outpatient. Discussion: Since being first reported in the 1950s, DIP has been associated with over 500 medications per the World Health Organization. It is a diagnosis of exclusion, with common etiologies of alcohol abuse, gallstone disease, and other metabolic derangements having to be ruled out first. TNF-a inhibitors are involved in the treatment of a variety of autoimmune conditions. AP is not a commonly reported effect of these medications. Limited prior case reports attribute pancreatitis to infliximab and adalimumab use. To our knowledge, there are only 2 prior case reports of AP in the setting of recent etanercept initiation. After excluding more common causes of AP via imaging and labs, medication review was only notable for etanercept, which was started recently. A variety of mechanisms for DIP have been proposed. These include pancreatic/biliary duct constriction, direct cytotoxic effects, metabolic effects, and accumulation of potentially toxic metabolites. We hope to bring greater awareness to etanercept as a cause of drug-induced pancreatitis. Further studies are needed to elucidate its association with pancreatitis.

S391 Co-Localization of Immunoglobulin G4 (IgG4) and Milk Proteins Is Associated With Eosinophilic Esophagitis Disease Activity

S391 Co-Localization of Immunoglobulin G4 (IgG4) and Milk Proteins Is Associated With Eosinophilic Esophagitis Disease Activity

Pucotenlimab: First Approval.

Pucotenlimab (Puyouheng™) is a humanised immunoglobulin (Ig) G4 monoclonal antibody (mAb) being developed by Lepu Biopharma for the treatment of solid tumours, including gastrointestinal cancer, metastatic melanoma, liver cancer, bladder cancer, non-small cell lung cancer and breast cancer. Pucotenlimab binds to PD-1 and blocks its interaction with its ligands, PD-L1 and PD-L2, thereby restoring the ability of immune cells to target cancer cells. In July 2022, pucotenlimab received conditional first approval in China for the treatment of patients with unresectable or metastatic microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) solid tumours, including patients with advanced colorectal cancer who have experienced disease progression after previous therapy with fluorouracil, oxaliplatin and irinotecan, as well as patients with other advanced solid tumours who have experienced disease progression after previous first-line therapy and have no satisfactory treatment alternatives. In September 2022, pucotenlimab was approved in China for the treatment of unresectable or metastatic melanomas after the failure of previous systemic therapy. This article summarizes the milestones in the development of pucotenlimab leading to the first approval for the treatment of MSI-H/dMMR advanced solid tumours.

S1731 Fibrosing Pancreatitis Initially Diagnosed as Ductal Adenocarcinoma by Endoscopic Ultrasound of a Pancreatic Mass in a Pediatric Patient

Introduction: Pancreatic cancer is very rare in the pediatric population. Incidence data is scarce, and few case reports have been published. Pancreatic ductal adenocarcinoma (PDA) is the most common subtype in adults, but is rare in children. We report a case of a benign pancreatic head mass in a pediatric patient initially diagnosed as PDA on endoscopic ultrasound (EUS) guided biopsy. Case Description/Methods: A 13-year-old male with past medical history of treated Helicobacter pylori infection 6 months prior was admitted for severe acute intermittent epigastric pain. Labs showed elevated transaminases and gamma-glutamyl transferase. Abdominal ultrasound demonstrated an indeterminate solid mass-like lesion of 3 cm at the pancreatic head, and the common bile duct (CBD) was dilated to 0.9 cm. Magnetic resonance cholangiopancreatography showed a 2.2 cm indeterminate lesion along the pancreatic head region with dilated CBD of 1.4 cm, tapering at the level of the lesion. On hospital day 3, the patient underwent esophagogastroduodenoscopy and EUS. A parenchymal mass of 2.2 cm was visualized in the head of pancreas, and fine needle biopsy was performed. Cytology diagnosis was well differentiated ductal adenocarcinoma. Serum carcinoembryonic antigen, carbohydrate antigen 19-9, and alpha-fetoprotein were all normal. The patient underwent elective Whipple procedure. Surprisingly, no malignancy was identified on the surgical specimen. Instead the findings supported a diagnosis of localized fibrosing pancreatitis with high background of immunoglobulin G4 with interlobular pattern. Patient was discharged home on post-operation day 13. EUS cytology was reviewed at a tertiary cancer center and later reported as acute on chronic inflammation without malignancy (Figure). Discussion: Despite increased use of EUS for diagnosis of pancreatic masses, 5-10% of patients who undergo Whipple procedure for presumed malignancy will have benign pathology: most commonly chronic fibrosing pancreatitis, chronic pancreatitis, or focal active pancreatitis. The false positive rate for diagnosing malignancy using EUS-fine needle aspiration (FNA) of solid pancreatic lesions is less than 1%. However, it may be higher in pediatrics as the prevalence of PDA is much lower in adults. For suspected cases of PDA in pediatric patients, additional review of EUS cytology at an experienced and dedicated cancer institution is advisable before further intervention to prevent the medical and psychosocial ramifications of a false positive cancer diagnosis.Figure 1.: (Left) A parenchymal mass (2.2 x 1.8 cm) in the head of the pancreas by endoscopic ultrasound (EUS) adjacent to the portal confluence, with the common bile duct dilated to 12.8 mm (marked by yellow cross signs). Initial cytopathology from EUS-FNA of pancreatic head mass A. Diff-Quik staining at low magnification, 4x. B. Smear is cellular and well preserved with sheets, clusters and single malignant cells, 10x. C. Cells have crowded nuclei, 20x. D. Malignant cells exhibit loss of polarity, irregular nuclear contours, finely granular chromatin and some with prominent nucleoli, 40x . Based on cytomorphological features, the mass is a well differentiated ductal adenocarcinoma of pancreatic head. Note: The review of this cytopathology by a tertiary cancer institution was inconsistent with malignancy. The glandular cells had mild cytologic atypia, and the acinar cells remained lobular in configuration. Although there was some higher nuclear to cytoplasmic ratio, no absolute nuclear enlargement was noticed.

Immunoglobulin G4-related disease diagnosed by prostate biopsy: a case report

BackgroundImmunoglobulin G4-related disease is characterized by swelling of various organs throughout the body and nodules/hypertrophic lesions. However, its cause remains unknown. We report a case of immunoglobulin G4-related disease that was diagnosed based on the histopathological findings of prostate biopsy.Case presentationA 72-year-old Japanese man had been treated by a nearby doctor for hypertension, but subsequently developed lower urinary tract symptoms and was prescribed an α1 blocker for 1 year. However, the patient was subsequently referred to our department because his symptoms did not improve. Prostate-specific antigen was 1.258 ng/ml; however, the nodule was palpable in the right lobe on digital rectal examination, and magnetic resonance imaging suggested Prostate Imaging and Reporting and Data System category 3. Therefore, transrectal prostate needle biopsy (12 locations) under ultrasound was performed. Histopathological examination revealed no malignant findings, although infiltration of lymphocytes and plasma cells, and partial fibrosis were observed. No remarkable findings of obstructive phlebitis were observed. Immunoglobulin G4-related disease was suspected, and immunoglobulin and immunoglobulin G4 immunostaining was performed. Immunoglobulin G4 positive plasma cells were observed in a wide range, immunoglobulin G4 positive cells were noted at > 10 per high-power field, and the immunoglobulin G4 positive/immunoglobulin G positive cell ratio was > 40%. Serum immunoglobulin G4 levels were high at 1600 mg/dl. Enhanced abdominal computed tomography findings suggested periaortitis. Additionally, multiple lymphadenopathies were observed around the abdominal aorta. The patient was accordingly diagnosed with immunoglobulin G4-related disease definite, diagnosis group (definite). We proposed steroid treatment for periaortic soft tissue lesions and lower urinary tract symptoms; however, the patient was refused treatment. A computed tomography scan 6 months after diagnosis revealed no changes in the soft tissue lesions around the aorta. Follow-up computed tomography examinations will be performed every 6 months.ConclusionIf immunoglobulin G4-related disease is suspected and a highly invasive examination is required for histopathological diagnosis, this can be performed by a relatively minimally invasive prostate biopsy for patients with lower urinary tract symptoms. Further evidence is needed to choose an optimal candidate for prostate biopsy for lower urinary tract symptoms patients with suspicion of immunoglobulin G4-related disease. For patients with lower urinary tract symptoms with immunoglobulin G4-related disease or a history, performing a prostate biopsy may avoid unnecessary treatment. However, if steroid therapy is ineffective, surgical treatment should be considered.

Vitiligo in a patient with metastatic melanoma receiving human immunoglobulin G4 monoclonal antibodynivolumab treatment

Vitiligo in a patient with metastatic melanoma receiving human immunoglobulin G4 monoclonal antibodynivolumab treatment

Navigating the Challenges Associated With a Diagnosis of Autoimmune Pancreatitis and IgG4-Related Sclerosing Cholangitis.

The pancreatobiliary tract exhibits a spectrum of heterogeneous fibroinflammatory conditions that may be the result of a primary immune-mediated mechanism, or a reaction to neoplasm. This often results in significant overlap regarding clinical presentation, symptoms, radiographic findings, serology, and histopathology between inflammatory and neoplastic lesions of the pancreas, which can lead to inadvertent surgical intervention. Among the multitude of primary fibroinflammatory pancreatic diseases, autoimmune pancreatitis, including type 1 and type 2 autoimmune pancreatitis, and immunoglobulin G4-related sclerosing cholangitis (IgG4-RSC) are particularly challenging and require a multidisciplinary perspective to reliably make a diagnosis. This is of particular significance because these diseases typically have a favorable prognosis and readily respond to steroid therapy. To present a multimodal approach to highlight distinctive and overlapping qualities that will aid in the diagnosis of these entities. The review and analysis of literature describing autoimmune pancreatitis types 1 and 2 and IgG4-RSC. Diagnosis of autoimmune pancreatitis types 1 and 2 and IgG4-RSC requires a multimodal approach that relies on clinical, radiographic, serologic, histopathologic, and immunohistochemical correlation.

The interruption of transmission of onchocerciasis in Kaduna, Kebbi and Zamfara states, Nigeria: another milestone achievement.

BackgroundMore than 40 million people live in onchocerciasis-endemic areas in Nigeria. For at least 19 y, mass drug administration (MDA) with ivermectin was implemented with at least 65% total population coverage in Kaduna, Kebbi and Zamfara states. Impact surveys done using skin biopsies yielded no infections. Serological and entomological assessments were undertaken to determine if onchocerciasis transmission had been interrupted and MDA could be stopped.MethodsThe presence of onchocerciasis-specific immunoglobulin G4 antibody was measured by enzyme=linked immunosorbent assay conducted on dried blood spots collected from 5- to 9-year-old children resident in each state. O-150 polymerase chain reaction testing of Simulium damnosum s.l. heads for Onchocerca volvulus DNA was done on black flies collected by human landing capture and Esperanza window traps.ResultsA total of 9078 children were surveyed across the three states. A total of 6139 vectors were collected from Kaduna state, 129 from Kebbi state and 2 from Zamfara state; all were negative. Kebbi and Zamfara states did thousands of hours of black fly catching and intensive river prospecting. The resulting low fly catch was due to a low fly population incapable of sustaining transmission.ConclusionOnchocerciasis transmission has been interrupted and the three states meet World Health Organization thresholds: seropositivity in children <0.1% and <1/2000 infective black flies with 95% confidence. The 2.2 million people in Kaduna state and 4 million in Kebbi and Zamfara states no longer need ivermectin for onchocerciasis.

It Melts Like Snow: Steroid Responsiveness of Immunoglobulin G4-Related Disease

Dear Editor, A 35-year-old male presented with insidious onset gradually progressive bilateral painless submandibular swelling, followed by periorbital swelling [Figure 1] for the past 7 years. He had no constitutional or sicca symptoms. He had no history of addiction or autoimmunity in the family. Systemic examination was unremarkable. On evaluation, he had raised inflammatory markers with a negative autoimmune panel. Magnetic resonance imaging orbit showed bilateral orbital extraconal soft-tissue masses with contrast enhancement. Incisional biopsy from the extraconal mass was suggestive of fibrocollagenous stroma with aggregation of lymphocytes, plasma cells, and histiocytes without any necrosis or granuloma. On further evaluation, submandibular gland biopsy showed chronic sialadenitis with immunoglobulin G4 (IgG4)-positive plasma cell >10/hpf and IgG4: IgG ratio >40% [Figure 2] without any major organ involvement on imaging. The diagnosis of IgG4-related disease was kept. He was started on oral steroid 0.5 mg/kg/day and observed a rapid clinical response within 15 days of steroid therapy. Later, he was started on azathioprine and continued with tapering dose of steroid. He was followed up every month for first 3 months and then every 3 monthly upto 16 months without any signs of recurrence. For a long-standing indolent disease of 7 years, drastic steroid response with resolution of clinical symptoms was quite evident in our case.Figure 1: (a) Pretreatment bilateral upper eyelid swelling, (b) pretreatment bilateral submandibular swelling, (c and d) during glucocorticoid therapy (day 15) resolution of orbital and submandibular swelling, respectivelyFigure 2: Salivary gland with seromucinous acini and ducts embedded in mildly fibrotic stroma with numerous lymphoid follicles with germinal centers (a and b: H and E). Clusters of plasma cells are highlighted with CD138 immunohistochemical stain (c). IgG4 positive cells, >10/hpf (d)IgG4-related disease (IgG4-RD) is a chronic, systemic, fibroinflammatory condition with variable organ manifestation. CD4+ T-cells and B-cells are central to the pathogenesis causing organ damage and fibrosis. Marked expansion of IgG4-secreting plasmablast in the blood is usually seen in active and untreated cases.[1] Key to diagnosis is the classical histopathological hallmarks of lymphoplasmacytic infiltrate, storiform fibrosis, and obliterative phlebitis. IgG4 RD usually has a good response to steroids but a variable relapse rate. Factors associated with lesser treatment response and relapse were well analyzed in a Japanese multicenter study. Multivariate analysis from the study revealed that intermediate steroid initial dose (0.4–0.69 mg/day), slow tapering regimen (<0.4 mg/day), and shorter disease duration were associated with a significantly lower rate of disease relapse.[2] The study of isolated IgG4 ophthalmic disease also echoed similar results regarding steroid response and relapse, with more relapse in those with elevated serum IgG4 levels and a shorter duration of initial steroid treatment (<5 months). Low-dose steroid maintenance should be considered to avoid recurrence in patients with elevated serum IgG4 levels.[3] Later on, rituximab therapy showed promising results in inducing remission[4] and steroid-free long-term maintenance.[5] Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Evaluating the Safety and Efficacy of Crenezumab vs Placebo in Adults With Early Alzheimer Disease

Alzheimer disease (AD), a neurodegenerative disease characterized by β-amyloid plaques and τ tangles in the brain, represents an unmet medical need with no fully approved therapeutics to modify disease progression. To investigate the safety and efficacy of crenezumab, a humanized monoclonal immunoglobulin G4 antibody targeting β-amyloid oligomers, in participants with prodromal to mild (early) AD. Two phase 3 multicenter randomized double-blind placebo-controlled parallel-group efficacy and safety studies of crenezumab in participants with early AD, CREAD and CREAD2, were initiated in 2016 and 2017, respectively, and were designed to evaluate the efficacy and safety of crenezumab in participants with early AD. CREAD (194 sites in 30 countries) and CREAD2 (209 sites in 27 countries) were global multicenter studies. A total of 3736 and 3664 participants were screened in CREAD and CREAD2, respectively. A total of 3736 and 3664 participants were screened in CREAD and CREAD2, respectively. Both trials enrolled individuals aged 50 to 85 years with early AD. Participants with some comorbidities and evidence of cerebral infarction or more than 4 microbleeds or areas of leptomeningeal hemosiderosis on magnetic resonance imaging were excluded. After 2923 and 2858 were excluded, respectively, 813 participants in CREAD and 806 in CREAD2 were randomly assigned in a 1:1 ratio to either placebo or crenezumab. In the final analysis, there were 409 participants in the placebo group and 404 in the crenezumab group in CREAD and 399 in the placebo group and 407 in the crenezumab group in CREAD2. Data were analyzed up until January 2019 and August 2019, respectively. Participants received placebo or 60 mg/kg crenezumab intravenously every 4 weeks for up to 100 weeks. The primary outcome was change from baseline to week 105 in Clinical Dementia Rating-Sum of Boxes (CDR-SB) score. There were 813 participants in CREAD (mean [SD] age, 70.7 [8.2] years; 483 female and 330 male) and 806 in CREAD2 (mean [SD] age, 70.9 [7.7] years; 456 female and 350 male). Baseline characteristics were balanced between both groups. The between-group difference in mean change from baseline in CDR-SB score (placebo minus crenezumab) was -0.17 (95% CI, -0.86 to 0.53; P = .63) at week 105 in the CREAD study (88 placebo; 86 crenezumab). Compared with previous trials, no new safety signals were identified, and amyloid-related imaging abnormalities with edema were rare, mild, and transient. No meaningful changes in AD biomarkers were observed. Both studies were discontinued following a preplanned interim analysis indicating that CREAD was unlikely to meet the primary end point. Crenezumab was well tolerated but did not reduce clinical decline in participants with early AD. ClinicalTrials.gov Identifiers: CREAD, NCT02670083; CREAD2, NCT03114657.

The Role of Endothelial Barrier Function in the Fibrosis of Salivary Gland

In the salivary glands, fibrosis occurs in many pathological conditions. Endothelial tight junction (TJ)–based barrier function plays a vital role in maintaining the homeostasis of the salivary glands. However, whether endothelial barrier function is changed and involved in the pathogenesis of glandular fibrosis is unknown. Here, by using a mouse model in which the main excretory duct of the submandibular gland (SMG) was ligated to induce inflammation and fibrosis, endothelial barrier function and TJ protein expression and distribution were examined. Both 4-kDa and 70-kDa fluorescence-labeled dextrans permeated more in the 1-, 3-, and 7-d ligated SMGs. Meanwhile, the mRNA level of claudin-5 was increased with an obvious redistribution from apicolateral membranes to lateral membranes and cytoplasm in the fibrotic glands. Notably, the TJ sealer AT1001 significantly attenuated the disrupted endothelial barrier function and thereby ameliorated the glandular fibrosis. Cytokine array detection showed that monocyte chemoattractant protein–1 (MCP-1) was highly enriched in the 3-d ligated SMGs, and MCP-1 directly impaired barrier function, increased claudin-5 expression, induced the relocalization of claudin-5, and activated p-ERK1/2 in cultured human endothelial cells. Furthermore, the upregulation and disorganization of claudin-5 as well as the elevation of MCP-1 and p-ERK1/2 signaling were also confirmed in fibrotic SMGs from patients with chronic sialadenitis and immunoglobulin G4–related sialadenitis. Altogether, our findings revealed that disrupted endothelial barrier function contributed to the progression of glandular fibrosis, and targeting endothelial TJs might be a promising approach to alleviate salivary gland fibrosis-related diseases.

Immunoglobulin G4-Related Disease of The Larynx Mimicking Malignancy: A Case Report and Review of the Literature

Immunoglobulin G4–related disease is characterized by increased serum immunoglobulin G4 level, enlargement in the relevant organs and histopathologically intense storiform fibrosis, lymphoplasmacytic infiltration rich in immunoglobulin G4 positive plasma cells, and obliterative phlebitis. In this report, a patient who underwent a laryngeal biopsy with a pre-diagnosis of malignancy, but had findings consistent with immunoglobulin G4–related disease in the biopsy sample, is described. Immunoglobulin G4–related disease can be seen in very rare localizations. It should be kept in mind in differential diagnosis when tissues especially containing inflammation rich in plasma cells are encountered. Clinical, laboratory and pathological correlation is extremely important in the diagnosis of an immunoglobulin G4-related disease.

EP08.01-081 A Phase I Dose-Escalation Study of HBM4003, an anti-CTLA-4 Heavy Chain Only Monoclonal Antibody, in Combination with Pembrolizumab

Combination therapy with ipilimumab plus PD-1 inhibitors has shown promising efficacy in various tumor types, demonstrating higher rates of response than either agent alone. HBM4003 is a fully human heavy chain only monoclonal antibody targeting CTLA-4, which has been engineered to deplete Treg cells and enhanced antibody-dependent cellular cytotoxicity. HBM4003 has shown preliminary clinical activity in phase (Ph) I trial in patients (pts) with advanced solid tumors. Pembrolizumab is a humanized immunoglobulin G4 monoclonal antibody against PD-1 and has been approved by FDA in various indications.

Combined use of UV and MS data for ICH Stability-Indication Method: Quantification and isoforms identification of intact nivolumab

Nivolumab (Opdivo®) is a fully human immunoglobulin G4 isotype approved for the treatment of many cancers. It acts as an immune checkpoint inhibitor by blocking the interaction between PD-1 (Programmed Cell Death Protein 1) – an inhibitory receptor expressed on activated T cells- and its ligands, PD-L1 and PD-L2. The quantification of therapeutic proteins in their medicines and pharmaceutical preparations remains challenging because the protein content, a critical quality attribute, must be rigorously calculated using a validated stability-indicating method, such as that indicated by the International Conference on Harmonization (ICH) quality guidelines, and this requires the analysis of the drug in the presence of its degraded products. In this work, we present an strategy based on the combined use of the UV and MS data to full file the requirement of the ICH-Q2(R1) to develop and validated as stability indicated a (RP)UHPLC/UV-(HESI/Orbitrap™)MS method for the quantification of nivolumab in medicinal products. A comparative study of all figures of merit of the method using UV or MS data are shown and discussed. The results show that linearity was similar for the two detectors and was established over a range of 4–45 μg/mL and 1–45 μg/mL for the UV and (HESI/Orbitrap™)MS signals, respectively. The sensitivity of the method was higher when using the (HESI/Orbitrap™)MS signal (0.2 μg/mL) than with the UV(2.0 μg/mL). However, the UV signal provided better accuracy and precision than the (HESI/Orbitrap™)MS signal, which did not meet the criteria for method robustness and system suitability. In spite of this, the MS signal plays a crucial role in this methodology by obtaining the molecular weight profile of the nivolumab isoforms, so enabling us to propose the glycans profile and detect structural modification due to degradation. The specificity of the method was evaluated by conducting forced degradation tests on samples of nivolumab in medicine form. The aim was to find out whether nivolumab suffers structural modifications when subject to stress. Structural modifications were detected by analysing the MS isoform profile, as changes of this kind promote new isoforms that are not chromatographically separated or detected by the UV signal. In this way, we demonstrated that the (RP)UHPLC/UV-(HESI/Orbitrap™)MS method was capable of detecting nivolumab degradation, and was suitable for use in nivolumab stability studies. Thus, the protein content in the daily surplus of the Opdivo® medicine, stored either at room temperature (20 °C) or refrigerated at 4 °C, could be tracked for 15 days.

680 An Incidental Finding of Pneumatosis of the Colon in a Patient with Mesothelioma Being Treated with Nivolumab

Abstract A 75-year-old woman attended a large academic teaching hospital for a computed tomography (CT) of the chest for a T3 N0 M0 epithelioid mesothelioma of the right pleura (to assess treatment response). The malignancy was diagnosed one year previously, and the patient was being treated with second line immunotherapy, Nivolumab (a human immunoglobulin G4 monoclonal antibody) with palliative intent. To date, the patient was showing a partial response to this treatment. The CT chest incidentally showed locules of gas under the right diaphragm and therefore an urgent CT of the abdomen and pelvis was performed. This scan re-demonstrated a small pneumoperitoneum, but also an incidental finding of pneumatosis involving the hepatic flexure. Prior to Nivolumab treatment, there were no abnormalities noted on the most recent abdominal CT scan. The patient was admitted to hospital as an emergency under the care of oncology. The patient was entirely asymptomatic with a soft, non-tender abdomen, with both a normal diet and bowel function. Observations including heart rate, temperature, blood pressure and respiratory rate were within normal limits. Blood testing showed a C-reactive protein of 86 mg/L and white cell count of 4.8 10^9. Based on the radiological findings, intravenous fluids and antibiotics were commenced and the patient was restricted to nil intake orally. A surgical review was also requested. Based on surgical advice, the patient was treated conservatively, and was discharged home without complication and no surgical follow up.

A 41-Year-Old Man With an Abdominal Mass and Hepatomegaly

A 41-Year-Old Man With an Abdominal Mass and Hepatomegaly