Positive Immunohistochemical Staining Research Articles

The relationship between clinical characteristics and pathological features in patients with pheochromocytomas/paragangliomas

Objective: To explore the correlation between clinical characteristics and pathological features in patients with pheochromocytoma/paraganglioma (PPGLs). Methods: A case series study. A retrospective analysis was conducted on patients with single and primary PPGLs after postoperative pathological diagnosis who were admitted to Peking Union Medical College Hospital between January 2019 and December 2022. The patients were divided into the Ki-67<3% group and the Ki-67≥3% group with Ki-67 proliferation index of 3% as the threshold. The relationship between clinical and pathological characteristics of PPGLs was analyzed. Results: A total of 399 PPGLs patients were included, with 177 males and 222 females, aged [M(Q1, Q3)] 45.0(35.5, 53.0) years. Among them, 226 (56.6%) cases originated from the adrenal gland, while 104 cases (26.1%) from the retroperitoneum. 20.9% (27/129) of the patients were found to harbor germline mutations of susceptibility genes, with SDHB mutations being the most common (10.1%, 13/129). The Ki-67 staining was performed on 302 cases, with a Ki-67 proliferation index [M(Q1, Q3)] of 2.0% (1.0%, 3.0%). There were 194 cases in Ki-67<3% group and 108 cases in Ki-67≥3% group. Compared with the patients in Ki-67<3% group, the age of onset in Ki-67≥3% group was younger (P=0.029). Compared with the patients with paragangliomas without SDHB or Cluster 1A-related gene mutations, positive 131I-meta-iodobenzylguanidine (131I-MIBG) imaging or negative O-6-methylguanine-DNA methyltransferase (MGMT) immunohistochemistry staining, those with SDHB or Cluster 1A-related gene mutations, negative 131I-MIBG imaging or positive MGMT immunohistochemistry staining had a higher Ki-67 index (all P<0.05). Compared with adrenal pheochromocytoma, retroperitoneal paragangliomas had a higher proportion of SDHB mutations and a higher proportion of normetanephrine (NMN) secretory types (all P<0.05). Compared with adrenal pheochromocytoma, the maximum diameter of head and neck paraganglioma tumors was smaller [3.0 (1.9, 3.8) cm vs 4.7 (3.4, 6.4) cm, P<0.001] and the proportion of Ki-67≥3% was higher (61.3% vs 33.8%, P=0.007). Conclusions: PPGLs patients with earlier onset age, SDHB or Cluster 1A-related gene mutations, negative 131I-MIBG imaging, or positive MGMT immunohistochemistry staining tend to have a higher Ki-67 index. Head and neck tumors, though smaller, exhibit a higher proliferation potential.

The Comparison of Real-Time PCR and Mutation-Specific Immunohistochemistry in EGFR Mutation Analysis of Non-Small Cell Lung Carcinomas

Objective: This study aims to identify activating mutations in the epidermal growth factor receptor (EGFR) gene in patients with non-small cell lung cancer (NSCLC) and to evaluate their correlation with responses to EGFR-tyrosine kinase inhibitors (TKI) treatment. This study aims to identify activating mutations in the epidermal growth factor receptor (EGFR) gene in patients with non-small cell lung cancer (NSCLC) and to evaluate their correlation with responses to EGFR-tyrosine kinase inhibitors (TKI) treatment. We conducted a comparative analysis of Real-Time PCR and immunohistochemistry to detect EGFR mutation status in non-small cell lung cancer patients, focusing on the sensitivity, specificity, and predictive values of immunohistochemistry. Material and Method: We evaluated 788 non-small cell lung cancer samples which were analyzed for EGFR mutation status by RT-PCR. We detected 126 EGFR mutated cases among these patients. We evaluated mutation-specific EGFR immunohistochemistry directed towards the exon 19 deletions (15 bp E746-A750) and exon 21 point mutation (L858R) to the 47 EGFR mutated patients histologic material and cell blocks of cytologic specimens. Results: 32 of the 47 cases (68%) had exon 19 deletion, 14 of them (30%) had point mutation in exon 21, and one of them (2%) showed exon 18 mutation. EGFR exon 19 (15 bp E746-A750 deletion) antibody showed a sensitivity of 100%, specificity of 40%, negative predictive value of 100%, and positive predictive value of 78%. The sensitivity of the exon 21 (L858R point mutation) antibody was 93%, specificity was 91%, negative predictive value was 97% and positive predictive value was 82%. Conclusion: Our investigation indicates that mutation-specific EGFR immunohistochemistry has demonstrated a notable sensitivity and specificity for exon 21. However, while sensitive, the exon 19 (15 bp E746-A750 deletion) antibody lacked specificity. While positive immunohistochemical staining may suggest the presence of an EGFR mutation, making the patient potentially eligible for TKI treatment, it should not be the sole determinant. If immunohistochemistry results are negative, it is essential to resort to molecular tests to ensure accurate diagnosis and appropriate therapeutic guidance. With evolving diagnostic landscapes, it is crucial to harness both IHC and molecular techniques judiciously for optimal patient care.

Sinonasal immunoglobulin G4-related disease: a case report of an atypical and rare entity

BackgroundImmunoglobulin G4-related disease is marked by extensive inflammation and fibrosis of an unknown autoimmune component, with an overall incidence ranging from 0.78 to 1.39 per 105 person-years. Sinonasal immunoglobulin G4-related disease is atypical and exceedingly uncommon in the existing literature, frequently manifesting clinically as chronic rhinosinusitis, epistaxis, and facial pain.Case presentationThis report describes a 25-year-old Iraqi female who has been suffering from symptoms of chronic rhinosinusitis for 8 years. Despite undergoing several surgeries, there has been no improvement in her symptoms. A tissue biopsy that revealed dense lymphoplasmocytosis with noticeable plasma cell infiltration, storiform fibrosis, and obliterative angitis, along with positive immunohistochemical staining for Immunoglobulin G4 plasma cells, finally confirmed the diagnosis of sinonasal immunoglobulin G4-related disease. The patient responded well to oral prednisolone and methotrexate treatments.ConclusionsThe main objective of the current report is to raise awareness among physicians about the significance of promptly identifying and diagnosing this rarity, thus preventing the adverse consequences linked to delayed diagnosis and treatment initiation.

The potential protective effect of Camellia Sinensis in mitigating monosodium glutamate-induced neurotoxicity: biochemical and histological study in male albino rats

Monosodium glutamate (MSG) is the sodium compound derived from glutamic acid. Excessive daily ingestion of MSG leads to elevated amounts of glutamic acid in the bloodstream, which can be detrimental to brain structures. Camellia sinensis, often known as green tea (GT), is a rich source of essential hexogen antioxidants that are necessary for the body. Thirty-two adult male albino rats were divided into four groups (n = 8). Group 1 served as a control -ve group. Group 2 was given GT (1.5 ml/rat/day). Group 3 was given MSG (600 mg/kg/day). Group 4 was given MSG (600 mg/kg/day) and GT (1.5 ml/rat/day). All treatments were given orally for 28 days. MSG administration resulted in significant neurotoxicity in rats that was revealed by the significant reduction of serum concentration of glutathione peroxidase (GPx) and nitric oxide (NO), and the significant elevation of total antioxidant capacity (TAC) accompanied by the significant reduction of levels of serum monoamines (dopamine, serotonin, and norepinephrine) and histological changes in the hippocampus area CA1, dentate gyrus, and cerebellar cortex and positive immunohistochemical staining of glial fibrillary acidic proteins (GFAP) and calretinin. Administration of GT with MSG counteracted the MSG-mediated oxidative stress by significantly increasing serum concentrations of GPX and NO and significantly decreasing concentrations of TAC. Furthermore, GT significantly increased levels of serum monoamines (dopamine, serotonin, and norepinephrine). Moreover, it ameliorated the histological changes, GFAP, and calretinin immunostaining in brain tissues. It is envisaged that GT will serve as a viable protective choice for the inclusion of the neurotoxicity treatment procedure.

Feline Facial Spindle Cell Tumors in 29 Cats: Histomorphological and Immunohistochemical Characterization.

Soft tissue tumors/sarcomas (STSs) in felines, encompassing a variety of mesenchymal tumors with similar histomorphological features, present diagnostic challenges due to their diverse cellular origins and the overlap with other tumor types such as feline sarcoid. This study aimed to delineate the clinical, histomorphological, and immunohistochemical characteristics of 34 feline facial spindle cell tumors affecting 29 cats, including testing for bovine papillomavirus type 14 (BPV14), the virus causing feline sarcoids. Only five out of 12 tumors previously diagnosed as feline sarcoids based on histomorphology were confirmed by PCR for BPV14, underscoring the importance of comprehensive diagnostic approaches to accurately distinguish between STSs and feline sarcoids. This study shows that most facial spindle cell tumors were compatible with peripheral nerve sheath tumors (PNSTs) based on positive immunohistochemical staining for Sox10 and other immunohistochemical markers such as GFAP, NSE, and S100. Some of these tumors displayed as multiple independent masses on the face or as erosive and ulcerative lesions without obvious mass formation, an atypical presentation and an important highlight for general practitioners, dermatologists, and oncologists. This study also describes periadnexal whorling of neoplastic cells as a novel histomorphologic finding in feline facial PNSTs and emphasizes Sox10 as a useful complementary immunohistochemical marker for the diagnosis of facial PNST in cats, providing valuable insights for veterinary pathologists.

Abstract 1032: Development of a novel companion diagnostic immunohistochemistry antibody for claudin 18.2-targeted therapies

Abstract Background: CLDN18.2, the isoform 2 of CLDN18, is physiologically confined to gastric mucosa tight junctions, the epitopes of which would be exposed on the cancer cell surface upon malignant transformation and is highly expressed in a significant proportion of cancers, e.g., gastric and pancreatic adenocarcinomas, which makes it a promising drug target for cancer therapy. Currently, multiple drug modalities, such as monoclonal antibodies, ADCs, and CARTs targeting CLDN18.2 are being evaluated in clinical trials. A substantial correlation exists between the expression of CLDN18.2 and the efficacy of the these therapies. However, to date, no companion diagnostic (CDx) antibodies that are specific to CLDN18.2 have been approved. Therefore, it is important to promptly develop an anti-CLDN18.2 CDx antibody with a high specificity, sensitivity, and suitability for immunohistochemistry (IHC). In this study, we present the discovery and validation of a novel, highly sensitive IHC antibody that selectively identifies CLDN18.2. Methods: 3 CLDN18.2 specific peptide fragments from extracellular domain of human CLDN18.2 were conjugated with KLH. Antibodies were discovered by immunizing BALB/c and SJL mice with these peptides-KLH conjugates. Screening and selection process was relied on positive ELISA results against the immunogen, as well as FACS and Acumen Explorer Microplate staining of CLDN18.2-experssing cells. Hit antibodies were evaluated for IHC on formalin-fixed paraffin-embedded CHOK1 cells expressing full-length CLDN18.2 or CLDN18.1. The antibodies were further validated on human gastric cancer tissue samples to establish the analytical sensitivity and specificity of the IHC assay. Results: The mAb clone 43F11 exhibited binding to a fusion polypeptide comprising the first extracellular loop of human CLDN18.2 (aa32-53) at a half maximal effective concentration (EC50) of 0.212 nM. 43F11 showed positive cell surface IHC staining on CLDN18.2-experssing cells after fixation but demonstrated no staining on CLDN18.1-experssing cells. The IHC test method was established by utilizing clinical tumor tissues and PDX samples that had predetermined expression levels of CLDN18.2. The 43F11 antibody accurately identified the expression level of CLDN18.2 in the IHC assay, with a minimum concentration of 0.25 μg/mL. When compared to the commercial CLDN18.2 IHC antibody EPR19202, 43F11 demonstrated greater sensitivity, allowing for positive staining on cancer tissues that have significantly lower levels of CLDN18.2 expression. Conclusion: 43F11 exhibits specific recognition of human CLDN18.2 in IHC assays, while showing no reactivity towards CLDN18.1. It demonstrated superior sensitivity compared to the benchmark antibody. These data suggest that 43F11 has the capacity to serve as an effective diagnostic tool for identifying patients who positively express CLDN18.2. Citation Format: Jishun Chen, Suya Bai, Yu Bai, Zaoshun Hu, Peng Chen, Jay Mei, Bo Shan, Bing Hou. Development of a novel companion diagnostic immunohistochemistry antibody for claudin 18.2-targeted therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1032.

REACTIVATION OF THE NUCLEUS PULPOUS CELLS BY PLATELET DERIVATIVES AS A NEW TOOL IN INTERVERTEBRAL DISC REGENERATION

Degenerative disc disease, associated to low back pain, afflicts more than 50% of humans, and represents a major healthcare problem, especially for the pathology initiation. Current treatments range from conservative strategies to more invasive surgical techniques, such as disc removal and vertebral fusion. In the Intervertebral Disease (IVD) the nucleus pulposus (NP) degeneration is a key factor for the pathology initiation. Several tissue engineering approaches aiming to restore the appropriate NP cell (NPCs) and matrix content, were attempted by using adult stromal cells either from bone marrow or adipose tissue, chondrocytes, notochordal cells and more recently also pluripotent stem cells. However, none was fully satisfactory since the NP acid and a-vascularized environment appeared averse to the implanted heterologous cells. Several studies demonstrated the efficacy of platelet derivatives such as platelet rich plasma (PRP) in promoting the regeneration of connective tissues. We investigated the efficacy of PRP on NPCs proliferation and differentiation with the goal to propose the direct stimulation of resident cells (stimulation of endogenous cells – less invasive surgical procedure) or the implantation of NPCs expanded in vitro in the presence of PRP as therapeutic agents in IVD degeneration.NPCs were isolated from small fragments of NP explants, cultivated in medium supplemented with PRP or FCS (standard condition control) and characterized by FACS analysis for the expression of the typical mesenchymal stem cells markers CD34, CD44, CD45, CD73, CD90 and CD105. NPCs cultured in PL showed a phenotypic profile like the cells cultured in FCS. However, compared to NPCs expanded in the presence of FCS, NPCs expanded in PRP showed a much better proliferation and differentiation capacity. NPCs differentiation was evaluated by the cell ability to produce an organized metachromatic cartilaginous matrix, confirmed by the positive immunohistochemical staining for chondrogenic markers.

Proliferation and Differentiation Potential of Bone Marrow-Derived Mesenchymal Stem Cells From Children With Polydactyly and Adults With Basal Joint Arthritis.

This study compared the proliferation and differentiation potential of bone marrow-derived mesenchymal stem cells (BMSCs) derived from infants with polydactyly and adults with basal joint arthritis. The proliferation rate of adult and infant BMSCs was determined by the cell number changes and doubling times. The γH2AX immunofluorescence staining, age-related gene expression, senescence-associated β-galactosidase (SA-β-gal) staining were analyzed to determine the senescence state of adult and infant BMSCs. The expression levels of superoxide dismutases (SODs) and genes associated with various types of differentiation were measured using Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR). Differentiation levels were evaluated through histochemical and immunohistochemical staining. The results showed that infant BMSCs had a significantly higher increase in cell numbers and faster doubling times compared with adult BMSCs. Infant BMSCs at late stages exhibited reduced γH2AX expression and SA-β-gal staining, indicating lower levels of senescence. The expression levels of senescence-related genes (p16, p21, and p53) in infant BMSCs were also lower than in adult BMSCs. In addition, infant BMSCs demonstrated higher antioxidative ability with elevated expression of SOD1, SOD2, and SOD3 compared with adult BMSCs. In terms of differentiation potential, infant BMSCs outperformed adult BMSCs in chondrogenesis, as indicated by higher expression levels of chondrogenic genes (SOX9, COL2, and COL10) and positive immunohistochemical staining. Moreover, differentiated cells derived from infant BMSCs exhibited significantly higher expression levels of osteogenic, tenogenic, hepatogenic, and neurogenic genes compared with those derived from adult BMSCs. Histochemical and immunofluorescence staining confirmed these findings. However, adult BMSCs showed lower adipogenic differentiation potential compared with infant BMSCs. Overall, infant BMSCs demonstrated superior characteristics, including higher proliferation rates, enhanced antioxidative activity, and greater differentiation potential into various lineages. They also exhibited reduced cellular senescence. These findings, within the context of cellular differentiation, suggest potential implications for the use of allogeneic BMSC transplantation, emphasizing the need for further in vivo investigation.

Musashi-1 Is a Novel Immunohistochemical Marker of Neuroendocrine Carcinoma of the Lung

Small cell lung cancer (SCLC) and large cell neuroendocrine carcinoma (LCNEC) have recently been grouped as lung neuroendocrine carcinomas (NECs). Because these lung NECs are clinically malignant and their treatment strategies differ from those of non-SCLC, the quality of diagnosis has a significant prognostic impact. The diagnosis of LCNEC requires positive immunohistochemical staining with chromogranin A, synaptophysin, and CD56, along with a morphological diagnosis, and insulinoma-associated protein 1 (INSM1) has been proposed as an additional marker but is still not an ideal or better marker. We investigated Musashi-1 as a novel immunohistochemical marker in 42 patients with SCLCs and 44 with LCNECs who underwent lung resection between 1998 and 2020 at our institution. We found Musashi-1 expression in 98% (41/42) SCLC and in 90% (40/44) LCNEC. These findings were similar to CD56 expression and superior to synaptophysin, chromogranin A, and INSM1. Musashi-1 also tended to show more diffuse and intense staining, especially in LCNEC, with more cases staining &gt; 10% than any other existing markers (Musashi-1, 77%; INSM1, 45%; chromogranin A, 34%; synaptophysin, 41%; and CD56, 66%). In conclusion, we identified Musashi-1 as a novel immunohistochemical staining marker to aid in the diagnosis of lung NEC.

SARS-CoV-2 Aerosol and Intranasal Exposure Models in Ferrets.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the worldwide COVID-19 pandemic. Animal models are extremely helpful for testing vaccines and therapeutics and for dissecting the viral and host factors that contribute to disease severity and transmissibility. Here, we report the assessment and comparison of intranasal and small particle (~3 µm) aerosol SARS-CoV-2 exposure in ferrets. The primary endpoints for analysis were clinical signs of disease, recovery of the virus in the upper respiratory tract, and the severity of damage within the respiratory tract. This work demonstrated that ferrets were productively infected with SARS-CoV-2 following either intranasal or small particle aerosol exposure. SARS-CoV-2 infection of ferrets resulted in an asymptomatic disease course following either intranasal or small particle aerosol exposure, with no clinical signs, significant weight loss, or fever. In both aerosol and intranasal ferret models, SARS-CoV-2 replication, viral genomes, and viral antigens were detected within the upper respiratory tract, with little to no viral material detected in the lungs. The ferrets exhibited a specific IgG immune response to the SARS-CoV-2 full spike protein. Mild pathological findings included inflammation, necrosis, and edema within nasal turbinates, which correlated to positive immunohistochemical staining for the SARS-CoV-2 virus. Environmental sampling was performed following intranasal exposure of ferrets, and SARS-CoV-2 genomic material was detected on the feeders and nesting areas from days 2-10 post-exposure. We conclude that both intranasal and small particle aerosol ferret models displayed measurable parameters that could be utilized for future studies, including transmission studies and testing SARS-CoV-2 vaccines and therapeutics.

Kaposiform hemangioendothelioma presented with raynaud phenomenon: a case report

BackgroundKaposiform hemangioendothelioma (KHE) is a rare vascular neoplasm affecting infants or young children. KHE includes a spectrum of lesions, ranging from small and superficial tumors to large and invasive lesions with Kasabach-Merritt phenomenon (KMP). Currently, no published studies have reported a KHE presenting as thrombocytopenia and Raynaud phenomenon.Case presentationA 2-year-old boy with right hand swelling and thrombocytopenia was admitted to our hospital. His right hand turned swelling and red, even occasionally cyanotic. This condition became worse in response to cool environments and improved with warming, and platelet counts were between 50 ~ 80 × 10^9/L. Physical examination on admission revealed the swelling and frostbite-like rash of the right-hand fingers, and the skin temperature of the right hand was lower than the left. On day 3 of admission, chest CT results showed an irregular mass on the right side of the spine. The puncture biopsy demonstrated positive CD31, D2-40, and FLI1 immunohistochemical staining, but negative GLUT1 staining, confirming the diagnosis of KHE. Furthermore, endothelin-1 (ET1) expression levels significantly increased, and eNOS and A20 expression levels significantly decreased comparing with control patients. The patient received methylprednisolone and sirolimus treatments, and his condition gradually improved during the follow-up.ConclusionsWe reported the first case of KHE presenting with thrombocytopenia and Raynaud phenomenon. The development of Raynaud phenomenon could be associated with increased ET-1 and reduced eNOS and A20 expressions. Careful differential diagnosis of hidden KHE should be considered in children with thrombocytopenia and Raynaud phenomenon.

Assessment of Fallopian Tube Epithelium Features Derived from Induced Pluripotent Stem Cells of Both Fallopian Tube and Skin Origins.

Fallopian tube epithelial cells (FTECs) play a significant role in the development of high-grade serous ovarian cancer (HGSOC), but their utilization in in vitro experiments presents challenges. To address these limitations, induced pluripotent stem cells (iPSCs) have been employed as a potential solution, driven by the hypothesis that orthologous iPSCs may offer superior differentiation capabilities compared with their non-orthologous counterparts. Our objective was to generate iPSCs from FTECs, referred to as FTEC-iPSCs, and compare their differentiation potential with iPSCs derived from skin keratinocytes (NHEK). By introducing a four-factor Sendai virus transduction system, we successfully derived iPSCs from FTECs. To assess the differentiation capacity of iPSCs, we utilized embryoid body formation, revealing positive immunohistochemical staining for markers representing the three germ layers. In vivo tumorigenesis evaluation further validated the pluripotency of iPSCs, as evidenced by the formation of tumors in immunodeficient mice, with histological analysis confirming the presence of tissues from all three germ layers. Quantitative polymerase chain reaction (qPCR) analysis illuminated a sequential shift in gene expression, encompassing pluripotent, mesodermal, and intermediate mesoderm-related genes, during the iPSC differentiation process into FTECs. Notably, the introduction of WNT3A following intermediate mesoderm differentiation steered the cells toward a FTEC phenotype, supported by the expression of FTEC-related markers and the formation of tubule-like structures. In specific culture conditions, the expression of FTEC-related genes was comparable in FTECs derived from FTEC-iPSCs compared with those derived from NHEK-iPSCs. To conclude, our study successfully generated iPSCs from FTECs, demonstrating their capacity for FTEC differentiation. Furthermore, iPSCs originating from orthologous cell sources exhibited comparable differentiation capabilities. These findings hold promise for using iPSCs in modeling and investigating diseases associated with these specific cell types.

Expression of Melan-A in cutaneous granular cell tumours: a diagnostic pitfall

Morphological overlap exists between cutaneous granular cell tumours (GCT) and malignant melanoma, with the melanocyte-specific markers HMB45 and Melan-A commonly used to support the diagnosis of melanoma. We recently encountered several cases of GCT in our practice showing strong expression of Melan-A. The aim of this study was to establish the prevalence of positive immunohistochemical staining for Melan-A and HMB45 in a series of unequivocal GCTs. We also aimed to assess the prevalence of staining for PRAME (PReferentially expressed Antigen in MElanoma), a marker expressed in >80% of primary melanomas as well as many non-melanocytic tumours. A total of 20 cutaneous/subcutaneous GCTs were evaluated using Melan-A, HMB45 and PRAME immunohistochemistry. Staining for Melan-A and HMB45 was scored using a semiquantitative scale from 0 (absent) to 3+ (staining present in >50% of tumour cells). PRAME expression was recorded as either positive (>75% of cell nuclei staining) or negative. Melan-A expression was observed in four GCTs (20%), with strong and diffuse (3+) staining seen in two cases (10%), both from anogenital areas. Weak patchy nuclear PRAME expression was seen in every case, interpreted to be negative. HMB45 was also negative in all cases (100%). Our study demonstrates that Melan-A expression can be strong and diffuse in a subset of otherwise unequivocal cutaneous GCTs, which may cause diagnostic confusion with malignant melanoma. HMB45 and PRAME did not stain any of the GCTs in our series.

Immune profiling of pancreatic cancer for radiotherapy with immunotherapy and targeted therapy: Biomarker analysis of a randomized phase 2 trial

PurposeImmunotherapy alone offered limited survival benefits in pancreatic cancer, while the role of immunotherapy-centric combined therapy remains controversial. Therefore, it is required to develop biomarkers to precisely deliver immunotherapy-based multimodality for pancreatic cancer. MethodsThis is a secondary analysis of an open label, randomized, phase 2 trial, whereas patients with locally recurrent pancreatic cancer after surgery were enrolled. Eligible patients with mutant KRAS and positive immunohistochemical staining of PD-L1 were randomly assigned to receive stereotactic body radiation therapy (SBRT) plus pembrolizumab and trametinib (SBRT + K + M) or SBRT and gemcitabine (SBRT + G). Meanwhile, patients were classified into PD-L1+/tumor infiltrating lymphocytes [TIL(s)]- and PD-L1+/TIL + group for each arm. ResultsA total of 170 patients were enrolled and randomly assigned to receive SBRT + K + M (n = 85) or SBRT + G (n = 85). The improved outcomes have been reported in patients with SBRT + K + M in the previous study. In this secondary analysis, the median overall survival (OS) was 17.2 months (95% CI 14.6–19.8 months) in patients with PD-L1+/TIL + and 12.7 months (95% CI 10.8–14.6 months) in patients with PD-L1+/TIL- (HR 0.62, 95% CI 0.39–0.97, p = 0.036) receiving SBRT + K + M. In SBRT + G group, the median OS was 13.1 months (95% CI 10.9–15.3 months) in patients with PD-L1+/TIL- and 12.7 months (95% CI 9.2–16.2 months) in patients with PD-L1+/TIL+ (HR 0.97, 95% CI 0.62–1.52, p = 0.896). Grade 3 or 4 adverse events were found in 16 patients (30.8%) and 10 patients (30.3%) with PD-L1+/TIL- and PD-L1+/TIL + in SBRT + K + M group respectively; whereas 9 (16.7%) and 8 patients (25.8%) with PD-L1+/TIL- and PD-L1+/TIL + in SBRT + G group. ConclusionPD-L1, TILs and mutant KRAS may be a biomarker to guide clinical practice of radiotherapy and immunotherapy-based regimens in pancreatic cancer if further combined with MEK inhibitors as targeted therapy.

FRI246 A Rare Case Of An Adrenal Gland Hemangioma In A 68-year-old Female

Abstract Disclosure: R. Daas: None. S. Logan: None. R. Voss: None. V. Tarasova: None. T. Glushko: None. J. Hernandez Prera: None. S. Agosto Salgado: None. J. Hallanger-Johnson: None. C. Veloski: None. Background: Adrenal gland hemangiomas are extremely rare, with less than one hundred cases reported in the literature. Although benign and usually asymptomatic, they can be confused with adenomas, pheochromocytomas, or malignant adrenal tumors and preoperative diagnosis is challenging. Clinical Case: A 68-year-old female with a history of breast cancer completes an abdominal/ pelvic MRI due to abdominal and back pain that reveals a 1.4 cm right adrenal mass with T2 bright enhancement prompting concern for pheochromocytoma, lipid poor adenoma, or metastasis. An adrenal protocol contrast CT abdomen redemonstrated a 1.3 cm brightly enhancing right adrenal nodule with precontrast Hounsfield units (HU) of 35, postcontrast HU of 236, and delayed HU of 81. Absolute washout was 77.1%, consistent with an adenoma, however, the enhancement profile was also concerning for pheochromocytoma. Labs showed ACTH 15.2 pg/mL (7.2 - 63.3 pg/mL), cortisol 14.7 ug/dL (3.7 - 19.4 ug/dL), dexamethasone suppression test with cortisol 1.3 ug/dL (3 – 41 ug/dL), aldosterone 12 ng/dL (4.0 - 31.0 ng/dL), renin 0.1 ng/mL/hr (0.5 - 4.0 ng/mL/hr), potassium 4.0 mmol/L (3.4 - 4.5 mmol/L), DHEA-S 122 ug/dL (9 - 246 ud/dL), total testosterone 41.38 ng/dL (3.00 – 41.00 ng/dL), free testosterone 3.7 pg/mL (0.6 - 3.8 pg/mL), plasma normetanephrines 0.82 nmol/L (0 - 0.89 nmol/L), and plasma metanephrines 0.14 nmol/L (0 - 0.49 nmol/L), 24-hour urine: norepinephrine 47 ug/d (14 – 120 ug/d), epinephrine &amp;lt;4 ug/d (1 – 14 ug/d), dopamine 236 ug/d (71 – 485 ug/d), metanephrines 86 ug/d (36 – 229 ug/d), and normetanephrines 258 ug/d (95 – 650 ug/d). The patient was asymptomatic, without high blood pressure, tachycardia, or hypokalemia. Despite the unremarkable lab workup, surgical excision of the nodule was recommended due to concern for silent pheochromocytoma or metastasis given the imaging findings and history of breast cancer. She was pretreated with doxazosin and had a right adrenalectomy. Pathology revealed a 1 cm hemangioma involving the periadrenal adipose tissue with ERG positive, CD31 positive, and D2-40 negative immunohistochemical staining. She was monitored post-operatively for transient hypotension and tachycardia and was discharged in stable condition. Conclusion: The differential diagnosis for adrenal gland incidentalomas is quite broad, however, patient history, along with laboratory and imaging studies, can help guide management. Adrenal gland hemangiomas are rare, non-functional, and have a propensity to bleed, but are benign and have a good prognosis. Presentation: Friday, June 16, 2023

SAT588 Cushing’s Syndrome Due To Ectopic ACTH Secretion From Ovarian Teratomas

Abstract Disclosure: Y. Kang: None. M.S. Gildenberg: None. B.J. Quade: None. R.A. Blair: None. Background: Approximately 9-18% of Cushing’s syndrome (CS) cases are secondary to ectopic ACTH secretion, most commonly from sources in the lung or mediastinum. However, ACTH-producing tumors are rarely found in distant organs, occasionally making the localization and management challenging. Clinical Case: A 32-year-old woman with class 3 obesity, hidradenitis suppurativa, anxiety, and depression experienced atraumatic pelvic and sacral fractures. DXA scan result showed Z-scores of -3.1 in the lumbar spine, -2.6 in the femur neck, and -0.5 in the total hip. She reported a steady weight-gain of 250 lbs over 7 years despite lifestyle modifications and liraglutide. On examination, she had a round face with plethora, acne, violaceous abdominal striae, and dorsocervical fat pad. Laboratory findings revealed elevated midnight salivary cortisol levels of 453 and 424 ng/dL (n: &amp;lt;100 ng/dL), elevated 24-hour urine cortisol levels of 254 and 741 (n: 3.5-45 mcg), and an abnormal 1 mg dexamethasone suppression test (DST) result at 15.1 ug/dL. AM plasma ACTH and cortisol levels were 190 pg/mL and 18.5 ug/dL, suggesting ACTH-dependent hypercortisolism. The plasma cortisol level after an 8 mg DST was unsuppressed at 13.1 ug/dL with a dexamethasone level of 3,380 ng/dL (n: &amp;gt;800 ng/dL). Abdominal CT and MRI scans showed large bilateral adnexal masses measuring up to 13.7 cm on the left and 9.3 cm on the right, with heterogeneous solid and cystic components, consistent with mature cystic ovarian teratomas. DOTATE-PET scan did not show any areas of increased uptake. The patient underwent a laparoscopic right cystectomy and left oophorectomy, with immediate drop in cortisol (1.6 ug/dL) and signs of adrenal insufficiency post-operatively, requiring hydrocortisone replacement. After holding hydrocortisone for 24 hours prior to laboratory assessment one week post-operatively, her ACTH and cortisol were undetectable, reflecting successful source removal. Pathology report showed neuroendocrine tumor with pituitary differentiation with positive ACTH immunohistochemical staining and Ki-67 proliferative index of 22.6% on the left adnexal mass, and a mature cystic teratoma on the right. Conclusion: Although rare, pituitary differentiation of ovarian teratomas should be considered as a possible source of ectopic ACTH secretion in CS patients without obvious sources identified in commonly involved organs. Presentation: Saturday, June 17, 2023

Meclizine moderates lipopolysaccharide-induced neuroinflammation in mice through the regulation of AKT/ NF-κβ/ERK/JNK signaling pathway

Neuroinflammation is identified as significant inflammatory reactions occurring in the central nervous system. Lipopolysaccharide (LPS) stimulates innate immune reactions and is used as an in vivo animal model for the investigation of inflammation. Meclizine (MCLZ) is a histamine antagonist with potential neuroprotective qualities. Forty adult male Swiss albino mice were divided into four groups (n = 10). Group 1 served as a control negative group. Groups 2–4 were injected with LPS (5 mg/kg; i.p). Group 2 served as LPS-control. Groups 3 & 4 were given MCLZ (12.5 & 25 mg/kg; p.o) respectively for 14 days. LPS administration resulted in significant neuroinflammation in mice as was revealed by significant inflammatory histopathological changes and positive immunohistochemical staining of glial fibrillary acidic proteins (GFAP) accompanied by significant elevations of brain tissue contents of interleukin-1-beta (IL-1β), tumor necrosis factor-alpha (TNF-α), nuclear factor kappa-beta (NF-κβ), protein kinase B (AKT), extracellular signal-regulated kinase (ERK) and C-Jun N-Terminal Kinases (JNK). MCLZ treatment significantly down-regulated all the aforementioned parameters in mice brains. Moreover, MCLZ treatment ameliorated the inflammatory histopathological changes and GFAP immunostaining in brain tissues. The current study identifies for the first time the protective anti-neuroinflammatory effects of MCLZ against LPS-induced neuroinflammation in mice. MCLZ protected against neuroinflammation via the amelioration of inflammatory histopathological changes as well as neuronal GFAP immunostaining and down-regulated the AKT/NF-κβ/ERK/JNK signaling pathway. MCLZ is anticipated as a potential protective candidate for the addition to the treatment protocol of neuroinflammation.

Single-cell transcriptome, phagocytic activity and immunohistochemical analysis of crucian carp (Carassius auratus) in response to Rahnella aquatilis infection.

In teleost fish, kidney is an important immune and hematopoietic organ with multiple physiological functions. However, the immune cells and cellular markers of kidney require further elucidation in crucian carp (C. auratus). Here we report on the single-cell transcriptional landscape in posterior kidney, immunohistochemical and phagocytic features of C. auratus with R. aquatilis infection. The results showed that a total of 18 cell populations were identified for the main immune cells such as monocytes/macrophages (Mo/Mϕ), dendritic cells (DCs), B cells, T cells, granulocytes and hematopoietic progenitor cells (HPCs). Pseudo-time trajectory analysis was reconstructed for the immune cells using Monocle2 to obtain additional insights into their developmental lineage relationships. In the detected tissues (liver, spleen, kidney, intestine, skin, and gills) of infected fish exhibited positive immunohistochemical staining with prepared for antibody to R. aquatilis. Apoptotic cells were fluorescently demonstrated by TUNEL assay, and bacterial phagocytic activity were observed for neutrophils and Mo/Mϕ cells, respectively. Moreover, a similar up-ward/down-ward expression trend of the selected immune and inflammatory genes was found in the kidney against R. aquatilis infection, which were significantly involved in TLR/NLR, ECM adhesion, phago-lysosome, apoptosis, complement and coagulation pathways. To our knowledge, this is the first report on the detailed characterization of immune cells and host-R. aquatilis interaction, which will contribute to understanding on the biology of renal immune cells and repertoire of potential markers in cyprinid fish species.

Expression and correlation of COX-2 and NUCB1 in colorectal adenocarcinoma.

To investigate the expression and correlation of COX-2 and NUCB1 in colorectal adenocarcinoma and adjacent tissues. The expression of COX-2 and NUCB1 and their effects on prognosis were predicted using bioinformatics. Immunohistochemistry was used to identify the expression of two molecules in 56 cases of colorectal adenocarcinoma and the surrounding tissues. The expression of two molecules and their association with clinicopathological variables were examined using the chi-square test. The association between COX-2 and NUCB1 was investigated using the Spearman correlation test. The STRING database revealed that COX-2 and NUCB1 were strongly linked. According to the UALCAN and HPA database, COX-2 was upregulated while NUCB1 was downregulated in colorectal adenocarcinoma, both at the protein and gene levels. The OS times for COX-2 and NUCB1 high expression, however, exhibited the same patterns. The rate of positive COX-2 immunohistochemical staining in cancer tissues was 69.64% (39/56), which was significantly higher than the rate in healthy tissues 28.57% (16/56). NUCB1 was expressed positively in cancer tissues at a rate of 64.29% (36/56) compared to just 19.64% (11/56) in neighboring tissues. The positive expression levels of COX-2 and NUCB1 were both closely related to clinical stage, differentiation degree, and lymphatic metastases (P < 0.05). In colorectal cancer, COX-2 and NUCB1 expression were significantly correlated (rs = 0.6312, P < 0.001). Both COX-2 and NUCB1 are overexpressed and significantly associated in colorectal adenocarcinoma.

Dual Antibody Treatment for Simultaneous Acute Cellular Rejection and Antibody-Mediated Rejection After Liver Transplantation: A Case Report

Antibody-mediated rejection (AMR) after liver transplantation is uncommon but sometimes has a grave prognosis. We herein describe a 40-year-old man who developed simultaneous acute cellular rejection and acute AMR due to de novo donor-specific anti-human leukocyte antigen antibodies after living donor liver transplantation. He underwent living donor liver transplantation with his brother-in-law as the donor. Hepatic function deteriorated on postoperative day 6, and a liver biopsy revealed histologic findings of typical acute cellular rejection. However, steroid pulse therapy and thymoglobulin did not produce a clinical response, and his liver function dramatically deteriorated on postoperative day 13 (aspartate aminotransferase, 2787 IU/L; total bilirubin, 14.1 mg/dL). We diagnosed acute AMR based on positive immunohistochemical staining for C4d in portal areas and added plasma exchange and high-dose intravenous immunoglobulin after rituximab. The patient's clinical state improved and ultimately resolved. To our knowledge, this is the first report of dual antibody treatment for simultaneous acute cellular rejection and acute AMR induced by de novo donor-specific anti-human leukocyte antigen antibodies. Despite his fulminant clinical course, we successfully rescued the recipient with immediate anti-humoral therapy. The rapid treatment decision and adequate understanding of the mechanisms of anti-humoral therapy were crucial to overcoming acute AMR in this case.