Here, we present the case of a 40-year-old man in whom the diagnosis of ectopic adrenocorticotropin (ACTH) syndrome went unrecognized despite evaluation by multiple providers until it was ultimately ...suspected by a nephrologist evaluating the patient for edema and weight gain. On urgent referral to endocrinology, screening for hypercortisolism was positive by both low-dose overnight dexamethasone suppression testing and 24-hour urinary free cortisol measurement. Plasma ACTH values confirmed ACTH-dependent Cushing syndrome. High-dose dexamethasone suppression testing was suggestive of ectopic ACTH syndrome. Inferior petrosal sinus sampling demonstrated no central-to-peripheral gradient, and
Ga-DOTATATE scanning revealed an avid 1.2-cm left lung lesion. The suspected source of ectopic ACTH was resected and confirmed by histopathology, resulting in surgical cure. While many patients with Cushing syndrome have a delayed diagnosis, this case highlights the critical need to increase awareness of the signs and symptoms of hypercortisolism and to improve the understanding of appropriate screening tests among nonendocrine providers.
•KIT D816V confers resistance to TNF via BIRC5 (survivin) and promotes clonal dominance.•High TNF levels are associated with inferior survival in SM.
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Systemic mastocytosis (SM) is ...defined by the expansion and accumulation of neoplastic mast cells (MCs) in the bone marrow (BM) and extracutaneous organs. Most patients harbor a somatic KIT D816V mutation, which leads to growth factor–independent KIT activation and accumulation of MC. Tumor necrosis factor α (TNF) is a proapoptotic and inflammatory cytokine that has been implicated in the clonal selection of neoplastic cells. We found that KIT D816V increases the expression and secretion of TNF. TNF expression in neoplastic MCs is reduced by KIT-targeting drugs. Similarly, knockdown of KIT or targeting the downstream signaling cascade of MAPK and NF-κB signaling reduced TNF expression levels. TNF reduces colony formation in human BM cells, whereas KIT D816V+ cells are less susceptible to the cytokine, potentially contributing to clonal selection. In line, knockout of TNF in neoplastic MC prolonged survival and reduced myelosuppression in a murine xenotransplantation model. Mechanistic studies revealed that the relative resistance of KIT D816V+ cells to TNF is mediated by the apoptosis-regulator BIRC5 (survivin). Expression of BIRC5 in neoplastic MC was confirmed by immunohistochemistry of samples from patients with SM. TNF serum levels are significantly elevated in patients with SM and high TNF levels were identified as a biomarker associated with inferior survival. We here characterized TNF as a KIT D816V-dependent cytokine that promotes clonal dominance. We propose TNF and apoptosis-associated proteins as potential therapeutic targets in SM.
Greiner et al investigated the role of tumor necrosis factor α (TNF) in KIT D816V+ systemic mastocytosis (SM). The authors demonstrate that KIT mutation increases expression and secretion of TNF. In turn, TNF suppresses colony formation of normal human bone marrow cells while the KIT-mutant cells are less susceptible to TNF, facilitating clonal dominance of mutant mast cells. Further studies show that resistance of KIT-mutant cells depends on an apoptosis mediator, BIRC5 (survivin). Elevated TNF levels are associated with inferior survival in patients with SM, and these studies suggest that TNF inhibitors may provide a targeted therapy for SM.
NK cells are innate lymphocytes responsible for lysis of pathogen‐infected and transformed cells. One of the major activating receptors required for target cell recognition is the NK group 2D (NKG2D) ...receptor. Numerous reports show the necessity of NKG2D for effective tumor immune surveillance. Further studies identified NKG2D as a key element allowing tumor immune escape. We here use a mouse model with restricted deletion of NKG2D in mature NKp46+ cells (NKG2DΔNK). NKG2DΔNK NK cells develop normally, have an unaltered IFN‐γ production but kill tumor cell lines expressing NKG2D ligands (NKG2DLs) less efficiently. However, upon long‐term stimulation with IL‐2, NKG2D‐deficient NK cells show increased levels of the lytic molecule perforin. Thus, our findings demonstrate a dual function of NKG2D for NK cell cytotoxicity; while NKG2D is a crucial trigger for cytotoxicity of tumor cells expressing activating ligands it is also capable to limit perforin production in IL‐2 activated NK cells.
NKG2D has a dual function in NK cell cytotoxicity; while NKG2D is a crucial trigger for cytotoxicity against tumor cells expressing activating ligands, it limits perforin production in IL‐2 activated NK cells. The increased perforin levels are not linked to an altered activation of the JAK/STAT pathway.
The mainstay of assessing guanosine diphosphate release by the α-subunit of a heterotrimeric G-protein is the ³⁵Sguanosine 5'-O-(3-thiotriphosphate) (GTPγS) radionucleotide-binding assay. This assay ...requires separation of protein-bound GTPγS from free GTPγS at multiple time points followed by quantification via liquid scintillation. The arduous nature of this assay makes it difficult to quickly characterize multiple mutants, determine the effects of individual variables (e.g., temperature and Mg(2+) concentration) on nucleotide exchange, or screen for small molecule modulators of Gα nucleotide binding/cycling properties. Here, we describe a robust, homogeneous, fluorescence polarization assay using a red-shifted fluorescent GTPγS probe that can rapidly determine the rate of GTPγS binding by Gα subunits.
T2D is a heterogeneous disease. Individuals in the Swedish All New Diabetics in Scania (ANDIS) cohort with newly diagnosed T2D were grouped by 6 demographic and clinical variables to show 4 distinct ...T2D subtypes with differential risk for nephropathy and retinopathy. We tested the predictive validity of this clustering system for patients with advanced T2D in DEVOTE (a large, global, randomized, double-blind, cardiovascular outcomes trial; median observation time: 1.99 years) for major adverse cardiovascular event (MACE)-free survival, severe hypoglycemia (SH)-free survival, and overall survival rates. Subjects (N=7637, mean age=65.0 years, mean T2D duration=16.4 years, mean glycated hemoglobin A1C=8.43%) were assigned to a cluster for which they had the smallest Euclidean distance to the cluster center based on available baseline variables: A1C, BMI, age, age at diagnosis. Insulin resistance and sensitivity measures were not available. The 4 DEVOTE clusters showed baseline characteristics consistent with the original ANDIS clusters, with significant differences in MACE-incidence and SH-incidence (Table). The results were confirmed using data from the LEADER trial (data not shown). The study suggests that clusters derived from early T2D can be replicated in long-standing T2D. Future work should characterize differences in treatment response across clusters to improve outcomes across the heterogeneous T2D population.
Disclosure
A.R. Kahkoska: None. E. Hachmann-Nielsen: Employee; Self; Novo Nordisk A/S. K. Klein: None. K.G. Kongsbak: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. K. Kvist: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. J.B. Buse: Consultant; Self; Neurimmune AG. Research Support; Self; AstraZeneca, National Center for Advancing Translational Sciences, National Institute of Diabetes and Digestive and Kidney Diseases, Novo Nordisk A/S, Sanofi, vTv Therapeutics. Stock/Shareholder; Self; Mellitus Health, PhaseBio Pharmaceuticals, Inc., Stability Health. Other Relationship; Self; ADOCIA, AstraZeneca, Dance Biopharm Holdings Inc., Eli Lilly and Company, MannKind Corporation, NovaTarg, Novo Nordisk A/S, Senseonics, vTv Therapeutics, Zafgen, Inc.
Funding
Novo Nordisk
We evaluated the performance of the iLet bionic pancreas (BP) in non-Hispanic White individuals (here referred to as "Whites") and in Black, Hispanic, and other individuals (here collectively ...referred to as "Minorities").
A multicenter, randomized controlled trial evaluated glycemic management with the BP versus standard of care (SC) in 161 adult and 165 pediatric participants with type 1 diabetes over 13 weeks.
In Whites (n = 240), the mean baseline-adjusted difference in 13-week HbA1c between the BP and SC groups was -0.45% (95% CI -0.61 to -0.29 -4.9 mmol/mol; -6.6 to -3.1; P < 0.001), while this difference among Minorities (n = 84) was -0.53% (-0.83 to -0.24 -6.0 mmol/mol; -9.2 to -2.8; P < 0.001). In Whites, the mean baseline-adjusted difference in time in range between the BP and SC groups was 10% (95% CI 7-12; P < 0.001) and in Minorities was 14% (10-18; P < 0.001).
The BP improves glycemic control in both Whites and Minorities and offers promise in decreasing health care disparities.
In humans, the absence of STAT5b mimics the abrogated NK cell terminal maturation observed in
Stat5b
−/−
mice. NK cells from STAT5b patients had a decreased cytolytic function and impaired ...convergence of lytic granules to the microtubule-organizing center.
Background: T cell lymphoma, comprising 15% of diagnosed US lymphomas, currently has no standard of care in the relapsed setting. Exposure to molds diminishes the numbers of T-helpers cells in ...peripheral blood. Aspergillus and Penicillium are known to produce small molecules called mycotoxins. Mycotoxins have previously been associated with immunosuppressive effects (Sutton et al., 1994, 1995), and a reduction of cytokine secretion (Rossano et al., 1999.) This study investigates the effects of two of these mycotoxins, Gliotoxin and Patulin, on the cellular components of mononuclear cells in peripheral blood of normal donors and T-cell lymphoma cells, examining viability and apoptotic damage in CD3+ (T cells), CD4+ (cytotoxic t cells), CD8+ (t helper cells), and CD16+ (NK cells), BDCA1+ and BDCA2+ (dendritic cells), CD14+ (monocytes), and CD19+ (B cells).
Methods: Two mycotoxins, Gliotoxin and Patulin were solubilized into methanol or ethanol and cultured with either normal ficolled blood samples, T-cell lymphoma or T-cell leukemic cells. We plated cells at a concentration of 1x 106 cells per well, treated them with concentrations of 0, 1, 10, 100, 1,000, or 10,000 ng/mL, and incubated for 24 hours. After incubation the cells were removed and washed, and stained with fluorescent antibodies. Cellular content was determined by flow cytometry (FACS). Prior to acquisition by FACS, counting beads were added to each sample to determine absolute counts of each population of cells. Populations of interest were CD3+, CD4+, CD8+, and CD16+, BDCA1+ and BDCA2+, CD14+, and CD19+. Annexin and Propidium Iodide (PI) were added to evaluate apoptotic and non-viable cells. FloJo software was used to analyze the FACS data. Absolute count of viable cells was then converted to percentages using solvent only control as 100% viable.
Results:
Cell Viability after 24 hr Incubation with MycotoxinsConcentrationNormal Peripheral Blood (n=9)T Cell Lymphoma (n=2)Gliotoxin (ng/mL)CD3+/CD4+CD3+/CD8+DC1DC2NKBCD3+01001001001001001001001127128219143104127961012612936691091178210015153252181101,000233331113113710,0004746631326274Patulin (ng/mL)01001001001001001001001666874866081931094100101114848833310084101791411101381521,000393822635276910,000534503439781Median Percent Viable when 0 ng/mL = 100% Viable
The dose of Gliotoxin, most effective for inducing apoptosis and cell death in normal donor T cells is 100 ng/mL, whereas the most effective dose of Patulin was 1,000 ng/mL. In the cell line, the lowest dose of both mycotoxins that produced significant apoptosis and cell death was 1,000 ng/mL.
Conclusion: Our results demonstrate that the mycotoxins, Patulin and Gliotoxin kill PBMC, and confirm the results found by Stanzani et al that Gliotoxin is most cytotoxic against the antigen presenting cells (APC), which impairs T cell response. Our experiment showed that Patulin had the same effect against APC. T cell viability itself was greatly influenced by the addition of Gliotoxin or Patulin, which supports previous evidence that mycotoxins suppress some populations of T cells. Certain issues, such as a less toxic solvent must be addressed; the data, however, shows that mycotoxins do have the ability to kill both normal and T cell leukemic/lymphoma cells.
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