Increased Expression of Toll-Like Receptors by Monocytes and Natural Killer Cells in ANCA-Associated Vasculitis

INTRODUCTION: Toll-like receptors (TLRs) are a family of receptors that sense pathogen associated patterns such as bacterial cell wall proteins. Bacterial infections are associated with anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV). Here, we assessed the expression of TLRs 2, 4, and 9 by peripheral blood leukocytes from patients with AAV, and investigated TLR mediated responses ex vivo. METHODS: Expression of TLRs was determined in 38 AAV patients (32 remission, 6 active disease), and 20 healthy controls (HC). Membrane expression of TLRs 2, 4, and 9, and intracellular expression of TLR9 by B lymphocytes, T lymphocytes, NK cells, monocytes and granulocytes was assessed using 9-color flowcytometry. Whole blood from 13 patients and 7 HC was stimulated ex vivo with TLR 2, 4 and 9 ligands and production of cytokines was analyzed. RESULTS: In patients, we observed increased proportions of TLR expressing NK cells. Furthermore, patient monocytes expressed higher levels of TLR2 compared to HC, and in a subset of patients an increased proportion of TLR4(+) monocytes was observed. Monocytes from nasal carriers of Staphylococcus aureus expressed increased levels of intracellular TLR9. Membrane expression of TLRs by B lymphocytes, T lymphocytes, and granulocytes was comparable between AAV patients and HC. Patients with active disease did not show differential TLR expression compared to patients in remission. Ex vivo responses to TLR ligands did not differ significantly between patients and HC. CONCLUSIONS: In AAV, monocytes and NK cells display increased TLR expression. Increased TLR expression by these leukocytes, probably resulting from increased activation, could play a role in disease (re)activation

Endothelial cells response to neutrophil‐derived extracellular vesicles miRNAs in anti‐PR3 positive vasculitis

In vasculitis disorders, inflammation affects blood vessels. Granulomatosis with polyangiitis (GPA) is a chronic systemic vasculitis distinguished by the presence of anti‐proteinase‐3 autoantibodies (anti‐PR3). In this study we analyzed the molecular signature of human umbilical endothelial cells (HUVECs) in response to neutrophil‐derived extracellular vesicles (EVs). EVs were obtained from anti‐PR3‐activated neutrophils, purified and characterized by flow cytometry, nanoparticle tracking and miRNA screening. HUVECs were stimulated with EVs and miRNA/mRNA expression was measured. Cell culture media proteins were identified by antibody microarrays and selected cytokines were measured. Comparison of differentially expressed miRNAs/mRNAs between non‐stimulated and EV‐stimulated HUVECs revealed two regulatory patterns. Significant up‐regulation of 14 mRNA transcripts (including CXCL8, DKK1, IL1RL1, ANGPT‐2, THBS1 and VCAM‐1) was accompanied by 11 miRNAs silencing (including miR‐661, miR‐664a‐3p, miR‐377‐3p, miR‐30d‐5p). Significant down‐regulation was observed for nine mRNA transcripts (including FASLG, CASP8, STAT3, GATA3, IRAK1 and IL6) and accompanied by up‐regulation of 10 miRNAs (including miR‐223‐3p, miR‐142‐3p, miR‐211‐5p). Stimulated HUVECs released IL‐8, Dickkopf‐related protein 1 (DKK‐1), soluble interleukin (IL)‐1 like receptor‐1 (ST2), growth differentiation factor 15 (GDF‐15), angiopoietin‐2, endoglin, thrombospondin‐1 and vascular adhesion molecule‐1 (VCAM‐1). Moreover, transfection of HUVECs with mimics of highly expressed in EVs miR‐223‐3p or miR‐142‐3p, stimulated production of IL‐8, ST2 and endoglin. Cytokines released by HUVECs were also elevated in blood of patients with GPA. The most increased were IL‐8, DKK‐1, ST2, angiopoietin‐2 and IL‐33. In‐vitro stimulation of HUVECs by neutrophil‐derived EVs recapitulates contribution of endothelium in autoimmune vasculitis. Proinflammatory phenotype of released cytokines corresponds with the regulatory network of miRNAs/mRNAs comprising both EVs miRNA and endothelial cell transcripts

Postoperative use of somatostatin analogs and mortality in patients with acromegaly

Objective: To assess the effect of somatostatin analogs (SSAs) on mortality in relation to disease control of acromegaly after pituitary surgery. Design: A retrospective study in two large tertiary referral centers in The Netherlands. Methods: Overall, 319 patients with acromegaly in whom pituitary surgery was performed as primary therapy between January 1980 and July 2017 were included. Postoperative treatment with SSA was prescribed to 174 (55%) patients because of persistent or recurrent disease. Disease control at last visit was assessed by IGF1 standard deviation score (SDS). Adequate disease control was defined as IGF1 SDS Results: In total, 27 deaths were observed. In univariate analysis, determinants of mortality were inadequate disease control (relative risk (RR): 3.41, P = 0.005), surgery by craniotomy (RR: 3.53, P = 0.013) and glucocorticoid substitution (RR: 2.11, P = 0.047). There was a strong trend toward increased mortality for patients who used SSA (RR: 2.01, P = 0.067) and/or dopamine agonists (RR: 2.54, P = 0.052) at last visit. The SMR of patients with adequate disease control who used SSA at any moment postoperatively (1.07, P = 0.785) and at last visit (1.19; P = 0.600) was not increased. Insufficiently controlled patients had a significantly raised SMR (3.92, P = 0.006). Conclusions: Postoperative use of SSA is not associated with increased mortality in patients with acromegaly who attain adequate disease control. In contrast, inadequate disease control, primary surgery by craniotomy and glucocorticoid substitution are associated with increased mortality