Citations

ObjectiveTo evaluate circulating cytokine profiles in patients with antineutrophil cytoplasmic antibody–associated vasculitis (AAV), classified by antineutrophil cytoplasmic antibody (ANCA) specificity (proteinase 3 ANCA [PR3‐ANCA] versus myeloperoxidase ANCA [MPO‐ANCA]) or by clinical diagnosis (granulomatosis with polyangiitis [GPA] versus microscopic polyangiitis [MPA]).MethodsA panel of 29 cytokines was tested in 186 patients with active AAV at inclusion into the Rituximab in AAV trial. Cytokine concentrations were compared between groups within each classification system. Multivariable analyses adjusted for age, sex, and renal insufficiency were performed, with each biomarker as a dependent variable and ANCA specificity and clinical diagnosis as explanatory variables of interest.ResultsLevels of 9 circulating cytokines (interleukin‐6 [IL‐6], granulocyte–macrophage colony‐stimulating factor [GM‐CSF], IL‐15, IL‐18, CXCL8/IL‐8, CCL‐17/thymus and activation–regulated chemokine [TARC], IL‐18 binding protein [IL‐18 BP], soluble IL‐2 receptor α [sIL‐2Rα], and nerve growth factor β [NGFβ]) were significantly higher in PR3‐AAV than MPO‐AAV, 4 cytokines (sIL6R, soluble tumor necrosis factor receptor type II [sTNFRII], neutrophil gelatinase–associated lipocalin [NGAL], and soluble intercellular adhesion molecule 1 [sICAM‐1]) were higher in MPO‐AAV than in PR3‐AAV, 6 cytokines (IL‐6, GM‐CSF, IL‐15, IL‐18, sIL‐2Rα, and NGFβ) were higher in GPA than in MPA, and 3 cytokines (osteopontin, sTNFRII, and NGAL) were higher in MPA than in GPA (all P < 0.05). For nearly all cytokines, the difference between PR3‐AAV and MPO‐AAV was larger than that between GPA and MPA. The multivariate analysis showed that 8 cytokines (IL‐15, IL‐8, IL‐18 BP, NGF‐β, sICAM‐1, TARC, osteopontin, and kidney injury molecule 1 (P < 0.05) distinguished patients with AAV better (lower P values and larger effect sizes) when grouped by ANCA specificity than by clinical diagnosis.ConclusionDistinct cytokine profiles were identified for PR3‐AAV versus MPO‐AAV and for GPA versus MPA. Differences in these circulating immune mediators are more strongly associated with ANCA specificity than with clinical diagnosis, suggesting that heterogeneity in the AAV subtypes extends beyond clinical phenotypes.

Key Points In the largest study of HMAs in RR-AML to date, 16% of patients achieved CR/CRi and experienced a median OS of 21 months. Low proliferative disease (peripheral blood blasts <5%) was associated with improved response and OS.

Secretin is an important regulator of pancreatic function, but the molecular basis of its actions is not well understood. We have, therefore, used in situ autoradiography, photoaffinity labeling, and RNase protection assays with healthy rat pancreas, dispersed acinar cells, and pancreas depleted of acinar cells to explore the cellular distribution and molecular identity of high-affinity secretin receptors in this complex organ. The autoradiographic examination of125I-labeled [Tyr10]rat secretin-27 binding to normal pancreas demonstrated saturable and specific high-affinity binding sites on both acinar and duct cells, with a uniform lobular distribution, but with no binding above background over islets or vascular structures. Photoaffinity labeling demonstrated that the ductular binding site in acinar cell-depleted copper-deficient rat pancreas represented the same glycoprotein with a molecular weight of 50,000–62,000 that was present on acinar cells. RNase protection assays confirmed the molecular identity of the secretin receptors expressed on these distinct cells. The apparent absence or extreme low density of similar secretin receptors on islets and pancreatic vascular structures suggests that the pharmacological effects of secretin on those cells may either be indirect or mediated by another secretin family receptor that recognizes this hormone with lower affinity.

The cholecystokinin (CCK) receptor on the rat pancreatic acinar cell is a guanine nucleotide-binding protein (G protein)-coupled receptor, which was recently demonstrated to be phosphorylated in response to agonist stimulation (Klueppelberg et al., J. Biol. Chem. 266: 17744-17746, 1991). In this work, we establish that this receptor is phosphorylated in response to a variety of homologous and heterologous secretagogues and that these phosphorylation events represent action by more than one protein kinase. One subgroup of kinases includes one or more isotype of protein kinase C (PKC), and is capable of playing a role in homologous and heterologous desensitization. A second subgroup of kinases that acts on the CCK receptor was defined by its resistance to 10 microM staurosporine, which was shown to inhibit all PKC in these cells. The activity of the second group of kinases was observed only in response to occupation of the CCK receptor by high concentrations of native hormone, raising the possibility of a "receptor-specific kinase." Similar to the prototypical kinase, beta-adrenergic receptor kinase (beta-ARK), this activity was inhibited in permeabilized cells by heparin. Furthermore, like this enzyme activity, beta-ARK was shown to be resistant to staurosporine. Based on its action on a G protein-coupled receptor, its activation at high concentrations of native agonist, and its pattern of inhibition, we believe that the staurosporine-insensitive CCK receptor kinase activity represents either beta-ARK or a closely related member of the receptor-specific kinase enzyme family.

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease associated with autoimmune phenomena targeting intrahepatic bile duct cells (cholangiocytes). Although its etiopathogenesis remains obscure, development of antimitochondrial autoantibodies against pyruvate dehydrogenase complex E2 is a common feature. MicroRNA (miR) dysregulation occurs in liver and immune cells of PBC patients, but its functional relevance is largely unknown. We previously reported that miR‐506 is overexpressed in PBC cholangiocytes and directly targets both Cl – / anion exchanger 2 and type III inositol 1,4,5‐trisphosphate receptor, leading to cholestasis. Here, the regulation of miR‐506 gene expression and its role in cholangiocyte pathophysiology and immune activation was studied. Several proinflammatory cytokines overexpressed in PBC livers (such as interleukin‐8 [IL8], IL12, IL17, IL18, and tumor necrosis factor alpha) stimulated miR‐506 promoter activity in human cholangiocytes, as revealed by luciferase reporter assays. Experimental overexpression of miR‐506 in cholangiocytes dysregulated the cell proteomic profile (by mass spectrometry), affecting proteins involved in different biological processes including mitochondrial metabolism. In cholangiocytes, miR‐506 (1) induced dedifferentiation with down‐regulation of biliary and epithelial markers together with up‐regulation of mesenchymal, proinflammatory, and profibrotic markers; (2) impaired cell proliferation and adhesion; (3) increased oxidative and endoplasmic reticulum stress; (4) caused DNA damage; and (5) sensitized to caspase‐3‐dependent apoptosis induced by cytotoxic bile acids. These events were also associated with impaired energy metabolism in mitochondria (proton leak and less adenosine triphosphate production) and pyruvate dehydrogenase complex E2 overexpression. Coculture of miR‐506 overexpressing cholangiocytes with PBC immunocytes induced activation and proliferation of PBC immunocytes. Conclusion : Different proinflammatory cytokines enhance the expression of miR‐506 in biliary epithelial cells; miR‐506 induces PBC‐like features in cholangiocytes and promotes immune activation, representing a potential therapeutic target for PBC patients. (H epatology 2018;67:1420‐1440)

ObjectiveTo estimate the annual incidence, prevalence, and mortality of antineutrophil cytoplasmic autoantibody (ANCA)–associated vasculitis (AAV) and its subsets, granulomatosis with polyangiitis (Wegener's) (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (Churg‐Strauss) (EGPA), in a US‐based adult population.MethodsAll medical records of patients with a diagnosis of, or suspicion of having, AAV in Olmsted County, Minnesota from January 1, 1996 to December 31, 2015 were reviewed. AAV incidence rates were age‐ and sex‐adjusted to the 2010 US white population. Age‐ and sex‐adjusted prevalence of AAV was calculated on January 1, 2015. Survival rates observed in the study cohort were compared with expected rates in the Minnesota population.ResultsOf the 58 incident cases of AAV in Olmsted County during the study period, 23 (40%) were cases of GPA, 28 (48%) were cases of MPA, and 7 (12%) were cases of EGPA. Overall, 28 (48%) of the patients with AAV were women and 57 (98%) were white. The mean ± SD age at diagnosis was 61.1 ± 16.5 years. Thirty‐four patients (61%) had myeloperoxidase (MPO)–ANCAs, and 17 (30%) were positive for proteinase 3 (PR3)–ANCAs; 5 (9%) were ANCA‐negative. The annual incidence of AAV was 3.3 per 100,000 population (95% confidence interval [95% CI] 2.4–4.1). The incidence rates of GPA, MPA, and EGPA were 1.3 (95% CI 0.8–1.8), 1.6 (95% CI 1.0–2.2), and 0.4 (95% CI 0.1–0.6), respectively. The overall prevalence of AAV was 42.1 per 100,000 (95% CI 29.6–54.6). The mortality rate among AAV patients overall, and among patients with EGPA, those with MPA, and those with MPO‐ANCAs, was increased in comparison to the Minnesota general population (each P < 0.05), whereas mortality rates among patients with GPA, those with PR3‐ANCAs, and ANCA‐negative patients did not differ from that in the general population.ConclusionThe annual incidence of AAV in Olmsted County, Minnesota over the 20 years of the study was 3.3 per 100,000, with a prevalence of 42.1 per 100,000, which is substantially higher than the rates reported in other areas worldwide. The incidence of GPA was similar to that of MPA. Patients with MPA and those with EGPA, but not patients with GPA, experienced higher rates of mortality than that in the Minnesota general population. MPO‐ANCAs were a marker of poor survival in this population of patients with AAV.