Blockade of neutrophil extracellular trap components ameliorates cholestatic liver disease in Mdr2 (Abcb4) knockout mice.

Primary sclerosing cholangitis (PSC) is an (auto)immune-mediated cholestatic liver disease with a yet unclear etiology. Increasing evidence points to an involvement of neutrophils in chronic liver inflammation and cirrhosis but also liver repair. Here, we investigate the role of the neutrophil extracellular trap (NET) component myeloperoxidase (MPO) and the therapeutic potential of DNase I and of neutrophil elastase (NE) inhibitor GW311616A on disease outcome in the multidrug resistance 2 knockout (Mdr2-/-) mouse, a PSC animal model. Initially, we observed the recruitment of MPO expressing cells and the formation of NETs in liver biopsies of PSC patients and in Mdr2-/- livers. Furthermore, sera of Mdr2-/- mice contained perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA)-like reactivity similar to PSC patient sera. Also, hepatic NE activity was significantly higher in Mdr2-/- mice than in wild type littermates. Flow cytometry analyses revealed that during disease development a highly active neutrophil subpopulation established specifically in the liver of Mdr2-/- mice. However, absence of their MPO activity, as in MPO-deficient Mdr2-/- mice, showed no effect on hepatobiliary disease severity. In contrast, clearance of extracellular DNA by DNase I reduced the frequency of liver-resident neutrophils, plasmacytoid dendritic cells (pDCs) and CD103+ conventional DCs and decreased cholangiocyte injury. Combination of DNase I with a pDC-depleting antibody was additionally hepatocyte-protective. Most importantly, GW311616A, an orally bioavailable inhibitor of human NE, attenuated hepatobiliary injury in a TNFα-dependent manner and damped hyperproliferation of biliary epithelial cells. Further, hepatic immigration and activity of CD11b+ DCs as well as the secretion of IFNγ by hepatic CD4 and CD8 T cells were reduced. Our findings delineate neutrophils as important participants in the immune cell crosstalk that drives cholestatic liver disease and identify NET components as potential therapeutic targets.

"One-stop" surgery: implications for anesthesiologists of an expedited pediatric surgical process.

BACKGROUND: "One-stop surgery" (OSS) allows pediatric patients to undergo initial surgical evaluation, anesthesia, surgery, and discharge home, on the same day. METHODS: Patients referred for umbilical hernia repair, circumcision, or central venous catheter removal completed a screening questionnaire, after which they were scheduled for initial surgical and anesthesia evaluation if eligible and had surgery if indicated on the same day. RESULTS: Three patients had comorbidity precluding OSS, two patients refused indicated surgery, two patients did not require surgery, and 12 patients did not keep their appointment. Eighty patients had surgery without complications. Average total time was significantly shorter for OSS than non-OSS for circumcision (120 vs 142 min) and umbilical hernia repair (139 vs 165 min) but similar for catheter removal (100 vs 109 min). All families were satisfied with OSS. CONCLUSIONS: One-stop surgery appears to be a safe, efficient, and convenient alternative to the traditional process for patients and their families.