Acetaminophen‐induced acute liver failure (AALF) is associated with innate immunity activation, which contributes to the severity of hepatic injury and clinical outcome. A marked increase in hepatic macrophages (h‐mϕ) is observed in experimental models of AALF, but controversy exists regarding their role, implicating h‐mϕ in both aggravation and resolution of liver injury. The role of h‐mϕ in human AALF is virtually unexplored. We sought to investigate the role of chemokine (C‐C motif) ligand 2 (CCL2) in the recruitment of circulating monocytes to the inflamed liver and to determine how the h‐mϕ infiltrate and liver microenvironment may contribute to tissue repair versus inflammation in AALF. We evaluated circulating monocytes, their chemokine (C‐C motif) receptor 2 (CCR2) expression, and serum CCL2 levels in patients with AALF. Cell subsets and numbers of circulation‐derived (MAC387+) or resident proliferating (CD68/Ki67+) h‐mϕ in hepatic immune infiltrates were determined by immunohistochemistry. Inflammatory cytokine levels were determined in whole and laser microdissected liver tissue by proteome array. In AALF, circulating monocytes were depleted, with the lowest levels observed in patients with adverse outcomes. CCL2 levels were high in AALF serum and hepatic tissue, and circulating monocyte subsets expressed CCR2, suggesting CCL2‐dependent hepatic monocyte recruitment. Significant numbers of both MAC387+ and CD68+ h‐mϕ were found in AALF compared with control liver tissue with a high proportion expressing the proliferation marker Ki67. Levels of CCL2, CCL3, interleukin (IL)‐6, IL‐10, and transforming growth factor‐β1 were significantly elevated in AALF liver tissue relative to chronic liver disease controls. Conclusion: In AALF, the h‐mϕ population is expanded in areas of necrosis, both through proliferation of resident cells and CCL2‐dependent recruitment of circulating monocytes. The presence of h‐mϕ within an anti‐inflammatory/regenerative microenvironment indicates that they are implicated in resolution of inflammation/tissue repair processes during AALF. (HEPATOLOGY 2012)

Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery datasets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5×10−8) and used pathway analysis to identify JAK-STAT/IL12/IL27 signaling and cytokine-cytokine pathways, for which relevant therapies exist.

AAS marketed as dietary supplements continue to cause hepatotoxicity in the UK; underlying mechanisms may include unmasking of genetic cholestatic syndromes.

):A1-A306 A191 BSG abstracts dependent-magnetic resonance imaging (BOLD-MRI) was used to quantify changes in renal oxygenation. Tissue expression and distribution of RLN receptor (RXFP1) was determined by qPCR and immunofluorescence. Expression of vasoconstrictor genes was quantified by qPCR array. Results RXFP1 was detected on glomerular podocytes, renal pericytes, and endothelial cells of the renal, segmental and interlobar arteries of cirrhotic rats. In CCl 4 cirrhosis, acute i.v. RLN (4µg) induced a 50% increase in RBF after 60 minutes (p < 0.01 vs. placebo, n = 6). BOLD-MRI showed increased tissue oxygenation at the same timepoint in renal cortex and medulla. Extended s.c. RLN increased RBF by 54% in CCl 4 (p < 0.01 vs. placebo, n = 8) and 57% in BDL (p < 0.001 vs. placebo, n = 5) and increased GFR by 138% in CCl 4 (p < 0.01 vs. placebo, n = 8) and 103% in BDL (p < 0.05 vs. placebo, n = 5). Mean arterial pressure was unaffected by RLN. L-NAME (250mg/L) orally (p.o.) abrogated the effect of RLN on RBF and GFR. The relative expression of vasoconstrictor genes in the kidney was markedly reduced by RLN treatment. Conclusion RLN increases RBF in experimental cirrhosis. Crucially, RLN also improves renal function and oxygenation but does not induce systemic hypotension even in decompensated disease. The effects of RLN are mediated via augmentation of NO and downregulation of vasoconstrictor genes known to be important in the pathogenesis of HRS. RLN has potential as a treatment for HRS and further translational studies are warranted. Disclosure of Interest None Declared.

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