The impact of cortisol in steatotic and non-steatotic liver surgery

The intent of this study was to examine the effects of regulating cortisol levels on damage and regeneration in livers with and without steatosis subjected to partial hepatectomy under ischaemia–reperfusion. Ultimately, we found that lean animals undergoing liver resection displayed no changes in cortisol, whereas cortisol levels in plasma, liver and adipose tissue were elevated in obese animals undergoing such surgery. Such elevations were attributed to enzymatic upregulation, ensuring cortisol production, and downregulation of enzymes controlling cortisol clearance. In the absence of steatosis, exogenous cortisol administration boosted circulating cortisol, while inducing clearance of hepatic cortisol, thus maintaining low cortisol levels and preventing related hepatocellular harm. In the presence of steatosis, cortisol administration was marked by a substantial rise in intrahepatic availability, thereby exacerbating tissue damage and regenerative failure. The injurious effects of cortisol were linked to high hepatic acethylcholine levels. Upon administering an α7 nicotinic acethylcholine receptor antagonist, no changes in terms of tissue damage or regenerative lapse were apparent in steatotic livers. However, exposure to an M3 muscarinic acetylcholine receptor antagonist protected livers against damage, enhancing parenchymal regeneration and survival rate. These outcomes for the first time provide new mechanistic insight into surgically altered steatotic livers, underscoring the compelling therapeutic potential of cortisol–acetylcholine–M3 muscarinic receptors.

The Effect of High-Mobility Group Box 1 in Rat Steatotic and Nonsteatotic Liver Transplantation From Donors After Brain Death

High-mobility group box 1 (HMGB1) has been described in different inflammatory disorders, and the deleterious effects of brain death (BD) may counteract the protection conferred by ischemic preconditioning (IP), the only surgical strategy that is being applied in clinical liver transplantation. Our study examined how HMGB1 may affect preconditioned and unpreconditioned steatotic and nonsteatotic liver grafts from donors after BD (DBDs) for transplantation. HMGB1 was pharmacologically modulated in liver grafts from DBDs, and HMGB1-underlying mechanisms were characterized. We found that BD decreased HMGB1 in preconditioned and unpreconditioned livers and was associated with inflammation and damage. Exogenous HMGB1 in DBDs activates phosphoinositide-3-kinase and Akt and reduces hepatic inflammation and damage, increasing the survival of recipients. Combination of IP and exogenous HMGB1 shows additional benefits compared with HMGB1 alone. This study provides new mechanistic insights into the pathophysiology of BD-derived liver graft damage and contributes to the development of novel and efficient strategies to ultimately improve liver graft quality.

The effect of brain death in rat steatotic and non-steatotic liver transplantation with previous ischemic preconditioning

BACKGROUND & AIMS

Most liver grafts undergoing transplantation derive from brain dead donors, which may also show hepatic steatosis, being both characteristic risk factors in liver transplantation. Ischemic preconditioning shows benefits when applied in non-brain dead clinical situations like hepatectomies, whereas it has been less promising in the transplantation from brain dead patients. This study examined how brain death affects preconditioned steatotic and non-steatotic liver grafts undergoing transplantation.

METHODS

Steatotic and non-steatotic grafts from non-brain dead and brain dead-donors were cold stored for 6h and then transplanted. After 2, 4, and 16 h of reperfusion, hepatic damage was analysed. In addition, two therapeutic strategies, ischemic preconditioning and/or acetylcholine pre-treatment, and their underlying mechanisms were characterized.

RESULTS

Preconditioning benefits in non-brain dead donors were associated with nitric oxide and acetylcholine generation. In brain dead donors, preconditioning generated nitric oxide but did not promote acetylcholine upregulation, and this resulted in inflammation and damage. Acetylcholine treatment in brain dead donors, through PKC, increased antioxidants and reduced lipid peroxidation, nitrotyrosines and neutrophil accumulation, altogether protecting against damage. The combination of acetylcholine and preconditioning conferred stronger protection against damage, oxidative stress and neutrophil accumulation than acetylcholine treatment alone. These superior beneficial effects were due to a selective preconditioning-mediated generation of nitric oxide and regulation of PPAR and TLR4 pathways, which were not observed when acetylcholine was administered alone.

CONCLUSIONS

Our findings propose the combination of acetylcholine+preconditioning as a feasible and highly protective strategy to reduce the adverse effects of brain death and to ultimately improve liver graft quality.

Type-1 hepatorenal syndrome associated with infections in cirrhosis: natural history, outcome of kidney function, and survival

Type-1 hepatorenal syndrome (HRS) is a common complication of bacterial infections in cirrhosis, but its natural history remains undefined. To assess the outcome of kidney function and survival of patients with type-1 HRS associated with infections, 70 patients diagnosed during a 6-year period were evaluated prospectively. Main outcomes were no reversibility of type-1 HRS during treatment of the infection and 3-month survival. Forty-seven (67%) of the 70 patients had no reversibility of type-1 HRS during treatment of the infection. [Correction to previous sentence added March 10, 2014, after first online publication: "Twenty-three (33%)" was changed to "Forty-seven (67%)."] The main predictive factor of no reversibility of type-1 HRS was absence of infection resolution (no reversibility: 96% versus 48% in patients without and with resolution of the infection; P < 0.001). Independent predictive factors of no reversibility of type-1 HRS were age, high baseline serum bilirubin, nosocomial infection, and reduction in serum creatinine <0.3 mg/dL at day 3 of antibiotic treatment. No reversibility was also associated with severity of circulatory dysfunction, as indicated by more marked activity of the vasoconstrictor systems. In the whole series, 3-month probability of survival was only 21%. Factors associated with poor prognosis were baseline serum bilirubin, no reversibility of type-1 HRS, lack of resolution of the infection, and development of septic shock after diagnosis of type-1 HRS.

CONCLUSION

Type-1 HRS associated with infections is not reversible in two-thirds of patients with treatment of infection only. No reversibility of type-1 HRS is associated with lack of resolution of the infection, age, high bilirubin, and no early improvement of kidney function and implies a poor prognosis. These results may help advance the management of patients with type-1 HRS associated with infections.

Resistin and visfatin in steatotic and non-steatotic livers in the setting of partial hepatectomy under ischemia-reperfusion

BACKGROUND & AIMS

This study examined whether the regulation of resistin and visfatin could reduce damage and improve regeneration in both steatotic and non-steatotic livers undergoing partial hepatectomy under ischemia-reperfusion, a procedure commonly applied in clinical practice to reduce bleeding.

METHODS

Resistin and visfatin were pharmacologically modulated in lean and obese animals undergoing partial hepatectomy under ischemia-reperfusion.

RESULTS

No evident role for these adipocytokines was observed in non-steatotic livers. However, obese animals undergoing liver surgery showed increased resistin in liver and plasma, without changes in adipose tissue, together with visfatin downregulation in liver and increment in plasma and adipose tissue. Endogenous resistin maintains low levels of visfatin in the liver by blocking its hepatic uptake from the circulation, thus regulating the visfatin detrimental effects on hepatic damage and regenerative failure. Indeed, the administration of anti-resistin antibodies increased hepatic accumulation of adipocyte-derived visfatin, exacerbating damage and regenerative failure. Interestingly, treatment with anti-visfatin antibodies protected steatotic livers, and similar results were obtained with the concomitant inhibition of resistin and visfatin. Thus, when visfatin was inhibited, the injurious effects of anti-resistin antibodies disappeared. Herein we show that upregulation of visfatin increased NAD levels in the remnant steatotic liver, whereas visfatin inhibition decreased them. These later observations suggest that visfatin may favour synthesis of NAD instead of DNA and induces alterations in amino acid metabolism-urea cycle and NO production, overall negatively affecting liver viability.

CONCLUSIONS

Our results indicate the clinical potential of visfatin blocking-based therapies in steatotic livers undergoing partial hepatectomy with ischemia-reperfusion.

Current knowledge on oxidative stress in hepatic ischemia/reperfusion

Ischemia/reperfusion (I/R) injury associated with hepatic resections and liver transplantation remains a serious complication in clinical practice, despite several attempts to solve the problem. The redox balance, which is pivotal for normal function and integrity of tissues, is dysregulated during I/R, leading to an accumulation of reactive oxygen species (ROS). Formation of ROS and oxidant stress are the disease mechanisms most commonly invoked in hepatic I/R injury. The present review examines published results regarding possible sources of ROS and their effects in the context of I/R injury. We also review the effect of oxidative stress on marginal livers, which are more vulnerable to I/R-induced oxidative stress. Strategies to improve the viability of marginal livers could reduce the risk of dysfunction after surgery and increase the number of organs suitable for transplantation. The review also considers the therapeutic strategies developed in recent years to reduce the oxidative stress induced by hepatic I/R, and we seek to explain why some of them have not been applied clinically. New antioxidant strategies that have yielded promising results for hepatic I/R injury are discussed.

Tauroursodeoxycholic acid affects PPARγ and TLR4 in Steatotic liver transplantation

Numerous steatotic livers are discarded for transplantation because of their poor tolerance to ischemia-reperfusion (I/R). We examined whether tauroursodeoxycholic acid (TUDCA), a known inhibitor of endoplasmic reticulum (ER) stress, protects steatotic and nonsteatotic liver grafts preserved during 6 h in University of Wisconsin (UW) solution and transplanted. The protective mechanisms of TUDCA were also examined. Neither unfolded protein response (UPR) induction nor ER stress was evidenced in steatotic and nonsteatotic liver grafts after 6 h in UW preservation solution. TUDCA only protected steatotic livers grafts and did so through a mechanism independent of ER stress. It reduced proliferator-activated receptor-γ (PPARγ) and damage. When PPARγ was activated, TUDCA did not reduce damage. TUDCA, which inhibited PPARγ, and the PPARγ antagonist treatment up-regulated toll-like receptor 4 (TLR4), specifically the TIR domain-containing adaptor inducing IFNβ (TRIF) pathway. TLR4 agonist treatment reduced damage in steatotic liver grafts. When TLR4 action was inhibited, PPARγ antagonists did not protect steatotic liver grafts. In conclusion, TUDCA reduced PPARγ and this in turn up-regulated the TLR4 pathway, thus protecting steatotic liver grafts. TLR4 activating-based strategies could reduce the inherent risk of steatotic liver failure after transplantation.

Retinol-binding protein 4 and peroxisome proliferator-activated receptor-γ in steatotic liver transplantation

Numerous steatotic livers are discarded for transplantation because of their poor tolerance of ischemia-reperfusion (I/R). The injurious effects of retinol-binding protein 4 (RBP4) in various pathologies are well documented. RBP4 levels are reduced by peroxisome proliferator-activated receptor-γ (PPARγ) agonists. Strategies aimed at increasing PPARγ protect steatotic livers under warm ischemia. Ischemic preconditioning (PC) based on brief periods of I/R protects steatotic liver grafts against I/R injury, but the responsible mechanism is poorly understood. We examined the roles of RBP4 and PPARγ in I/R injury associated with steatotic liver transplantation and the benefits of PC in such situations. We report that RBP4 and PPARγ expression levels in nonsteatotic livers were similar to those found in the sham group. However, reduced RBP4 and increased PPARγ levels were observed in steatotic livers. Treatment with either RBP4 or a PPARγ antagonist was effective only in steatotic livers. PC, which increased RBP4 levels, and RBP4 treatment both reduced PPARγ levels and hepatic injury in steatotic livers. When PPARγ was activated, neither RBP4 treatment nor PC (despite RBP4 induction) protected steatotic livers. In conclusion, steatotic liver grafts are more predisposed to down-regulate RBP4 and overexpress PPARγ. RBP4 treatment and PC, through RBP4 induction, reduced PPARγ levels in steatotic liver grafts, thus protecting them from the PPARγ detrimental effects.

Prognostic importance of the cause of renal failure in patients with cirrhosis

BACKGROUND & AIMS

The prognostic value of the different causes of renal failure in cirrhosis is not well established. This study investigated the predictive value of the cause of renal failure in cirrhosis.

METHODS

Five hundred sixty-two consecutive patients with cirrhosis and renal failure (as defined by serum creatinine > 1.5 mg/dL on 2 successive determinations within 48 hours) hospitalized over a 6-year period in a single institution were included in a prospective study. The cause of renal failure was classified into 4 groups: renal failure associated with bacterial infections, renal failure associated with volume depletion, hepatorenal syndrome (HRS), and parenchymal nephropathy. The primary end point was survival at 3 months.

RESULTS

Four hundred sixty-three patients (82.4%) had renal failure that could be classified in 1 of 4 groups. The most frequent was renal failure associated with infections (213 cases; 46%), followed by hypovolemia-associated renal failure (149; 32%), HRS (60; 13%), and parenchymal nephropathy (41; 9%). The remaining patients had a combination of causes or miscellaneous conditions. Prognosis was markedly different according to cause of renal failure, 3-month probability of survival being 73% for parenchymal nephropathy, 46% for hypovolemia-associated renal failure, 31% for renal failure associated with infections, and 15% for HRS (P < .0005). In a multivariate analysis adjusted for potentially confounding variables, cause of renal failure was independently associated with prognosis, together with MELD score, serum sodium, and hepatic encephalopathy at time of diagnosis of renal failure.

CONCLUSIONS

A simple classification of patients with cirrhosis according to cause of renal failure is useful in assessment of prognosis and may help in decision making in liver transplantation.

Improved rat steatotic and nonsteatotic liver preservation by the addition of epidermal growth factor and insulin-like growth factor-I to University of Wisconsin solution

This study examined the effects of epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) supplementation to University of Wisconsin solution (UW) in steatotic and nonsteatotic livers during cold storage. Hepatic injury and function were evaluated in livers preserved for 24 hours at 4 degrees C in UW and in UW with EGF and IGF-I (separately or in combination) and then perfused ex vivo for 2 hours at 37 degrees C. AKT was inhibited pharmacologically. In addition, hepatic injury and survival were evaluated in recipients who underwent transplantation with steatotic and nonsteatotic livers preserved for 6 hours in UW and UW with EGF and IGF-I (separately or in combination). The results, based on isolated perfused liver, indicated that the addition of EGF and IGF-I (separately or in combination) to UW reduced hepatic injury and improved function in both liver types. A combination of EGF and IGF-I resulted in hepatic injury and function parameters in both liver types similar to those obtained by EGF and IGF-I separately. EGF increased IGF-I, and both additives up-regulated AKT in both liver types. This was associated with glycogen synthase kinase-3beta (GSK3(beta)) inhibition in nonsteatotic livers and PPAR gamma overexpression in steatotic livers. When AKT was inhibited, the effects of EGF and IGF-I on GSK3(beta), PPAR gamma, hepatic injury and function disappeared. The benefits of EGF and IGF-I as additives in UW solution were also clearly seen in the liver transplantation model, because the presence of EGF and IGF-I (separately or in combination) in UW solution reduced hepatic injury and improved survival in recipients who underwent transplantation with steatotic and nonsteatotic liver grafts. In conclusion, EGF and IGF-I may constitute new additives to UW solution in steatotic and nonsteatotic liver preservation, whereas a combination of both seems unnecessary.

Endoplasmic reticulum stress inhibition protects steatotic and non-steatotic livers in partial hepatectomy under ischemia-reperfusion

During partial hepatectomy, ischemia–reperfusion (I/R) is commonly applied in clinical practice to reduce blood flow. Steatotic livers show impaired regenerative response and reduced tolerance to hepatic injury. We examined the effects of tauroursodeoxycholic acid (TUDCA) and 4-phenyl butyric acid (PBA) in steatotic and non-steatotic livers during partial hepatectomy under I/R (PH+I/R). Their effects on the induction of unfolded protein response (UPR) and endoplasmic reticulum (ER) stress were also evaluated. We report that PBA, and especially TUDCA, reduced inflammation, apoptosis and necrosis, and improved liver regeneration in both liver types. Both compounds, especially TUDCA, protected both liver types against ER damage, as they reduced the activation of two of the three pathways of UPR (namely inositol-requiring enzyme and PKR-like ER kinase) and their target molecules caspase 12, c-Jun N-terminal kinase and C/EBP homologous protein-10. Only TUDCA, possibly mediated by extracellular signal-regulated kinase upregulation, inactivated glycogen synthase kinase-3β. This is turn, inactivated mitochondrial voltage-dependent anion channel, reduced cytochrome c release from the mitochondria and caspase 9 activation and protected both liver types against mitochondrial damage. These findings indicate that chemical chaperones, especially TUDCA, could protect steatotic and non-steatotic livers against injury and regeneration failure after PH+I/R.

Matrix metalloproteinase 2 in reduced-size liver transplantation: beyond the matrix

We studied the contribution of matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9) to the beneficial effects of preconditioning (PC) in reduced-size orthotopic liver transplantation (ROLT). We also examined the role of c-Jun N-terminal kinase (JNK) and whether it regulates MMP2 in these conditions. Animals were subjected to ROLT with or without PC and pharmacological modulation, and liver tissue samples were then analyzed. We found that MMP2, but notMMP9, is involved in the beneficial effects of PC in ROLT. MMP2 reduced hepatic injury and enhanced liver regeneration. Moreover, inhibition of MMP2 in PC reduced animal survival after transplantation. JNK inhibition in the PC group decreased hepatic injury and enhanced liver regeneration. Furthermore, JNK upregulated MMP2 in PC. In addition, we showed that Tissue inhibitors of matrix metalloproteinases 2 (TIMP2) was also upregulated in PC and that JNK modulation also altered its levels in ROLT and PC. Our results open up new possibilities for therapeutic treatments to reduce I/R injury and increase liver regeneration after ROLT, which are the main limitations in living-donor transplantation.

Addition of carvedilol to University Wisconsin solution improves rat steatotic and nonsteatotic liver preservation

Here we examine the effect of adding carvedilol (CVD) to University of Wisconsin (UW) solution on the preservation of steatotic and nonsteatotic livers during cold ischemia and after normothermic reperfusion. We used an isolated perfused rat liver model. The following protocols were evaluated. Protocol 1 concerned the effect of CVD after cold ischemia. Steatotic and nonsteatotic livers were preserved for 24 hours in UW solution alone or with CVD. Livers without cold ischemia were used as controls. Transaminases were evaluated in the flushing effluent. Protocol 2 involved the effect of CVD after reperfusion. Both liver types were preserved for 24 hours in UW solution alone or with CVD and then perfused ex vivo for 2 hours at 37 degrees C. Livers flushed and perfused without ischemia were used as controls. Hepatic injury and functionality [transaminases, bile production, and hepatic clearance of sulfobromophthalein (BSP)] were evaluated after reperfusion. In addition, factors potentially involved in hepatic ischemia-reperfusion injury, including oxidative stress (malondialdehyde and superoxide anion levels), mitochondrial damage (glutamate dehydrogenase activity), microcirculatory disorders (flow rate and vascular resistance), and adenosine triphosphate (ATP) depletion, were evaluated after reperfusion. After cold ischemia, steatotic livers preserved in UW solution showed higher transaminase levels than nonsteatotic livers. After reperfusion, steatotic livers preserved in UW solution showed higher transaminase levels and lower bile production and BSP clearance than nonsteatotic livers. Alterations in the perfusion flow rate and vascular resistance, mitochondrial damage, and reduced ATP content were more evident in steatotic livers preserved in UW solution. The addition of CVD to UW solution reduced hepatic injury, obstructed its mechanisms, and improved hepatic functionality in both liver types. We conclude that CVD is a useful additive for UW solution that improves the preservation of steatotic and nonsteatotic livers subjected to prolonged cold ischemia.

Insulin-like growth factor and epidermal growth factor treatment: new approaches to protecting steatotic livers against ischemia-reperfusion injury

Hepatic steatosis is a major risk factor in ischemia-reperfusion (I/R). IGF-binding proteins (IGFBPs) modulate IGF-I action by transporting circulating IGF-I to its sites of action. Epidermal growth factor (EGF) stimulates IGF-I synthesis in vitro. We examined the effect of IGF-I and EGF treatment, separately or in combination, on the vulnerability of steatotic livers to I/R. Our results indicated that I/R impaired IGF-I synthesis only in steatotic livers. Only when a high dose of IGF-I (400 microg/kg) was given to obese animals did they show high circulating IGF-I:IGFBP levels, increased hepatic IGF-I levels, and protection against damage. In lean animals, a dose of 100 microg/kg IGF-I protected nonsteatotic livers. Our results indicated that the combined administration of IGF-I and EGF resulted in hepatic injury parameters in both liver types similar to that obtained by IGF-I and EGF separately. IGF-I increased egf expression in both liver types. The beneficial role of EGF on hepatic I/R injury may be attributable to p38 inhibition in nonsteatotic livers and to PPAR gamma overexpression in steatotic livers. In conclusion, IGF-I and EGF may constitute new pharmacological strategies to reduce the inherent susceptibility of steatotic livers to I/R injury.

Therapeutic targets in liver transplantation: angiotensin II in nonsteatotic grafts and angiotensin-(1-7) in steatotic grafts

Numerous steatotic livers are discarded as unsuitable for transplantation because of their poor tolerance of ischemia-reperfusion(I/R). The injurious effects of angiotensin (Ang)-II and the benefits of Ang-(1-7) in various pathologies are well documented. We examined the generation of Ang II and Ang-(1-7) in steatotic and nonsteatotic liver grafts from Zucker rats following transplantation. We also studied in both liver grafts the effects of Ang-II receptors antagonists and Ang-(1-7) receptor antagonists on hepatic I/R damage associated with transplantation. Nonsteatotic grafts showed higher Ang II levels than steatotic grafts, whereas steatotic grafts showed higher Ang-(1-7) levels than nonsteatotic grafts. Ang II receptor antagonists protected only nonsteatotic grafts against damage, whereas Ang-(1-7) receptor antagonists were effective only in steatotic grafts. The protection conferred by Ang II receptor antagonists in nonsteatotic grafts was associated with ERK 1/2 overexpression, whereas the beneficial effects of Ang-(1-7) receptor antagonists in steatotic grafts may be mediated by NO inhibition. Our results show that Ang II receptor antagonists are effective only in nonsteatotic liver transplantation and point to a novel therapeutic target in liver transplantation based on Ang-(1-7), which is specific for steatotic liver grafts.

Vascular endothelial growth factor and angiopoietin-2 play a major role in the pathogenesis of vascular leakage in cirrhotic rats

BACKGROUND AND AIMS

The extent and molecular mechanisms governing plasma extravasation and formation of ascites in cirrhosis are unknown. Vascular endothelial growth factor-A (VEGF-A) and angiopoietin-2 (Ang-2) are endogenous substances with powerful vascular permeability effects. We assessed regional blood flow, vascular leakage, mRNA and tissular expression of VEGF-A and Ang-2 and vascular permeability following VEGF receptor 2 blockade in control and cirrhotic rats to define the vascular territories showing altered vascular permeability in cirrhosis and to determine whether VEGF-A and Ang-2 are involved in this phenomenon.

METHODS

Arterial blood flow was analysed with the coloured microsphere method. Vascular leakage was measured and visualised with the dye Evan's Blue and colloidal carbon techniques, respectively. VEGF-A and Ang-2 expression were determined by real-time polymerase chain reaction (RT-PCR), immunohistochemistry and western blot. The effect on vascular permeability induced by VEGFR(2) blockade was assessed by administration of the receptor inhibitor SU11248.

RESULTS

Arterial blood flow was increased in the mesentery, pancreas and small intestine but not in the kidney and spleen of cirrhotic rats as compared to controls. Increased vascular leakage was observed in the mesentery and liver, where colloidal carbon spread from microvessels to the adjacent fibrotic tracts. Increased hepatic and mesenteric expression of VEGF-A and Ang-2 was found in cirrhotic rats as compared to controls. Blockade of VEGFR(2) markedly reduced hepatic and mesenteric vascular leakage in cirrhotic rats.

CONCLUSIONS

Enhanced endothelial permeability is restricted to the hepatic and mesenteric vascular beds in cirrhotic rats with ascites and VEGF-A and Ang-2 are key factors in the signalling pathways regulating this dysfunction.

Are angiotensin II receptor antagonists useful strategies in steatotic and nonsteatotic livers in conditions of partial hepatectomy under ischemia-reperfusion?

We examined whether angiotensin (Ang) II receptor antagonists could be considered a therapeutic strategy in steatotic and nonsteatotic livers in conditions of partial hepatectomy under ischemia-reperfusion (I/R), which is commonly applied in clinical practice to reduce blood loss. We report that Ang II type I receptor (AT1R) antagonist, but not Ang II type II receptor (AT2R) antagonist, increased regeneration in nonsteatotic livers. In the presence of steatosis, both AT1R and AT2R antagonists increased liver regeneration. This effect was stronger when the two were combined. Neither of the Ang II receptor antagonists protected nonsteatotic livers against damage. Only the AT1R antagonist, through nitric oxide inhibition, reduced damage in steatotic livers. The combination of the AT1R and AT2R antagonists in steatotic livers conferred a similar degree of protection to AT1R antagonist alone. Herein, we show that p38 mitogen-activated protein kinase (p38) was a key mechanism in the regeneration induced by the Ang II receptor antagonists in both liver types because when this signaling pathway was inhibited, the beneficial effects of the Ang II receptor antagonists on liver regeneration disappeared, regardless of hepatocyte growth factor or transforming growth factor beta-hepatic levels. In conclusion, in conditions of partial hepatectomy under I/R, the AT1R antagonist for nonsteatotic livers and the AT1R and AT2R antagonists for steatotic livers improved regeneration in the remnant liver through p38 activation. In addition, the combination of the AT1R and AT2R antagonists in steatotic livers led to stronger liver regeneration than either antagonists used separately and also provided the same protection against damage as that afforded by AT1R antagonist alone.

Terlipressin and albumin vs albumin in patients with cirrhosis and hepatorenal syndrome: a randomized study

BACKGROUND & AIMS

Hepatorenal syndrome is common in patients with advanced cirrhosis and constitutes a major problem in liver transplantation. There is no effective medical treatment for hepatorenal syndrome.

METHODS

Forty-six patients with cirrhosis and hepatorenal syndrome, hospitalized in a tertiary care center, were randomly assigned to receive either terlipressin (1-2 mg/4 hour, intravenously), a vasopressin analogue, and albumin (1 g/kg followed by 20-40 g/day) (n = 23) or albumin alone (n = 23) for a maximum of 15 days. Primary outcomes were improvement of renal function and survival at 3 months.

RESULTS

Improvement of renal function occurred in 10 patients (43.5%) treated with terlipressin and albumin compared with 2 patients (8.7%) treated with albumin alone (P = .017). Independent predictive factors of improvement of renal function were baseline urine volume, serum creatinine and leukocyte count, and treatment with terlipressin and albumin. Survival at 3 months was not significantly different between the 2 groups (terlipressin and albumin: 27% vs albumin 19%, P = .7). Independent predictive factors of 3-month survival were baseline model for end-stage liver disease score and improvement of renal function. Cardiovascular complications occurred in 4 patients treated with albumin alone and in 10 patients treated with terlipressin and albumin, yet permanent terlipressin withdrawal was required in only 3 cases.

CONCLUSIONS

As compared with albumin, treatment with terlipressin and albumin is effective in improving renal function in patients with cirrhosis and hepatorenal syndrome. Further studies with large sample sizes should be performed to test whether the improvement of renal function translates into a survival benefit.

Antiangiogenic treatment with sunitinib ameliorates inflammatory infiltrate, fibrosis, and portal pressure in cirrhotic rats

Liver cirrhosis is a very complex disease in which several pathological processes such as inflammation, fibrosis, and pathological angiogenesis are closely integrated. We hypothesized that treatment with pharmacological agents with multiple mechanisms of action will produce superior results to those achieved by only targeting individual mechanisms. This study thus evaluates the therapeutic use of the multitargeted receptor tyrosine kinase inhibitor Sunitinib (SU11248). The in vitro effects of SU11248 were evaluated in the human hepatic stellate cell line LX-2 by measuring cell viability. The in vivo effects of SU11248 treatment were monitored in the livers of cirrhotic rats by measuring angiogenesis, inflammatory infiltrate, fibrosis, alpha-smooth muscle actin (alpha-SMA) accumulation, differential gene expression by microarrays, and portal pressure. Cirrhosis progression was associated with a significant enhancement of vascular density and expression of vascular endothelial growth factor-A, angiopoietin-1, angiopoietin-2, and placental growth factor in cirrhotic livers. The newly formed hepatic vasculature expressed vascular cellular adhesion molecule 1 and intercellular adhesion molecule 1. Interestingly, the expression of these adhesion molecules was adjacent to areas of local inflammatory infiltration. SU11248 treatment resulted in a significant decrease in hepatic vascular density, inflammatory infiltrate, alpha-SMA abundance, LX-2 viability, collagen expression, and portal pressure.

CONCLUSION

These results suggest that multitargeted therapies against angiogenesis, inflammation, and fibrosis merit consideration in the treatment of cirrhosis.

Impaired extracellular matrix degradation in aortic vessels of cirrhotic rats

BACKGROUND/AIMS

Thinning of the vascular wall occurs in conductance vessels of cirrhotic rats. Increased nitric oxide synthase (NOS) activity has been involved in the pathogenesis of this phenomenon. Therefore, we assessed the NO-regulated cell signaling pathways participating in vascular remodeling in cirrhosis.

METHODS

Aortas were obtained from 15 control and 15 cirrhotic rats. Phosphorylated p38 MAPK and ERK1/2 were used to evaluate the activation of cell MAPK signaling pathways. Extracellular matrix (ECM) turnover was estimated by measuring matrix metalloproteinases (MMPs) activity and protein expression of collagen IV, MMP-2, MMP-9 and tissue inhibitor of MMPs (TIMP)-2. Thereafter, 12 control and 12 cirrhotic rats received Nomega-nitro-L-arginine-methyl-ester or vehicle daily for 11 weeks.

RESULTS

Cirrhotic vessels showed a reduction in ERK1/2 phosphorylation, lower MMP activity, decreased MMPs expression and higher collagen IV and TIMP-2 abundance, compared to control rats. Chronic NOS inhibition normalized ERK1/2 phosphorylation and MMPs activity, increased MMPs abundance and decreased TIMP-2 expression in cirrhotic rats.

CONCLUSIONS

Vascular remodeling in cirrhotic rats is mediated by down-regulation of cell growth and impaired ERK1/2 activation and subsequent imbalance of ECM turnover. These results further stress the importance of vascular NO overactivity in the reduction of vascular wall thickness in cirrhosis.

Docosahexaenoic acid (DHA) blunts liver injury by conversion to protective lipid mediators: protectin D1 and 17S-hydroxy-DHA

Docosahexaenoic acid (DHA) is a omega-3 essential fatty acid that reduces the incidence and severity of a number of diseases. Recently, a novel series of DHA-derived lipid mediators with potent protective actions has been identified. In this study we demonstrate that dietary amplification of these DHA-derived products protects the liver from necroinflammatory injury. In vitro, supplementation of hepatocytes with DHA significantly reduced hydrogen peroxide-induced DNA damage, evaluated by the "comet assay," and oxidative stress, determined by measurement of malondialdehyde levels. In vivo, dietary supplementation of mice with DHA ameliorated carbon tetrachloride-induced necroinflammatory damage. In addition, hepatic cyclooxygenase-2 expression and PGE2 levels were significantly reduced in mice fed DHA-enriched diets. In these animals, increased hepatic formation of DHA-derived lipid mediators (i.e., 17S-hydroxy-DHA (17S-HDHA) and protectin D1) was detected by HPLC-gas chromatography/mass spectrometry analysis. Consistent with these findings, synthetic 17-HDHA abrogated genotoxic and oxidative damage in hepatocytes and decreased TNF-alpha release and 5-lipoxygenase expression in macrophages. In a transactivation assay, 17-HDHA acted in a concentration-dependent manner as a PPARgamma agonist. Taken together, these findings identify a potential role for DHA-derived products, specifically 17S-HDHA and protectin D1, in mediating the protective effects of dietary DHA in necroinflammatory liver injury.

Gene expression profiling of renal dysfunction in rats with experimental cirrhosis

BACKGROUND/AIMS

Renal dysfunction is a frequent complication in advanced cirrhosis. The mechanisms underlying this complication have classically been addressed through conventional methods of study of candidate genes, but never on a genome-wide scale. In this investigation, we used microarrays to monitor global gene expression changes in the kidney of cirrhotic rats.

METHODS

Renal samples were obtained from control and carbon tetrachloride-induced cirrhotic rats. RNA samples were reverse-transcribed into Cy5-labeled cDNA, combined with a Cy3-labeled reference and hybridized to oligonucleotide microarrays. Microarrays were scanned in a Genepix 4000B and data analyzed by Luminator v2.0 software.

RESULTS

A total of 620 genes were differentially regulated (354 up and 266 down) in the cirrhotic kidney, accounting for approximately 11% of all analyzed transcripts. Functional grouping of these genes revealed that 47 were related to the category of vascular tone and 85 to transporters/channels. Among these, we identified genes and pathways already associated with renal dysfunction as well as a new subset of genes previously unknown to participate in this complication, including a G protein-coupled receptor that binds apelin, a protein phosphatase (calcineurin B) and a number of neuropeptide receptors and growth factors.

CONCLUSIONS

These findings furnish new data for mechanistic investigation into renal dysfunction in cirrhosis.

Characterization and differentiation of autoimmune versus viral liver involvement in patients with Sjögren's syndrome

OBJECTIVE

To analyze the prevalence and clinical significance of liver involvement in patients with Sjögren's syndrome (SS), focusing on the characterization and differentiation of autoimmune versus chronic viral liver disease.

METHODS

We investigated liver involvement (clinical signs, analytical data, chronic viral infections, and autoantibodies) in 475 consecutive patients with SS. All patients fulfilled 4 or more of the 1993 European Community Study Group criteria for SS.

RESULTS

Liver involvement was detected in 129 (27%) patients. After ruling out chronic illnesses or use of hepatotoxic drugs, the main etiologies were chronic viral liver disease in 64 (13%) cases [chronic hepatitis C virus (HCV) infection in 63 and HBV infection in one] and autoimmune liver diseases in 24 (5%; primary biliary cirrhosis in 16 patients and type-1 autoimmune hepatitis in 8). The analytical liver profile was not useful in differentiating between viral and autoimmune liver disease. In contrast, patients with SS and autoimmune liver disease presented higher mean values of erythrocyte sedimentation rate (p = 0.044), circulating gammaglobulins (p = 0.007), and a higher prevalence of antinuclear antibodies (p < 0.001), antimitochondrial antibodies (p < 0.001), anti-smooth muscle antibodies (p = 0.026), anti-Ro/SSA (p < 0.001), and anti-La/SSB (p = 0.01), while patients with chronic viral liver disease had a higher frequency of cryoglobulinemia (p < 0.001) and hypocomplementemia (p < 0.001).

CONCLUSION

Chronic viral liver disease (associated overwhelmingly with HCV) was the main cause of liver involvement in our patients with SS, with a prevalence of 13%, nearly 3-fold greater than that observed for autoimmune liver involvement. The immunological pattern played a key role in the differentiation of viral (predominance of cryoglobulins and low complement levels) and autoimmune (higher frequency of autoantibodies) liver involvement.

Excellent long-term survival in patients with primary biliary cirrhosis and biochemical response to ursodeoxycholic Acid

BACKGROUND & AIMS

Because the efficacy of UDCA on long-term outcome of primary biliary cirrhosis (PBC) has not been completely elucidated, we have assessed the course and survival of patients with PBC treated with UDCA and compared with the survival predicted by the Mayo model and the estimated survival of a standardized population.

METHODS

(One hundred ninety-two patients [181 women] with PBC treated with UDCA [15 mg/kg per day] for 1.5-14 years.) Response to treatment was defined by an alkaline phosphatase decrease greater than 40% of baseline values or normal levels after 1 year of treatment. The predicted survival was obtained by the Mayo model and the estimated survival was taken from the standardized matched Spanish population.

RESULTS

Seventeen patients died or fulfilled criteria for liver transplantation (8.9%). The observed survival was higher than that predicted by the Mayo model and lower than that of the control population (P < .001). One hundred seventeen patients (61%) responded to treatment. The survival of responders was significantly higher than that predicted by the Mayo model and similar to that estimated for the control population (P = .15). By contrast, the survival of patients without biochemical response was lower than that estimated for the Spanish population (P < .001) although higher than that predicted by the Mayo model.

CONCLUSIONS

Biochemical response to UDCA after 1 year is associated with a similar survival to the matched control population, clearly supporting the favorable effects of this treatment in PBC. The suboptimal survival of nonresponders identifies the group for further treatments.

Sustained aquaretic effect of the V2-AVP receptor antagonist, RWJ-351647, in cirrhotic rats with ascites and water retention

1 A disturbance in body water homeostasis is a common feature in advanced cirrhosis. This disturbance is always associated with the existence of ascites and is characterized by an inability to adjust the amount of water excreted in the urine to the amount of water ingested. Vasopressin (AVP) is of major importance in the pathogenesis of water retention and hyponatremia in cirrhosis. 2 The current study assessed the renal, hormonal and hemodynamic effects induced by 10-day chronic oral administration of RWJ-351647 (0.5 mg kg(-1) daily), a new nonpeptide V(2)-AVP antagonist, in rats with CCl(4)-induced cirrhosis, ascites and severe water retention. Urine volume (UV), urine osmolality and sodium and potassium excretion were measured daily. At the end of the study, systemic hemodynamic parameters were also assessed. 3 Long-term administration of RWJ-351647 has an aquaretic effect in rats with cirrhosis, ascites, water retention and hypo-osmolality. It increases UV (ANOVA: F=7.32, P<0.0001) and reduces urine osmolality (ANOVA: F=12.69, P<0.0001) throughout the entire period of treatment, thereby leading to a greater renal ability to excrete a water load at the end of the 10-day treatment period (the percentage of water load excreted improved from 30+/-8 to 92+/-21%, P<0.025). 4 The nonpeptide AVP V(2)-receptor antagonist RWJ-351647 also increased sodium excretion without affecting creatinine clearance and blood pressure. 5 These data suggest that RWJ-351647 could be therapeutically useful in the treatment of water retention in human cirrhosis.

Renal failure in patients with cirrhosis and sepsis unrelated to spontaneous bacterial peritonitis: value of MELD score

BACKGROUND & AIMS

Although renal failure is a common complication of sepsis and patients with cirrhosis frequently develop sepsis, there have been no studies specifically assessing renal function in patients with cirrhosis and sepsis unrelated to spontaneous bacterial peritonitis. The aim of this study was to investigate prospectively the frequency, characteristics, and outcome of renal failure in patients with cirrhosis and sepsis unrelated to spontaneous bacterial peritonitis.

METHODS

One hundred six consecutive patients with cirrhosis and sepsis were studied prospectively. Patients with spontaneous bacterial peritonitis were excluded.

RESULTS

Twenty-nine out of 106 patients (27%) with cirrhosis and sepsis developed acute renal failure as compared with only 8 of 100 patients (8%) from a control group of cirrhotic patients without infection (P < .0001). Renal failure in the sepsis group was reversible in 22 (76%; 21% of all patients) patients and nonreversible in 7 (24%; 6% of all patients) patients. Renal failure was associated with impairment of effective arterial blood volume, without evidence of tubular damage. The occurrence and type of renal failure correlated strongly with mortality (mortality at 3 months: nonreversible renal failure, 100%; reversible renal failure, 55%; no renal failure, 13%). Among variables obtained at diagnosis of sepsis, the Model for End-Stage Liver Disease (MELD) score was the only independent predictive factor of mortality.

CONCLUSIONS

Renal failure is common in patients with cirrhosis and sepsis unrelated to spontaneous bacterial peritonitis and is associated with arterial underfilling and renal vasoconstriction. Outcome is poor, even in the setting of reversible renal failure. The MELD score is the best prognostic marker of patients with cirrhosis and sepsis.

Antimitochondrial antibodies in patients with chronic hepatitis C virus infection: description of 18 cases and review of the literature

To describe the clinical and immunologic patterns of disease expression of patients with chronic hepatitis C virus (HCV) infection and positive antimitochondrial antibodies (AMA). We investigated the presence of AMA in 237 consecutive HCV patients with extrahepatic manifestations from an International Registry. AMA were detected by indirect immunofluorescence in triple rat tissue (liver, stomach and kidney), aceton-fixed criosections and FITC-conjugated rabbit anti-human immunoglobulins. We found positive AMA in 18 (8%) out of 237 HCV patients. All patients were female with a mean age at protocol inclusion of 65.8 years (ranging from 37 to 87 years). Twelve (67%) patients fulfilled classification criteria for systemic autoimmune diseases (SAD), including Sjögren's syndrome (n = 7), systemic sclerosis (n = 3) and systemic lupus erythematosus (n = 2). Fourteen (78%) of the HCV-AMA patients presented at least one of the highly suggestive characteristics of primary biliary cirrhosis (PBC): 9 (50%) had a specific M2 pattern, 6 (33%) had more than twice normal levels of alkaline phosphatase, 5 (28%) had raised IgM levels and 4 (22%) a histological pattern compatible with PBC. Five (28%) patients developed neoplasia after detection of AMA. Seven (39%) patients died, due to neoplasia (n = 4), cirrhotic complications (n = 2) and hepatopulmonary syndrome (n = 1). We describe a subset of HCV patients with positive AMA who presented a broad spectrum of clinical features, including liver, autoimmune and neoplasic manifestations. Two-thirds of these patients presented an associated SAD, mainly Sjögren's syndrome or systemic sclerosis, together with a high frequency of multiple autoantibodies and an increased prevalence of cirrhosis and neoplasia.

Antimitochondrial antibodies in patients with chronic hepatitis C virus infection: description of 18 cases and review of the literature

To describe the clinical and immunologic patterns of disease expression of patients with chronic hepatitis C virus (HCV) infection and positive antimitochondrial antibodies (AMA). We investigated the presence of AMA in 237 consecutive HCV patients with extrahepatic manifestations from an International Registry. AMA were detected by indirect immunofluorescence in triple rat tissue (liver, stomach and kidney), aceton-fixed criosections and FITC-conjugated rabbit anti-human immunoglobulins. We found positive AMA in 18 (8%) out of 237 HCV patients. All patients were female with a mean age at protocol inclusion of 65.8 years (ranging from 37 to 87 years). Twelve (67%) patients fulfilled classification criteria for systemic autoimmune diseases (SAD), including Sjögren's syndrome (n = 7), systemic sclerosis (n = 3) and systemic lupus erythematosus (n = 2). Fourteen (78%) of the HCV-AMA patients presented at least one of the highly suggestive characteristics of primary biliary cirrhosis (PBC): 9 (50%) had a specific M2 pattern, 6 (33%) had more than twice normal levels of alkaline phosphatase, 5 (28%) had raised IgM levels and 4 (22%) a histological pattern compatible with PBC. Five (28%) patients developed neoplasia after detection of AMA. Seven (39%) patients died, due to neoplasia (n = 4), cirrhotic complications (n = 2) and hepatopulmonary syndrome (n = 1). We describe a subset of HCV patients with positive AMA who presented a broad spectrum of clinical features, including liver, autoimmune and neoplasic manifestations. Two-thirds of these patients presented an associated SAD, mainly Sjögren's syndrome or systemic sclerosis, together with a high frequency of multiple autoantibodies and an increased prevalence of cirrhosis and neoplasia.

Microarray analysis of endothelial differentially expressed genes in liver of cirrhotic rats

BACKGROUND & AIMS

There is a long-standing interest in the identification of endothelial-specific pathways for therapeutic targeting in cirrhosis. Therefore, the aim of this study was to evaluate differences in gene expression patterns between liver endothelial cells (LECs) from control and cirrhotic rats by using microarrays.

METHODS

LECs were obtained by isopycnic centrifugation. LECs gene expression was then analyzed on high-density oligonucleotide microarrays.

RESULTS

Analysis of gene expression revealed that most of the differentially expressed mRNA in cirrhosis are associated with extracellular matrix remodeling, inflammation, antioxidant/stress response, and cell signaling.

CONCLUSIONS

The collective expression changes observed within some functional groups of genes indicate that LECs in cirrhotic livers may contribute to lymphangiogenesis, enhancement of fibrogenesis and inflammatory processes, changes in cell-cell interaction with up-regulation of adherens junction proteins, and alterations in the intrahepatic vascular tone because of the down-regulation of genes involved in vasodilatation.

Prevalence and mechanisms of hyperhomocysteinemia in chronic alcoholics

BACKGROUND

Homocysteine (Hcy) is formed as an intermediary in methionine metabolism. Impairment of Hcy remethylation or transulfuration leads to hyperhomocysteinemia, which is considered as a risk factor for atherosclerotic vascular disease and stroke in chronic alcoholics. The aim of the study was to investigate the prevalence of hyperhomocysteinemia in chronic alcoholics and the influence of alcohol consumption, vitamin deficiencies and liver damage on the plasma levels of Hcy.

METHODS

228 chronic alcoholic patients consecutively admitted for detoxication, classified according to clinical and biochemical data in normal liver (n = 117), and in mild to moderate liver disease (n = 111), and 49 healthy controls were studied. Blood levels of Hcy, vitamin B6, vitamin B12 and folate were measured.

RESULTS

Plasma Hcy was significantly higher in chronic alcoholics than in controls (9.66 +/- 8.1 vs. 6.93 +/- 2.33 mumol/liter, p < 0.025). Furthermore, plasma Hcy levels were significantly higher in chronic alcoholics with liver injury (12.17 +/- 10.14 mumol/liter) than in those with normal liver and in controls (p < 0.001). The prevalence of hyperhomocysteinemia was also significantly higher in alcoholics with liver damage than in those with normal liver and in controls (29.7%, 5.1%, and 2%, respectively, p < 0.001). Serum folate values were lower in chronic alcoholics than in controls (4.7 +/- 2.6 vs. 7.6 +/- 2.4 nmol/liter, p < 0.001). The lowest values of folate were found in alcoholics with liver disease, especially in those with hyperhomocysteinemia, with a negative correlation between the two parameters.

CONCLUSIONS

Moderate hyperhomocysteinemia is common in chronic alcoholics, mainly in those with liver damage, suggesting that, although folate deficiencies may have a contributory role, liver impairment, through changes in methionine metabolism, is the most important mechanism for the elevated plasma Hcy found in these patients.

Ascites from cirrhotic patients induces angiogenesis through the phosphoinositide 3-kinase/Akt signaling pathway

BACKGROUND/AIMS

Ascites in patients with cirrhosis is associated with worsening of systemic hemodynamics. Thus, the aim of this study was to investigate the biological activity of ascites on endothelial cells.

METHODS

Human umbilical vein endothelial cells (HUVECs) were used to investigate the angiogenic activity of ascites obtained from cirrhotic patients.

RESULTS

Ascites-induced Akt activation, cell migration and tube formation in HUVECs. The pretreatment of HUVECs with the phosphatidylinositide 3-kinase (PI3-kinase) inhibitor LY294002, resulted in a decrease in chemotaxis and cell tube formation induced by ascites. Moreover, the inhibition of Akt activity in HUVECs by transduction of an inactive phosphorylation Akt mutant (AA-Akt), blocked tube formation. These angiogenic effects of ascites were also operative in vivo showing a PI3-kinase activation dependence in the angiogenesis induced by ascites. In addition, the preincubation of ascites with anti-fibronectin antibody led to a significant decrease in HUVECs migration, cell tube formation and in vivo angiogenesis.

CONCLUSIONS

These results confirm the novel concept that ascites is a bioactive fluid which can modify vascular properties through the activation of the PI3-kinase/Akt pathway in endothelial cells. Furthermore, our results demonstrated that this ascites-induced mechanism is mediated, at least in part, by fibronectin.

Inhibition of VEGF receptor-2 decreases the development of hyperdynamic splanchnic circulation and portal-systemic collateral vessels in portal hypertensive rats

BACKGROUND/AIMS

Portal hypertension is characterized by the development of a hyperdynamic splanchnic circulation. To determine whether this process is angiogenesis-dependent, we assessed the effects of SU5416, a specific inhibitor of VEGF receptor-2, in portal hypertensive rats.

METHODS

Rats with portal hypertension induced by partial portal vein ligation were treated with SU5416 or vehicle during 5 days. Then, hemodynamic studies were performed using radioactive microspheres. Protein expressions of CD31, VEGF receptor-2 and VEGF were also determined by Western blotting.

RESULTS

Treatment of portal hypertensive rats with SU5416 resulted in a significant and marked decrease (by 44%) in portal venous inflow, and increases in splanchnic arteriolar resistance (by 68%) and portal venous resistance (by 93%). In addition, SU5416 administration significantly inhibited the formation of portal-systemic collateral vessels (52% inhibition), as well as the splanchnic CD31 and VEGF receptor-2 protein expressions in portal hypertensive rats, compared with those receiving vehicle.

CONCLUSIONS

This study demonstrates that the development of hyperdynamic splanchnic circulation and the formation of portal-systemic collateral vessels in portal hypertensive rats are angiogenesis-dependent processes that can be markedly inhibited by blockade of the VEGF signaling pathway. Therefore, modulation of angiogenesis may represent a potential target in the treatment of portal hypertension.

MELD score and clinical type predict prognosis in hepatorenal syndrome: relevance to liver transplantation

Important progress has been made recently regarding the pathogenesis and treatment of hepatorenal syndrome (HRS). However, scant information exists about factors predicting outcome in patients with cirrhosis and HRS. Moreover, the prognostic value of the model of end-stage liver disease (MELD) score has not been validated in the setting of HRS. The current study was designed to assess the prognostic factors and outcome of patients with cirrhosis and HRS. The study included 105 consecutive patients with HRS. Forty-one patients had type 1 HRS, while 64 patients had type 2 HRS. Patients with type 1 HRS not only had more severe liver and renal failure than type 2 patients, they also had greater impairment of circulatory function, as indicated by lower arterial pressure and higher activation of vasoconstrictor factors. In the whole series, the median survival was 3.3 months. In a multivariate analysis of survival, only HRS type and MELD score were associated with an independent prognostic value. All patients with type 1 HRS had a high MELD score (> or =20) and showed an extremely poor outcome (median survival: 1 mo). By contrast, the survival of patients with type 2 HRS was longer and dependent on MELD score (> or =20, median survival 3 mo; <20, median survival 11 mo; P < .002). In conclusion, the outcome of patients with cirrhosis and HRS can be estimated by using two easily available variables, HRS type and MELD score. These data can be useful in the management of patients with HRS, particularly for patients who are candidates for liver transplantation.

Sinusoidal endothelial COX-1-derived prostanoids modulate the hepatic vascular tone of cirrhotic rat livers

CCl(4) cirrhotic rat liver exhibits a hyperresponse to the alpha(1)-adrenergic agonist methoxamine (Mtx) that is associated with enhanced thromboxane A(2) (TXA(2)) production and is abrogated by indomethacin. To further elucidate the molecular mechanisms involved in the hyperresponse to vasoconstrictors, portal perfusion pressure dose-response curves to Mtx were performed in CCl(4) cirrhotic rats livers after preincubation with vehicle, the cyclooxygenase (COX)-1 selective inhibitor SC-560, and the COX-2 selective inhibitor SC-236. TXA(2) production was determined in samples of the perfusate. COX-1 expression was analyzed and quantified in hepatocytes, Kupffer cells, sinusoidal endothelial cells (SEC), and hepatic stellate cells (HSC) isolated from control and cirrhotic rat livers by double-immunofluorescence staining, with specific markers for each population using flow cytometry or Western blot analysis. COX-1 protein levels were not significantly increased in cirrhotic livers, but COX-2 protein expression was increased. COX-1 inhibition, but not COX-2, significantly attenuated the response to Mtx and prevented the increased production of TXA(2). Cirrhotic livers showed an increased expression of COX-1 in SEC and reduced expression in HSC compared with control livers, whereas COX-1 was similarly distributed in Kupffer cells. Despite abundant hepatic COX-2 expression, the increased response to Mtx of cirrhotic livers is mainly dependent of COX-1. Upregulation of COX-1 in cirrhotic SEC may be responsible for the hyperesponse to Mtx.

Severity of cholestasis and advanced histological stage but not menopausal status are the major risk factors for osteoporosis in primary biliary cirrhosis

BACKGROUND

Since primary biliary cirrhosis (PBC) is usually diagnosed in postmenopausal women with minor cholestasis, it has been questioned whether PBC itself represents a further risk for osteoporosis.

AIM

To assess the prevalence and risk factors for osteoporosis in an unselected series of women with PBC.

PATIENTS AND METHODS

142 women with PBC (age: 54.3+/-0.8 years) and an age-matched control group. Osteoporosis was established by densitometry (bone mineral density below -2.5 T-score). Age, duration and severity of PBC, body mass index, menopausal status, histological stage and markers of bone turnover were assessed.

RESULTS

Prevalence of osteoporosis was higher in PBC (32.4%) than in normal women (11. 1%) (RR: 3.83, 95%CI: 2.59-5.67, P<0.001). Osteoporosis was associated with older age, menopausal status, body mass index, longer PBC duration, advanced histological stage, high bilirubin and alkaline phosphatase, and low albumin and prothrombin index. Regression analysis identified older age, higher Mayo risk score, lower body mass index and advanced histological stage but not menopause as the independent risk factors for osteoporosis.

CONCLUSIONS

Osteoporosis is more prevalent in women with PBC than in the general population. Age and severity of the disease, but not menopausal status, are the main risk factors for osteoporosis in this liver disease.

Increased anandamide induced relaxation in mesenteric arteries of cirrhotic rats: role of cannabinoid and vanilloid receptors

BACKGROUND AND AIMS

Anandamide is an endocannabinoid that evokes hypotension by interaction with peripheral cannabinoid CB1 receptors and with the perivascular transient receptor potential vanilloid type 1 protein (TRPV1). As anandamide has been implicated in the vasodilated state in advanced cirrhosis, the study investigated whether the mesenteric bed from cirrhotic rats has an altered and selective vasodilator response to anandamide.

METHODS

We assessed vascular sensitivity to anandamide, mRNA and protein expression of cannabinoid CB1 receptor and TRPV1 receptor, and the topographical distribution of cannabinoid CB1 receptors in resistance mesenteric arteries of cirrhotic and control rats.

RESULTS

Mesenteric vessels of cirrhotic animals displayed greater sensitivity to anandamide than control vessels. This vasodilator response was reverted by CB1 or TRPV1 receptor blockade, but not after endothelium denudation or nitric oxide inhibition. Anandamide had no effect on distal femoral arteries. CB1 and TRPV1 receptor protein was higher in cirrhotic than in control vessels. Neither CB1 mRNA nor protein was detected in femoral arteries. Immunochemistry showed that CB1 receptors were mainly in the adventitia and in the endothelial monolayer, with higher expression observed in vessels of cirrhotic rats than in controls.

CONCLUSIONS

These results indicate that anandamide is a selective splanchnic vasodilator in cirrhosis which predominantly acts via interaction with two different types of receptors, CB1 and TRPV1 receptors, which are mainly located in perivascular sensory nerve terminals of the mesenteric resistance arteries of these animals.

Gene polymorphisms as predictors of decreased bone mineral density and osteoporosis in primary biliary cirrhosis

Osteoporosis is a common complication observed in patients with primary biliary cirrhosis (PBC), with a prevalence of around 25%. The pathogenesis of bone loss in PBC is not well understood, since low bone formation and high resorption have been described. Bone disease is influenced by the duration and severity of the disease and oestrogen deficiency secondary to menopause. Genetic susceptibility has also been considered for osteoporosis in PBC, including vitamin D receptor genotypes, the gene encoding collagen type I alpha1 and insulin growth factor 1 gene microsatellite repeat polymorphism. Based on current evidence, the proposed genotypes either do not influence the development of osteoporosis in PBC or play only a minor role in it. The duration as well the severity of cholestasis are the main factors for such a disturbance since they are associated with the degree of bone loss. These features may exceed the potential effect of gene polymorphisms on osteoporosis in PBC.

Hepatorenal syndrome

Hepatorenal syndrome (HRS) is a major complication of patients with cirrhosis, with the annual incidence in patients with ascites being approximately 8% []. This syndrome develops in the latest phase of the disease and there is now evidence that it is an important determinant of patient survival. Many aspects of HRS are, however, still poorly understood. There are two types of HRS: type 1 or progressive HRS which is associated with a very poor prognosis (median survival rate lower than 2 weeks), and type 2 HRS which is characterized by a steady impairment in circulatory and renal function. The pathogenesis of HRS is a deterioration in effective arterial blood volume due to splanchnic arterial vasodilation and a reduction in venous return and cardiac output. It is therefore not surprising that the syndrome can be reversed by the simultaneous intravenous administration of albumin and arterial vasoconstrictors. Intrarenal mechanisms are also important and require prolonged improvement in circulatory function to be deactivated. Long-term administration of intravenous albumin and vasoconstrictors or the correction of portal hypertension with a transjugular intrahepatic portacaval shunt are effective in the treatment of HRS. They also appear to improve survival and may serve as a bridge to liver transplantation, which is the treatment of choice in these patients.

Nosocomial transmission of HCV in the liver unit of a tertiary care center

Despite its medical and legal implications, there are no prospective studies analyzing the incidence and mechanisms involved in the nosocomial transmission of hepatitis C virus (HCV) in liver units. This study prospectively investigates the nosocomial transmission of HCV in the liver unit of a tertiary care center from August 2000 to October 2002. The median prevalence of HCV infection among hospitalized patients was 50%. Anti-HCV-negative patients admitted to the liver unit during the study period were prospectively followed, and serum markers of HCV infection were repeated 6 months after discharge. All known risk factors for HCV transmission (including the physical allocation of HCV-infected and noninfected patients during hospitalization) were recorded. Complete follow-up data were available in 1301 (84.5%) of 1540 patients. Six patients (0.46%) acquired HCV infection (annual incidence: 0.27/100 admissions). Phylogenetic analyses of recovered HCV sequences identified the source of infection as an HCV-infected roommate (3 cases) and a patient receiving care by the same nurse team (1 case). The most relevant risk factors associated with HCV acquisition were duration of hospitalization (>10 days; OR, 35; 95% CI, 1.96-622) and hospitalization with an HCV-infected roommate (>5 days; OR, 12; 95% CI, 1.39-103). In fact, HCV infection occurred in 1.7% of the 357 patients hospitalized longer than 10 days. In conclusion, HCV nosocomial infection appears to occur via patient-to-patient transmission in liver units, particularly in individuals who require long hospitalizations. Continuous reinforcement of universal prevention measures and, when possible, isolation of patients at higher risk might further reduce nosocomial HCV transmission.

Bacterial infections in cirrhosis

Spontaneous bacterial peritonitis, urinary tract infections, respiratory infections and bacteremia are the most frequent infective complications in cirrhosis. These infections are due to the concomitant presence of different facilitating mechanisms including changes in the intestinal flora and in the intestinal barrier, depression of activity of the reticuloendothelial system, decreased opsonic activity of the ascitic fluid, neutrophil leukocyte dysfunction and iatrogenic factors among others. The fact, that the probability of having a microorganism responsible for the infection quinolone resistant is higher than 30% should be taken into account when treating any infection in a cirrhotic patient receiving selective intestinal decontamination with quinolones, and therefore, quinolones as empiric treatment are not indicated.

Increased apoptosis dependent on caspase-3 activity in polymorphonuclear leukocytes from patients with cirrhosis and ascites

BACKGROUND/AIMS

Patients with decompensated cirrhosis are prone to develop neutropenia. Although hypersplenism and increased clearance of polymorphonuclear leukocytes (PMN) in the spleen are thought to contribute to neutropenia in these patients, other factors cannot be excluded. The aim of the current study was to investigate whether the presence of increased PMN apoptosis could also contribute to the appearance of neutropenia in these patients.

METHODS

PMN were isolated by Ficoll-Hypaque gradient centrifugation from 17 patients with decompensated cirrhosis (CH group) and 13 patients with compensated chronic liver disease (CT group). PMN were incubated in RPMI 1640 medium at 37 degrees C in a 5% CO(2) atmosphere and viability and frequency of apoptosis were evaluated after 0, 10, 20 and 40 h of culture. Viability was determined by the MTT assay and apoptosis by microscopic examination of cell morphology (Diff-Quik staining), DNA fragmentation by agarose gel electrophoresis (DNA laddering) and caspase-3 activity by DVDE-p-nitroanilide cleavage.

RESULTS

Compared to CT patients, PMN isolated from CH patients exhibited a decreased PMN viability and a marked accelerated apoptosis as revealed by an increased number of condensed nuclei, increased DNA laddering and significantly higher caspase-3 activity.

CONCLUSIONS

These findings indicate that shortening of PMN survival via apoptosis may explain in part the neutropenia present in decompensated cirrhotic patients with ascites, thus favoring the development of bacterial infections in these patients.

Extracorporeal albumin dialysis: a procedure for prolonged relief of intractable pruritus in patients with primary biliary cirrhosis

BACKGROUND AND AIMS

Pruritus is a distressing symptom in patients with primary biliary cirrhosis, and when uncontrollable it is an indication for liver transplantation. Since pruritus can result from unknown substances that accumulate systemically as a consequence of impaired biliary secretion, we have assessed whether a new extracorporeal albumin dialysis (ECAD) procedure, the molecular-adsorbing recirculating system-MARS, has any effect on pruritus of cholestasis.

METHODS

Four patients with primary biliary cirrhosis and resistant pruritus were treated with two 7-h ECAD sessions 1 day apart. Pruritus was recorded from 15 days before the first session, before and after each session, and during the follow-up using a visual analogue scale (VAS). Standard liver tests as well as serum bile acid levels were also measured.

RESULTS

There was a clear association between ECAD treatment and relief of itching, which promptly disappeared in two patients, or decreased markedly in the other two. One patient was free of pruritus for 18 months except for short periods with mild pruritus. The second patient experienced amelioration of itching, which almost disappeared completely and recurred mildly 4 months later. In the other two patients pruritus was alleviated markedly after ECAD but gradually recurred. These two patients were treated again 9 and 7 months later with favorable effects on pruritus. The scratching skin lesions improved or disappeared in parallel with the alleviation of itching. The albumin dialysis procedure did not result in liver test changes, except for circulating bile acids, which decreased in all the patients. No significant adverse effects were observed.

CONCLUSIONS

The ECAD procedure seems to be an effective alternative for the treatment of patients with pruritus of cholestasis who do not respond to other therapeutic methods.