Plasma phospholipids and fatty acid composition differ between liver biopsy-proven nonalcoholic fatty liver disease and healthy subjects

Background:

There is growing evidence that nonalcoholic fatty liver disease (NAFLD) is associated with perturbations in liver lipid metabolism. Liver phospholipid and fatty acid composition have been shown to be altered in NAFLD. However, detailed profiles of circulating lipids in the pathogenesis of NAFLD are lacking.

Objective:

Therefore, the objective of the present study was to examine circulating lipids and potential mechanisms related to hepatic gene expression between liver biopsy-proven simple steatosis (SS), nonalcoholic steatohepatitis (NASH) and healthy subjects.

Subjects:

Plasma phospholipid and fatty acid composition were determined in 31 healthy living liver donors as healthy controls (HC), 26 patients with simple hepatic steatosis (SS) and 20 with progressive NASH. Hepatic gene expression was analyzed by Illumina microarray in a subset of 22 HC, 16 SS and 14 NASH.

Results:

Concentrations of phosphatidylethanolamine (PE) increased relative to disease progression, HC<SS<NASH (170<210<250 μg ml⁻¹), and was significantly different (P<0.05) between HC and NASH. Circulating phosphatidylserine (PS) and phosphatidylinositol were higher in SS and NASH compared with HC (P<0.05), but there was no difference between SS and NASH. Fatty acid composition of phospholipids was also remodeled. In particular, docosahexaenoic and arachidonic acid were higher (P<0.05) in SS and NASH relative to HC in PS. Differentially expressed hepatic genes included ETNK1 and PLSCR1 that are involved in PE synthesis and PS transport, respectively.

Conclusions:

The present study demonstrates that there is a disruption in phospholipid metabolism that is present in SS, but more pronounced in NASH. Intervention studies targeted at lipid metabolism could benefit SS and NASH.

MicroRNA-130a inhibits HCV replication by restoring the innate immune response

Hepatitis C virus (HCV) infection is a major cause of chronic hepatitis and hepatocellular carcinoma. Currently pegylated interferon (IFN) combined with ribavirin remains the best therapeutic approach, although patients infected with HCV genotype I may benefit from adding protease inhibitors as 'triple therapy'. MicroRNAs (miRNAs) are endogenous small noncoding RNAs that regulate gene expression and have recently been shown to play an important role in human innate immune response and as an antiviral in chimpanzees. We studied the effect of miR-130a on the HCV replication. We found that miR-130a significantly inhibits HCV replication in both HCV replicon and J6-/JFH1-infected cells. Over expression of miR-130a upregulated the expression of type I IFN (IFN-α/IFN -β), ISG15, USP18 and MxA, which are involved in innate immune response and decreased expression of miR-122, a well-defined miRNA promoting HCV production. In conclusion, miR-130a inhibits HCV replication/production by restoring host innate immune responses and/or downregulating pro-HCV miR-122. miR-130a might be a potential drug target by modulating host innate immune responses to combat HCV infection.

Routine induction therapy in living donor liver transplantation prevents rejection but may promote recurrence of hepatitis C

BACKGROUND

Routine induction therapy in living donor liver transplantation (LDLT) has not been well described.

METHODS

We reviewed outcomes of induction therapy with rabbit antithymocyte globulin (rATG) or basiliximab within 1 year of LDLT.

RESULTS

Between 2002 and 2007, 184 adults underwent LDLT and received induction therapy in addition to standard immunosuppression. Acute cellular rejection (ACR) developed in 17 of 130 patients (13.1%) who received rATG and 13 of 54 patients (24.1%) who received basiliximab (P = .066). The interval between transplantation and rejection as well as rejection severity was similar in patients who received rATG and those who received basiliximab. Hepatitis C (HCV) recurrence requiring initiation of antiviral therapy was more common in patients who received rATG compared with basiliximab (34.5% vs 8.7%; P = .021), and in those who received induction combined with tacrolimus as opposed to cyclosporine (38.5% vs 3.9%; P = .001). rATG and basiliximab were associated with excellent patient and graft survivals well as low rates of opportunistic infections and malignancies.

CONCLUSION

Induction with rATG or basiliximab was well tolerated and highly effective at preventing ACR within 1 year of LDLT, but may be associated with a higher risk of clinically significant HCV recurrence in some patients.

Adult living liver donors have excellent long-term medical outcomes: the University of Toronto liver transplant experience

Right lobe living donor liver transplantation is an effective treatment for selected individuals with end-stage liver disease. Although 1 year donor morbidity and mortality have been reported, little is known about outcomes beyond 1 year. Our objective was to analyze the outcomes of the first 202 consecutive donors performed at our center with a minimum follow-up of 12 months (range 12-96 months). All physical complications were prospectively recorded and categorized according to the modified Clavien classification system. Donors were seen by a dedicated family physician at 2 weeks, 1, 3 and 12 months postoperatively and yearly thereafter. The cohort included 108 males and 94 females (mean age 37.3 +/- 11.5 years). Donor survival was 100%. A total of 39.6% of donors experienced a medical complication during the first year after surgery (21 Grade 1, 27 Grade 2, 32 Grade 3). After 1 year, three donors experienced a medical complication (1 Grade 1, 1 Grade 2, 1 Grade 3). All donors returned to predonation employment or studies although four donors (2%) experienced a psychiatric complication. This prospective study suggests that living liver donation can be performed safely without any serious late medical complications and suggests that long-term follow-up may contribute to favorable donor outcomes.

In situ hypothermic liver preservation during radical liver resection with major vascular reconstruction

BACKGROUND

The in situ hypothermic liver preservation technique may allow a more aggressive approach to tumours of the caval confluence and/or all three hepatic veins, which would otherwise be deemed irresectable.

METHODS

All descriptive data regarding patient demographics, operative characteristics, perioperative complications and outcomes of nine patients in whom this technique was used were collected prospectively.

RESULTS

Seven patients underwent liver trisegmentectomy and two had primary retrohepatic venal caval resection. Total hepatic vascular occlusion with in situ hypothermic liver preservation was used for venous reconstruction in all patients. The vena cava was reconstructed with prosthetic graft in seven patients. All main hepatic veins were reconstructed in the seven liver resections. In situ hypothermic liver preservation was well tolerated as evidenced by preserved hepatic synthetic function early after operation. One patient died 66 days after surgery. There were two recurrences after a median follow-up of 14 (range 2-33) months; local recurrence was identified in one patient after 4 months and distant metastasis in another after 8 months.

CONCLUSION

The in situ hypothermic liver preservation technique appears to be a useful adjunct to radical hepatobiliary tumour excision procedures that require total hepatic vascular exclusion and major vascular reconstruction.

Percutaneous Ethanol Injection of Unresectable Medium-to-Large-Sized Hepatomas Using a Multipronged Needle: Efficacy and Safety

Fine needles with an end hole or multiple side holes have traditionally been used for percutaneous ethanol injection (PEI) of hepatomas. This study retrospectively evaluates the safety and efficacy of PEI of unresectable medium-to-large (3.5-9 cm) hepatomas using a multipronged needle and with conscious sedation. Twelve patients, eight men and four women (age 51-77 years; mean: 69) received PEI for hepatomas, mostly subcapsular or exophytic in location with average tumor size of 5.6 cm (range: 3.5-9.0 cm). Patients were consciously sedated and an 18G retractable multipronged needle (Quadrafuse needle; Rex Medical, Philadelphia, PA) was used for injection under real-time ultrasound guidance. By varying the length of the prongs and rotating the needle, the alcohol was widely distributed within the tumor. The progress of ablation was monitored by contrast-enhanced ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) after each weekly injection and within a month after the final (third) injection and 3 months thereafter. An average total of 63 mL (range: 20-154 ml) of alcohol was injected per patient in an average of 2.3 sessions. Contrast-enhanced CT, ultrasound, or MRI was used to determine the degree of necrosis. Complete necrosis was noted in eight patients (67%), near-complete necrosis (90-99%) in two (16.7%), and partial success (50-89%) in two (16.7%). Follow-up in the first 9 months showed local recurrence in two patients and new lesions in another. There was no mortality. One patient developed renal failure, liver failure, and localized perforation of the stomach. He responded to medical treatment and surgery was not required for the perforation. One patient had severe postprocedural abdominal pain and fever, and another had transient hyperbilirubinemia; both recovered with conservative treatment. PEI with a multipronged needle is a new, safe, and efficacious method in treating medium-to-large-sized hepatocellular carcinoma under conscious sedation. Its survival benefits require further investigations.

Fulminant viral hepatitis: molecular and cellular basis, and clinical implications

Fulminant hepatic failure is defined by the sudden onset of severe liver injury accompanied by hepatic encephalopathy in an individual who previously had no evidence of liver disease. This disease causes multiple organ failure and is associated with a high mortality. The most frequently recognised cause of fulminant or subfulminant hepatic failure is viral hepatitis. Data are now emerging to support the hypothesis that, irrespective of the aetiology of fulminant hepatic failure, the host's immune response (including production of proinflammatory cytokines and mediators) contributes to microcirculatory disturbances that result in hypoxic injury and cell death (apoptosis). Impairment of the scavenger function of the reticuloendothelial cell system further contributes to reduced hepatic blood flow and ischaemic necrosis. An increased understanding of the molecular pathogenesis of fulminant hepatic failure now enables new molecular therapeutic modalities to be tested. Given the complexity of this multi-dimensional disorder, the challenge is to provide a rational basis for treatment. This might include enhancement or suppression of immune responsiveness by manipulation of endogenous cytokine synthesis or by cytokine administration and, at the same time, use of strategies to increase hepatic regeneration.

Inactivation of rat liver microsomal steroid hydroxylations by 4-alkyl analogues of 3,5-diethoxycarbonyl-1,4-dihydro-2,4,6-trimethylpyridine: evidence for selectivity among steroid-inducible cytochrome P450IIIA forms

Various 4-alkyl analogues of 3,5-diethoxycarbonyl-1,4-dihydro-2,4,6- trimethylpyridine (DDC) cause mechanism-based inactivation of cytochrome P-450 (P-450) via destruction of the heme prosthetic group. This is an important component of these compounds' porphyrinogenic mechanism. In an attempt to map the P-450 isozyme selectivities of DDC analogues, we have examined the effects of these compounds on the regioselective and stereoselective hydroxylation of androstenedione (AD) and progesterone (PG) in rat liver microsomal systems. In microsomes from phenobarbital-treated male rats, DDC analogues did not cause time-dependent inactivation of AD 7 alpha-hydroxylase, AD 16 beta-hydroxylase, and PG 21-hydroxylase, selective markers for P450IIA 1/2, IIB1, and IIC6, respectively. In contrast, DDC analogues were effective inactivators of PG 2 alpha-hydroxylase and steroid 6 beta-hydroxylases, selective markers for P450IIC11 and IIIA forms, respectively. We conclude that differences in porphyrinogenicity observed with various DDC analogues are not likely to be due to the selective destruction of different P-450 isozymes by different analogues, but rather to properties of the DDC analogues themselves. 4-Ethyl DDC was found to be capable of discriminating between P450IIIA subfamily forms. In microsomes from untreated male rats, which express P450IIIA2 but not IIIA1, 4-ethyl DDC inactivated both AD and PG 6 beta-hydroxylases. However, in microsomes from dexamethasone-treated female rats, which express P450IIIA1 but not IIIA2, no inactivation of the steroid 6 beta-hydroxylases was observed. Thus, 4-ethyl DDC appears to be a potentially valuable tool for differentiating between P450IIIA forms.