Pro-inflammatory cytokine release and mediation of the acute phase protein response in fulminant hepatic failure

Novel Serum Biomarkers Associated With Pediatric Hepatic Encephalopathy: A Systematic Review

BACKGROUND

The pathophysiology of pediatric hepatic encephalopathy (HE) is not well understood. Various serum biomarkers associated with HE may provide insight into its pathology, but their use and interpretation in clinical practice for diagnosis and prognostication remain undetermined. We sought to investigate reported correlations of serum biomarkers with presence and degree of HE in children.

METHODS

We conducted a systematic review of studies examining novel serum biomarkers and cytokines in association with HE that included children on PubMed, Embase, Lilacs, and Scopus. We utilized Covidence for abstract and text review by 2 independent reviewers for each study.

RESULTS

We reviewed 2824 unique publications; 15 met criteria for inclusion. Categories of biomarkers reported were inflammatory cytokines, products of amino acid metabolism, trace elements and vitamins, and hepatic and neuro biomarkers. Of 19 individual biomarkers, only 5 were measured in more than 1 study. Elevations in interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) were most commonly reported as associated with HE. Notably, we observed lower average IL-6 and TNF-alpha levels in pediatric-only studies compared to mixed age studies. Overall, high bias and poor applicability to our review question was observed. We encountered low numbers of studies with pediatric focus, and few conducted with low bias study designs.

CONCLUSION

Investigated biomarkers span a large range of categories and suggest potentially useful correlations with HE. Further well-designed prospective biomarker research is necessary to better elucidate the pathogenesis of HE in children and improve early detection and clinical care.

Delta Neutrophil Index as a New Early Mortality Predictor after Liver Transplantation

Background: Patients with liver disease display numerous defects of the immune system, so infection is a frequent complication of both acute and chronic liver disease. These infections are independently associated with poor outcomes after liver transplantation. Our objective was to evaluate the delta neutrophil index (DNI), a new inflammation marker, as a predictor of survival after liver transplantation (LT). Methods: This observational study retrospectively evaluated the records of 712 patients who underwent LT from January 2010 to February 2018. DNI was evaluated at pre-transplantation and 1, 7, 14, and 30 days after operation. Statistical analysis was performed using the T-test or chi-square test, and logistic regression analysis. Results: The mean MELD score was 16.7 ± 9.4 (0–48). There were 125 mortality cases (17.8%) after liver transplantation. Mean DNI was 1.61 at pre-transplantation, 3.94 one day after operation, 2.67 seven days after operation, 1.61 fourteen days after operation, and 1.64 thirty days after operation, respectively. In multivariate analysis, DNI seven and fourteen days after operation was revealed as an independent prognostic factor for mortality after liver transplantation (p = 0.040 and p < 0.0001). Conclusions: The DNI is a simple and reliable predictor of patient mortality after liver transplantation.

Prognostic, clinical, and therapeutic importance of RANTES-CCR5 axis in hepatitis A infection: A multiapproach study

Fulminant hepatic failure (FHF) is a lethal manifestation of hepatitis A virus (HAV) infection, whose underlying mechanisms are poorly understood. We aimed to evaluate the importance of the modulation of the RANTES-chemokine receptor type 5 (CCR5) signaling axis and its immunomodulatory effects in directing hepatitis A disease pathogenesis using an in silico, in vitro and patient cohort-based approach. In silico interaction studies were performed using computation approaches with suitable software. Differential expression of relevant cytokines and immune cell markers were studied using real-time quantitative reverse transcription PCR (qRT-PCR), enzyme-linked immunosorbent assay, and flow-cytometry-based methods. In the HepG2 cell line, we studied inflammatory responses and susceptibility to HAV infection following RANTES stimulation and antibody blockade of CCR5. The HAV-VP3 region exhibited high interaction in CCR5: HAV complexes. RANTES levels were significantly increased in FHF cases. Reduced monocyte and T-cell activation were observed in FHF cases. RANTES expression inversely correlated with viremia but positively correlated with proinflammatory responses. Hyper Th1-biased immune responses, marked by high interleukin (IL)-12/IL-10 ratio were observed in FHF cases, which were also characterized by upregulated tumor necrosis factor-alpha (TNF-α) expression and reduced interferon-gamma expression. In vitro, RANTES was protective against HAV infection but resulted in upregulated TNF-α expression. Although viral load increased upon the regulation of inflammatory responses by CCR5 blocking, it was still significantly lower compared to control HAV-infected cells. Our study suggests the importance of RANTES-CCR5 signaling and linked-immunomodulation in HAV disease pathogenesis, as well as highlights the utility of CCR5 antagonists as a risk-reduction strategy in FHF patients. Our findings, therefore, have important implications for the management of high-risk HAV infections.

Acute Liver Failure: Mechanisms of Disease and Multisystemic Involvement

Acute liver failure is accompanied by a pathologic syndrome common to numerous different etiologies of liver injury. This acute liver failure syndrome leads to potentially widespread devastating end-organ consequences. Systemic dysregulation and dysfunction is likely propagated via inflammation as well as underlying hepatic failure itself. Decoding the mechanisms of the disease process and multisystemic involvement of acute liver failure offers potential for targeted treatment opportunities and improved clinical outcomes in this sick population.

Prognostic significance of infections in critically ill adult patients with acute liver injury: a retrospective cohort study

BACKGROUND AND AIMS

Patients with acute liver failure have high rates of infections, likely from defects in immune function. Whether infections are independently associated with poor outcomes is unclear. We hypothesized that patients with acute liver injury who developed infections were at increased risk of adverse outcomes.

METHODS

We conducted a retrospective analysis of 150 critically ill adult patients admitted with acute liver dysfunction at a single academic institution between 2005 and 2011. We excluded patients with immunocompromised states, patients with chronic liver disease and patients who died or were discharged within 48 h of admission. Our primary endpoint was a 30-day event-free survival, with events defined as either death or liver transplantation. Our secondary endpoint was length of stay. Univariate and multivariate analyses were performed to determine associations between presence of infection and our primary and secondary endpoints.

RESULTS

Of our cohort of 150 patients, 62 (41%) were infected and 88 (59%) were not infected. Of the infected patients, 45% died or underwent transplantation, compared to 22% for the non-infected patients (P = 0.003). Univariate and multivariate analyses demonstrated that infections in patients with acute liver dysfunction were an independent predictor of poor outcome (i.e. death or transplantation). In addition, specific types of infection, including pneumonia, independently led to a 48% increase in length of stay (P = 0.002).

CONCLUSIONS

Infections in patients with acute liver dysfunction are associated with increased risk of death or transplant and increased hospital length of stay.

Role of inflammation and infection in the pathogenesis of human acute liver failure: Clinical implications for monitoring and therapy

Acute liver failure is a rare and devastating clinical condition. At present, emergency liver transplantation is the only life-saving therapy in advanced cases, yet the feasibility of transplantation is affected by the presence of systemic inflammation, infection and resultant multi-organ failure. The importance of immune dysregulation and acquisition of infection in the pathogenesis of acute liver failure and its associated complications is now recognised. In this review we discuss current thinking regarding the role of infection and inflammation in the pathogenesis of and outcome in human acute liver failure, the implications for the management of such patients and suggest directions for future research.

Neuroinflammation in hepatic encephalopathy: mechanistic aspects

Hepatic encephalopathy (HE) is a major neurological complication of severe liver disease that presents in acute and chronic forms. While elevated brain ammonia level is known to be a major etiological factor in this disorder, recent studies have shown a significant role of neuroinflammation in the pathogenesis of both acute and chronic HE. This review summarizes the involvement of ammonia in the activation of microglia, as well as the means by which ammonia triggers inflammatory responses in these cells. Additionally, the role of ammonia in stimulating inflammatory events in brain endothelial cells (ECs), likely through the activation of the toll-like receptor-4 and the associated production of cytokines, as well as the stimulation of various inflammatory factors in ECs and in astrocytes, are discussed. This review also summarizes the inflammatory mechanisms by which activation of ECs and microglia impact on astrocytes leading to their dysfunction, ultimately contributing to astrocyte swelling/brain edema in acute HE. The role of microglial activation and its contribution to the progression of neurobehavioral abnormalities in chronic HE are also briefly presented. We posit that a better understanding of the inflammatory events associated with acute and chronic HE will uncover novel therapeutic targets useful in the treatment of patients afflicted with HE.

Lung injury and its prognostic significance in acute liver failure

OBJECTIVE

Hypoxemia is a feared complication of acute liver failure, and high oxygen requirements will frequently lead to removal of patients from the transplant list. As data regarding the prevalence and outcome of acute respiratory distress syndrome in acute liver failure are scant and hypoxemia being a commonly encountered systemic complication, we analyzed radiological, gas exchange, and ventilator data in consecutive patients admitted with acute liver failure.

PATIENTS

Acute liver failure patients receiving mechanical ventilation admitted between January 2007 and February 2011 were included.

INTERVENTIONS

Patients were categorized according to the Berlin definition as: no acute respiratory distress syndrome, acute respiratory distress syndrome (PaO2/FIO2 < 300 mm Hg), and subdivisions of mild, moderate, and severe acute respiratory distress syndrome (200-300 mm Hg, 100-200 mm Hg, and < 100 mm Hg, respectively). Chest radiographs were independently assessed by two observers for the presence or absence of acute respiratory distress syndrome. Absence of left atrial pressure elevation was based on combined hemodynamic and echocardiographic assessment.

MEASUREMENTS AND MAIN RESULTS

Two hundred acute liver failure patients were admitted during the study period of whom 148, median age 39 years (16-74 yr), were included. Thirty-one (21%) had acute respiratory distress syndrome (17 mild acute respiratory distress syndrome [12%], 9 moderate acute respiratory distress syndrome [12%], and 5 severe acute respiratory distress syndrome) within the first 72 hours following admission. Acute respiratory distress syndrome patients required higher positive end-expiratory pressure (7 vs 6 vs 10 vs 15 cm H2O for no, mild, moderate, or severe acute respiratory distress syndrome, p = 0.014), had reduced respiratory system compliance (34 vs 29 vs 30 vs 23 L/cm H2O, p = 0.028), and an increased number of ventilator days (no acute respiratory distress syndrome, 10 d; mild acute respiratory distress syndrome acute lung injury, 12 d; moderate acute respiratory distress syndrome, 23 d; severe acute respiratory distress syndrome, 22 d; p = 0.097). Duration of liver intensive therapy unit stay (p = 0.175), survival (p = 0.877), inotrope requirements (p = 0.495), need for extracorporeal renal support (p = 0.565), and severity of organ failure scores were not affected. Extravascular lung water index had a moderate sensitivity of 65% and specificity of 77% for the prediction of acute respiratory distress syndrome.

CONCLUSION

The prevalence of lung injury is relatively low in acute liver failure, where 21% fulfilled acute respiratory distress syndrome criteria. Overall presence of acute respiratory distress syndrome appeared to have a limited impact on outcome.

Functional role of monocytes and macrophages for the inflammatory response in acute liver injury

Different etiologies such as drug toxicity, acute viral hepatitis B, or acetaminophen poisoning can cause acute liver injury or even acute liver failure (ALF). Excessive cell death of hepatocytes in the liver is known to result in a strong hepatic inflammation. Experimental murine models of liver injury highlighted the importance of hepatic macrophages, so-called Kupffer cells, for initiating and driving this inflammatory response by releasing proinflammatory cytokines and chemokines including tumor necrosis factor (TNF), interleukin-6 (IL-6), IL-1beta, or monocyte-chemoattractant protein-1 (MCP-1, CCL2) as well as activating other non-parenchymal liver cells, e.g., endothelial or hepatic stellate cells. Many of these proinflammatory mediators can trigger hepatocytic cell death pathways, e.g., via caspase activation, but also activate protective signaling pathways, e.g., via nuclear factor kappa B (NF-κB). Recent studies in mice demonstrated that these macrophage actions largely depend on the recruitment of monocytes into the liver, namely of the inflammatory Ly6c+ (Gr1+) monocyte subset as precursors of tissue macrophages. The chemokine receptor CCR2 and its ligand MCP-1/CCL2 promote monocyte subset infiltration upon liver injury. In contrast, the chemokine receptor CX3CR1 and its ligand fractalkine (CX3CL1) are important negative regulators of monocyte infiltration by controlling their survival and differentiation into functionally diverse macrophage subsets upon injury. The recently identified cellular and molecular pathways for monocyte subset recruitment, macrophage differentiation, and interactions with other hepatic cell types in the injured liver may therefore represent interesting novel targets for future therapeutic approaches in ALF.

Lipopolysaccharide binding protein is down-regulated during acute liver failure

BACKGROUND AND AIMS

Lipopolysaccharide binding protein (LBP) is involved in the modulation of acute liver injury and failure caused by acetaminophen (APAP). Although the biological activity of LBP is concentration dependent, little is known about its levels in acute liver failure.

METHODS

Serum and hepatic LBP were measured in acute APAP-induced liver injury in mice. Serum LBP was measured in patients with acute liver failure from APAP and non-APAP causes.

RESULTS

Interestingly, contrary to other diseases, serum and hepatic LBP levels decreased significantly in mice within 24 h after being subjected to APAP-induced injury compared to the control (1.6 ± 0.1 vs. 3.5 ± 1.6 μg/ml, respectively; P < 0.05). Similar decreases were noted in another mouse model of acute liver injury due to carbon tetrachloride. Among patients with acute liver failure due to APAP (n = 5) and non-APAP (n = 5) causes, admission LBP levels were decreased compared to those of healthy controls (5.4 ± 1.4 vs. 3.2 ± 0.2 μg/ml, normal vs. acute liver failure; P = 0.07). However, the levels were not associated with the etiology of acute liver failure or 3-week outcome.

CONCLUSIONS

Serum and hepatic LBP levels are significantly reduced early after the induction of severe acute liver injury/failure due to acetaminophen and other liver injuries. This reduction in LBP production is specific to acute liver failure and may be important in developing future diagnostic and therapeutic approaches for patients with acute liver failure.

Role of monocytes and macrophages in experimental and human acute liver failure

Acute liver failure (ALF) is a devastating clinical syndrome characterised by progressive encephalopathy, coagulopathy, and circulatory dysfunction, which commonly leads to multiorgan failure and death. Central to the pathogenesis of ALF is activation of the immune system with mobilisation of cellular effectors and massive production of cytokines. As key components of the innate immune system, monocytes and macrophages are postulated to play a central role in the initiation, progression and resolution of ALF. ALF in humans follows a rapidly progressive clinical course that poses inherent difficulties in delineating the role of these pivotal immune cells. Therefore, a number of experimental models have been used to study the pathogenesis of ALF. Here we consider the evidence from experimental and human studies of ALF on the role of monocytes and macrophages in acute hepatic injury and the ensuing extrahepatic manifestations, including functional monocyte deactivation and multiple organ failure.

Expression of C-Reactive Protein in Rectal Cancer

BACKGROUND

The possible involvement of inflammation on colorectal carcinogenesis has potential prognostic, preventive and therapeutic implications. We investigated immunohistochemically whether C-reactive protein is expressed in human primary rectal adenocarcinoma and assessed its relationship with clinicopathological findings.

METHODS

Ninety-one rectal cancer samples and 22 normal control samples were immunohistochemically analysed.

RESULTS

Cell accumulation of C-reactive protein was observed in 65 (71%) out of 91 patients with rectal adenocarcinoma and in all 22 control cases (p < 0.01). No significant difference was observed regarding to clinicopathological features or survival rates, but a linear correlation between the positivity proportion of C-reactive protein and Dukes-Turnbull stage (p = 0.005) was observed.

CONCLUSIONS

These data suggest that C-reactive protein might play a role in rectal carcinogenesis, but seems not to affect prognosis. Additional studies are warranted in larger population samples.

The importance of immune dysfunction in determining outcome in acute liver failure

Acute liver failure (ALF) shares striking similarities with septic shock with regard to the features of systemic inflammation, progression to multiple organ dysfunction and functional immunoparesis. While the existence of opposing systemic pro- and anti-inflammatory profiles resulting in organ failure and immune dysfunction are well recognised in septic shock, characterization of these processes in ALF has only recently been described. This review explores the evolution of the systemic inflammation in acute liver failure, its relation to disease progression, exacerbation of liver injury and development of innate immune dysfunction and extra-hepatic organ failure as sequelae. Defects in innate immunity are described in hepatic and extra-hepatic compartments. Clinical studies measuring levels of pro- and anti-inflammatory cytokines and expression of the antigen presentation molecule HLA-DR on monocytes, in combination with ex-vivo experiments, demonstrate that the persistence of a compensatory anti-inflammatory response syndrome, leading to functional monocyte deactivation, is a central event in the evolution of systemic immune dysfunction. Accurate immune profiling in ALF may permit the development of immunomodulatory strategies in order to improve outcome in this condition.

Association of multiple inflammatory markers with carotid intimal medial thickness and stenosis (from the Framingham Heart Study)

Inflammatory markers, particularly C-reactive protein (CRP), predict incident cardiovascular disease and are associated with the presence of subclinical atherosclerosis. The relations between multiple inflammatory markers and direct measures of atherosclerosis are less well established. Participants in the Offspring Cohort of the Framingham Heart Study (n = 2,885, 53% women, mean age 59 years) received routine assessments of common carotid artery intima-media thickness (CCA-IMT), internal carotid artery intima-media thickness (ICA-IMT), and the presence or absence of > or =25% carotid stenosis by ultrasonography. Circulating inflammatory markers assessed from an examination 4 years later included CRP, interleukin-6 (IL-6), intercellular adhesion molecule-1, monocyte chemoattractant protein-1, P-selectin, and CD40 ligand. Assessed as a group, inflammatory markers were significantly associated with ICA-IMT (p = 0.01), marginally with carotid stenosis (p = 0.08), but not with CCA-IMT. Individually, with an increase from the 25th to 75th percentile in IL-6, there were significant increases in ICA-IMT and carotid stenosis (for ICA-IMT, estimated fold increase 1.04, 95% confidence interval 1.03 to 1.06, p = 0.0004; for carotid stenosis, odds ratio 1.25, 95% confidence interval 1.06 to 1.47, p = 0.007) after adjustment for age, gender, and established risk factors for atherosclerosis. There was a similar significant multivariate-adjusted association of CRP with ICA-IMT but not with carotid stenosis. Smoking appeared to modify the associations of ICA-IMT with CRP (p = 0.009) and with IL-6 (p = 0.006); the association was more pronounced in current (vs former or never) smokers. In conclusion, there were modest associations of inflammatory markers, particularly IL-6, with carotid atherosclerosis. This association appears more pronounced in current smokers than in former smokers and nonsmokers.

Pathogenesis of hepatic encephalopathy: the tumour necrosis factor-alpha theory

Hepatic encephalopathy (HE) is a major complication for acute and chronic liver failure. Despite several decades of intensive clinical and basic research, the pathogenesis of HE is still incompletely understood, and the precise mechanisms causing brain dysfunction in liver failure are still not fully established. Several theories concerning the pathogenesis of HE have been previously suggested, including the ammonia theory, which received the most attention. These theories are not mutually exclusive and the validity of none of them has been definitely proved experimentally. In this review article, an attractive theory concerning the pathogenesis of HE, the tumour necrosis factor-alpha (TNF) theory, is presented and comprehensively discussed after accumulation of sufficient data which indicate that the pro-inflammatory cytokine, TNF, is strongly involved in the pathogenesis of HE associated with both acute and chronic liver failure. This theory seems to be superior to all other previous theories in the pathogenesis of HE, and may induce development of other beneficial therapeutical modalities for HE directed towards inhibition of TNF production and/or action, and towards enhancement of its degradation.

Endothelium-derived hyperpolarization factor (EDHF) is up-regulated in a pig model of acute liver failure

BACKGROUND

Acute liver failure (ALF) is hemodynamically characterized by hyperdynamic circulation, but the pathophysiologic mechanisms underlying these disturbances are not known. The purposes of the present experiments were: to study systemic and peripheral hemodynamics in vivo, to measure changes in vascular reactivity in vitro, and to determine the role of endothelium-dependent vasodilator pathways in a well-validated porcine model of ALF.

METHODS

Landrace pigs (24-29 kg) were allocated to sham operation (n=8) or ALF induced by hepatic devascularization (n=9). Systemic and regional hemodynamics were monitored. Femoral artery rings were prepared for isometric tension recordings 8 h after ALF induction. Contractile responses to phenylephrine were assessed in ring segments of endothelium-intact femoral arteries in the absence or presence of inhibitors of endothelium-derived hyperpolarizing factor, nitric oxide synthase, cyclooxygenase and heme oxygenase pathways.

RESULTS

Pigs with ALF developed a hyperdynamic circulation. Cardiac index increased (PGT<0.001), while mean arterial pressure (PGT=0.012) and systemic vascular resistance decreased (PGT<0.001) in this group. Femoral artery blood flow decreased in controls, while it remained unchanged in ALF (PGT=0.010). Accordingly, vascular resistance across the hind leg was significantly decreased (PGT<0.001) in ALF. The combination of Ca2+-activated potassium channel inhibitors charybdotoxin and apamin, which block the release of endothelium-derived hyperpolarizing factor, increased the contraction force (ANOVA, PGT=0.05) and Emax (P=0.01) to phenylephrine in ALF. In contrast, inhibitors of nitric oxide synthase, cyclooxygenase and heme oxygenase pathways did not increase isometric contraction force.

CONCLUSIONS

Endothelium dependent hyperpolarization of vascular smooth muscle contributes to the development of hyperdynamic circulation in ALF.

The routine use of C-reactive protein in forensic investigations

In clinical medicine, C-reactive protein (CRP) is extensively used as a general marker for immune system activation, and post-mortem applicability has been established [M.Q. Fujita, B.L. Zhu, K. Ishida, L. Quan, S. Oritani, H. Maeda, Serum C-reactive protein levels in postmortem blood-an analysis with special reference to the cause of death and survival time, Forensic Sci. Int. 130 (2002) 160-166; L. Uhlin-Hansen, C-reactive protein (CRP), a comparison of pre- and post-mortem blood levels, Forensic Sci. Int. 124 (2001) 32-35]. We have analysed the routine use of CRP in non-selected cases. Scarcity of blood available for analysis is a common problem in forensic investigation, and in response to this we have developed a method using liver as a source. In 50 consecutive autopsy cases, we have evaluated method, validated results and discussed their interpretation. In three cases the analysis was not possible. For each of the remaining cases (n=47) we have analysed whole blood, serum and/or liver samples. 57% (n=25) had serum CRP > 10 mg/L. Serum levels were higher than in whole blood or liver. CRP levels in serum and whole blood samples were stable in more than one month after death, making storage for later analysis possible. Liver levels peaked at one week, but after one month putrefaction was obvious. CRP levels were independent of the post-mortem interval. The use of liver as a source has not yet been described in literature. Our results in liver samples correlate well with plasma results, and liver is a good post-mortem alternative when blood is not available. We conclude that CRP measurements are easy, viable and inexpensive in a forensic setting, and that the number of cases with CRP elevation is high in a non-selected forensic material. In cases of doubt, marked elevation of CRP is an indicator of natural mode of death, and in cases of trauma, it indicates vital reaction. It can be used as a pre-autopsy screening, leading to a more extensive search for diseases not easily diagnosed, such as sepsis or ketoacidosis.

Treatment of fulminant hepatic failure in rats using a bioartificial liver device containing porcine hepatocytes producing interleukin-1 receptor antagonist

Fulminant hepatic failure (FHF) is a serious clinical condition that is associated with high mortality. There is evidence that FHF is an inflammatory disease, which is supported clinically by elevated serum levels of cytokines. In an effort to develop hepatocytes with additional functions for use in our bioartificial liver (BAL) device, we focused on interleukin-1 (IL-1) blockade as a therapeutic modality. Primary porcine hepatocytes were isolated from the livers of miniature swine and then transfected with an adenoviral vector encoding human interleukin-1 receptor antagonist (AdIL-1Ra). The transfected hepatocytes secreted human IL-1Ra. These transfected hepatocytes were incorporated into a flat-plate BAL device to evaluate their efficacy in treating D-galactosamine (GalN)- induced FHF in a rat model. After extracorporeal perfusion with the BAL device containing the transfected hepatocytes, there were significant reductions in the plasma levels of hepatic enzymes (aspartate aminotransferase and alanine aminotransferase) and cytokines (IL-1 and IL-6), indicating a beneficial effect. Animal survival was significantly improved in the treated group compared to the control group. These experiments demonstrate that combining inflammatory cytokine blockade with a functional BAL device may be an effective therapeutic option in the treatment of FHF.

Reduced monocyte HLA-DR expression: a novel biomarker of disease severity and outcome in acetaminophen-induced acute liver failure

Acute liver failure (ALF) shares striking similarities with septic shock where a decrease in HLA-DR expression on monocytes is associated with disease severity and predicts outcome. We investigated monocyte HLA-DR expression in ALF in relation to inflammatory mediator levels and clinical outcome. Monocyte HLA-DR expression was determined in 50 patients with acetaminophen-induced ALF (AALF) and 20 non-acetaminophen-induced ALF (NAALF). AALF patients were divided into dead/transplanted (AALF-NS, n = 26) and spontaneous survivors (AALF-S, n = 24). Fifty patients with chronic liver disease (CLD) and 50 healthy volunteers served as controls. Monocyte HLA-DR expression was determined by double-color flow-cytometry with monoclonal antibodies detecting HLA-DR and monocyte specific CD14. Serum levels of interleukin (IL) -4, -6, -10, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma were concomitantly measured by ELISA. Compared to healthy volunteers (75%) and CLD (67%) monocyte HLA-DR percentage expression was lower in AALF (15%, P < .001) and NAALF (22 %, P < .001). Compared to AALF-S, AALF-NS had lower monocyte HLA-DR % (11% vs. 36%, P < .001) and higher levels of IL-4, IL-6, IL-10 and TNF-alpha (P < .001). HLA-DR percentage negatively correlated with INR, blood lactate, pH and levels of encephalopathy (r = -0.8 to -0.5, P < .01), IL-10 (r = -0.8, P < .0001), TNF-alpha (r = -0.4, P = .02). HLA-DR percentage level <or=15% has a 96% sensitivity and 100% specificity and 98% accuracy in predicting poor prognosis. In conclusion, the strong relationship of monocyte HLA-DR expression with indices of disease severity, mediators of inflammation and outcome indicates a key role for this molecule as a biomarker of disease severity and prognosis.

Inflammatory cytokines induce protein tyrosine nitration in rat astrocytes

Protein tyrosine nitration may be relevant for the pathogenesis of hepatic encephalopathy (HE). Infections, sepsis, and trauma precipitate HE episodes. Recently, serum levels of tumor necrosis factor (TNF)-alpha were shown to correlate with severity of HE in chronic liver failure. Here the effects of inflammatory cytokines on protein tyrosine nitration in cultured rat astrocytes and rat brain in vivo were studied. In cultured rat astrocytes TNF-alpha (50 pg/ml-10 ng/ml) within 6h increased protein tyrosine nitration. TNF-alpha-induced tyrosine nitration was related to an increased formation of reactive oxygen and nitrogen intermediates, which was downstream from a NMDA-receptor-dependent increase of intracellular [Ca(2+)](i) and nNOS-catalyzed NO production. Astroglial tyrosine nitration was also elevated in brains of rats receiving a non-lethal injection of lipopolysaccharide, as indicated by colocalization of nitrotyrosine immunoreactivity with glial fibrillary acidic protein and glutamine synthetase, and by identification of the glutamine synthetase among the tyrosine-nitrated proteins. It is concluded that reactive oxygen and nitrogen intermediates as well as protein tyrosine nitration by inflammatory cytokines may alter astrocyte function in an NMDA-receptor-, Ca(2+)-, and NOS-dependent fashion. This may be relevant for the pathogenesis of HE and other conditions involving cytokine exposure the brain.

Up-regulation of hepatocyte growth factor caused by an over-expression of transforming growth factor beta, in the rat model of fulminant hepatic failure

BACKGROUND

The role of transforming growth factor beta (TGF-beta), a potent regulator of cellular growth, was investigated in the rat model of fulminant hepatic failure (FHF).

MATERIALS AND METHODS

The rat FHF model was created by a combination of a 68% partial hepatectomy (PH) and 7% of necrosis (each n = 25 in Groups 1, 2 and 3). Adenovirus mediated gene transfer of mature human TGF-beta1 gene was performed by the systemic injection of AxCAhTGFb1 (1 x 10(9) pfu) in Group 1, 3 days before FHF. In control Groups 2 and 3, recombinant lacZ adenovirus (AxCAlacZ, Group 2) and normal saline (1 ml, Group 3) were used, instead of AxCAhTGFb1.

RESULTS

An excessive expression of TGF-beta1 in Group 1 resulted in an inhibition of hepatocyte proliferation (24-48 h after FHF) and gaining of liver weight (24-48 h), increased expression of HGF in liver tissue (24 h), and decreased expression of TGF-alpha (24 h), compared to those in control Groups 2 and 3. Serum IL-6 levels were also elevated by a TGF-beta1 over-expression at 24 hrs after FHF in Group 1.

CONCLUSIONS

The forced expression of TGF-beta1 in the FHF liver yields both a secondary increase of HGF production and a suppression of liver regeneration, which might explain the mechanism of increased serum HGF observed in a clinical FHF. TGF-beta1 is thus thought to have an important role in inhibiting liver regeneration after FHF.

Human lung fibroblasts express interleukin-6 in response to signaling after mast cell contact

Asthma is a chronic inflammatory disease of the airways. Mast cell-derived cytokines may mediate both airway inflammation and remodeling. It has also been shown that fibroblasts can be the source of proinflammatory cytokines. In the human airways, mast cell-fibroblast interactions may have pivotal effects on modulating inflammation. To study this further, we cocultured normal human lung fibroblasts (NHLF) with a human mast cell line (HMC-1) and assayed for production of interleukin (IL)-6, an important proinflammatory cytokine. When cultured together, NHLF/HMC-1 contact induced IL-6 secretion. Separation of HMC-1 and NHLF cells by a porous membrane inhibited this induction. HMC-1-derived cellular membranes caused an increase in IL-6 production in NHLF. Activation of p38 MAPK was also seen in cocultures by Western blot, whereas IL-6 production in cocultures was significantly inhibited by the p38 inhibitor SB203580. IL-6 production in cocultures was minimally inhibited by a chemical inhibitor of nuclear factor-kappaB (Bay11), indicating that nuclear factor-kappaB may have a minimal role in signaling IL-6 production in mast cell/fibroblasts cocultures. Blockade of inter-cellular adhesion molecule-1, tumor necrosis factor-RI, and surface IL-1beta with neutralizing antibodies failed to significantly decrease IL-6 production in our coculture, indicating that other receptor-ligand associations may be responsible for this activation. These novel studies reveal the importance of cell-cell interactions in the complex milieu of airway inflammation.

Immunohistochemical expression of C-reactive protein in squamous cell carcinoma of the esophagus - significance as a tumor marker

C-reactive protein (CRP) is a prototype acute phase protein which has been known to be synthesized in hepatocytes. Although serum elevation of CRP has been reported to be an indicator of the unfavorable outcome of the patients in some malignant tumors, the expression of the protein in carcinoma cells has not been investigated. The aim of the current study was to assess the immunohistochemical expression of CRP in squamous cell carcinoma (SCC) of the esophagus and to find its biological significance. Immunohistochemical examination for CRP expression was performed for 37 advanced esophageal SCCs with the depth of T2, T3 or T4, which had been surgically resected without preoperative therapy for the patients. Eighteen carcinomas (48.6%) demonstrated immunohistochemical CRP expression. Univariate analysis showed that the prognosis of the patients with esophageal SCCs expressing CRP was significantly worse than that in patients with tumors without CRP expression (P=0.017). Moreover, CRP expression was found to be an independent prognosticator in patients with esophageal SCCs in the multivariate analysis (P=0.036). To the best of authors' knowledge, this is the first report that demonstrated the possible carcinoma-related expression of CRP in SCCs of the esophagus and its biological significance as the prognosticator of the patients.

Effect of interleukin-2 on peripheral blood mononuclear cell cytokine production and the hepatic acute phase protein response

This study investigated the ability of recombinant interleukin-2 (IL-2) to modulate the ability of peripheral blood mononuclear cells (PBMCs) to stimulate an acute phase protein response in isolated human hepatocytes. The effect of IL-2 on the production of tumour necrosis factor-alpha (TNF) and interleukin-6 (IL-6) by PBMCs isolated from patients with gastrointestinal cancer, multiple organ failure, and healthy controls was also studied. The ability of supernatants from IL-2-treated PBMCs to elicit an acute phase response in hepatocytes was then investigated. IL-2 had no effect on IL-6 or TNF production by PBMCs isolated from any group in the presence or absence of bacterial lipopolysaccharide (LPS). Despite this, preincubation of PBMCs with IL-2 significantly reduced the potential of LPS-stimulated PBMC supernatants to stimulate production of alpha1 antichymotrypsin, alpha1-acid glycoprotein, and C-reactive protein by hepatocytes. These observations were not due to a direct effect of IL-2 on hepatocyte acute phase protein production. These findings suggest that in this model IL-2 may modulate PBMC-induced acute phase protein production through an IL-6 and TNF-independent pathway.

Immature granulocyte count after liver transplantation

We evaluated the significance of immature granulocyte (IG) count during the clinical course after liver transplantation. We counted IG using the flow cytometric method with CD16, CD11b, and CD45 antibodies. Samples were obtained from 31 patients in the Department of Transplantation and Immunology, and we determined (i) the distribution of IG peak value, (ii) the distribution of IG peak time-points, (iii) the clinical background of patients with high IG, and (iv) the clinical course of high IG cases. We observed the appearance of IG (100/microl or higher) in the majority of the patients (23 out of 31 patients; 74.2%). The IG peak was detected on the 19th day after transplantation. We observed serious complications, such as melena, rejection, or severe infection, in high IG (500/microl or higher) cases. We observed instances of inflammation with low C-reactive protein (CRP) value in the presence of IG. We believe that IG is a useful marker to monitor inflammation.

Energy expenditure in acetaminophen-induced fulminant hepatic failure

OBJECTIVE

To determine energy expenditure in critically ill patients suffering from acetaminophen-induced fulminant hepatic failure and compare it with values obtained in matched, healthy control subjects and in patients studied during the anhepatic period of elective liver transplantation.

DESIGN

Prospective, controlled, observational study.

SETTING

A ten-bed intensive therapy unit and a liver transplant unit at a University teaching hospital.

PATIENTS AND SUBJECTS

Sixteen patients suffering from acetaminophen-induced fulminant hepatic failure who were sedated, paralyzed, and mechanically ventilated; 16 age-, gender-, and weight-matched, awake, healthy control subjects; and 16 patients with chronic liver disease, undergoing elective liver transplantation, who were studied during the anhepatic period of surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The mean energy expenditure was calculated in each case for a 30-min period, using indirect calorimetry. In the patients undergoing liver transplantation, measurements were performed after clamping the hepatic veins and recipient hepatectomy. Energy expenditure was markedly increased in the fulminant hepatic failure group (mean energy expenditure, 4.05 [SD 0.52] kJ x kg(-1) x hr(-1)), in comparison with healthy control subjects (mean, 3.44 [0.27] kJ x kg(-1) x hr(-1); mean difference, 18%; p < .001) and in comparison with patients during the anhepatic period of liver transplantation (mean, 3.15 [0.61] kJ x kg(-1) x hr(-1); mean difference, 29%; p < .001). These differences were even more pronounced when a correction factor for differences in core temperature was included in the calculation. Harris-Benedict predictions of energy expenditure were unreliable in the patients with acute liver failure. No correlations were found among energy expenditure and hemodynamic variables, the requirement for vasoconstrictors, or the presence of renal failure.

CONCLUSIONS

Despite the loss of functioning liver cell mass, the metabolic rate is substantially increased in patients with acetaminophen-induced fulminant hepatic failure. This finding is consistent with the marked systemic inflammatory response, which accompanies acute hepatic failure. The Harris-Benedict equation is unreliable when an estimation of energy expenditure is required in patients with this condition.

Relationships of serum pro-inflammatory cytokines and vascular endothelial growth factor with liver dysfunction in severe ovarian hyperstimulation syndrome

The aims of this study were to determine if differences in serum pro-inflammatory cytokines, vascular endothelial growth factor (VEGF) and clinical pregnancy rate, could be observed in women with severe ovarian hyperstimulation syndrome (OHSS) in those who did and did not have liver dysfunction. Twenty-nine in-vitro fertilization patients with severe OHSS were included. The patients were divided into the normal liver function tests (LFT) group (n = 14) and the abnormal LFT group (n = 15) according to the LFT on day of admission. Periodic measurements of serum interleukin (IL)-6, IL-8, tumour necrosis factor-alpha (TNF-alpha), VEGF, oestradiol, progesterone concentrations, and LFT were performed during hospitalization. Concentrations of IL-6 in the active phase of OHSS were significantly higher in the abnormal LFT group than in the normal LFT group (19.7 +/- 15.7 versus 8.1 +/- 7.0 pg/ml, respectively). The severity of liver dysfunction was not correlated with concentrations of oestradiol, progesterone, haematocrit, white blood cell counts, or any studied cytokine. The clinical pregnancy rate was significantly lower in the abnormal LFT group (46.7%) than in the normal LFT group (85.7%). These results suggest that IL-6 cytokine system may play a role in the pathogenesis of liver dysfunction in severe OHSS. Abnormal LFT were associated with lower clinical pregnancy rates.