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Biomedical subjects

Julie R Jonsson

Publications and source records attributed to Julie R Jonsson.

15 recordsLinked to original sources
PubMed2006

Relationship between steatosis, inflammation, and fibrosis in chronic hepatitis C: a meta-analysis of individual patient data.

BACKGROUND & AIMS: Steatosis is a frequent histologic finding in chronic hepatitis C (CHC), but it is unclear whether steatosis is an independent predictor for liver fibrosis. We evaluated the association between steatosis and fibrosis and their common correlates in persons with CHC and in subgroup analyses according to hepatitis C virus (HCV) genotype and body mass index. METHODS: We conducted a meta-analysis on individual data from 3068 patients with histologically confirmed CHC recruited from 10 clinical centers in Italy, Switzerland, France, Australia, and the United States. RESULTS: Steatosis was present in 1561 patients (50.9%) and fibrosis in 2688 (87.6%). HCV genotype was 1 in 1694 cases (55.2%), 2 in 563 (18.4%), 3 in 669 (21.8%), and 4 in 142 (4.6%). By stepwise logistic regression, steatosis was associated independently with genotype 3, the presence of fibrosis, diabetes, hepatic inflammation, ongoing alcohol abuse, higher body mass index, and older age. Fibrosis was associated independently with inflammatory activity, steatosis, male sex, and older age, whereas HCV genotype 2 was associated with reduced fibrosis. In the subgroup analyses, the association between steatosis and fibrosis invariably was dependent on a simultaneous association between steatosis and hepatic inflammation. CONCLUSIONS: In this large and geographically different group of CHC patients, steatosis is confirmed as significantly and independently associated with fibrosis in CHC. Hepatic inflammation may mediate fibrogenesis in patients with liver steatosis. Control of metabolic factors (such as overweight, via lifestyle adjustments) appears important in the management of CHC.

Adult↗
PubMed2005

Adiponectin and its receptors in patients with chronic hepatitis C.

BACKGROUND/AIMS: There is increasing interest in the influence of excess body weight and associated metabolic factors on the liver. In patients with non-alcoholic steatohepatitis, lower levels of adiponectin were associated with higher grades of hepatic steatosis and necroinflammatory activity, suggesting a pathophysiological role for this adipokine in liver disease. METHODS: We studied 194 consecutive patients with untreated chronic HCV, to assess the relationship between adiponectin and its receptors and hepatic steatosis, fibrosis and inflammation. RESULTS: Significant negative correlations between serum adiponectin and male gender, body mass index and serum insulin were observed. However, there was no association between serum adiponectin and stage of fibrosis and lower levels of serum adiponectin were associated with the presence of steatosis in males only. In contrast, there was a significant increase in serum adiponectin and hepatic adiponectin immunoreactivity with increasing inflammation. The hepatic mRNA expression of the adiponectin receptors, AdipoR1 and AdipoR2, displayed significant but opposite associations with phosphoenolpyruvate carboxykinase (PEPCK) gene expression, a substitute marker of hepatic insulin sensitivity. CONCLUSIONS: In patients with chronic HCV, adiponectin was associated with steatosis only in males and was paradoxically increased with inflammation. Our results suggest that the role of adiponectin in chronic liver diseases may be linked to gender and etiology.

Adiponectin↗
PubMed2005

Fibrosis correlates with a ductular reaction in hepatitis C: roles of impaired replication, progenitor cells and steatosis.

The mechanisms for progressive fibrosis and exacerbation by steatosis in patients with chronic hepatitis C (HCV) are still unknown. We hypothesized that proliferative blockade in HCV-infected and steatotic hepatocytes results in the default activation of hepatic progenitor cells (HPC), capable of differentiating into both biliary and hepatocyte lineages, and that the resultant ductular reaction promotes portal fibrosis. To study this concept, 115 liver biopsy specimens from subjects with HCV were scored for steatosis, inflammation, and fibrosis. Biliary epithelium and HPC were decorated by cytokeratin 7 immunoperoxidase, and the replicative state of hepatocytes was assessed by p21 and Ki-67 immunohistochemistry. A ductular reaction at the portal interface was common. There was a highly significant correlation between the area of ductular reaction and fibrosis stage (r = 0.453, P < .0001), which remained independently associated after multivariate analysis. HPC numbers also correlated with fibrosis (r = 0.544, P < .0001) and the ductular area (r = 0.624, P < .0001). Moreover, steatosis correlated with greater HPC proliferation (r = 0.372, P = .0004) and ductular reaction (r = 0.374, P < .0001) but was not an obligate feature. Impaired hepatocyte replication by p21 expression was independently associated with HPC expansion (P = .002) and increased with the body mass index (P < .001) and lobular inflammation (P = .005). In conclusion, the strong correlation between portal fibrosis and a periportal ductular reaction with HPC expansion, the exacerbation by steatosis, and the associations with impaired hepatocyte replication suggest that an altered regeneration pathway drives the ductular reaction. We believe this triggers fibrosis at the portal tract interface. This may be a stereotyped response of importance in other chronic liver diseases.

Adult↗
PubMed2005

Steatosis: co-factor in other liver diseases.

The prevalence of fatty liver is rising in association with the global increase in obesity and type 2 diabetes. In the past, simple steatosis was regarded as benign, but the presence of another liver disease may provide a synergistic combination of steatosis, cellular adaptation, and oxidative damage that aggravates liver injury. In this review, a major focus is on the role of steatosis as a co-factor in chronic hepatitis C (HCV), where the mechanisms promoting fibrosis and the effect of weight reduction in minimizing liver injury have been most widely studied. Steatosis, obesity, and associated metabolic factors may also modulate the response to alcohol- and drug-induced liver disease and may be risk factors for the development of hepatocellular cancer. The pathogenesis of injury in obesity-related fatty liver disease involves a number of pathways, which are currently under investigation. Enhanced oxidative stress, increased susceptibility to apoptosis, and a dysregulated response to cellular injury have been implicated, and other components of the metabolic syndrome such as hyperinsulinemia and hyperglycemia are likely to have a role. Fibrosis also may be increased as a by-product of altered hepatocyte regeneration and activation of bipotential hepatic progenitor cells. In conclusion, active management of obesity and a reduction in steatosis may improve liver injury and decrease the progression of fibrosis.

Apoptosis↗
PubMed2005

Steatosis is a cofactor in liver injury in hemochromatosis.

BACKGROUND & AIMS: Obesity-related steatosis is an increasingly common histologic finding and often coexists with other chronic liver diseases. Although obesity and steatosis are recognized risk factors for more advanced fibrosis in chronic hepatitis C and alcoholic liver disease, it has not been determined whether these factors influence the progression of other diseases in which steatosis is not a feature of the primary liver insult. METHODS: We studied 214 patients with hemochromatosis who were homozygous for the C282Y substitution in HFE and had undergone liver biopsy prior to phlebotomy. RESULTS: Steatosis was present in 41.1% of these patients, and 14.5% had moderate or severe steatosis. Median serum alanine aminotransferase (ALT) and ferritin levels were higher (P < .001), and median transferrin saturation (P = .01) and hepatic iron concentration (HIC) were lower (P = .003) in subjects with steatosis compared with subjects without steatosis. Bivariate analysis revealed a significant association between steatosis and fibrosis (P = .001). Following multiple logistic regression, steatosis was independently associated with fibrosis (odds ratio [OR] 4.3, 95% confidence interval [CI]: 2.1-8.8; P < .001) along with male sex (OR, 5.1; 95% CI: 2.0-12.5; P < .001), excess alcohol consumption (males > or = 50 g/day, females > or = 40 g/day) (OR, 3.9; 95% CI: 1.8-8.5; P = .001), and hepatic iron content (OR, 1.4; 95% CI: 1.2-1.6; P < .001). Both higher BMI (OR, 3.3; 95% CI: 1.8-6.3; P < .001) and alcohol consumption (males > or = 30 g/day, females > or = 10 g/day) (OR, 3.4; 95% CI: 1.2-10.0; P = .023) were independently associated with the presence of steatosis. CONCLUSIONS: These findings indicate that obesity-related steatosis may have a role as a cofactor in liver injury in hemochromatosis. This has important clinical implications and suggests that obesity should be actively addressed in the management of patients with hemochromatosis, as well as other liver diseases.

Adolescent↗
PubMed2004

Virus-specific CD8+ T lymphocytes within the normal human liver.

The frequency and phenotype of human antiviral memory CD8(+) T cells in blood are well studied, yet little is known about their distribution within tissues. Analysis of antiviral CD8(+) T cell populations derived from a unique set of normal liver and blood samples identified a consistent population of virus-specific cells within the liver. In comparison to the circulating T cells, the liver-derived T cells were present at frequencies which were variably enriched compared to that in the blood, and showed significant differences with regard to the expression of CD45RA, CD45RO, CD95, CCR7, CD27 and CD28. The differences in these cell surface markers are consistent with a mature 'effector memory' phenotype of antigen-specific CD8(+) T cells within the liver. An enrichment of an activated subset of NKT cells (V alpha 24/V beta 11) was also observed, a finding which may be relevant to the regulation of the antiviral populations.

Animals↗
PubMed2004

Steatosis and liver cell apoptosis in chronic hepatitis C: a mechanism for increased liver injury.

Steatosis is increasingly recognized as a cofactor influencing the progression of fibrosis in chronic hepatitis C; however, the mechanisms by which it contributes to liver injury remain uncertain. We studied 125 patients with chronic hepatitis C to assess the effect of steatosis on liver cell apoptosis and the expression of Bcl-2, Bcl-x(L), Bax, and tumor necrosis factor alpha (TNF-alpha) and the relationship between liver cell apoptosis and disease severity. A significant increase in liver cell apoptosis was seen in liver sections with increasing grade of steatosis (r = 0.42; P <.0001). Hepatic steatosis and previous heavy alcohol consumption were the only two variables independently associated with the apoptotic index. Increasing steatosis was associated with decreased Bcl-2 mRNA levels and an increase in the proapoptotic Bax/Bcl-2 ratio (r = -0.32, P =.007; and r = 0.27, P =.02, respectively). In the absence of steatosis, increased liver cell apoptosis was not associated with stellate cell activation or fibrosis (r = 0.26, P =.11; r = 0.06, P =.71, respectively). In contrast, in the presence of steatosis, increasing apoptosis was associated with activation of stellate cells and increased stage of fibrosis (r = 0.35, P =.047; r = 0.33, P =.03, respectively), supporting the premise that the steatotic liver is more vulnerable to liver injury. In patients with hepatitis C virus genotype 3, there was a significant correlation between TNF-alpha mRNA levels and active caspase-3 (r = 0.54, P =.007). In conclusion, these observations suggest a mechanism whereby steatosis contributes to the progression of liver injury in chronic hepatitis C. Further investigation will be required to determine the molecular pathways responsible for the proapoptotic effect of steatosis and whether this increase in apoptosis contributes directly to fibrogenesis.

Adult↗
PubMed2004

Increased mononuclear cell activation and apoptosis early after human liver transplantation is associated with a reduced frequency of acute rejection.

Experimental models of orthotopic liver transplantation (OLT) have shown that the very early events post-OLT are critical in distinguishing immunogenic and tolerogenic reactions. In rodents, increased leukocyte apoptosis and cytokine expression have been demonstrated in tolerogenic strain combinations. Information from human OLT recipients is less abundant. The aim of this study was to determine the amount of early leukocyte activation and apoptosis following human OLT, and to correlate this with subsequent rejection status. Peripheral blood mononuclear cells (PBMC) were isolated from 76 patients undergoing OLT - on the day prior, 5 hrs after reperfusion (day 0), and 18-24 hrs post-OLT (day 1). The mean level of apoptotic PBMCs on post OLT day 1 was higher than healthy recipients (0.9% +/- 0.2 vs. 0.2% +/- 0.1, p=0.013). Apoptosis was greater in nonrejecting (NR) (1.1% +/- 0.3) compared with acutely-rejecting (R) (0.3% +/- 0.1, p=0.021) patients. On day 1, PBMC from NR patients had increased expression of IFN-gamma (p=0.006), IL-10 (p=0.016), and CD40 ligand (p=0.02) compared with R. Donor cell chimerism on day 1 did not differ between the groups indicating that this was unlikely to account for increased PBMC apoptosis in the NR group. Interestingly, the level of chimerism on day 0 was significantly higher in NR (3.8% +/- 0.6) compared with R (1.2% +/- 0.4, p=0.004) patients and there was a close correlation between chimerism on day 0 and cytokine expression on day 1. These results imply that similar mechanisms are occurring in the human liver to promote graft acceptance as in the experimental models of liver transplantation and suggest that strategies that promote liver transplant acceptance in rodents might be applicable to humans.

Acute Disease↗
PubMed2003

Pro-fibrotic polymorphisms predictive of advanced liver fibrosis in the severely obese.

BACKGROUND/AIMS: Insulin resistance and systemic hypertension are predictors of advanced fibrosis in obese patients with non-alcoholic fatty liver disease (NAFLD). Genetic factors may also be important. We hypothesize that high angiotensinogen (AT) and transforming growth factor-beta1 (TGF-beta1) producing genotypes increase the risk of liver fibrosis in obese subjects with NAFLD. METHODS: One hundred and five of 130 consecutive severely obese patients having a liver biopsy at the time of laparoscopic obesity surgery agreed to have genotype analysis. Influence of specific genotype or combination of genotypes on the stage of hepatic fibrosis was assessed after controlling for known risk factors. RESULTS: There was no fibrosis in 70 (67%), stages 1-2 in 21 (20%) and stages 3-4 fibrosis in 14 (13%) of subjects. There was no relationship between either high AT or TGF-beta1 producing genotypes alone and hepatic fibrosis after controlling for confounding factors. However, advanced hepatic fibrosis occurred in five of 13 subjects (odds ratio 5.7, 95% confidence interval 1.5-21.2, P=0.005) who inherited both high AT and TGF-beta1 producing polymorphisms. CONCLUSIONS: The combination of high AT and TGF-beta1 producing polymorphisms is associated with advanced hepatic fibrosis in obese patients with NAFLD. These findings support the hypothesis that angiotensin II stimulated TGF-beta1 production may promote hepatic fibrosis.

Adult↗
PubMed2003

In overweight patients with chronic hepatitis C, circulating insulin is associated with hepatic fibrosis: implications for therapy.

BACKGROUND/AIMS: Host factors such as increased body mass index (BMI) and genotype-specific viral factors contribute to the development of steatosis in patients with chronic hepatitis C (HCV). We hypothesized that host metabolic factors associated with increased BMI may play a role in disease progression. METHODS: Fasting serum was collected from 160 patients with chronic HCV at the time of liver biopsy and 45 age, gender and BMI matched controls, and assessed for levels of insulin, c-peptide and leptin. RESULTS: Patients with viral genotype 3 had more severe steatosis (P=0.0001) and developed stages 1 and 2 fibrosis at a younger age (P<0.05) than patients with genotype 1. For both genotypes, overweight patients had significantly more steatosis and increased insulin and leptin levels. In contrast to lean patients, there was a statistically significant increase in circulating insulin levels with increasing fibrosis in overweight patients with chronic HCV (P=0.03). Following multivariate analysis, insulin was independently associated with fibrosis (P=0.046) but not inflammation (P=0.83). There was no association between serum leptin levels and stage of fibrosis. CONCLUSIONS: Increasing circulating insulin levels may be a factor responsible for the association between BMI and fibrosis in patients with HCV, irrespective of viral genotype.

Adult↗
PubMed2003

Steatosis in chronic hepatitis C: association with increased messenger RNA expression of collagen I, tumor necrosis factor-alpha and cytochrome P450 2E1.

BACKGROUND: Increased levels of tumor necrosis factor (TNF)-alpha and oxidative stress have been implicated as factors contributing to hepatic injury in fatty liver diseases. As steatosis is associated with an accelerated progression of fibrosis in chronic hepatitis C (HCV), we hypothesized that the messenger (m)RNA expression of genes involved with the production of reactive oxygen species, inflammation and cellular injury would be increased in liver tissue from subjects with steatosis and chronic HCV. METHODS: Real-time polymerase chain reaction was performed to determine relative mRNA expression levels of collagen I, TNF-alpha, cytochrome P450 2E1 (CYP 2E1), transforming growth factor-beta1 and CD14 in liver biopsies from 38 patients with chronic HCV. The mRNA expression levels were compared between subjects with and without steatosis, fibrosis, and inflammation. RESULTS: Multivariate analysis demonstrated that collagen I mRNA expression was increased by 199% in steatosis (P = 0.02), 85% in moderate to severe fibrosis (P = 0.02) and 157% in inflammation (P = 0.03). Livers of patients with steatosis also had an increase in TNF-alpha mRNA expression by 50% (P = 0.03) and CYP 2E1 expression by 37% (P = 0.04) compared with non-steatotic livers. Tumor necrosis factor-alpha protein was localized to Kupffer cells, bile ducts and portal inflammatory cells by immunohistochemistry. CONCLUSION: Increased expression of TNF-alpha may be involved in the pathogenesis of liver injury and progression of fibrosis in individuals who have steatosis in association with chronic HCV.

Adult↗
PubMed2002

Lymphocyte apoptosis and cell replacement in human liver allografts.

BACKGROUND: Apoptosis of graft-infiltrating T cells has been described after rodent liver transplantation. The aim of this study was to assess lymphocyte apoptosis in human allografts. Additionally, kinetics of leukocyte turnover were studied to determine whether apoptotic cells were likely to be of donor or recipient origin. METHODS: Liver biopsy specimens (n=36) taken between days 3 and 1855 were stained with terminal deoxynucleotidyl transferase dUTP nick end-labeling and anti-CD3 to detect apoptotic lymphocytes. Renal allograft and hepatitis C biopsy specimens served as controls. Donor cell turnover was studied in sex-mismatched grafts using Y-chromosome in situ hybridization to detect recipient cells and double immunostaining for leukocyte phenotyping. RESULTS: T-cell apoptosis was prominent in hepatic sinusoids (72% of biopsy specimens) as early as day 3. It ranged from 0% to 18.2% of CD3+ cells (mean 5.28+/-0.82%) and persisted for >14 days, including time points >1 year. There was no difference between biopsy specimens with or without rejection (6.34+/-1.14% and 4.61+/-1.13%, P=NS). Apoptotic cells in portal tracts were less frequent (33% of biopsy specimens) and less abundant (1.13+/-0.36%, P<0.0001). No lymphocyte apoptosis was seen in renal allograft biopsy specimens or hepatitis C biopsy specimens, indicating that it is a distinctive feature of the liver allograft. Persisting lymphocyte apoptosis even after donor lymphocytes had been replaced suggests that recipient lymphocyte deletion must occur. Donor Kupffer cells persisted for many months. CONCLUSIONS: Our results suggest that the sinusoidal microenvironment promotes recipient lymphocyte apoptosis, which may account for the improved outcome of liver grafts compared with other organ allografts.

Acute Disease↗
PubMed1991

Differential effect of glucocorticoids on abdominal pain induced by morphine.

In patients with unexplained pain after cholecystectomy, morphine often induces pain and may increase plasma aspartate aminotransferase (AST) activity because of exaggerated or prolonged rises in pressure within the biliary system. These anomalous effects of morphine may be mediated by activation of autonomic or related afferent nuclei. In this study, 16 patients with pain and increases in AST after morphine were further studied after pre-treatment with dexamethasone and hydrocortisone. Pre-treatment with dexamethasone decreased scores for pain and nausea and prevented or attenuated increases in plasma AST and glucose; these effects were not observed after pre-treatment with hydrocortisone. Serial changes in plasma concentrations of catecholamines were determined in 8 patients and showed that pre-treatment with dexamethasone, but not hydrocortisone, was associated with lower concentrations of norepinephrine and epinephrine with overall reductions of 53% and 67%, respectively. These observations are consistent with a role for sympatho-adrenomedullary activation in abdominal pain induced by morphine. The different effects of dexamethasone and hydrocortisone raise the possibility that sympatho-adrenomedullary activation after morphine is influenced by the interaction of cortisol with type I glucocorticoid receptors which have a low affinity for dexamethasone and a high affinity for cortisol.

Abdominal Pain↗
PubMedDate not supplied

Association between apolipoprotein E epsilon4 and neuropsychiatric symptoms during interferon alpha treatment for chronic hepatitis C.

Neuropsychiatric complications are common in patients with chronic hepatitis C undergoing treatment with interferon alpha. These side effects include alterations of mood, cognition, and neuroendocrine function and are unpredictable. In a number of neurological disorders characterized by neuropsychiatric symptoms and cognitive dysfunction, inheritance of an apolipoprotein E (APOE) epsilon4 allele is associated with adverse neuropsychiatric outcomes. The authors present evidence that the APOE genotype may influence a patient's neuropsychiatric response to interferon alpha treatment. The inheritance of APOE genotypes was examined in 110 patients with chronic hepatitis C treated with interferon alpha. A retrospective investigation was conducted by assessing the rates of psychiatric referral and neuropsychiatric symptoms experienced during treatment along with other complaints indicating psychological distress. A highly statistically significant association was seen between APOE genotypes and interferon-induced neuropsychiatric symptoms. Patients with an epsilon4 allele were more likely to be referred to a psychiatrist and had more neuropsychiatric symptoms during antiviral treatment than those without an epsilon4 allele. Additionally, patients with an epsilon4 allele were more likely to experience irritability or anger and anxiety or other mood symptoms. These data demonstrate that an individual's APOE genotype may influence the neuropsychiatric response to antiviral therapy with interferon alpha. Prospective studies evaluating the importance of APOE in susceptibility to interferon alpha-induced neuropsychiatric complications are needed. Moreover, pathways involving APOE should be considered in understanding the pathophysiology of interferon alpha-induced neuropsychiatric complications.

Adult↗