Biomedical subjects
Janus P Ong
Publications and source records attributed to Janus P Ong.
Gene expression of leptin, resistin, and adiponectin in the white adipose tissue of obese patients with non-alcoholic fatty liver disease and insulin resistance.
BACKGROUND: Adipose tissue is an active endocrine organ that secretes a variety of metabolically important substances including adipokines. These factors affect insulin sensitivity and may represent a link between obesity, insulin resistance, type 2 diabetes (DM), and nonalcoholic fatty liver disease (NAFLD). This study uses real-time polymerase chain reaction (PCR) quantification of mRNAs encoding adiponectin, leptin, and resistin on snap-frozen samples of intra-abdominal adipose tissue of morbidly obese patients undergoing bariatric surgery. METHODS: Morbidly obese patients undergoing bariatric surgery were studied. Patients were classified into two groups: Group A (with insulin resistance) (N=11; glucose 149.84 +/- 40.56 mg/dL; serum insulin 8.28 +/- 3.52 microU/mL), and Group B (without insulin resistance) (N=10; glucose 102.2 +/- 8.43 mg/dL; serum insulin 3.431 +/- 1.162 microU/mL). RESULTS: Adiponectin mRNA in intra-abdominal adipose tissue and serum adiponectin levels were significantly lower in Group A compared to Group B patients (P<0.016 and P<0.03, respectively). Although serum resistin was higher in Group A than in Group B patients (P<0.005), resistin gene expression was not different between the two groups. Finally, for leptin, neither serum level nor gene expression was different between the two groups. Serum adiponectin level was the only predictor of nonalcoholic steatohepatitis (NASH) in this study (P=0.024). CONCLUSIONS: Obese patients with insulin resistance have decreased serum adiponectin and increased serum resistin. Additionally, adiponectin gene expression is also decreased in the adipose tissue of these patients. This low level of adiponectin expression may predispose patients to the progressive form of NAFLD or NASH.
Depression, anemia and health-related quality of life in chronic hepatitis C.
BACKGROUND/AIMS: Hepatitis C (HCV) infected patients have significant health-related quality of life (HRQL) impairment which worsens during anti-viral therapy. Our aim was to examine the association of HRQL with treatment-induced depression and anemia. METHODS: Two hundred and seventy-one HCV patients who received pegylated interferon alfa 2b and ribavirin were included. Data on HRQL, depressive symptoms, laboratory values and socio-demographic characteristics were collected. RESULTS: Mean age was 47.1+/-6.5, 69% were male, and 73% were White. HCV patients' HRQL declined during anti-viral therapy but returned to or exceeded baseline levels within 24 weeks of completion. Anemia and depression were both associated with HRQL impairment. The effects of depression on HRQL were strong; once depression scores were included other factors were no longer significant. Patients' depressive symptoms tended to increase during the initial half of treatment regimen. Those with higher body mass index (BMI), cirrhosis, and women reported more HRQL impairments. HRQL scales were generally not associated with alcohol abuse, age, race, ALT and HCV RNA levels. CONCLUSIONS: Anti-viral therapy for HCV is associated with diminished HRQL. Although anemia and depression were associated with this impairment, depression was the most consistent predictor. Future studies are needed to see whether proactive management of these side effects can improve patients' HRQL and the efficacy of antiviral therapy for hepatitis C.
A genomic and proteomic study of the spectrum of nonalcoholic fatty liver disease.
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and some of its forms are progressive. This study describes the profiling of hepatic gene expression and serum protein content in patients with different subtypes of NAFLD. Liver biopsy specimens from 98 bariatric surgery patients were classified as normal, steatosis alone, steatosis with nonspecific inflammation, and nonalcoholic steatohepatitis (NASH). Microarray hybridizations were performed in triplicate and the microarray expression levels of a selected group of genes were confirmed using real-time quantitative reverse-transcriptase polymerase chain reaction. Serum protein profiles of the same patients were determined by SELDI-TOF mass spectrometry. Of 98 obese patients, 91 were diagnosed with NAFLD (12 steatosis alone, 52 steatosis with nonspecific inflammation, and 27 NASH), and 7 patients without NAFLD served as obese controls. Each group of NAFLD patients was compared with the obese controls, and 22 genes with more than twofold differences in expression levels were revealed. Proteomics analyses were performed for the same group comparisons and revealed twelve significantly different protein peaks. In conclusion, this genomic/proteomic analysis suggests differential expression of several genes and protein peaks in patients within and across the forms of NAFLD. These findings may help clarify the pathogenesis of NAFLD and identify potential targets for therapeutic intervention.
Pegylated interferon alpha-2b, ribavirin and amantadine for chronic hepatitis C.
In an attempt to improve the efficacy of antiviral therapy for chronic hepatitis C, a three-drug combination of pegylated interferon alpha-2b, ribavirin, and amantadine has been suggested. Despite the initial enthusiasm, the role of amantadine in the treatment of chronic hepatitis C remains controversial. In a multi-center, open-label clinical trial, the potential efficacy and safety of this triple combination regimen were assessed. In this open-label pilot study, two separate patient populations with chronic hepatitis C and viremia were enrolled: treatment-naive and those who had failed a previous course of treatment. Patients were started on pegylated interferon alpha-2b at a dose of 1.5 microg/kg weekly with ribavirin, 1000-1200 mg/day, and amantadine, 200 mg/day, for 4 weeks, followed by pegylated interferon alpha-2b, 0.5 microg/kg weekly, ribavirin, 1000-1200 mg/day, and amantadine, 200 mg/day, for another 20 weeks. Patients with undetectable HCV RNA at week 24 continued this regimen for a total of 48 weeks and were followed for another 24 weeks. Patients with undetectable virus (<50 IU/mL) after 24 weeks of follow-up were considered to have SVR. Health-related quality of life and safety data were also collected. Sixty-nine treatment-naive and 99 nonresponder patients with chronic hepatitis C were enrolled in the study. Of all patients enrolled, 74% were male, aged 47.27+/-5.76 years; their body mass index (BMI) was 28.87+/-5.05 kg/m2, 79.4% were white, 85% had HCV genotypes 1 and 4, and 36% had cirrhosis. Their baseline HCV RNA was 689,242+/-698,030 IU/mL, with a baseline ALT of 107.25+/-79.08. Of the entire cohort, 35 (21%) discontinued early due to side effects or loss to follow-up. Significant anemia (hemoglobin, < 10 g/dL) occurred in 11% (19/168), while severe anemia (hemoglobin, <8.5 g/dL) occurred in 0.6% (1/168). In the treatment-naive group, sustained virologic response (SVR) was 34.3%, versus 19.4% for the group who had previously failed to respond to a course of treatment (P = 0.01). For both groups combined, virologic response after 24 weeks of therapy was 40.5%, with an end-of-treatment virologic response of 35.7% and a SVR of 26.2%. Patients with genotypes 1 and 4 had lower response rates than those with genotypes 2 and 3 (SVR, 21 vs. 46%; P = 0.001). Patients with advanced fibrosis (Metavir stages 3 and 4) tended to have lower response rates than those with minimal or mild fibrosis (Metavir stages 0-2) (SVR, 10 vs. 30%; P = 0.08). African-American patients with HCV had lower response rates than Caucasians or other ethnic groups (SVR, 4 vs. 29 vs. 20%; P = 0.04). Age, gender, and BMI did not affect SVR. The addition of amantadine to pegylated interferon alpha-2b and ribavirin does not seem to increase the efficicacy of this regimen.
Approach to the diagnosis and treatment of nonalcoholic fatty liver disease.
Nonalcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease in the United States. It describes several clinicopathologic entities from simple hepatic steatosis to nonalcoholic steatohepatitis, cirrhosis, and hepatocellular carcinoma. This article describes the epidemiology, clinical features, natural history, and pathogenesis of NAFLD.
High rates of uninsured among HCV-positive individuals.
BACKGROUND AND GOALS: There are no published data on the health insurance status of Hepatitis C virus (HCV)-positive individuals. To address this issue, we analyzed data from the Third National Health and Nutrition Examination Survey (NHANES III). STUDY: Individuals 18 years of age and older who participated in NHANES III were included in the study. We determined the rates of health insurance coverage according to HCV status. We also determined healthcare status and health service utilization according to health insurance status among HCV-positive persons. RESULTS: HCV-positive individuals were more likely to be uninsured compared with those who were HCV-negative (29.6% vs. 12.2%, P = 0.0002). Among those with health insurance, HCV-positive individuals were more likely to have government insurance compared with those who were HCV-negative (42.9% vs. 27.6%, P < 0.005). Among HCV-positive individuals, being uninsured was associated with younger age, being unmarried, living in the South, Mexican-American race/ethnicity, and not graduating from high school. Additionally, the uninsured were less likely than their insured counterparts to identify a healthcare facility for sick or routine care, and less likely to have regular contact with a healthcare professional. CONCLUSIONS: A high proportion of HCV-positive individuals are uninsured, and many HCV-positive individuals with health insurance have publicly funded insurance. This finding may have implications for access to health care and for liver-related disease outcomes in HCV-positive persons.
Hepatic gene expression in patients with obesity-related non-alcoholic steatohepatitis.
BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is among the most common causes of chronic liver disease. NAFLD includes a spectrum of clinicopathologic syndromes that includes non-alcoholic steatohepatitis (NASH) that has potential for progression. The pathogenesis of NASH is poorly characterized. AIM: This study was designed to identify differences in hepatic gene expression in patients with NASH and to relate such differences to their clinical characteristics. DESIGN: Consecutive patients undergoing bariatric surgery were prospectively recruited. Extensive clinical data and two liver biopsy specimens were obtained at the time of enrollment. A single hepatopathologist reviewed and classified the liver biopsies. Patients with excessive alcohol use and other causes of liver disease were excluded. A group of 29 NASH patients, 12 with steatosis alone, seven obese controls and six non-obese controls were selected for further investigation. Customized cDNA microarrays containing 5220 relevant genes were designed specifically for this study. Microarray experiments were run in triplicate for each sample and a selected group of genes were confirmed using real-time PCR. OUTCOME MEASURE: Differential hepatic gene expressions in patients with NASH as compared with controls. RESULTS: Thirty-four genes with significant differential expression were identified in patients with NASH when compared with non-obese controls. Moreover, 19 of these genes showed no significant expression differences in obese vs. non-obese controls, suggesting a stronger association of these genes to NASH. CONCLUSIONS: Several differentially expressed genes in patients with NASH are related to lipid metabolism and extracellular matrix remodeling. Additionally, genes related to liver regeneration, apoptosis, and the detoxification process were differentially expressed. These findings may help clarify the molecular pathogenesis of NASH and identify potential targets for therapeutic intervention.
Predictors of nonalcoholic steatohepatitis and advanced fibrosis in morbidly obese patients.
BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a common form of chronic liver disease in the United States. It is commonly associated with the components of the metabolic syndrome including obesity. From the spectrum of NAFLD, only patients with nonalcoholic steatohepatitis (NASH) have been convincingly shown to have a potential for progression to cirrhosis. We report the prevalence of NAFLD and NASH as well as predictors of NASH and advanced fibrosis in morbidly obese patients. METHODS: 212 consecutive patients who underwent bariatric surgery were enrolled in the study. A liver biopsy was performed at the time of the surgery. Causes of chronic liver disease other than NAFLD were excluded by clinical and laboratory evaluation. RESULTS: The prevalence of NAFLD was 93%. Of those with NAFLD, 26% had NASH. 17 patients (9%) had advanced fibrosis (i.e., bridging fibrosis or cirrhosis). Male gender, AST, and type 2 diabetes mellitus were independently associated with NASH. Waistto-hip ratio, AST, and focal hepatocyte necrosis on liver biopsy were independently associated with advanced fibrosis. Interestingly, while AST was associated with NASH and advanced fibrosis, the majority of the patients with either NASH or advanced fibrosis had normal AST. CONCLUSIONS: NAFLD and NASH are very common in morbidly obese patients undergoing bariatric surgery. Features associated with the metabolic syndrome and liver cell injury are independently associated with either NASH or advanced fibrosis.
Obesity and non-alcoholic fatty liver disease in chronic hepatitis C.
BACKGROUND: Superimposed non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) may affect HCV-related fibrosis. We performed a study to determine the relationship between NAFLD and chronic hepatitis C. METHODS: One hundred and twenty patients with chronic hepatitis C and available liver biopsies were included. Baseline liver biopsies were read by 1 hepatopathologist using Metavir, as well as a fatty liver pathology protocol. Patients' baseline clinical, demographic, and virologic data were associated with the extent of steatosis (>33% vs. < or =33%), the type of fatty liver (no steatosis vs. steatosis only vs. NASH), and the stage of fibrosis seen on the liver biopsy. RESULTS: Seventy percent of patients were men and 80% were white. The mean age was 47.48+/-5.70 years, mean BMI was 29.01 +/-5.01 kg/m, and mean waist to hip ratio (W/H) was 0.90+/-0.08. Patients with higher grade of steatosis had higher BMI (32.83+/-6.26 vs. 28.49+/-4.62, P = 0.034), more likely to have genotype 3 (21.4% vs. 5.7%, P = 0.037) and advanced fibrosis (92.9% vs. 62.3%, P = 0.033) than those with lower grade of steatosis. Of these, only HCV-genotype 3 remained independently associated with higher grade of steatosis. When patients with superimposed NASH (n = 22) were compared with those with only steatosis (n = 49) and those without steatosis (n = 49), patients with superimposed NASH had more evidence of obesity (BMI: 30.64+/-5.23 vs. 29.90+/-5.35 vs. 27.33+/-4.07, P = 0.008; W/H: 0.97+/-0.06 vs. 0.91+/-0.08 vs. 0.87+/-0.07, P < 0.001), more commonly infected with HCV genotype 3 (14% vs. 12% vs. 0%, P = 0.036) and had more advanced fibrosis (95.5% vs. 75.5% vs. 42.9%, P < 0.001). Race, gender, and age did not affect extent of steatosis or presence of superimposed NASH. CONCLUSION: In conclusion, markers of obesity (BMI and W/H) and HCV genotype 3 are associated with the extent of steatosis and type of fatty liver. Higher grade of steatosis and presence of superimposed NASH are both associated with advanced hepatic fibrosis.
Nonalcoholic fatty liver disease and the epidemic of obesity.
Nonalcoholic fatty liver disease (NAFLD) is common in patients with the metabolic syndrome, and it is expected to become more common in countries where obesity, one of the components of the metabolic syndrome, is increasing.
Managing the hematologic side effects of antiviral therapy for chronic hepatitis C: anemia, neutropenia, and thrombocytopenia.
Hematologic abnormalities such as anemia, neutropenia, and thrombocytopenia are common during combination therapy with pegylated (or standard) interferon and ribavirin for chronic hepatitis C. Ribavirin-induced hemolytic anemia is a common cause of dose reduction or discontinuation. Bone marrow suppression also contributes to the anemia and is the predominant mechanism for interferon-induced neutropenia and thrombocytopenia. Although dose reduction or discontinuation of combination therapy can reverse these abnormalities, they may reduce virologic response. Hematopoietic growth factors may provide a useful alternative for managing these hematologic side effects without reducing the optimal dose of the combination antiviral regimen. Treatment of anemia also may improve patients' health-related quality of life and their adherence to combination antiviral therapy. The impact of growth factors on sustained virologic response and their cost-effectiveness in patients with chronic hepatitis C need further assessment.
Correlation between ammonia levels and the severity of hepatic encephalopathy.
PURPOSE: Because the correlation between ammonia levels and the severity of hepatic encephalopathy remains controversial, we prospectively evaluated the correlation in 121 consecutive patients with cirrhosis. METHODS: The diagnosis of hepatic encephalopathy was based on clinical criteria, and the severity of hepatic encephalopathy was based on the West Haven Criteria for grading of mental status. Arterial and venous blood samples were obtained from each patient. Four types of ammonia measurements were analyzed: arterial and venous total ammonia, and arterial and venous partial pressure of ammonia. Spearman rank correlations (r(s)) were calculated. RESULTS: Of the 121 patients, 30 (25%) had grade 0 encephalopathy (no signs or symptoms), 27 (22%) had grade 1, 23 (19%) had grade 2, 28 (23%) had grade 3, and 13 (11%) had grade 4 (the most severe signs and symptoms). Each of the four measures of ammonia increased with the severity of hepatic encephalopathy: arterial total ammonia (r(s) = 0.61, P < or = 0.001), venous total ammonia (r(s) = 0.56, P < or = 0.001), arterial partial pressure of ammonia (r(s) = 0.55, P < or = 0.001), and venous partial pressure of ammonia (r(s) = 0.52, P < or = 0.001). CONCLUSION: Ammonia levels correlate with the severity of hepatic encephalopathy. Venous sampling is adequate for ammonia measurement. There appears to be no additional advantage of measuring the partial pressure of ammonia compared with total ammonia levels.
Challenges of designing hepatic encephalopathy treatment trials.
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Nonalcoholic fatty liver disease (NAFLD)--two decades later: are we smarter about its natural history?
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Non-alcoholic fatty liver disease: an overview.
Non-alcoholic fatty liver disease (NAFL) includes a spectrum of clinicopathological conditions with increasing prevalence in the developed world. Although steatosis alone seems to have a benign course, those patients with the diagnosis of non-alcoholic steatohepatitis (NASH) can have a progressive course. Additionally, there is now evolving, indirect evidence that some of the patients with cryptogenic cirrhosis may be the result of 'burned-out' NASH. Although NAFL and NASH are associated with insulin-resistance syndrome, some patients with NAFL may have no obvious risk factors. Despite preliminary data from a number of pilot studies, no established therapies can be offered to patients with NASH. Over the next few years, a number of exciting research projects dealing with the epidemiology as well as the pathogenesis of NAFL are expected to be completed. It is anticipated that, through a better understanding of NAFL, more effective treatment protocols can be developed targeting only those patients with NASH that are at the highest risk for progression to cirrhosis and liver failure.
Is hepatocellular carcinoma part of the natural history of nonalcoholic steatohepatitis?
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The utility of radiological imaging in nonalcoholic fatty liver disease.
BACKGROUND & AIMS: This prospective study evaluates the role of radiological modalities in establishing the diagnosis of nonalcoholic steatohepatitis (NASH). METHODS: Consecutive patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD) were enrolled (2000-2001). Patients with other liver diseases and significant alcohol consumption (>20 g/day) were excluded. Clinicodemographic data were gathered at the time of liver biopsy. Each biopsy specimen was assessed by a hepatopathologist. Each patient underwent a limited abdominal ultrasonography (US), computerized tomography (CT), and magnetic resonance imaging (MRI). Films were interpreted by a radiologist who used a predetermined radiological protocol. Each radiological study was reread by the same radiologist and a second radiologist. RESULTS: Patients with NASH had greater aspartate aminotransferase levels (P = 0.03), greater ferritin levels (P = 0.05), more hepatocyte ballooning (P < 0.0001), and more fibrosis (P = 0.002). None of the radiological features distinguished between NASH and other types of NAFLD. No radiological modality detected the presence of hepatocyte ballooning, Mallory's hyaline, or fibrosis, which are important features in the diagnosis of NASH. The presence of >33% fat on liver biopsy was optimal for detecting steatosis on radiological imaging. CONCLUSIONS: Differences between NASH and nonprogressive NAFLD were not apparent with any radiological modality. Of the pathologic features important for establishing the diagnosis of NASH, only the severity of steatosis was reflected in these radiological modalities. Good intraobserver agreement was evident for each modality (US, CT, and MRI) that was superior to interobserver agreement.