Gerald Y. Minuk

Fatty infiltration of liver in hyperlipidemic patients

Hyperlipidemia is a known risk factor for fatty infiltration of the liver, a condition that can progress to cirrhosis and liver failure. The objectives of this study were to document the prevalence of fatty infiltration in the livers of hyperlipidemic patients and to identify the predictor variables associated with this condition. Over an 18-month recruitment period, clinical, biochemical, and radiologic assessments were performed in a cross-sectional manner in 95 adult patients referred to an urban hospital-based lipid clinic for evaluation and management of hyperlipidemia. The mean (±sd) age of the patients was 55 ± 13 years. Forty-eight (51%) were male. Fifty-two patients (55%) had hypercholesterolemia, 25 (26%) severe hypertriglyceridemia, 14 (15%) mixed hyperlipidemia, and 4 (4%) moderate hypertriglyceridemia. Obesity and diabetes were present in 36 (38%) and 12 (12%) of cases, respectively. A total of 61 (64%) patients had elevated liver enzyme tests. The most common enzyme abnormalities were an elevated serum ALT in 45 (47%) and GGT in 43 (45%) of patients. Ultrasound findings revealed diffuse fatty liver in 47 patients (50%), of which 21 cases (22%) were mild, 18 (19%) moderate, and 8 (9%) severe. The majority of patients with hypercholesterolemia [35/52 (67%)] had normal ultrasounds, whereas severe hypertriglyceridemia and mixed hyperlipidemia were frequently associated with radiologic evidence of fatty liver (odds ratios 5.9 and 5.1 respectively, P < 0.01). Independent predictors of fatty liver were; AST (P = 0.001), hyperglycemia (P = 0.02), and age (P = 0.04). In a model incorporating known risk factors for fatty liver, diabetes was the only risk factor other than hypertriglyceridemia that was significantly associated with fatty infiltration. No such effect was seen with age, gender, obesity, or alcohol consumption. In conclusions, the results of this study indicate that ultrasonographic evidence of fatty infiltration of the liver is evident in approximately 50% of patients with hyperlipidemia. Hypertriglyceridemia is the lipid profile most often associated with this condition. Serum AST values, hyperglycemia, and age independently predict the presence of fatty infiltration, while hypertriglyceridemia and diabetes are the only risk factors that significantly increase the risk of fatty infiltration in hyperlipidemic patients.

Treatment of Hepatitis B e Antigen-Positive Chronic Hepatitis with Telbivudine or Adefovir: A Randomized Trial

BACKGROUND The efficacy of nucleoside and nucleotide analogues for hepatitis B has been linked to the magnitude and durability of hepatitis B virus (HBV) suppression. OBJECTIVE To compare the antiviral efficacy of telbivudine and adefovir dipivoxil, and the effects of switching from adefovir to telbivudine, in hepatitis B e antigen (HBeAg)-positive patients with chronic hepatitis B. DESIGN Randomized, controlled, open-label trial. SETTING 16 outpatient clinics. PATIENTS 135 treatment-naive, HBeAg-positive adults with chronic hepatitis B. INTERVENTION Patients were randomly assigned in a 1:1:1 ratio to 52 weeks of telbivudine (group A) or adefovir (group B), or 24 weeks of adefovir and then telbivudine for the remaining 28 weeks (group C). One hundred thirty-one patients completed 52 weeks of treatment. MEASUREMENTS The primary efficacy comparison was serum HBV DNA reduction at week 24, with a secondary comparison at week 52. RESULTS At week 24, mean HBV DNA reduction was greater in group A than in pooled groups B and C (-6.30 vs. -4.97 log10 copies/mL; difference, -1.33 log10 copies/mL [95% CI, -1.99 to -0.66 log(10) copies/mL]; P < 0.001), and more patients in group A were polymerase chain reaction-negative (39% vs. 12%; odds ratio, 4.46 [CI, 1.86 to 10.72]; P = 0.001). At week 52, the mean residual HBV DNA level was lower in group A and group C than in group B (3.01 log10 copies/mL [group A] and 3.02 log10 copies/mL [group C] vs. 4.00 log10 copies/mL [group B]; difference, -0.99 log10 copies/mL [CI, -1.67 to -0.32 log10 copies/mL] and -0.98 log10 copies/mL [CI, -1.64 to -0.32 log10 copies/mL]; P = 0.004). Adverse events were similar across groups; the most common were upper respiratory symptoms, headache, back pain, and diarrhea. LIMITATIONS The trial was open-label and was not of sufficient size or duration to compare clinical outcomes and long-term efficacy. CONCLUSION Telbivudine demonstrated greater and more consistent HBV DNA suppression than adefovir after 24 weeks of treatment. After 52 weeks, HBV DNA suppression was greater in patients who had received continuous telbivudine or were switched to telbivudine after 24 weeks than in those who received continuous adefovir.

Antioxidative function of L‐FABP in L‐FABP stably transfected Chang liver cells

Liver fatty acid binding protein (L‐FABP) contains amino acids that are known to possess antioxidant function. In this study, we tested the hypothesis that L‐FABP may serve as an effective endogenous cytoprotectant against oxidative stress. Chang liver cells were selected as the experimental model because of their undetectable L‐FABP mRNA level. Full‐length L‐FABP cDNA was subcloned into the mammalian expression vector pcDNA3.1 (pcDNA‐FABP). Chang cells were stably transfected with pc‐DNA‐FABP or vector (pcDNA3.1) alone. Oxidative stress was induced by incubating cells with 400 μmol/L H2O2 or by subjecting cells to hypoxia/reoxygenation. Total cellular reactive oxygen species (ROS) was determined using the fluorescent probe DCF. Cellular damage induced by hypoxia/reoxygenation was assayed by lactate dehydrogenase (LDH) release. Expression of L‐FABP was documented by regular reverse transcription polymerase chain reaction (RT‐PCR), real‐time RT‐PCR, and Western blot. The pcDNA‐FABP–transfected cells expressed full‐length L‐FABP mRNA, which was absent from vector‐transfected control cells. Western blot showed expression of 14‐kd L‐FABP protein in pcDNA‐FABP–transfected cells, but not in vector‐transfected cells. Transfected cells showed decreased DCF fluorescence intensity under oxidative stress (H2O2 and hypoxia/reoxygenation) conditions versus control in inverse proportion to the level of L‐FABP expression. Lower LDH release was observed in the higher L‐FABP–expressed cells in hypoxia/reoxygenation experiments. In conclusion, we successfully transfected and cloned a Chang liver cell line that expressed the L‐FABP gene. The L‐FABP–expressing cell line had a reduced intracellular ROS level versus control. This finding implies that L‐FABP has a significant role in oxidative stress. (HEPATOLOGY 2005;42:871–879.)

Molecular Evolution of Hepatitis B Virus over 25 Years

ABSTRACT Determining the longitudinal molecular evolution of hepatitis B virus (HBV) is difficult due to HBVs genomic complexity and the need to study paired samples collected over long periods of time. In this study, serial samples were collected from eight hepatitis B virus e antigen-negative asymptomatic carriers of HBV genotype B in 1979 and 2004, thus providing a 25-year period to document the long-term molecular evolution of HBV. The rate, nature, and distribution of mutations that emerged over 25 years were determined by phylogenetic and linear regression analysis of full-length HBV genome sequences. Nucleotide hypervariability was observed within the polymerase and pre-S/S overlap region and within the core gene. The calculated mean number of nucleotide substitutions/site/year (7.9 × 10−5) was slightly higher than published estimates (1.5 × 10−5 to 5 × 10−5). Nucleotide changes in the quasispecies population did not significantly alter the molecular evolutionary rate, based on linear regression analysis of evolutionary distances among serial clone pre-S region sequences. Therefore, the directly amplified or dominant sequence was sufficient to estimate the putative molecular evolutionary rate for these long-term serial samples. On average, the ratio of synonymous (dS) to nonsynonymous (dN) substitutions was highest for the polymerase-coding region and lowest for the core-coding region. The low dS/dN ratios observed within the core suggest that selection occurs within this gene region, possibly as an immune evasion strategy. The results of this study suggest that HBV sequence divergence may occur more rapidly than previously estimated, in a host immune phase-dependent manner.

Occult hepatitis B virus infection in a North American adult hemodialysis patient population

Hepatitis B virus (HBV) infections continue to occur in adult hemodialysis units. A possible contributing factor is the presence of occult HBV (serum hepatitis B surface antigen [HBsAg] negative but HBV DNA positive). Two hundred forty‐one adult hemodialysis patients were screened for occult HBV. HBV DNA testing was performed by real‐time polymerase chain reaction (PCR) with 2 independent primer sets (core promoter and surface). Two (0.8%) of the 241 patients were HBsAg positive. Of the remaining 239 HBsAg‐negative patients, 9 (3.8%) were HBV DNA positive. Viral loads in these individuals were low (102‐104 viral copies/mL). Seven of the 9 (78%) were nt 587 mutation (sG145R mutant) positive. Demographic, biochemical, and HBV serological testing did not help to identify those with occult HBV. In conclusion, the prevalence of occult HBV in adult hemodialysis patients in this North American urban center is approximately 4 to 5 times higher than standard HBsAg testing would suggest. The majority of these infections are associated with low viral loads and a high prevalence of the sG145R mutant. Finally, the demographic, biochemical, and/or serological features of HBV DNA–positive subjects do not distinguish these individuals from the remainder of the dialysis patient population. (HEPATOLOGY 2004; 40:1072–1077.)

Risk of sedation for upper GI endoscopy exacerbating subclinical hepatic encephalopathy in patients with cirrhosis

BACKGROUND The risk of exacerbating subclinical hepatic encephalopathy associated with the administration of sedative drugs in patients with cirrhosis undergoing diagnostic upper gastrointestinal (GI) endoscopy for portal hypertension remains to be determined. METHODS Ten adult patients with cirrhosis completed number connection tests before sedation for endoscopy and at discharge from the endoscopy unit 2 hours post-procedure. Control patients consisted of five patients with cirrhosis undergoing the same procedure for the same indication who did not receive sedation and 12 patients with no evidence of liver disease who received sedation before diagnostic endoscopy for a variety of GI complaints. The control populations were age, gender, education level, and, in the case of patients with cirrhosis, Child Pugh s score matched to the patients with cirrhosis who received sedation. RESULTS The mean (+/- SEM) age of patients with cirrhosis who received sedation was 59.6 +/- 3.8 years. Seven of the ten (70%) were men. Their mean Child Pugh s score was 7.2 +/- 1.5. Nine of the ten (90%) had abnormal baseline number connection tests results (mean for the group 52.3 +/- 6.7 seconds) the extent of which correlated with Child Pugh s scores (p < 0.005). Individually, the baseline number connection tests results were normal in one (10%), mild in six (60%), moderate in one (10%), and severe in two (20%). After the procedure (before discharge) the mean number connection tests result was 61.5 +/- 7.9 seconds (p = 0.01 when compared with baseline). The results were now normal in none (0%), mild in four (40%), moderate in four (40%), and severe in two (20%). Pre- and post-procedure number connection tests results did not change in the non-sedated cirrhotic or sedated non-liver disease control patients. CONCLUSIONS The results of this study indicate that (1) the majority of patients with cirrhosis and suspected portal hypertension have evidence of subclinical hepatic encephalopathy, (2) the extent of encephalopathy correlates with the Child Pughs score, (3) sedation with midazolam for upper GI endoscopy exacerbates the encephalopathy, and (4) this adverse effect is still evident 2 hours after the procedure.

Symptoms of obstructive sleep apnea in patients with nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is a term often used to describe two related conditions: a relatively benign, nonalcoholic fatty liver (NAFL) and potentially aggressive, nonalcoholic steatohepatitis (NASH). Both conditions (NAFL and NASH) occur in the setting of peripheral insulin resistance. Recently, obstructive sleep apnea (OSA) has been proposed as an independent risk factor for insulin resistance. To date, few studies have documented the prevalence of OSA or symptoms of OSA (SOSA) in NAFLD patients. The objectives of this study were (1) to document the prevalence of SOSA in patients with NAFLD and (2) to determine whether prevalence rates for SOSA differ in NAFL versus NASH patients. One hundred ninety biochemically defined NAFLD patients (116 NAFL and 74 NASH), of whom 50 (18 NAFL and 32 NASH) had undergone liver biopsy, completed a Modified Berlin Sleep Apnea Questionnaire for SOSA. Risk factors for NAFLD were also documented in NAFL and NASH patients. Eighty-seven of the 190 (46%) NAFLD patients met questionnaire criteria for SOSA. The prevalence of SOSA was similar in both biochemically (45% versus 49%, respectively; P= 0.66) and histologically (39% versus 63%, respectively; P= 0.11) defined NAFL and NASH patients. Other risk factors for NAFLD such as body mass index, plasma cholesterol and triglyceride levels, and prevalence of diabetes were also similar in the two groups. Approximately one-half of NAFLD patients, whether NAFL or NASH, have SOSA. Further studies are required to determine whether a causal link exists between NAFLD and OSA.

Classification of Hepatitis B Virus Genotype B into 2 Major Types Based on Characterization of a Novel Subgenotype in Arctic Indigenous Populations

Hepatitis B virus genotype B (HBV/B) has been classified into 5 subgenotypes. Except for Bj/B1 in Japan, the subgenotypes (Ba/B2-B5) have undergone recombination with HBV/C in the core promoter/precore/core genomic region. Phylogenetic analyses of complete sequences show that the Arctic strains belong to a novel subgenotype (HBV/B6) without the recombination, analogous to what is seen with Bj/B1. Comparison of 50 HBV/B6 carriers from the Arctic versus 50 Bj and 50 Ba age- and sex-matched carriers from Asia revealed that clinical characteristics of HBV/B6 carriers were similar to those of Bj/B1 carriers in Japan. The results suggest that HBV/B may be classified into nonrecombinant (Bj/B1 and B6) and recombinant (Ba/B2-B5) types.

The expression of insulin-like growth factor binding proteins in human hepatocellular carcinoma.

Insulin-like growth factors (IGF), IGF receptors and IGF binding proteins (IGFBPs) play an important role in cell growth and differentiation. The liver is the major source of IGF-1 and at least two IGFBPs (IGFBP-1 and IGFBP-3). IGFBPs most often serve to attenuate the effects of IGF at the receptor level and thereby limit IGF-induced cell growth and differentiation. Although changes in IGFBP expression have been described during controlled liver growth such as hepatic regeneration following partial hepatectomy, there is limited knowledge of IGFBPs gene expression in uncontrolled growth or hepatocellular carcinoma. In the present study, we employed Northern blotting techniques to document the expression of IGFBP-1, 3 and 4 in normal human livers, cirrhotic and hepatocellular carcinoma tissues. The results revealed no differences in IGFBP-1, 3 and 4 mRNA levels between normal and cirrhotic tissues. However, the expression of all three IGFBPs mRNA were significantly down regulated in hepatocellular carcinoma tissues. These findings are in keeping with IGFBPs playing an important inhibitory role in the development and/or growth of hepatocellular carcinoma in humans.

Hepatorenal syndrome: diagnostic accuracy, clinical features, and outcome in a tertiary care center

Hepatorenal syndrome: diagnostic accuracy, clinical features, and outcome in a tertiary care center