Hepatitis B viral load predicts survival of HCC patients undergoing systemic chemotherapy

HCC is a common cause of morbidity and mortality. For patients who are not candidates for curative surgery, systemic chemotherapy is one of the standard treatments. In parts of China and the Far East, over 80% of HCC patients have chronic HBV infection. In this study, we aimed to assess the relationship between pre-chemotherapy HBV viral load and the survival of HCC patients. HBV infection status was determined prior to chemotherapy in 188 patients, 170 of whom had evidence of HBV chronic infection/exposure (160 hepatitis B surface antigen [HBsAg]-positive, 10 HBsAg-negative/hepatitis B core antibody-positive). Of these, 125 had pretreatment HBV DNA levels determined via real-time PCR. Virological data were analyzed using conventional clinical variables to identify factors that influenced survival. Multivariate analysis revealed that high total bilirubin (P = 0.0016; hazard ratio = 1.040 per 1 muM increase; 95% CI 1.015-1.065), HCV infection (P = 0.0095; hazard ratio = 6.955; 95% CI 1.606-30.129), and high HBV DNA level (P = 0.0217; hazard ratio = 1.650; 95% CI 1.076-2.531) affected survival significantly. Exploratory analysis revealed that high levels of pretreatment HBV DNA had a significantly higher incidence of severe hepatitis during chemotherapy.

CONCLUSION

For HCC patients with HBV chronic infection/exposure, a high viral load prior to treatment is an adverse factor for survival and may be associated with a higher incidence of severe hepatitis during chemotherapy. Future strategies to improve the prognosis of HCC patients undergoing chemotherapy should consider supportive therapy that incorporates antiviral therapies to reduce HBV viral load.

Factors affecting serum concentrations of hepatitis C virus (HCV) RNA in HCV genotype 1-infected patients with chronic hepatitis

The serum concentration of hepatitis C virus (HCV) RNA is usually stable (4 to 8 log(10) IU/ml) in untreated patients with chronic hepatitis C. While this baseline HCV RNA concentration ([HCV RNA](BL)) is predictive of a sustained virologic response to treatment, its determinants are only partially identified. We therefore analyzed the baseline characteristics of 2,472 HCV genotype 1-infected patients to identify correlations with gender, age, race, weight, body mass index (BMI), HCV acquisition mode, HCV subtype, alanine aminotransferase concentration, or histopathologic changes in the liver. After separation of the data according to four [HCV RNA](BL) groups (< or =5.0, >5.0 to 5.6, >5.6 to 5.9, and >5.9 log(10) IU/ml), we determined that increasing [HCV RNA](BL) correlated (P < 0.05) with increasing proportions of patients who were male, >40 years of age, or heavier (a weight of >85 kg or a BMI of >27 kg/m(2)). Histologic activity index (HAI) data were available for 1,304 of these patients: increasing [HCV RNA](BL) correlated with higher fibrosis and necrosis-inflammation scores. As a continuous variable, [HCV RNA](BL) correlated with age, gender, weight (continuous or < or =85 versus >85 kg), BMI (continuous or < or =27 versus >27 kg/m(2)), subtype, fibrosis score, and necrosis-inflammation score; however, multiple-regression analysis yielded P values of <0.1 only for age, gender, BMI (< or =27 versus >27 kg/m(2)), and fibrosis score. While our findings are suggestive of a role for these factors in maintenance of the pretreatment state of HCV infection, the multiple-regression model accounted for only < or =4.6% of the [HCV RNA](BL) differences between individuals (R(2) = 0.046 for 1,304 patients with HAI scores; 0.043 for all 2,472 patients).

Determination of the activities of glutamic oxaloacetic transaminase and glutamic pyruvic transaminase in a microfluidic system

A microfluidic system for the analysis of the activities of glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) was fabricated. The device consists of a glass chip with a micro-electrochemical L-glutamate sensor and a polydimethylsiloxane (PDMS) sheet with a Y-shaped micro-flow channel. A sample solution and a substrate solution for the enzymes were introduced from two injection ports at the end of the flow channel. When the flows were stopped, substrates in a solution mixed immediately with either of the enzymes by diffusion in a mixing channel. L-glutamate produced by the enzymatic reaction of GOT or GPT in the flow channel was detected by using the L-glutamate sensor. A distinct current increase was observed immediately after mixing, and the initial slope of the response curve varied in proportion to the activity of GOT or GPT. The relation between the slope of the response curve and the enzyme activity was linear between 7 and 228 U l-1 for GOT and 9 and 250 U l-1 for GPT. The quality of the response curve was improved with an increase in the channel height. The measurement based on the rate analysis in the micro-flow channel facilitated the reduction of the influence of interferents. The influence of the viscosity of the sample solution was also checked for the analysis of real samples. The determination of the enzyme activities was also conducted in a system with micropumps fabricated for a sample injection. Two solutions could be mixed in the mixing channel, and the activity of the enzymes could be measured as in the experiments using microsyringe pumps.

The Clinical Biochemistry of Obesity—More Than Skin Deep

While obesity has a high prevalence in developed countries, the routine abnormalities seen from the clinical biochemistry laboratory that may be caused by obesity related pathology do not seem to be as common. Insulin resistance, which is often associated with obesity, is difficult to assess as formal procedures are too complex for clinical practice. Furthermore the interpretation of insulin levels is hampered by their in vivo variability, assay differences and the lack of reference intervals from an unaffected reference population. Interpretation of fasting glucose levels between 5.5 and 6.0mmol/L are also being debated however, it is useful to understand the age related changes in this parameter, which may also be due to increasing obesity in the reference population. The association of obesity and dyslipidaemia in the metabolic syndrome should focus on elevated triglycerides (>1.5mmol/L), which is associated with low HDLC and correlates with atherogenic small dense LDL. High triglycerides are also predictive of fatty liver and the common abnormality of an elevated ALT may not be appreciated if laboratories allow their reference intervals to increase as the population gets more obese with aging. SHBG levels fall with insulin resistance/hyperinsulinaemia and this needs to be taken into account when testosterone is measured. However, low SHBG is showing huge potential as a disease and prognostic marker in obesity. These commonly available tests provide useful insights for the obese patient and their utility may improve with future research into the growing problem of obesity.

An official ATS statement: hepatotoxicity of antituberculosis therapy

Drug-induced liver injury (DILI) is a problem of increasing significance, but has been a long-standing concern in the treatment of tuberculosis (TB) infection. The liver has a central role in drug metabolism and detoxification, and is consequently vulnerable to injury. The pathogenesis and types of DILI are presented, ranging from hepatic adaptation to hepatocellular injury. Knowledge of the metabolism of anti-TB medications and of the mechanisms of TB DILI is incomplete. Understanding of TB DILI has been hampered by differences in study populations, definitions of hepatotoxicity, and monitoring and reporting practices. Available data regarding the incidence and severity of TB DILI overall, in selected demographic groups, and in those coinfected with HIV or hepatitis B or C virus are presented. Systematic steps for prevention and management of TB DILI are recommended. These include patient and regimen selection to optimize benefits over risks, effective staff and patient education, ready access to care for patients, good communication among providers, and judicious use of clinical and biochemical monitoring. During treatment of latent TB infection (LTBI) alanine aminotransferase (ALT) monitoring is recommended for those who chronically consume alcohol, take concomitant hepatotoxic drugs, have viral hepatitis or other preexisting liver disease or abnormal baseline ALT, have experienced prior isoniazid hepatitis, are pregnant or are within 3 months postpartum. During treatment of TB disease, in addition to these individuals, patients with HIV infection should have ALT monitoring. Some experts recommend biochemical monitoring for those older than 35 years. Treatment should be interrupted and, generally, a modified or alternative regimen used for those with ALT elevation more than three times the upper limit of normal (ULN) in the presence of hepatitis symptoms and/or jaundice, or five times the ULN in the absence of symptoms. Priorities for future studies to develop safer treatments for LTBI and for TB disease are presented.

A simple approach to noninvasively identifying significant fibrosis in chronic hepatitis C patients in clinical practice

BACKGROUND

Identification of the presence of significant fibrosis is an important part of the diagnostic work-up of patients with chronic hepatitis C (CHC).

AIM

To evaluate the performance of the aspartate to alanine aminotransferase ratio (AST/ALT ratio) and platelet count in reducing the number of liver biopsies and diagnosing the presence/absence of significant fibrosis in a large cohort of patients with CHC seen at 2 tertiary referral centers.

METHODS

Liver biopsies of 409 patients with CHC were evaluated. Staging was carried out by means of the Ishak and METAVIR scores in the Italian and US series, respectively. Prevalence of significant fibrosis was 43%. Receiver operating characteristic curves were used to identify AST/ALT ratio and platelet count cutoffs with the highest accuracy for the diagnosis of significant fibrosis. These cutoffs were used to devise a diagnostic algorithm for reducing the number of liver biopsies and diagnosing/ruling out significant fibrosis.

RESULTS

AST/ALT ratios increased and platelet counts decreased as liver fibrosis worsened. Both AST/ALT ratio (c-index=0.747) and platelet count (c-index=0.733) had high accuracy for the diagnosis of significant fibrosis. The use of AST/ALT ratio and platelet count cutoffs in a diagnostic algorithm would have avoided liver biopsy in 68.9% of the patients and would have correctly identified the absence/presence of significant fibrosis in 80.5% of these cases.

CONCLUSIONS

In clinical practice, the use of simple, reproducible, and inexpensive parameters such as the AST/ALT ratio and platelet count can reduce the need for liver biopsy in a substantial proportion of patients with CHC.

The presence of anti-mitochondrial antibodies in Chinese patients with liver involvement in systemic lupus erythematosus

Sixty-six hospitalized patients with systemic lupus erythematosus (SLE) were enrolled into this study. The test for anti-mitochondrial antibodies (AMAs) was performed and biochemical parameters were determined. AMAs were detected in 15 of the 66 patients with SLE. Meanwhile, we compared enzymatic levels in AMA-positive and -negative patients and found that serum aminotransferase levels were significantly higher in AMA-positive patients than in AMA-negative individuals. Furthermore, we found a positive correlation between serum AMA titration and serum aminotransferase levels. This study suggests that AMAs might contribute to the elevation of aminotransferases. Although much remains to be learned about the pathogenesis of autoimmune liver disease associated with AMAs, this report might provide greater insight into the metabolic mechanisms of AMAs in AMA-positive patients.

Increased serum aminotransferases associated with anti-mitochondrial antibodies in systemic lupus erythematosus patients with autoimmune liver disease

BACKGROUND

Serum aminotransferase activities are increased in many liver diseases, but the causes for the elevation might be difficult to determine. Whether the elevation of aminotransferases correlates with anti-mitochondrial antibodies (AMA) in systemic lupus erythematosus (SLE) patients with autoimmune liver disease deserves further consideration.

METHODS

A meticulous review was done in a large SLE cohort searching for laboratory features of the presence of AMA. Forty-eight hospitalized SLE patients with AMA and 60 randomly selected SLE patients without AMA as a matched case control were enrolled into the retrospective study. Laboratory data were collected, analyzed and compared in SLE patients with and without AMA.

RESULTS

Serum activities of aminotransferases were significantly increased in the 48 SLE patients with AMA compared with the 60 subjects without AMA. Meanwhile, we found a positive correlation between serum AMA titers and serum aminotransferase activities.

CONCLUSION

Although much remains to be learned about the pathogenesis of autoimmune liver disease associated with AMA, it is possible to suggest that AMA might contribute to the elevation of aminotransferases in SLE patients with the progressive disease.

Predominance of released mitochondrial enzymes by partial hepatectomy-induced rat regenerating liver is controlled by hemodynamic changes and not related to mitochondrial damage

OBJECTIVE

Serum activities of assumed organ-specific enzymes are useful protein markers in the diagnosis of necrotic liver diseases. However, after partial hepatectomy (PH) in rats, remaining hepatocytes proliferate to restore the lost liver mass, even when there is a drastic but selective elevation of serum enzyme activities. The aim of the present study was to elucidate the underlying mechanisms involved in this PH-induced enhancement of enzyme release.

MATERIAL AND METHODS

Routine spectrophotometric methods were used to measure nine "marker" enzyme activities in sera, in effluents from isolated perfused livers, as well as in the incubation media used for liver slices and isolated cells from either sham-operated or 70%-PH rats.

RESULTS

PH induced a drastic increase in serum activities of liver enzymes, predominantly of mitochondrial localization. In the control and 70%-PH groups, liver enzymes were differentially released by varying in vitro flow rate/liver mass ratio, using livers perfused at variable flow rates. This event was reversible and not associated with liver structural or functional alterations, but was dependent on the flow-bearing physical forces and independent of production of extra-hepatic factors. Liver slices and isolated cells were used to identify additional flow-independent enzyme release. The 70%-PH-induced drastic release of specific enzymes (predominantly those from mitochondria) could be mimicked in control livers by changing the hepatic blood flow/mass ratio, and closely resembled urea production by these livers.

CONCLUSIONS

PH-induced effects were not associated with liver necrosis or mitochondrial dysfunction and evidenced previously unrecognized mechanisms controlling the rate of enzyme release into the bloodstream, which might have clear clinical implications.

Intermethod calibration of alanine aminotransferase (ALT) and γ-glutamyltransferase (GGT) results: application to Fibrotest® and Actitest® scores

Two multi-component scores (Fibrotest

Proliferative effect of the aqueous extract of Hyptis pectinata on liver regeneration after partial hepatectomy in rats

PURPOSE: This study was carried out to assess the effects of the aqueous extract of Hyptis pectinata leaves on liver regeneration and on serum enzymes (AST, ALT and gamma-GT) after 67% partial hepatectomy in rats. METHODS: AST, ALT and gamma-GT, were determined by conventional procedures using a spectrophotometer (Model E2250-CELM). Liver regeneration was evaluated by immunohistochemical staining for proliferating cell nuclear antigen (PCNA). RESULTS:Oral pretreatment during 4 days at 100 mg/kg increased liver regeneration index. At 200 mg/kg, AST level was statistically decreased in comparison to the group submited to distilled water administration. The other enzymes assessed disclosed no difference when all groups were compared. CONCLUSION: The present study shows that the aqueous extract of Hyptis pectinata leaves contains some biological active principles that stimulate liver regeneration at 100 mg/kg and cause slight hepatic protection at 200 mg/kg.

Electrochemical determination of γ-glutamyl transpeptidase activity and its application to a miniaturized analysis system

A novel method to determine the activity of gamma-glutamyl transpeptidase (gamma-GTP) was developed. gamma-l-glutamyl-l-glutamate and glycyl-glycine were used as the substrates for gamma-GTP. l-glutamate produced by the enzymatic reaction was measured with an amperometric l-glutamate sensor. Following the mixing of the substrate solution and a sample solution, the current generated on the l-glutamate sensor continued to increase at a constant rate. The method was used to construct a miniaturized analysis system for the determination of gamma-GTP activity. The system consisted of the l-glutamate sensor formed on a glass substrate and a polydimethylsiloxane (PDMS) flow channel. Since the l-glutamate concentration in the solution increased as the solution was mobilized through the flow channel, a constant current increase was observed. The relation between the slope of the response curve and the activity of gamma-GTP was linear between 35 U l(-1) and 659 U l(-1). The rate analysis in the micro flow channel minimized the influence of interferents. The reproducibility of the output of the micro system was found to be good with a relative standard deviation (R.S.D.) of 5.6% at 659 U l(-1). The activities of gamma-GTP in human serum samples were also determined and compared with values obtained with a conventional spectroscopic method. The values obtained by the two methods were consistent with a correlation coefficient of 0.953.

Liver fatty acid-binding protein: an early and sensitive plasma marker of hepatocellular damage and a reliable predictor of graft viability after liver transplantation from non-heart-beating donors

OBJECTIVE

Liver fatty acid-binding protein (L-FABP) is a small protein (15 kD) involved in the intracellular transport of long-chain fatty acids in the liver. The L-FABP is regarded as a sensitive marker for liver cell damage. In a pig model for liver transplantation (LTx) from non-heart-beating donors (NHBD), we evaluated plasma changes of L-FABP early after reperfusion of grafts exposed to increasing periods of warm ischemia (WI).

METHODS

Porcine livers were procured after 0, 15, 30, 45, and 60 minutes' WI. After 4 hours' cold ischemia (CI), LTx was performed. Primary graft nonfunction (PNF) and day 4 survival were recorded. Plasma samples were collected prior to and 15, 60, and 180 minutes after graft reperfusion for determination of L-FABP and aspartate transaminase (AST).

RESULTS

Early after reperfusion, levels of L-FABP correlated well with the duration of WI. The PNF developed in 100% of animals after 60 minutes of WI, 50% after 30, and 45 minutes' WI, and was absent after no WI and 15 minutes of WI. Day 4 survival was 100% in 0 minutes' WI, 83% in 15 minutes' WI, 50% in 30 and 45 minutes' WI, and 0% in 60 minutes of WI.

CONCLUSIONS

Plasma levels of L-FABP correlated well with WI and concomitant hepatocellular damage in LTx from NHBD. Monitoring of posttransplant L-FABP plasma levels is a valuable new tool to quantify early the extent of parenchymal cell damage of NHBD livers and to predict their viability and function.

Serum albumin in Down Syndrome with and without Alzheimer's Disease

AIMS

We investigated whether or not serum albumin concentrations in Down Syndrome were lower than those of a cohort of similarly moderately- to-severely-disabled institutionalised patients without Down Syndrome and, if so, whether or not this could be ascribed to the presence of liver disease. We also sought to determine the influence of Down Syndrome, age, liver disease, and Alzheimer's Disease on the serum albumin concentration.

METHODS

We performed a cross-sectional study on 205 institutionalised patients with Learning Disabilities (47 with Down Syndrome, 158 without), and used multiple regression techniques to determine the relative effects of age, liver disease, and the presence or absence of Down Syndrome on the serum albumin concentration. Among Down Syndrome patients. We also sought to determine the association between serum albumin concentration and the presence of Dementia of Alzheimer's Type.

RESULTS

Down Syndrome patients had lower serum albumin levels than non-Down Syndrome patients. Serum albumin concentrations declined with age at a similar rate in both groups, such that the effect on serum albumin of having Down Syndrome was equivalent to an additional 44 years of age. The serum albumin concentration in Down Syndrome patients with Alzheimer's Disease was greater than that in Down Syndrome patients without Alzheimer's Disease.

CONCLUSIONS

Down Syndrome is associated with a low serum albumin concentration, independently of the presence of liver disease. The advent of Alzheimer's Disease in Down Syndrome is not associated with a further fall, and may be associated with a rise, in serum albumin concentrations.

In vivo effects of chronic contamination with depleted uranium on CYP3A and associated nuclear receptors PXR and CAR in the rat

In addition to its natural presence at high concentrations in some areas, uranium has several civilian and military applications that could cause contamination of human populations, mainly through chronic ingestion. Reports describe the accumulation of this radionuclide in some organs (including the bone, kidney, and liver) after acute or chronic contamination and show that it produces chemical or radiological toxicity or both. The literature is essentially devoid of information about uranium-related cellular and molecular effects on metabolic functions such as xenobiotic detoxification. The present study thus evaluated rats chronically exposed to depleted uranium in their drinking water (1mg/(ratday)) for 9 months. Our specific aim was to evaluate the hepatic and extrahepatic mRNA expression of CYP3A1/A2, CYP2B1, and CYP1A1 as well as of the nuclear receptors PXR, CAR, and RXR in these rats. CYP3A1 mRNA expression was significantly higher in the brain (200%), liver (300%), and kidneys (900%) of exposed rats compared with control rats, while CYP3A2 mRNA levels were higher in the lungs (300%) and liver (200%), and CYP2B1 mRNA expression in the kidneys (300%). Expression of CYP1A1 mRNA did not change significantly during this study. PXR mRNA levels increased in the brain (200%), liver (150%), and kidneys (200%). Uranium caused CAR mRNA expression in the lungs to double. Expression of RXR mRNA did not change significantly in the course of this study, nor did the hepatic activity of CYP2C, CYP3A, CYP2A, or CYP2B. Uranium probably affects the expression of drug-metabolizing CYP enzymes through the PXR and CAR nuclear receptors. These results suggest that the stimulating effect of uranium on these enzymes might lead to hepatic or extrahepatic toxicity (or both) during drug treatment and then affect the entire organism.

Human monocyte-derived neohepatocytes: a promising alternative to primary human hepatocytes for autologous cell therapy

BACKGROUND

There is growing interest in new therapeutic options for the treatment of end-stage liver diseases. In addition to mechanical devices supporting liver function, such as bioreactors, the transplantation of hepatocyte-like cells derived from (adult) stem cells offer great perspectives. We have generated hepatocyte-like (NeoHep) cells from terminally differentiated peripheral blood monocytes and, in this study, have evaluated these cells as a possible tool for autologous cell therapy.

METHODS

Peripheral blood monocytes were cultured under conditions that promote hepatocyte-like differentiation and were characterized for hepatocyte marker expression by reverse-transcriptase polymerase chain reaction, immunohistochemistry, and immunoblotting and for specific secretory and metabolic functions with the appropriate biochemical assays.

RESULTS

NeoHep cells resembled primary human hepatocytes with respect to morphology, expression of hepatocyte markers (albumin, cytochrome P450 isoenzymes, asialoglycoprotein receptor, coagulation factor VII), various secretory and metabolic functions (albumin secretion, urea production, lactate formation, and lactate dehydrogenase and aspartate transaminase release), and drug detoxification activities (phase I metabolization of ethoxycoumarin into 7OH-coumarin after stimulation with 3-methylcholanthren, induction of CYP3A4 activity, and phase II metabolization through UDP-glucuronidation of 4-methyl-umbelliferone).

CONCLUSIONS

These data convincingly show that NeoHep cells display a phenotype and specific in vitro metabolic functions that are quantitatively and qualitatively comparable in part with those of primary human hepatocytes. These cells could thus be clinically applied in an autologous setting for the treatment of end-stage liver diseases or for improving liver function in patients who have undergone critical liver-mass resection.

Evaluation of the COBAS Hepatitis C Virus (HCV) TaqMan analyte-specific reagent assay and comparison to the COBAS Amplicor HCV Monitor V2.0 and Versant HCV bDNA 3.0 assays

Performance characteristics of the COBAS hepatitis C virus (HCV) TaqMan analyte-specific reagent (TM-ASR) assay using the QIAGEN BioRobot 9604 for RNA extraction were evaluated and compared to the COBAS Amplicor HCV Monitor V2.0 (Amplicor) and Versant HCV bDNA 3.0 (Versant) assays using clinical samples. Calibration of TM-ASR using Armored RNA allowed determination of the distribution of HCV RNA in clinical samples, using 22,399 clinical samples. Limit of detection, linearity, and inter- and intraassay assay precision were determined for the TM-ASR assay using multiple clinical specimen panels across multiple determinations. Genotype specificity for the TM-ASR assay was determined using samples with different HCV RNA genotypes evaluated and compared against predetermined results. Contamination control of the TM-ASR assay was evaluated using pools of HCV RNA-positive and -negative samples tested in a checkerboard pattern over 12 runs of 96 samples. Correlation of the TM-ASR, Amplicor, and Versant assays was determined using 100 paired clinical samples and Deming regression analysis. The TM-ASR performed well with respect to linearity, precision, and contamination control. The correlation between TM-ASR and the Amplicor and Versant assays was poor, with large differences between assay results for individual samples. Calibration of the TM-ASR assay with Armored RNA allowed for a wide dynamic range and description of the distribution of HCV RNA in clinical samples.

Enhancement of liver regeneration by the association of Hyptis pectinata with laser therapy

Since new molecules that normally would accelerate regeneration can also be potentialized by light, the use of new substances combined with laser therapy seems to be a natural type of experiment. Therefore, the purpose of this study was to assess the effects of Hyptis pectinata leaves on liver regeneration after partial hepatectomy (PH) associated with laser therapy. Twenty-four rats were divided into four groups--PH(control), PHL (laser therapy), PH200 (200 mg/kg of Hyptispectinata), and PHL200 (200 mg/kg of the plant and laser)--which were submitted to 67% hepatectomy. Laser treatment consisted of focusing the light on the remaining liver after hepatectomy. The data analyzed were serum levels of aminotransferases, liver regeneration, and mitochondrial function. Group PH200 showed a statistically significant decrease in AST levels, and PHL200 disclosed an augmentation in ALT levels. The liver regeneration index was significantly increased in group PHL200. Concerning liver mitochondrial respiratory assay, groups PH200 and PHL200 showed lower state 3 levels than groups PH and PHL. Group PHL showed an increase in state 4 levels and a reduction in membrane potential and RCR. The present study shows that the association of the aqueous extract of Hyptis pectinata leaves at 200 mg/kg with intraoperative laser therapy can stimulate liver regeneration and cause a reduction in liver mitochondrial respiratory function without altering its phosphorylative activity.

Cost effectiveness of testing strategies for chronic hepatitis C

OBJECTIVE

This paper compares nine strategies for determining hepatitis C antibody and viral status. They combine two tests for antibodies (enzyme immunoassays (EIA), recombinant immunoblot assays (RIBA)) and one for viremia (reverse transcription polymerase chain reaction (PCR)). Using optical density to divide EIA results into three categories (high positive, low positive, negative) was also considered.

METHODS

Decision analysis compared strategies on cost as well as sensitivity and specificity with regard to antibody and viral status. Parameters in the decision tree included antibody prevalence, proportion viremic, sensitivity, specificity, and cost of individual tests.

RESULTS

The two best strategies are EIA followed by PCR (EIA-->PCR); and EIA with three levels of optical density (EIA-OD), followed by RIBA for EIA-OD low positives, and then PCR for all positives (EIA-OD-->RIBA-->PCR). EIA-->PCR has equal viral sensitivity, slightly lower cost, slightly higher antibody sensitivity, but lower antibody specificity compared to EIA-OD-->RIBA-->PCR. The cost per false antibody positive avoided using EIA-OD-->RIBA-->PCR rather than EIA-->PCR is $36 when prevalence is 5%, and $193 when prevalence is 50%. Using EIA-OD-->RIBA-->PCR rather than EIA-->PCR results in 112 false antibody positives avoided for every true antibody positive missed when prevalence is 5%; this ratio is 18:1 when prevalence is 25%; and 6:1 when prevalence is 50%.

CONCLUSIONS

EIA-OD-->RIBA-->PCR is the best choice when prevalence in the tested group is below 20%. As prevalence increases, the choice of EIA-OD-->RIBA-->PCR versus EIA-->PCR will depend on the relative importance of avoiding false antibody positives versus missing true antibody positives. Our analysis makes explicit the magnitude of this trade-off.

Fatty acid-binding proteins as plasma markers of tissue injury

BACKGROUND

One of the novel and promising plasma markers for detection of tissue injury is the family of 15 kDa cytoplasmic fatty acid-binding proteins of which various tissue-specific types occur.

AIMS AND OBJECTIVES

The present status of heart-type fatty acid-binding protein (H-FABP) as a diagnostic and prognostic marker for acute and chronic cardiac injury, as well as the preliminary diagnostic use of other types of FABP for detecting injury in other organs, is reviewed.

METHODS

This review is based on an overview of the literature on clinical diagnostics of various forms of organ injury, and uses additional literature on physiological aspects relevant for the interpretation of plasma marker concentrations.

RESULTS

H-FABP not only proves to be an excellent early marker for cardiac injury in acute coronary syndromes, but also allows detection of minor myocardial injury in heart failure and unstable angina. Preliminary results indicate that sensitivity, rule-out power and prognostic value of H-FABP in cardiac injury surpass the performance of the standard early marker myoglobin. The liver only contains liver-type FABP (L-FABP), but co-expression of H-FABP and L-FABP occurs in the kidney. Similarly, intestinal-type FABP (I-FABP) and L-FABP are found in intestines, and brain-type FABP (B-FABP) and H-FABP occur in the brain. Preliminary but promising applications of these proteins have been demonstrated for liver rejection, viability selection of kidneys from non-heart-beating donors (NHBD), inflammatory and ischemic bowel disease, traumatic brain injury and in the prevention of muscle injury in trained athletes.

CONCLUSIONS

Further study of the diagnostic and prognostic use of various FABP types is warranted, but their clinical application will require further commercialization of automated and rapid assays.

Effects of beta-carotene on cell viability and antioxidant status of hepatocytes from chronically ethanol-fed rats

The purpose of the present study was to evaluate the effects of beta-carotene on the cell viability and antioxidant status of hepatocytes from chronically ethanol-fed rats. Rats in the ethanol group were given an ethanol-containing liquid diet that provided 36 % of total energy as ethanol, while rats in the control group were fed an isoenergetic diet without ethanol. After 4 weeks, hepatocytes were taken out and cultured for 24 h. Hepatocytes from the rats in the control and ethanol groups were cultured in medium without (HC, HE) or with beta-carotene (HC+B, HE+B). The results showed that lactate dehydrogenase leakage was significantly increased in the HE compared with that in the HC group. However, lactate dehydrogenase leakage of the HE+B group was similar to that of the HC group. When compared with the HC group, activities of glutathione peroxidase and catalase in the HE group were significantly decreased by 54 and 31 %, respectively. Catalase activity in the HE+B group was significantly increased by 61 % compared with that in the HE group. However, activities of glutathione reductase and superoxide dismutase showed no difference among the groups. The level of glutathione in the HC+B and HE+B groups was significantly increased to 155 and 143 % compared with those in the HC and HE groups, respectively. The concentration of lipid peroxides showed no difference among the groups. The present results demonstrate that beta-carotene improved the cell viability of hepatocytes, and increased catalase activities and glutathione levels in hepatocytes from chronically ethanol-fed rats.

Nuclear import of proinflammatory transcription factors is required for massive liver apoptosis induced by bacterial lipopolysaccharide

Stimulation of macrophages with lipopolysaccharide (LPS) leads to the production of cytokines that elicit massive liver apoptosis. We investigated the in vivo role of stress-responsive transcription factors (SRTFs) in this process focusing on the precipitating events that are sensitive to a cell-permeant peptide inhibitor of SRTF nuclear import (cSN50). In the absence of cSN50, mice challenged with LPS displayed very early bursts of inflammatory cytokines/chemokines, tumor necrosis factor alpha (1 h), interleukin 6 (2 h), interleukin 1 beta (2 h), and monocyte chemoattractant protein 1 (2 h). Activation of both initiator caspases 8 and 9 and effector caspase 3 was noted 4 h later when full-blown DNA fragmentation and chromatin condensation were first observed (6 h). At this time an increase of pro-apoptotic Bax gene expression was observed. It was preceded by a decrease of anti-apoptotic Bcl2 and BclX(L) gene transcripts. Massive apoptosis was accompanied by microvascular injury manifested by hemorrhagic necrosis and a precipitous drop in blood platelets observed at 6 h. An increase in fibrinogen/fibrin degradation products and a rise in plasminogen activator inhibitor 1 occurred between 4 and 6 h. Inhibition of SRTFs nuclear import with the cSN50 peptide abrogated all these changes and increased survival from 7 to 71%. Thus, the nuclear import of SRTFs induced by LPS is a prerequisite for activation of the genetic program that governs cytokines/chemokines production, liver apoptosis, microvascular injury, and death. These results should facilitate the rational design of drugs that protect the liver from inflammation-driven apoptosis.

Activation of serum aminotransferases by pyridoxal-5′-phosphate in epileptic patients treated with anticonvulsant drugs

OBJECTIVES

Significant decreases in the serum concentration of pyridoxal-5' -phosphate (PLP) have been described in epileptic patients treated with anticonvulsant drugs. This would be expected to lead to a decrease in the sensitivity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) for the detection of hepatocellular damage in these patients if optimized methods with coenzyme supplementation are not used. The aim of our study was to evaluate this hypothesis.

DESIGN AND METHODS

The serum activities of AST and ALT (with and without the addition of PLP) were determined in a group of 90 adult epileptic patients (56 male, 34 female) undergoing chronic treatment polytherapy with phenobarbital, phenytoin, carbamazepine, and valproic acid. As a control group, 49 clinically healthy individuals were studied with a similar distribution for age and sex.

RESULTS

Supplementation with PLP produced an activation of AST and ALT in both the control and patient groups with a highly significant correlation between the enzyme activities with and without the addition of PLP (r > or = 0.956, P < 0.001). The differences between the control and patient groups for the PLP activation of both aminotransferases were not clinically significant. The increases in AST (9%) and ALT (28%) in the patient group compared to the control group were lower than those found for alcohol dehydrogenase (ADH, 82%) and alpha-glutathione S-transferase (alphaGST, 76%).

CONCLUSIONS

It does not appear that in the epileptic patients studied the in vitro addition of PLP increased the diagnostic sensitivity of AST and ALT for hepatocellular injury. The lower responses of both aminotransferases to the action of anticonvulsant drugs in relation to other cytosolic enzymes may be due to the preferred periportal localization of AST and ALT in the hepatic lobe.

The influence of diet upon liver function tests and serum lipids in healthy male volunteers resident in a Phase I unit

AIM

To investigate the effect of diet upon liver function tests and serum lipids within the restricted environment of a Phase I unit.

METHODS

An open randomized three-way crossover study was designed with subjects consuming three types of diet. The diets comprised, a balanced normal calorie diet, a high-carbohydrate high-calorie diet and a high-fat high-calorie diet. Each diet was consumed in a randomized sequence over 8 days with a recovery period of 14 days between periods. The blood concentrations of various laboratory parameters were measured at intervals throughout each dietary period and during the recovery periods.

RESULTS

Blood transaminase activity and triglyceride concentrations increased significantly whilst subjects consumed a high-carbohydrate high-calorie diet but not when fed either a high-fat high-calorie diet or a balanced normal calorie diet.

CONCLUSIONS

The rises in transaminases and triglycerides were caused by the carbohydrate content of the diet rather than its calorific value. Sucrose rather than starch was the carbohydrate which caused the rise in transaminases and triglycerides. The importance of controlling diet in Phase I studies is stressed.

Hepatitis B viremia is associated with increased risk of hepatocellular carcinoma in chronic carriers

The role of quantitative viral load in development of hepatocellular carcinoma (HCC) among chronic hepatitis B virus (HBV) carriers was evaluated using real-time PCR (TaqMan PCR), a highly sensitive method for quantitative detection of HBV DNA. Serum samples collected at study entry from HCC cases and matched controls were chosen separately from ongoing prospective cohort studies in Senegal, West Africa, and Haimen City, China. For 14 HCC cases and 28 controls from Senegal, the relative risk (RR, 95% CI) of HCC was 15.6 (2.0-124.3) for those positive by the TaqMan PCR assay. Average length of follow-up (study entry to death from HCC) among cases was 2.8 (+/-1.6) years. The paired median difference between cases and controls was 3.8 x 10(4) virions/ml, with cases higher (P = 0.09). In order to clarify the relationship with lower-titer viremia, we selected 55 cases and 55 matched controls from the Chinese cohort all negative for serum HBV DNA by conventional dot blot hybridization. In this group, the RR associated with HBV DNA positivity by TaqMan PCR was 3.1 (1.1-9.2), with an average duration of follow-up of 3.3 (+/-2.1) years. The median difference in quantitative viremia between cases and controls was 6.0 x 10(4) virions/ml, with cases higher (P < 0.0001). Increased risk appeared to be confined to subjects with viral loads >2.3 x 10(4) virions/ml. In conclusion, HBV viremia, except perhaps at extremely low levels, is associated with increased risk for HCC in prospective studies of chronic carriers in two disparate populations.

Low-positive anti-hepatitis C virus enzyme immunoassay results: an important predictor of low likelihood of hepatitis C infection

BACKGROUND

Tests for hepatitis C antibodies (anti-HCV enzyme immunoassays) are usually described as positive or negative. Several studies, mainly in blood donors, have found that specimens with low signal/cutoff (S/C) ratios are commonly negative when tested with a recombinant immunoblot assay (RIBA) or for HCV RNA.

METHODS

We retrospectively reviewed 17 418 consecutive anti-HCV results from a screening program for high-risk veterans; 2986 (17.1%) samples were anti-HCV-positive, and 490 (16.4%) had S/C ratios <or=3.7 (low positive). Additional tests were performed in 1814 anti-HCV-positive individuals.

RESULTS

RIBA was performed in 263 patients with low-positive anti-HCV; results were negative in 86%, indeterminate in 12%, and positive in 2%. Only 16 of 140 individuals (11%) with low-positive anti-HCV values were HCV RNA-positive, whereas HCV RNA was positive in 90% of 1435 individuals with high-positive anti-HCV values (P <0.0001). Compared with those with high-positive anti-HCV, individuals with low-positive anti-HCV values were older (P <0.0001) and were less likely to have risk factors for HCV (P <0.0001 for most), multiple increased alanine aminotransferase (ALT) activity values (30% vs 81%; P <0.0001), or positive anti-hepatitis B core antigen (19% vs 59%; P <0.0002). Among 634 individuals with high anti-HCV titers and multiple increased ALT activity values, 95% were HCV RNA-positive.

CONCLUSIONS

The S/C ratio is important even in high-risk individuals; laboratories should report the S/C ratio along with anti-HCV EIA results and perform supplemental RIBA testing in those with low-positive values to avoid reporting false-positive results.

Liver function: test selection and interpretation of results

Liver function tests are used to detect, specifically diagnose, and estimate the severity of hepatic disease. Effective interpretation of the hepatic function panel requires knowledge of underlying pathophysiology and the characteristics of panel tests. This article includes a working classification of liver disease, a list of liver functions with the tests appropriate to each function, and a guide to panel interpretation and further laboratory investigation.

13C-aminopyrine breath test to evaluate severity of disease in patients with chronic hepatitis C virus infection

BACKGROUND

There are few data on the use of the 13C-aminopyrine breath test to evaluate the severity of disease in patients with hepatitis C virus-related chronic liver disease, although these patients represent one of the most important problems in clinical hepatology.

AIMS

To compare 13C-aminopyrine breath test results of patients with hepatitis C virus-related chronic hepatitis and Child-Pugh class A cirrhosis with those of normal subjects, and to evaluate different methods of expressing 13C-aminopyrine breath test results.

METHODS

Twenty-four patients with hepatitis C virus-related chronic hepatitis and 17 patients with Child-Pugh class A cirrhosis underwent 13C-aminopyrine breath test. Breath samples were collected every 30 min up to 2 h after 13C-aminopyrine administration. 13C-Aminopyrine breath test results were expressed as a percentage of the administered dose of 13C recovered per hour (% dose/h) and the cumulative percentage of administered dose of 13C recovered over time (% dose cum). Nineteen healthy subjects served as controls. Patients with hepatitis C virus-related chronic hepatitis were divided into subgroups on the basis of histological staging and grading.

RESULTS

The 13C-aminopyrine breath test result (% dose/h) at 30 min was significantly different among the three subgroups of subjects (normal subjects, 11.5 +/- 3.5; chronic hepatitis patients, 8.1 +/- 4.1; cirrhosis patients, 5.0 +/- 3.1; P < 0.0005). Moreover, the differences between chronic hepatitis and cirrhosis patients were statistically significant (P < 0.03). The fibrosis score showed a significant inverse correlation with the 13C-aminopyrine breath test result (% dose/h) at 30 min (rs=- 0.409, P=0.05). The 13C-aminopyrine breath test result (% dose/h) at 30 min also allowed normal subjects and chronic hepatitis patients with low (< or = 2) or high (> 2) fibrosis scores to be distinguished. The 13C-aminopyrine breath test results (% dose cum) at 30, 60 and 90 min allowed discrimination between normal subjects and chronic hepatitis and cirrhosis patients. The 13C-aminopyrine breath test result (% dose cum) was also able to distinguish between normal subjects and chronic hepatitis patients with high but not low fibrosis scores. Both 13C-aminopyrine breath test results (% dose/h and % dose cum) at 120 min allowed the differentiation between normal subjects and chronic hepatitis patients with high (> or = 6) necro-inflammatory activity.

CONCLUSIONS

In patients with hepatitis C virus-related chronic liver disease, the 13C-aminopyrine breath test proved to be safe and easy to perform, and was able to evaluate different degrees of liver function impairment which were partly correlated to clinical and histological evaluation. In future studies, 13C-aminopyrine breath test results should be expressed in a standardized fashion to permit comparison.

Laboratory diagnosis of viral hepatitis

Both serologic and molecular assays are useful in the diagnosis of viral hepatitis. They may detect early infections before other signs of disease appear, differentiate acute from chronic infections, and detect persistence of viremia or verify development of immunity. Molecular assays may also be used to monitor responses to antiviral therapy, and in the future, be a primary method to screen blood and organ donors (NAT). EIA serologies are used to diagnose acute HAV infections or establish immune status. Similar immunoassays are used to detect HBV infections, verify persistence of antigenemia and degree of infectivity, and indicate immunity (including the response to vaccination). HBV molecular assays can shorten the diagnostic window period, verify persistence of viremia, including monitoring response to antiviral therapy, and be useful in NAT screening of donors. Molecular assays play a major role in HCV diagnosis where serologic tests can document past or present infection but cannot differentiate one from the other. A variety of molecular tests can be used as sensitive (and early) detectors of viremia (and serve as confirmatory tests for positive serologies and as donor NAT methods), document its persistence as an indicator of chronic infection, and monitor responses to antiviral therapy. Both qualitative and quantitative molecular assays are available, and their efficient use requires familiarity with the sensitivity and dynamic ranges of each method.

Overview of Evidence-based Medicine: Challenges for Evidence-based Laboratory Medicine

Evidence-based medicine (EBM) has been driven by the need to cope with information overload, by cost-control, and by a public impatient for the best in diagnostics and treatment. Clinical guidelines, care maps, and outcome measures are quality improvement tools for the appropriateness, efficiency, and effectiveness of health services. Although they are imperfect, their value increases with the quality of the evidence they incorporate. Laboratory professionals must direct more effort to demonstrating the impact of laboratory tests on a greater variety of clinical outcomes. Laboratory and clinical practitioners must be familiar with many of the accessible electronic and paper tools for searching for evidence. Detailed statistical and epidemiologic knowledge is not essential, but critical appraisal skills and a competent understanding of the strengths and weaknesses of systematic review and metaanalysis are necessary. Overemphasis on complexity and failure to recognize time limitations are major barriers to translating EBM into everyday practice. Emphasizing and practicing the role of the laboratory professional as a skilled clinical consultant strongly grounded in evidence as well, in addition to better integration of laboratory and clinical information and improved laboratory reports will overcome most barriers. There is a poverty of good, primary studies of test evaluations. Institution of more consistent standards for the design and reporting of studies on diagnostic accuracy should improve the situation. If nothing else, systematic reviews have demonstrated the need for more good-quality primary research in laboratory medicine.

Diagnosis and monitoring of hepatic injury. II. Recommendations for use of laboratory tests in screening, diagnosis, and monitoring

Purpose: To review information on the use of laboratory tests in screening, diagnosis, and monitoring of acute and chronic hepatic injury.

Data Sources and Study Selection: A MEDLINE search was performed for key words related to hepatic diseases, including acute hepatitis, chronic hepatitis, alcoholic hepatitis, cirrhosis, hepatocellular carcinoma, and etiologic causes. Abstracts were reviewed, and articles discussing use of laboratory tests selected for review. Additional articles were selected from the references.

Guideline Preparation and Review: Drafts of the guidelines were posted on the Internet, presented at the AACC Annual Meeting in 1999, and reviewed by experts. Areas requiring further amplification or literature review were identified for further analysis. Specific recommendations were made based on analysis of published data and evaluated for strength of evidence and clinical impact.

Recommendations: Although many specific recommendations are made in the guidelines, only some summary recommendations are listed here. In acute hepatic injury, prothrombin time and, to a lesser extent, total bilirubin are the best indicators of severity of disease. Although ALT is useful for detecting acute and chronic hepatic injury, it is not related to severity of acute hepatic injury and only weakly related to severity of chronic hepatic injury. Specific tests of viral markers should be the initial differential tests in both acute and chronic hepatic injury; when positive, they are also useful for monitoring recovery from hepatitis B and C.