Elevated Liver Enzymes in Asymptomatic Patients - What Should I Do?

Elevated liver enzymes are a common scenario encountered by physicians in clinical practice. For many physicians, however, evaluation of such a problem in patients presenting with no symptoms can be challenging. Evidence supporting a standardized approach to evaluation is lacking. Although alterations of liver enzymes could be a normal physiological phenomenon in certain cases, it may also reflect potential liver injury in others, necessitating its further assessment and management. In this article, we provide a guide to primary care clinicians to interpret abnormal elevation of liver enzymes in asymptomatic patients using a step-wise algorithm. Adopting a schematic approach that classifies enzyme alterations on the basis of pattern (hepatocellular, cholestatic and isolated hyperbilirubinemia), we review an approach to abnormal alteration of liver enzymes within each section, the most common causes of enzyme alteration, and suggest initial investigations.

Acute acalculous cholecystitis: a review.

Although recognized for more than 150 years, acute acalculous cholecystitis (AAC) remains an elusive diagnosis. This is likely because of the complex clinical setting in which this entity develops, the lack of large prospective controlled trials that evaluate various diagnostic modalities, and thus dependence on a small data base for clinical decision making. AAC most often occurs in critically ill patients, especially related to trauma, surgery, shock, burns, sepsis, total parenteral nutrition, and/or prolonged fasting. Clinically, AAC is difficult to diagnose because the findings of right upper-quadrant pain, fever, leukocytosis, and abnormal liver tests are not specific. AAC is associated with a high mortality, but early diagnosis and intervention can change this. Early diagnosis is the crux of debate surrounding AAC, and it usually rests with imaging modalities. There are no specific criteria to diagnose AAC. Therefore, this review discusses the imaging methods most likely to arrive at an early and accurate diagnosis despite the complexities of the radiologic modalities. A pragmatic approach is vital. A timely diagnosis will depend on a high index of suspicion in the appropriate patient, and the combined results of clinical findings (admittedly nonspecific), plus properly interpreted imaging. Sonogram (often sequential) and hepatic iminodiacetic acid scans are the most reliable modalities for diagnosis. It is generally agreed that cholecystectomy is the definitive therapy for AAC. However, at times a diagnostic/therapeutic drainage via interventional radiology/surgery may be necessary and life-saving, and may be the only treatment needed.

Importance of changes in adipose tissue insulin resistance to histological response during thiazolidinedione treatment of patients with nonalcoholic steatohepatitis.

UNLABELLED: Pioglitazone treatment improves insulin resistance (IR), glucose metabolism, hepatic steatosis, and necroinflammation in patients with nonalcoholic steatohepatitis (NASH). Because abnormal lipid metabolism/elevated plasma free fatty acids (FFAs) are important to the pathophysiology of NASH, we examined the impact of pioglitazone therapy on adipose tissue insulin resistance (Adipo-IR) during the treatment of patients with NASH. To this end, we assessed glucose/lipid metabolism in 47 patients with impaired glucose tolerance/type 2 diabetes mellitus and NASH and 20 nondiabetic controls. All individuals underwent a 75-g oral glucose tolerance test (OGTT) in which we measured glucose tolerance, IR, and suppression of plasma FFAs. We also measured Adipo-IR index (fasting, FFAs x insulin), hepatic fat by magnetic resonance spectroscopy, and liver histology (liver biopsy). Patients were randomized (double-blind) to diet plus pioglitazone (45 mg/day) or placebo for 6 months, and all measurements were repeated. We found that patients with NASH had severe Adipo-IR and low adiponectin levels. Fasting FFAs were increased and their suppression during the OGTT was impaired. Adipo-IR was strongly associated with hepatic fat (r= 0.54) and reduced glucose clearance both fasting (r=0.34) and during the OGTT (r=0.40, all P <0.002). Pioglitazone significantly improved glucose tolerance and glucose clearance, steatosis and necroinflammation (all P<0.01-0.001 versus placebo). Fasting/postprandial plasma FFAs decreased to levels of controls with pioglitazone (P<0.02 versus placebo). Adipo-IR decreased by 47% and correlated with the reduction of hepatic fat (r=0.46, P=0.009) and with the reduction in hepatic necroinflammation (r=0.47, P=0.0007). CONCLUSION: Patients with NASH have severe Adipo-IR independent of the degree of obesity. Amelioration of Adipo-IR by pioglitazone is closely related to histological improvement and plays an important role during treatment of patients with NASH.

Ethanol-mediated DNA damage and PARP-1 apoptotic responses in cultured fetal cortical neurons.

BACKGROUND: Prior studies by many laboratories have illustrated that ethanol can elicit a cascade of caspase-dependent apoptotic events in cultured neurons. Studies in our laboratory have connected this to oxidative stress and effects on fetal cortical neuron glutathione homeostasis. AIMS: The intent of the following studies is to address mechanisms underlying ethanol-associated DNA damage that may be connected to apoptotic death of neurons. METHODS: Cultures of fetal rat cerebral cortical neurons were utilized. Estimates of DNA damage was determined by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and nuclear condensation; Poly(ADP-ribose) polymerase-1 (PARP-1) expression was determined by immunostaining and Western blotting; and occurrence of parylation and AIF translocations were assessed by Western blotting. RESULTS: Ethanol treatment of the neurons generated increases in DNA damage by 4 hours while nuclear condensation was low at the short exposure period but increased markedly by 24 hours. This was temporally related to a marked up-regulation of PARP-1 expression. Activity of PARP-1, as assessed by PolyADP-ribose (PAR) formation, occurred within 15 minutes and peaked by 6 to 8 hours of ethanol treatment. An almost complete translocation of apoptosis inducing factor (AIF) from mitochondria to the nucleus occurred by 24 hours of ethanol treatment (4.0 mg/ml). Ethanol treatment for 4, 12, and 24 hours elicited an increasing caspase-mediated cleavage of PARP-1 to its 24 kDa fragment. CONCLUSIONS: These data illustrate the rapid occurrence of DNA damage following ethanol exposure and that PARP-1 pathways may play a role in the subsequent apoptotic death of these neurons.

Glutathione content as a potential mediator of the vulnerability of cultured fetal cortical neurons to ethanol-induced apoptosis.

Ethanol ingestion during pregnancy elicits damage to the developing brain, some of which appears to result from enhanced apoptotic death of neurons. A consistent characteristic of this phenomenon is a highly differing sensitivity to ethanol within specific neuron populations. One possible explanation for this "selective vulnerability" could be cellular variations in glutathione (GSH) homeostasis. Prior studies have illustrated that ethanol elicits apoptotic death of neurons in the developing brain, that oxidative stress may be an underlying mechanism, and that GSH can be neuroprotective. In the present study, both multiphoton microscopy and flow cytometry demonstrate a striking heterogeneity in GSH content within cortical neuron populations. Ethanol differentially elicits apoptotic death and oxidative stress in these neurons. When neuron GSH content is reduced by treatment with butathione sulfoxamine, the ethanol-mediated enhancement of reactive oxygen species is exacerbated. Sorting of cells into high- and low-GSH populations further exemplifies ethanol-mediated oxidative stress whereby apoptotic indices are preferentially elevated in the low-GSH population. Western blot analysis of the low-GSH subpopulations shows higher ethanol-mediated expression of active caspase 3 and 24-kDa PARP-1 fragments compared with the high-GSH subpopulation. In addition, neuronal content of 4-hydroxynonenal adducts is higher in low-GSH neurons in response to ethanol. These studies suggest that GSH content is an important predictor of neuronal sensitivity to ethanol-mediated oxidative stress and subsequent cell death. The data support the proposition that the differences in proapoptotic responses to ethanol within specific neuron populations reflect a heterogeneity of neuron GSH content.

Pioglitazone treatment increases whole body fat but not total body water in patients with non-alcoholic steatohepatitis.

BACKGROUND/AIMS: Non-Alcoholic Steatohepatitis (NASH) is a chronic liver disease frequently associated with insulin resistance and type 2 diabetes mellitus (T2DM). Pioglitazone reverses the metabolic and histological abnormalities of patients with impaired glucose tolerance or T2DM and NASH, but also leads to weight gain. To understand the nature of weight gain associated with pioglitazone treatment in NASH we analyzed 35 patients who completed tests for determination of whole body fat (WBF) and total body water (TBW). METHODS: Twenty-one patients received pioglitazone and 14 placebo in a double-blind, randomized fashion for a period of 6 months. WBF and TBW were measured before and after treatment using DXA, a water dilution technique and bioimpedance. RESULTS: Pioglitazone increased body weight (from 93.6+/-4.2 to 96.1+/-4.5 kg, p<0.003) and WBF measured with DXA (from 32.9+/-2.1 to 35.4+/-2.5 kg, p<0.002) while no changes were seen with placebo. Total body water was not altered significantly either after pioglitazone (from 45.4+/-2.3 to 45.6+/-2.7 l, p=NS) or placebo. Muscle hydration and extracellular water were unchanged both by pioglitazone and placebo treatments. CONCLUSIONS: Six months of pioglitazone treatment in patients with NASH is associated with weight gain that is attributable to an increase in adipose tissue mass and not to water retention.

A placebo-controlled trial of pioglitazone in subjects with nonalcoholic steatohepatitis.

BACKGROUND: No pharmacologic therapy has conclusively proved to be effective for the treatment of nonalcoholic steatohepatitis, which is characterized by insulin resistance, steatosis, and necroinflammation with or without centrilobular fibrosis. Pioglitazone is a thiazolidinedione that ameliorates insulin resistance and improves glucose and lipid metabolism in type 2 diabetes mellitus. METHODS: We randomly assigned 55 patients with impaired glucose tolerance or type 2 diabetes and liver biopsy-confirmed nonalcoholic steatohepatitis to 6 months of treatment with a hypocaloric diet (a reduction of 500 kcal per day in relation to the calculated daily intake required to maintain body weight) plus pioglitazone (45 mg daily) or a hypocaloric diet plus placebo. Before and after treatment, we assessed hepatic histologic features, hepatic fat content by means of magnetic resonance spectroscopy, and glucose turnover during an oral glucose tolerance test ([14C]glucose given with the oral glucose load and [3H]glucose given by intravenous infusion). RESULTS: Diet plus pioglitazone, as compared with diet plus placebo, improved glycemic control and glucose tolerance (P<0.001), normalized liver aminotransferase levels as it decreased plasma aspartate aminotransferase levels (by 40% vs. 21%, P=0.04), decreased alanine aminotransferase levels (by 58% vs. 34%, P<0.001), decreased hepatic fat content (by 54% vs. 0%, P<0.001), and increased hepatic insulin sensitivity (by 48% vs. 14%, P=0.008). Administration of pioglitazone, as compared with placebo, was associated with improvement in histologic findings with regard to steatosis (P=0.003), ballooning necrosis (P=0.02), and inflammation (P=0.008). Subjects in the pioglitazone group had a greater reduction in necroinflammation (85% vs. 38%, P=0.001), but the reduction in fibrosis did not differ significantly from that in the placebo group (P=0.08). Fatigue and mild lower-extremity edema developed in one subject who received pioglitazone; no other adverse events were observed. CONCLUSIONS: In this proof-of-concept study, the administration of pioglitazone led to metabolic and histologic improvement in subjects with nonalcoholic steatohepatitis. Larger controlled trials of longer duration are warranted to assess the long-term clinical benefit of pioglitazone. (ClinicalTrials.gov number, NCT00227110 [ClinicalTrials.gov] .).

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.

Astrocyte control of fetal cortical neuron glutathione homeostasis: up-regulation by ethanol.

Ethanol increases apoptotic neuron death in the developing brain and at least part of this may be mediated by oxidative stress. In cultured fetal rat cortical neurons, Ethanol increases levels of reactive oxygen species (ROS) within minutes of exposure and reduces total cellular glutathione (GSH) shortly thereafter. This is followed by onset of apoptotic cell death. These responses to Ethanol can be blocked by elevating neuron GSH with N-acetylcysteine or by co-culturing neurons with neonatal cortical astrocytes. We describe here mechanisms by which the astrocyte-neuron gamma-glutamyl cycle is up-regulated by Ethanol, enhancing control of neuron GSH in response to the pro-oxidant, Ethanol. Up to 6 days of Ethanol exposure had no consistent effects on activities of gamma-glutamyl cysteine ligase or glutathione synthetase, and GSH content remained unchanged (p < 0.05). However, glutathione reductase was increased with 1 and 2 day Ethanol exposures, 25% and 39% for 2.5 and 4.0 mg/mL Ethanol by 1 day, and 11% and 16% for 2.5 and 4.0 mg/mL at 2 days, respectively (p < 0.05). A 24 h exposure to 4.0 mg/mL Ethanol increased GSH efflux from astrocyte up to 517% (p < 0.05). Ethanol increased both gamma-glutamyl transpeptidase expression and activity on astrocyte within 24 h of exposure (40%, p = 0.05 with 4.0 mg/mL) and this continued for at least 4 days of Ethanol treatment. Aminopeptidase N activity on neurons increased by 62% and 55% within 1 h of Ethanol for 2.5 and 4.0 mg/mL concentration, respectively (p < 0.05), remaining elevated for 24 h of treatment. Thus, there are at least three key points of the gamma-glutamyl cycle that are up-regulated by Ethanol, the net effect being to enhance neuron GSH homeostasis, thereby protecting neurons from Ethanol-mediated oxidative stress and apoptotic death.

The role of nutritional therapy in alcoholic liver disease.

Alcoholic liver disease (ALD) evolves through various stages, and malnutrition correlates with the severity of ALD. Poor nutrition is caused both by the substitution of calories from alcohol for calories from food and by the malabsorption and maldigestion of various nutrients attributed to ALD. The only established therapy for ALD consists of abstinence from alcohol. Sufficient nutritional repletion coupled with appropriate supportive treatment modalities may be effective in reducing complications associated with ALD---particularly infection. Nutrition makes a significant positive contribution in the treatment of ALD, especially in selected malnourished patients.

Astrocytes protect neurons from ethanol-induced oxidative stress and apoptotic death.

Ethanol induces oxidative stress in cultured fetal rat cortical neurons and this is followed by apoptotic death, which can be prevented by normalization of cell content of reduced glutathione (GSH). Because astrocytes can play a central role in maintenance of neuron GSH homeostasis, the following experiments utilized cocultures of neonatal rat cortical astrocytes and fetal cortical neurons to determine if astrocytes could protect neurons from ethanol-mediated apoptotic death via this mechanism. In cortical neurons cultured in the absence of astrocytes, ethanol (2.5 and 4 mg/ml; 6-, 12-, and 24-hr exposures) decreased trypan blue exclusion and the MTT viability measures by up to 45% (P < 0.05), increased levels of reactive oxygen species (ROS) by up to 81% (P < 0.05), and decreased GSH within 1 hr of treatment by 49 and 51% for 2.5 and 4 mg/ml, respectively (P < 0.05). This was followed by onset of apoptotic cell death as determined by increased Annexin V binding and DNA fragmentation by 12 hr of ethanol exposure. Coculturing neurons with astrocytes prevented GSH depletion by 2.5 mg/ml ethanol, whereas GSH content was increased over controls in neurons exposed to 4 mg/ml ethanol (by up to 341%; P < 0.05). Ethanol generated increases in neuron ROS and apoptosis; decreases in viability were also prevented by coculture. Astrocytes were largely insensitive to ethanol, using the same measures. Only exposure to 4.0 mg/ml ethanol decreased GSH content in astrocytes, concomitant with a 204% increase in GSH efflux (P < 0.05). These studies illustrate that astrocytes can protect neurons from ethanol-mediated apoptotic death and that this may be related to maintenance of neuron GSH.

Ethanol-induced oxidative stress precedes mitochondrially mediated apoptotic death of cultured fetal cortical neurons.

In utero ethanol exposure elicits apoptotic cell death in the fetal brain, and this may be mediated by oxidative stress. Our studies utilize cultured fetal rat cortical neurons and illustrate that ethanol elicits a rapid onset of oxidative stress, which culminates in mitochondrially mediated apoptotic cell death. Cells exposed to ethanol (2.5 mg/ml) remained attached to their polylysine matrix during a 24-hr exposure, but they exhibited distinct signs of oxidative stress, decreased viability, and apoptosis. Confocal microscopy of live cortical neurons pretreated with dichlorodihydrofluorescein diacetate demonstrated an increase in reactive oxygen species (ROS) within 5 min of ethanol exposure. The levels of ROS further increased by 58% within 1 hr (P <.05) and by 82% within 2 hr (P <.05), accompanied by increases of mitochondrial 4-hydroxynonenal (HNE). These early events were followed by decreased trypan blue exclusion of 10% to 32% (P <.05) at the 6- to 24-hr time points, respectively. This culminates in apoptotic death, with increases of Annexin V binding of 43%, 89%, 123%, and 238%, at 2, 6, 12, and 24 hr of ethanol treatment, respectively, as well as DNA fragmentation increases of 50% and 65% by 12 and 24 hr, respectively. Release of cytochrome c by mitochondria increased by 53% at 6 hr of exposure (P <.05), concomitant with activation of caspase 3 (52% at 12 hr, P <.05). Pretreatment with N-acetylcysteine increased cellular glutathione and prevented apoptosis. These studies provide a time line illustrating that oxidative stress and formation of a proapoptotic lipid peroxidation product, HNE, precede a cascade of mitochondrially mediated events in cultured fetal cortical neurons, culminating in apoptotic death. The prevention of apoptosis by augmentation of glutathione stores also strongly supports a role for oxidative stress in ethanol-mediated apoptotic death of fetal cortical neurons.

I. Veterans Affairs Cooperative Study of polyenylphosphatidylcholine in alcoholic liver disease: effects on drinking behavior by nurse/physician teams.

BACKGROUND: This multicenter prospective, randomized, double-blind placebo-controlled trial was designed to evaluate the effectiveness of polyenylphosphatidylcholine against the progression of liver fibrosis toward cirrhosis in alcoholics. Seven hundred eighty-nine alcoholics with an average intake of 16 drinks per day were enrolled. To control excessive drinking, patients were referred to a standard 12-step-based alcoholism treatment program, but most patients refused to attend. Accordingly, study follow-up procedures incorporated the essential features of the brief-intervention approach. An overall substantial and sustained reduction in drinking was observed. Hepatic histological and other findings are described in a companion article. METHODS: Patients were randomized to receive daily three tablets of either polyenylphosphatidylcholine or placebo. Monthly follow-up visits included an extensive session with a medical nurse along with brief visits with a study physician (hepatologist or gastroenterologist). A detailed physical examination occurred every 6 months. In addition, telephone consultations with the nurse were readily available. All patients had a liver biopsy before entry; a repeat biopsy was scheduled at 24 and 48 months. RESULTS: There was a striking decrease in average daily alcohol intake to approximately 2.5 drinks per day. This was sustained over the course of the trial, lasting from 2 to 6 years. The effect was similar both in early dropouts and long-term patients, i.e., those with a 24-month biopsy or beyond. CONCLUSIONS: In a treatment trial of alcoholic liver fibrosis, a striking reduction in alcohol consumption from 16 to 2.5 daily drinks was achieved with a brief-intervention approach, which consisted of a relative economy of therapeutic efforts that relied mainly on treatment sessions with a medical nurse accompanied by shorter reinforcing visits with a physician. This approach deserves generalization to address the heavy drinking problems commonly encountered in primary care and medical specialty practices.

II. Veterans Affairs Cooperative Study of polyenylphosphatidylcholine in alcoholic liver disease.

BACKGROUND: Polyenylphosphatidylcholine (PPC) has been shown to prevent alcoholic cirrhosis in animals. Our aims were to determine the effectiveness of PPC in preventing or reversing liver fibrosis in heavy drinkers and to assess the extent of liver injury associated with the reduced drinking achieved in these patients. METHODS: This randomized, prospective, double-blind, placebo-controlled clinical trial was conducted in 20 Veterans Affairs Medical Centers with 789 patients (97% male; mean age, 48.8 years) averaging 16 drinks per day (1 drink = 14 g of alcohol) for 19 years. A baseline liver biopsy confirmed the presence of perivenular or septal fibrosis or incomplete cirrhosis. They were randomly assigned either PPC or placebo. Liver biopsy was repeated at 24 months, and the main outcome measure was the stage of fibrosis compared with baseline. Progression was defined as advancing to a more severe stage. RESULTS: The 2-year biopsy was completed in 412 patients. PPC did not differ significantly from placebo in its effect on the main outcome. Alcohol intake was unexpectedly reduced in both groups to approximately 2.5 drinks per day. With this intake, 21.4% advanced at least one stage (22.8% of PPC patients and 20.0% of placebo patients). The hepatitis C virus-positive subgroup exhibited accelerated progression. Improvement in transaminases and bilirubin favoring PPC was seen at some time points in other subgroups (hepatitis C virus-positive drinkers or heavy drinkers). CONCLUSIONS: PPC treatment for 2 years did not affect progression of liver fibrosis. A trend in favor of PPC was seen for transaminases and bilirubin (in subgroups). One of five patients progressed even at moderate levels of drinking, and thus health benefits commonly associated with moderate drinking do not necessarily extend to individuals in the early stages of alcoholic liver disease.