David Herion

Efficacy and Safety of Troglitazone in the Treatment of Lipodystrophy Syndromes

Obesity causes insulin resistance, a central feature in the pathogenesis of type 2 diabetes (1). Paradoxically, the absence of adipose tissue also causes insulin resistance and diabetes in humans (2, 3) and genetically engineered animal models (4-6). Lipoatrophy and lipodystrophy are features of a group of heterogeneous syndromes characterized by a paucity of fat, insulin resistance, and hypertriglyceridemia (7). If patients develop diabetes, the syndrome is referred to as lipoatrophic diabetes. The disease has several genetic forms, including face-sparing partial lipoatrophy (the Dunnigan syndrome or the KoberlingDunnigan syndrome, OMIM [Online Mendelian Inheritance in Man] 308980), an autosomal dominant form caused by mutations in the lamin A/C gene (8), and congenital generalized lipoatrophy (the SeipBerardinelli syndrome, OMIM 269700), an autosomal recessive form mapping to chromosome 9q34 in some pedigrees (9). These diseases are rare; reported estimated prevalences are less than 1 in 10 million (10), although our experience suggests that the actual prevalences may be somewhat higher. An association between lipoatrophy and autoimmune disease, such as juvenile dermatomyositis, has also been described (11), suggesting that autoimmune destruction of adipose tissue results in a form of lipoatrophy. Thiazolidinediones, a new class of antidiabetic drugs (12), are ligands for peroxisome proliferatoractivated receptor- (PPAR-), a nuclear receptor expressed predominantly in adipose tissue (13). Thiazolidinediones are believed to exert their primary actions in adipose tissue and to indirectly increase insulin sensitivity in other tissues (14). Because thiazolidinediones have been reported to both increase insulin sensitivity (15, 16) and promote adipocyte development (17), these drugs seemed ideally suited to treat lipoatrophic diabetes. Troglitazone, the first thiazolidinedione to be approved for therapeutic use in the United States, has been shown to improve glycemic control and ameliorate hypertriglyceridemia in patients with type 2 diabetes (18). However, the use of troglitazone is complicated by a rare form of severe, irreversible hepatotoxicity. Two additional thiazolidinediones, rosiglitazone and pioglitazone, were recently approved for use. These drugs are also effective in improving glycemic control in patients with type 2 diabetes (19). Although initial studies of rosiglitazone and pioglitazone suggested that they might not be toxic to the liver, recent reports have raised the possibility that rosiglitazone may rarely cause hepatotoxicity (19, 20). Because PPAR- ligands promote adipocyte differentiation in vitro (13), we hypothesized that troglitazone would promote adipocyte development in patients with various forms of lipoatrophy. This hypothesis implicitly assumes that some lipoatrophic patients possess pre-adipocytes that could be stimulated by troglitazone to complete adipocyte differentiation. In addition, we sought to determine whether troglitazone therapy would improve metabolic control in patients with various forms of lipoatrophy. In light of data suggesting that troglitazone exerts its primary effects on adipocytes, it was uncertain whether the drug would be effective in such patients. Methods Patients Potential study participants were referred by multiple physicians in the United States and Canada in response to advertisements placed in medical journals, notices on the Internet, or word-of-mouth. Some patients had been followed at the National Institutes of Health for varying periods of time (up to 20 years). Because of the rarity of the syndrome, it was not practical to conduct population-based recruitment. To be eligible for the study, patients had to have both insulin resistance and lipoatrophy. For our purposes, insulin resistance was defined as either a fasting plasma insulin level greater than 143 pmol/L or impaired response to intravenous insulin (0.15 U/kg). The latter criterion was defined as a decrease in plasma glucose of less than 50% in patients with fasting glucose levels of 11 mmol/L or less ( 200 mg/dL) or a decrease of 5.5 mmol/L or less (<100 mg/dL) in patients with fasting glucose levels greater than 11.1 mmol/L (>200 mg/dL). Of 33 patients screened for this study, 8 were excluded because serum aminotransferase concentrations were abnormal (range, 833 to 6666 nkat/L) and liver biopsies showed steatohepatitis with varying degrees of fibrosis. Five patients were excluded for various reasons, such as the inability to give informed consent or adhere to the study follow-up schedule. The remaining 20 patients were recruited into the study (Table). Table. Characteristics of the Study Patients Fat distribution was assessed by physical examination and magnetic resonance imaging (MRI). A region of the body was defined as affected if MRI showed a marked decrease in fat in that region. Four patients had generalized lipoatrophy, defined as involvement of the following nine regions: face, neck, upper trunk, abdominal subcutaneous fat, visceral fat, and all four extremities. Two of these patients (U1 and P1) had near-total absence of fat throughout their bodies; the other two (A1 and A2) had a generalized decrease in fat but retained some fat in their visceral abdomen. Sixteen patients, including 7 patients with the Dunnigan syndrome, had partial lipoatrophy affecting five to eight fat depots. Six patients had accompanying autoimmune disease or results on three or more laboratory tests that suggested autoimmunity (for example, antinuclear antibody, rheumatoid factor, and elevated erythrocyte sedimentation rate); these patients therefore were presumed to have an autoimmune cause of their lipoatrophy. The cause of lipoatrophy appeared to be genetic in 10 patients; lipoatrophy appeared shortly after birth in 1 patient, and 9 patients had several affected relatives. Seven of these 9 patients had Dunnigan partial lipodystrophy (21) (Table); the 7 patients were members of three pedigrees. After completion of the study, the diagnosis of the Dunnigan syndrome was confirmed by identifying the R482Q mutation in the lamin A/C gene in all three pedigrees (22). In 4 patients, the cause of disease was unknown. Of the 20 study patients (Table), 14 had diabetes and 2 had impaired glucose tolerance according to the 1997 American Diabetes Association criteria (23). Most diabetic patients were receiving pharmacotherapy before study entry. Five patients were receiving insulin (0.5 to 2 U/kg of body weight per day) and 5 were receiving sulfonylureas; patients continued to receive these therapies during the study. Two patients were receiving metformin, but this therapy was discontinued 6 weeks before initiation of troglitazone treatment. Syndromes of lipoatrophy are associated with substantial comorbid conditions. Of the 8 patients with triglyceride levels greater than 4.5 mmol/L (400 mg/dL), 6 had a history of pancreatitis. Seventeen patients had acanthosis nigricans, a dermatologic condition associated with insulin resistance. Twelve of the 18 female participants had histories of irregular menses and polycystic ovaries as documented by ultrasonography; 6 of these women had hirsutism. Of the 6 remaining female participants, 4 were postmenopausal, 1 was perimenopausal, and 1 was prepubertal. Fatty liver is another important feature sometimes associated with lipoatrophy. To be included in the study, patients had to have normal biochemical function of the liver (Table). Nevertheless, results of ultrasonography in 12 patients suggested fatty infiltration of the liver. Lipoatrophic diabetes was associated with chronic complications of diabetes in some patients. Six patients had albuminuria, seven had diabetic polyneuropathy, and three had diabetic retinopathy (one of whom had proliferative retinopathy). One patient had three-vessel coronary artery disease. Design Patients were treated with troglitazone in an open-label prospective trial in which each patient was compared with his or her own baseline state. Because of the rarity of lipoatrophy syndromes and the variability of the clinical features, it was not feasible to use a randomized, placebo-controlled design. The study was approved by the institutional review board of the National Institute of Diabetes and Digestive and Kidney Diseases. Informed consent was obtained from the patient or his or her legal guardian. The decision to analyze the data after 6 months of therapy was made before the study was begun. Patients were evaluated as inpatients at the Clinical Center of the National Institutes of Health before treatment with troglitazone was initiated. They were admitted again after 6 weeks, 3 months, and 6 months of treatment. Before starting troglitazone therapy, diabetic patients were followed for at least 6 weeks while receiving stable doses of medication. Patients receiving insulin or sulfonylureas continued therapy with these drugs; however, metformin therapy was discontinued before troglitazone therapy was initiated. In diabetic patients, troglitazone therapy was started at a dosage of 200 mg/d and was increased to 400 to 600 mg/d over the course of 6 to 12 weeks, with the goal of optimizing glycemic control. The slow titration was chosen to minimize the risk for hypoglycemia. Doses of insulin or sulfonylureas were decreased if this was necessary to prevent hypoglycemia. Patients received stable doses of lipid-lowering medication for at least 6 weeks before starting troglitazone therapy. In nondiabetic adult participants, troglitazone was prescribed at a dosage of 400 mg/d. In one 6-year-old child weighing 15 to 18 kg, the dosage was 100 mg/d. Liver function tests and blood counts were performed every 3 to 4 weeks. Patients completed weekly questionnaires about their symptoms to identify potential side effects. Patients were instructed not to change their diet and exercise habits during this study. Information about dietary habits was collected by using

Hepatitis C Virus-like Particles Synthesized in Insect Cells as a Potential Vaccine Candidate

BACKGROUND & AIMS Hepatitis C virus (HCV) is a leading cause of chronic hepatitis in the world. Successful vaccine development is crucial in controlling global HCV infection. We have previously described the generation of HCV-like particles (HCV-LPs) in insect cells using a recombinant baculovirus containing the complementary DNA of the HCV structural proteins. These HCV-LPs had similar morphological and biophysical properties as the putative virions. In this study, we analyzed the structural features, antigenic composition, seroreactivity, and immunogenicity of purified HCV-LPs. METHODS HCV-LPs were analyzed by electron microscopy and antibody immunolabeling and precipitation. An enzyme-linked immunosorbent assay (ELISA) using HCV-LPs was developed. The humoral response to HCV-LPs in mice was studies by core and envelope ELISAs, Western immunoblotting, and immunofluorescence. RESULTS Structural and antigenic compositions of HCV-LPs were shown to be similar to those of putative HCV virions. Using the HCV-LP ELISA, high-titer anti-HCV antibodies were detected in individuals infected with various HCV genotypes. In vivo, HCV-LPs elicited a humoral response broadly directed against HCV structural proteins. CONCLUSIONS HCV-LPs resemble HCV virions and are capable of inducing a humoral response targeted against various regions of HCV structural proteins, suggesting that HCV-LPs may be promising as a potential vaccine candidate.

Case study: Risperidone-induced hepatotoxicity in pediatric patients

The purpose of this case study is to document hepatic adverse effects associated with long-term risperidone use in pediatric populations. Charts of all patients admitted to the National Institute of Mental Health (NIMH) from December 1993 to April 1996 who had been treated with risperidone were screened for hepatotoxicity and weight gain. From the medical records of 13 psychotic children admitted to the NIMH and treated with risperidone, 2 children (both male) who presented with obesity, liver enzyme abnormalities, and confirmatory evidence of fatty liver were identified. In each case liver damage was reversed after discontinuation of risperidone and/or associated weight loss. The observations suggest that long-term risperidone therapy is possibly associated with hepatotoxicity in male pediatric patients. It is recommended that pediatric patients treated with risperidone have baseline liver function tests, careful monitoring of weight, and periodic monitoring of liver function tests during the maintenance phase of therapy.

Integrating pharmacogenetic information and clinical decision support into the electronic health record

Pharmacogenetics (PG) examines gene variations for drug disposition, response, or toxicity. At the National Institutes of Health Clinical Center (NIH CC), a multidepartment Pharmacogenetics Testing Implementation Committee (PGTIC) was established to develop clinical decision support (CDS) algorithms for abacavir, carbamazepine, and allopurinol, medications for which human leukocyte antigen (HLA) variants predict severe hypersensitivity reactions. Providing PG CDS in the electronic health record (EHR) during order entry could prevent adverse drug events. Medical Logic Module (MLM) programming was used to implement PG CDS in our EHR. The MLM checks to see if an HLA sequence-based gene test is ordered. A message regarding test status (result present, absent, pending, or test not ordered) is displayed on the order form, and the MLM determines if the prescriber can place the order, place it but require an over-ride reason, or be blocked from placing the order. Since implementation, more than 725 medication orders have been placed for over 230 patients by 154 different prescribers for the three drugs included in our PG program. Prescribers commonly used an over-ride reason when placing the order mainly because patients had been receiving the drug without reaction before implementation of the CDS program. Successful incorporation of PG CDS into the NIH CC EHR required a coordinated, interdisciplinary effort to ensure smooth activation and a positive effect on patient care. Prescribers have adapted to using the CDS and have ordered PG testing as a direct result of the implementation.

Compartmental analysis of plasma and liver n-3 essential fatty acids in alcohol-dependent men during withdrawal

The mechanism by which chronic ethanol consumption reduces concentrations of long chain polyunsaturated (LCP) fatty acids (FA) in tissues of humans was investigated in alcohol-dependent (AD) men during early withdrawal and to a well-matched control group by fitting the concentration-time curves of d5-labeled n-3 FA from plasma and liver, which originated from an oral dose of d5-linolenic acid (d5-18:3n-3) ethyl ester to a compartmental model. Blood sampled over 168 h and a liver specimen obtained 96 h after isotope administration were analyzed for d5-18:3n-3, d5-20:5n-3, d5-22:5n-3, and d5-22:6n-3. Plasma 20:5n-3 and 22:5n-3 were lower in AD subjects, compared with controls (20:5n-3: -50%, 22:5n-3: -34%). Increased amounts of d5-18:3n-3 were directed toward synthesis of d5-20:5n-3 in AD subjects (P < .05). However, this effect was offset by larger amounts of 20:5n-3 lost from plasma (control: 2.0 vs. AD: 4.2 mg d−1). In livers of AD subjects, more d5-18:3n-3 and d5-22:5n-3 were utilized for synthesis of d5-20:5n-3 (+200%) and d5-22:6n-3 (+210%), respectively, than was predicted from plasma kinetics. Although, the potential to utilize linolenic acid for synthesis of LCP FA was greater in AD subjects compared with controls, heightened disappearance rates of 20:5n-3 reduced overall plasma concentrations of several endogenous n-3 LCP FA.

Adult‐onset cystic fibrosis liver disease: Diagnosis and characterization of an underappreciated entity

Cystic fibrosis (CF) liver disease (CFLD), a leading cause of death in CF, is mostly described in pediatric populations. Adult‐onset CFLD lacks sufficient characterization and diagnostic tools. A cohort of CF patients without CFLD during childhood were followed for up to 38 years with serologic testing, imaging, and noninvasive fibrosis markers. Historical CFLD diagnostic criteria were compared with newly proposed CFLD criteria. Thirty‐six CF patients were followed for a median of 24.5 years (interquartile range 15.6‐32.9). By the last follow‐up, 11 (31%) had died. With conventional criteria, 8 (22%) patients had CFLD; and by the new criteria, 17 (47%) had CFLD at a median age of 36.6 years (interquartile range 26.5‐43.2). By the new criteria, those with CFLD had higher median alanine aminotransferase (42 versus 27, P = 0.005), aspartate aminotransferase (AST; 26 versus 21, P = 0.01), direct bilirubin (0.13 versus 0.1, P = 0.01), prothrombin time (14.4 versus 12.4, P = 0.002), and AST‐to‐platelet ratio index (0.31 versus 0.23, P = 0.003) over the last 2 years of follow‐up. Subjects with a FibroScan >6.8 kPa had higher alanine aminotransferase (42 versus 28U/L, P = 0.02), AST (35 versus 25U/L, P = 0.02), AST‐to‐platelet ratio index (0.77 versus 0.25, P = 0.0004), and Fibrosis‐4 index (2.14 versus 0.74, P = 0.0003) and lower platelet counts (205 versus 293, P = 0.02). One CFLD patient had nodular regenerative hyperplasia. Longitudinally, mean platelet counts significantly declined in the CFLD group (from 310 to 230 U/L, P = 0.0005). Deceased CFLD patients had lower platelet counts than those alive with CFLD (143 versus 258 U/L, P = 0.004) or those deceased with no CFLD (143 versus 327U/L, P = 0.006). Conclusion: Adult‐onset CFLD may be more prevalent than previously described, which suggests a later wave of CFLD that impacts morbidity; routine liver tests, radiologic imaging, noninvasive fibrosis markers, and FibroScan can be used algorithmically to identify adult CFLD; and further evaluation in other CF cohorts should be performed for validation. (Hepatology 2017;66:591–601).

19 Hepatitis C virus infection and alcohol

Publisher Summary This chapter discusses the relationship between alcohol consumption and chronic hepatitis C virus (HCV) infection. Although alcohol use can be expressed in a number of ways, it is average daily consumption that has been applied most often to studies of liver disease. People who drink—particularly who drink excessively—are more likely to be infected with HCV, probably because of increased exposure to the virus rather than increased susceptibility. A substantial proportion of cirrhosis among alcoholics can actually be attributed to HCV infection. Alcohol consumption at a level that can cause cirrhosis also increases the risk of cirrhosis in persons infected with HCV. It is unclear whether there is an interaction between these two factors such that the risk of cirrhosis is increased disproportional to the amount of alcohol consumed in patients with chronic hepatitis C. In addition, it is unknown whether there is a safe level of drinking in persons with hepatitis C. Heavy alcohol consumption may increase the risk of hepatocellular carcinoma, but much of this risk can be attributed to an increased risk of cirrhosis.

The biometric measurement of alcohol consumption.

BACKGROUND Proper ascertainment of the history of alcohol consumption by an individual is an important component of medical diagnosis of disease and influences the implementation of appropriate treatment strategies that include prescription of medication, as well as intervention for the negative physical and social consequences of hazardous/harmful levels of alcohol consumption. Biological (biometric) diagnostic tests that provide information on current and past quantity and frequency of alcohol consumption by an individual, prior to onset of organ damage, continue to be sought. METHODS Platelet monoamine oxidase B (MAO-B) protein was quantitated in 2 populations of subjects who had histories of different levels of alcohol consumption. Levels were assayed by immunoblotting or by ELISA. The development and evaluation of the new ELISA-based measure of platelet MAO-B protein levels is described. RESULTS One subject population constituted a nontreatment-seeking, cross-sectional subject sample, and the other population was a longitudinally followed, hospitalized group of subjects. An algorithm combining measures of platelet MAO-B protein with the plasma levels of carbohydrate-deficient transferrin (CDT) and with liver enzymes (aspartate aminotransferase or γ-glutamyltransferase [GGT]) can detect hazardous/harmful alcohol use (HHAU) with the highest sensitivity and specificity in the cross-sectional nontreatment-seeking population. In the treatment-seeking population, low MAO-B protein levels at admission are associated with heavy drinking prior to admission, and these protein levels increase over a period of abstinence from alcohol. CONCLUSIONS The platelet MAO-B protein measurement is particularly effective for male alcohol consumers. The combined use of MAO-B protein measures together with measures of CDT and GGT does, however, improve the diagnostic utility of both markers for ascertaining HHAU in women. Furthermore, measurement of changes in platelet MAO-B protein levels during treatment for alcohol dependence may help monitor the success of the treatment program.