Validation of noninvasive methods for detecting hepatic steatosis in patients with human immunodeficiency virus infection.

Nonalcoholic fatty liver disease (NAFLD) is common among patients with human immunodeficiency virus (HIV) infection; a reliable noninvasive method of detection is needed. We aimed to validate noninvasive means of identifying steatosis in HIV-positive patients. We performed a single-center retrospective study to validate the abilities of the liver fat score (LFS) and the lipid accumulation product (LAP) to detect hepatic steatosis in HIV-positive patients, compared with HIV-negative individuals (controls); NAFLD was confirmed by histology, and findings were compared with those from ultrasonography. These models then were validated in HIV-positive patients with NAFLD vs patients co-infected with HIV and hepatitis C virus (HCV) infection, without hepatic steatosis. LFS identified hepatic steatosis in HIV-positive subjects, compared with controls, with an area under the receiver operating curve value of 0.971 ± 0.027 (95% confidence interval, 0.91-1.000). At a cut-off value of -0.945, the LFS identified patients with steatosis with 100% sensitivity and 84% specificity. At a cut-off of value of -0.234, the LFS differentiated between HIV-positive subjects with NAFLD and patients co-infected with HIV and HCV with 100% sensitivity and 74% specificity. LAP scores ≥38 identified HIV-positive patients with steatosis with 89% sensitivity and 83% specificity. LAP scores ≥42 differentiated between HIV-positive subjects with steatosis and patients co-infected with HIV and HCV with 89% specificity and 70% sensitivity. We validated the accuracy of LFS and LAP in detecting hepatic steatosis in HIV-positive patients.

Vanadium pentoxide phytotoxicity: effects of species selection and nutrient concentration.

Vanadium concentrations in soil can be increased through anthropogenic inputs and can be harmful to plants. A Petri dish experiment was conducted to assess the effect of vanadium toxicity on the germination and survival of the garden lettuce, Lactuca sativa. A second study was conducted in a greenhouse to investigate the influence of species selection and nutrient concentration on the toxicity of vanadium pentoxide to plants. L. sativa and four non-crop native plant species, two grasses (Elymus virginicus and Panicum virgatum) and two broad-leaved species (Lycopus americanus and Prunella vulgaris) were selected. Artificial soil was used in both experiments, and a geometric progression of five vanadium concentrations plus controls was selected for the soil treatments. Results of the Petri dish experiment showed that seedling survival is a less sensitive end point than above-ground dry weight (DW) as measured in the greenhouse experiment. Nutrient level (100, 10, and 1 kg/ha) was found to strongly influence vanadium toxicity in the greenhouse study. At 100 kg/ha, plant tolerance to vanadium was greatest, as indicated by higher no-observed, lowest-observed, and percentage effect concentration values. Results showed that forbs (L. americanus and P. vulgaris) tended to be more sensitive than both the crop (L. sativa) and grasses (E. virginicus and P. virgatum) at high concentrations of vanadium. Soil concentrations resulting in a 25 % decrease in shoot DW were generally less than the Canadian soil quality guideline for vanadium, suggesting that 130 mg/kg may not be protective of the Canadian native plant species used in this study.

Hepatic steatosis in human immunodeficiency virus: a prospective study in patients without viral hepatitis, diabetes, or alcohol abuse.

BACKGROUND AND AIMS: Abnormal liver enzymes (LEs) are common in those infected with human immunodeficiency virus (HIV). Histologic data on those with abnormal LE without viral hepatitis are lacking. METHODS: HIV-positive subjects without hepatitis C virus, hepatitis B virus, alcohol abuse, and diabetes mellitus with more than 1 abnormal LE, defined as 1.25 ULN in aspartate aminotransferase, alanine aminotransferase, or alkaline phosphatase, over 6 months were included. Subjects underwent a 2-hour oral glucose tolerance test, fasting lipids, insulin and glucose for insulin resistance (IR) by homeostasis model assessment for insulin resistance (HOMA-IR) and dual-energy X-ray absorptiometry for fat distribution. Biopsies were read blindly to clinical data, and scored by Ishak histologic activity index for inflammation and fibrosis and NAFLD activity score. RESULTS: Fourteen patients underwent biopsy. All were on highly active antiretroviral therapy with undetectable HIV RNA and mean CD4 614. The histologic activity index scores for inflammation and fibrosis were 3.43(1.4) and 1.71(1.26), respectively, and 2 patients had advanced fibrosis (bridging fibrosis/cirrhosis). The majority (65%) of patients had steatosis: grade 1: 21%, grade 2: 28%, and grade 3: 14%. Hepatocyte ballooning was seen in 7 (40%) but nonalcoholic steatohepatitis (NASH) was diagnosed only in 4 (26%). NAFLD activity score of all biopsies of 3.07 (2.2; range, 0 to 5). HOMA-IR was higher in those with compared with those without steatosis (3.52 vs. 1.91; P = 0.11) and highest in those with NASH (4.89). Using multivariate logistic regression, only increased γ-glutamyl transpeptidase (P = 0.0009) predicted steatosis whereas HOMA-IR (P = 0.0046) predicted NASH. CONCLUSIONS: Although steatosis is common in HIV patients with abnormal LE without diabetes mellitus, alcohol, or viral hepatitis coinfection, NASH was observed in only 26%. The only clinical or laboratory feature associated with biopsy proven steatosis and NASH were γ-glutamyl transpeptidase and a calculated measure of insulin resistance, respectively. Further studies are needed in this population to determine the long-term clinical significance.

Comparison of FIB-4 and APRI in HIV-HCV coinfected patients with normal and elevated ALT.

BACKGROUND AND AIMS: Liver biopsy is standard for assessment of disease severity in patients with chronic HCV. However, associated risks have led to the development of simple non-invasive models. However, their utility in those with normal ALT is unknown. METHODS: FIB-4 and APRI were calculated for patients with HIV-HCV coinfection undergoing biopsy. The performance of each model and AUROC for predicting significant fibrosis (Ishak 4-6) were determined for the entire cohort and stratified by elevated (≥60 U/l in men and ≥40 U/l in women) and normal ALT. RESULTS: Two-hundred and ninety-five liver biopsies from 237 patients were included. Elevated ALT was observed in 55, and 15% had significant fibrosis. The AUROC curve for patients with elevated ALT was 0.8 for FIB-4 and 0.76 for APRI, compared with 0.90 for the FIB-4 and 0.85-0.95 for the APRI in those with normal ALT. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FIB-4 were 1.0, 0.91, 0.50, and 1.0 for patients with normal ALT; the values were 0.67, 0.99, 0.67, and 0.99 for APRI. CONCLUSIONS: Both FIB-4 and APRI are useful for highly accurate identification of those without advanced fibrosis. However, because they have poor positive predictive value, liver biopsy will continue to be used for assessment of patients with coinfection.

Similar progression of fibrosis between HIV/HCV-infected and HCV-infected patients: Analysis of paired liver biopsy samples.

BACKGROUND & AIMS: Fibrosis progression might be accelerated in patients who are coinfected with human immunodeficiency virus (HIV) and HCV (HIV/HCV). However, no studies have directly compared fibrosis progression by paired liver biopsy between patients infected with HIV and HCV versus those infected with only HCV. METHODS: Liver biopsy samples were collected from patients with HIV/HCV (n = 306) and those with HCV; biopsies from 59 without a sustained virologic response (SVR) or cirrhosis were matched with those from patients with only HCV (controls) for initial fibrosis stage, demographics, and HCV treatment. For HIV/HCV patients, categorical variables at baseline and the area under the curve of continuous variables per unit time were analyzed for associations with fibrosis progression. RESULTS: Liver biopsies from HIV/HCV patients had more piecemeal necrosis than controls (P = .001) and increased lobular inflammation (P = .002); HIV/HCV patients also had shorter intervals between liver biopsies (4.7 vs 5.9 years, P < .0001). Between the first and second biopsies, fibrosis remained unchanged or progressed 1 or 2 units in 55%, 18%, and 18% of HIV/HCV patients, respectively, compared with 45%, 30%, and 9% of controls. The fibrosis progression rate was similar between HIV/HCV and control patients (0.12 ± 0.40 vs 0.091 ± 0.29 units/y; P = .72). In paired biopsies from 66 patients, including those with SVR, there were no associations between fibrosis progression and demographics; numbers of CD4+ T cells; levels of aspartate aminotransferase or alanine aminotransferase; use of highly active antiretroviral therapy; response to HCV therapy (no treatment, SVR, or non-response); baseline levels of FIB-4; or histologic features including inflammation, fibrosis, or steatosis. CONCLUSIONS: On the basis of analysis of liver biopsy samples, fibrosis progression was similar between HIV/HCV-infected and HCV-infected patients; no clinical or laboratory parameters predicted disease progression.

Response to hepatitis A and B vaccine alone or in combination in patients with chronic hepatitis C virus and advanced fibrosis.

Patients with advanced fibrosis are at increased risk of severe outcomes if they develop acute infection with hepatitis A (HAV) or hepatitis B (HBV) viruses. There are no data on the efficacy of combined HAV/HBV vaccination in patients with advanced fibrosis. Our aim was to evaluate the response to the HAV and HBV vaccine alone or in combination for patients with chronic hepatitis C (HCV) and advanced fibrosis and to evaluate the impact of administering the vaccine while patients were receiving peginterferon for treatment of chronic HCV. In this prospective study of patients with advanced fibrosis (Ishak 3-6), those without serologic evidence of prior exposure were vaccinated with either Havrix HAV, Engerix( HBV, or the TWINRIX HAV/HBV combination vaccine as appropriate, and response was defined as the development of anti-HAV or anti-HBV surface antibodies. Of the 162 eligible patients, the prevalence of prior exposure to HAV and HBV was 30 and 18%, respectively. Of the 84 patients vaccinated, 38% received Havrix, 14% Engerix, and 48% TWINRIX. The response to the HAV vaccine was 75% in those receiving Havrix compared to 78% receiving TWINRIX. In contrast, the response to HBV vaccination was 42% in patients receiving Engerix compared to 60% in those vaccinated with TWINRIX (difference 18.3%; OR 0.29; 95% CI: 0.57-7.79). The presence of diabetes was the only risk factor identified for reduced HBV response (P = 0.01). Responses to both HAV and HBV vaccines when administered alone or in combination were lower than expected in patients with HCV and advanced fibrosis, especially in those with diabetes. The observation that the decline in HBV vaccine response was somewhat lower when this was administered alone as opposed to the combination A/B vaccine suggests that the administration of a combination vaccine may enhance the vaccination response to HBV.

Steatohepatitis: Risk factors and impact on disease severity in human immunodeficiency virus/hepatitis C virus coinfection.

UNLABELLED: Hepatic steatosis has been reported in human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfection. However, the features of steatohepatitis, including cytologic ballooning and pericellular fibrosis, its risk factors, and the impact on disease severity in such patients are unknown. To assess this, we prospectively reviewed liver histology in consecutive coinfected patients to define the prevalence and severity of the features of steatohepatitis, its risk factors, and its impact on the severity of liver disease. A total of 222 subjects (74% male, mean age 45, 78% African American, 90% genotype 1) were studied. The mean body mass index (BMI) was 26, and 18% had a BMI >30. The prevalence of risk factors for steatosis were: diabetes (31%), hypertension (15%), dyslipidemia (8%), metabolic syndrome (9%), and alcohol abuse (21%). Steatosis was present in 23% and steatohepatitis was present in 17%. The steatosis was mild (5%-33%) in 19%, and moderate to severe (>33%) in 4%. Cytologic ballooning and pericellular fibrosis were present in 30% and 13%, respectively. The mean Ishak score was 6.9, and 33% had bridging fibrosis or cirrhosis. Both steatosis and cytologic ballooning were associated with BMI, metabolic syndrome, and insulin resistance, and presence of either was strongly associated with advanced fibrosis (P < 0.0001). By multiple logistic regressions, the following associations were identified: increased BMI, diabetes, and genotype 3 with steatosis; diabetes with cytologic ballooning; and longer duration of infection with steatohepatitis. CONCLUSION: Steatosis and steatohepatitis are present in 23% and 30%, respectively, of patients with HIV/HCV coinfection, and both are associated with an increased risk of having advanced fibrosis. Although we did identify genotype 3, increased BMI, and diabetes as risk factors, we found no independent association with antiretroviral therapy.

An investigation of arsenic compounds in fur and feathers using X-ray absorption spectroscopy speciation and imaging.

The accumulation of arsenic in fur and feathers has been used as an indicator of environmental quality and animal health. However, difficulties remain in distinguishing between arsenic present from external sources versus ingestion. In addition, low extraction efficiencies limit the complete characterization of arsenic compounds in such tissues by conventional analytical techniques (e.g. high performance liquid chromatography inductively coupled plasma mass spectrometry, HPLC-ICP-MS). X-ray absorption spectroscopy (XAS) provides an alternative method for determining the speciation of arsenic compounds directly. Inorganic arsenic is hypothesized to bind to thiol groups present in keratin-rich fur and feathers; however, arsenic-sulphur compounds are rarely reported in extracts of these tissues. Here we report that 5-58% of the total detected arsenic in rodent fur (vole, deer mouse, red squirrel) and bird feathers (gray jay, American tree sparrow, dark-eyed junco) from animals living in areas of elevated arsenic best resembled an arsenic(III)-sulphur compound as determined using XAS. In addition, fur and feathers with non-detectable levels of arsenic by XAS, were able to reduce pentavalent arsenic applied as either contaminated soil or an arsenate solution. XAS-imaging was used to localize dominant trivalent (AsIII) and pentavalent (AsV) arsenic compounds, and results were used to produce a "map" of arsenic in the sample. It is believed that the some of the reduced arsenic was absorbed, while external AsV compounds associated with soil/dust particles were easily distinguished on goose feathers. However, distinguishing whether internal arsenic arose from exogenous (from the environment) or endogenous (from the body) sources proved difficult with this technique.

Uptake, transport and transformation of arsenate in radishes (Raphanus sativus).

The localization and identification of arsenic compounds in terrestrial plants are important for the understanding of arsenic uptake, transformation and translocation within these organisms, and contributes to our understanding of arsenic cycling in the environment. High performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS), and X-ray absorption near-edge structure (XANES) analysis identified arsenite, arsenate and arsenic(III)-sulphur compounds in leaf, stem and root sections of Rhaphanus sativus (radish) plants grown in both arsenic contaminated mine waste, and arsenic amended liquid cultures. The total arsenic distribution was similar between the plants grown in mine waste and those grown hydroponically. Arsenate was the predominant form of arsenic available in the growth mediums, and after it was taken up by roots, X-ray absorption spectroscopy (XAS) imaging indicated that some of the arsenate was transported to the shoots via the xylem. Additionally, arsenate was reduced by the plant and arsenic(III)-sulphur compound(s) accounted for the majority of arsenic in the leaf and stem of living plants. In this study the application of synchrotron techniques permitted the identification of arsenic(III)-sulphur species which were "invisible" to conventional HPLC-ICP-MS analysis.

Arsenic speciation analysis of cultivated white button mushrooms (Agaricus bisporus) using high-performance liquid chromatography-inductively coupled plasma mass spectrometry, and X-ray absorption spectroscopy.

Agaricus bisporus mushrooms were grown in compost amended with either arsenic-contaminated mine waste or an arsenate solution, to a final concentration of approximately 200 microg g(-1). Fungi were cultivated at a small-scale mushroom facility in Vineland (ON), where the controlled environment allowed for a large number of fruiting bodies (mushrooms) to be produced. The total arsenic concentrations as well as speciation were examined for each treatment over several harvests (breaks). Total concentrations were determined by acid digestion and inductively coupled plasma mass spectrometry (ICP-MS) detection and ranged from 2.3 to 16 microg g(-1) dry mass in treatment mushrooms. Arsenic compounds were extracted from mushrooms with methanol/water (1:1 v/v), and separated by high-performance liquid chromatography (HPLC, anion/cation exchange) before detection with ICP-MS. Fruiting bodies from all treatments contained arsenite, dimethylarsinic acid (DMA), and arsenobetaine (AB), and to a lesser extent arsenate and trimethylarsine oxide (TMAO). The ratio of arsenic compounds did not vary greatly over the first three harvests. AB was absent in compost not inoculated with A. bisporus supporting the hypothesis that AB is a product of fungal, not microbial, arsenic metabolism. X-ray absorption spectroscopy results lead us to hypothesize that AB plays a role in nutrient translocation within the fruiting body, as well as maintaining turgor pressure to ensure the mushroom cap remains elevated for maximum spore dispersal.

X-ray absorption near-edge structure analysis of arsenic species for application to biological environmental samples.

Arsenic is an element that is ubiquitous in the environment and is known to form compounds with toxic, even carcinogenic properties. Arsenic toxicity is a function of its chemical form (species). Identification of arsenic species is necessary to accurately determine the transformation and fate of arsenicals as well as the actual risk posed by arsenic contamination. We report X-ray absorption near-edge structure (XANES) measurements of 16 biologically important arsenic compounds. Solid and aqueous standards were studied for differences in XANES spectral features, white line positions, stability during exposure to the beam, and stability between two beam exposures separated by 48 h. Samples containing As(III) (11870.0-11871.7+/-0.5 eV) and As(V) (11872.6-11875.3+/-0.5 eV) were easily distinguished by white line energies and could be further subdivided into a total of seven groups. Valuable examples include As(III)-sulfur compounds (11870.0+/-0.5 eV), arsenobetaine and arsenocholine (11872.6+/-0.5 eV), and a dimethyl arsinyl riboside (11873.3+/-0.5 eV). A growing number of environmental and biological studies use X-ray absorption spectroscopy (XAS) results to complement their more traditional analyses. Results provided here are intended to help make XAS more accessible to new users interested in the study of arsenic in the environment.