Hepeviridae: An expanding family of vertebrate viruses

The hepatitis E virus (HEV) was first identified in 1990, although hepatitis E-like diseases in humans have been recorded for a long time dating back to the 18th century. The HEV genotypes 1–4 have been subsequently detected in human hepatitis E cases with different geographical distribution and different modes of transmission. Genotypes 3 and 4 have been identified in parallel in pigs, wild boars and other animal species and their zoonotic potential has been confirmed. Until 2010, these genotypes along with avian HEV strains infecting chicken were the only known representatives of the family Hepeviridae. Thereafter, additional HEV-related viruses have been detected in wild boars, distinct HEV-like viruses were identified in rats, rabbit, ferret, mink, fox, bats and moose, and a distantly related agent was described from closely related salmonid fish. This review summarizes the characteristics of the so far known HEV-like viruses, their phylogenetic relationship, host association and proposed involvement in diseases. Based on the reviewed knowledge, a suggestion for a new taxonomic grouping scheme of the viruses within the family Hepeviridae is presented.

Gallbladder and Pancreas in Henoch-Schönlein Purpura: Review of the Literature

OBJECTIVE Involvement of the pancreato-biliary system has been occasionally noted in Henoch-Schönlein purpura. Furthermore, cases of this vasculitis syndrome sometimes develop in the context of a viral hepatitis or after hepatitis vaccination. METHODS We completed a review of the literature. RESULTS Fifty reports published between 1977 and 2015 were retained for the analysis. A pancreato-biliary involvement was recognized in 34 individually well-described patients (♂:♀ = 19:15) with severe abdominal pain: pancreatitis (N = 20), acalculous cholecystitis (N = 11), both pancreatitis and cholecystitis (N = 3). In all of the pancreatitis patients, full recovery occurred (within ≤3 weeks in three-fourths of the patients). Cholecystectomy was performed in 8 cholecystitis patients. Seventeen Henoch-Schönlein patients (♂:♀ = 9:8) were associated with a viral liver disease and 4 (♂:♀ = 1:3) with a hepatitis vaccination. The vasculitis syndrome rapidly remitted in the 7 patients accompanying hepatitis A or E, in 2 patients of hepatitis B, and in the 4 patients preceded by a vaccination. Henoch-Schönlein purpura seemed to be serious in 5 patients with chronic hepatitis B and in 3 with chronic hepatitis C. CONCLUSIONS This analysis indicates that pancreato-biliary involvement is unusual in Henoch-Schönlein purpura. This complication deserves consideration in patients with especially severe abdominal pain. Finally, viral hepatitides and hepatitis vaccinations seem to be rare triggers of Henoch-Schönlein purpura.

Modelling the impact of deferring HCV treatment on liver-related complications in HIV coinfected men who have sex with men

BACKGROUND AND AIMS Hepatitis C (HCV) is a leading cause of morbidity and mortality in people who live with HIV. In many countries, access to direct acting antiviral agents to treat HCV is restricted to individuals with advanced liver disease (METAVIR stage F3 or F4). Our goal was to estimate the long term impact of deferring HCV treatment for men who have sex with men (MSM) who are coinfected with HIV and often have multiple risk factors for liver disease progression. METHODS We developed an individual-based model of liver disease progression in HIV/HCV coinfected men who have sex with men. We estimated liver-related morbidity and mortality as well as the median time spent with replicating HCV infection when individuals were treated in liver fibrosis stages F0, F1, F2, F3 or F4 on the METAVIR scale. RESULTS The percentage of individuals who died of liver-related complications was 2% if treatment was initiated in F0 or F1. It increased to 3% if treatment was deferred until F2, 7% if it was deferred until F3 and 22% if deferred until F4. The median time individuals spent with replicating HCV increased from 5 years if treatment was initiated in F2 to almost 15 years if it was deferred until F4. CONCLUSIONS Deferring HCV therapy until advanced liver fibrosis is established could increase liver-related morbidity and mortality in HIV/HCV coinfected individuals, and substantially prolong the time individuals spend with replicating HCV infection.

A cross sectional examination of risky sexual behaviors among a population of drug users

This study is a secondary data analysis that assesses the relationship between risky sexual behaviors and sexually transmitted infections (STIs) among drug users. This study analyzes data collected from drug users in the Houston Metropolitan area during 2004 and through August 2005, by researchers with the DASH (Drugs, AIDS, STDs and Hepatitis) project at The University of Texas at Houston School of Public Health. Specifically, the sexually transmitted infections that will be of interest in this proposed study are Human Immunodeficiency Virus (HIV) and Hepatitis B Virus (HBV). Risky sexual behaviors that will be examined include lack of condom use, sexual orientation, trading sex for drugs, trading sex for money, and number of male and female sexual partners in the last 4 weeks. ^ Unadjusted, gender, sexual orientation, number of recent male and female sex partners, and a history of injection drug use were all found to be significant independent variables that increased the odds of STI status. When included in an overall model, these variables significantly increased the odds of STI status, including HBV infection, HIV infection, and HBV/HIV co-infection. History of injection drug use was significant for both HBV and HBV/HIV co-infection, whereas a gay sexual orientation was significant for both HIV and HBV/HIV co-infection. Additionally, having excessive female sex partners was significant for HIV infection. This significant association increases the need for implementation of stronger intervention programs tailored to suit this population's needs such as a combination of drug and sexually transmitted disease (STD) treatment. ^ The importance of these findings is that they establish the strength of associations between the previously mentioned risky sexual behaviors and STI status among drug users. This is crucial for assessing future risk of infection as well as for serving as a necessary component in intervention and treatment programs both for drug use and STIs. ^

Racial disparities in patient survival after liver transplantation in the United States

Background. Racial disparities in healthcare span such areas as access, outcomes after procedures, and patient satisfaction. Previous work suggested that minorities experience less healthcare and worse survival rates. In adult orthotopic liver transplantation (OLT) mixed results have been reported, with some showing African-American recipients having poor survival compared to Caucasians, and others finding no such discrepancy. ^ Purpose. This study’s purpose was to analyze the most recent United Network for Organ Sharing (UNOS) data, both before and after the implementation of the Model for End-Stage Liver Disease (MELD)/Pediatric End-Stage Liver Disease (PELD) scoring system, to determine if minority racial groups still experience poor outcomes after OLT. ^ Methods. The UNOS dataset for 1992-2001 (Era I) and 2002-2007 (Era II) was used. Patient survival rates for each Era and for adult and pediatric recipients were analyzed with adjustment. A separate multivariate analysis was performed on African-American adult patients in Era II in order to identify unique predictors for poor patient survival. ^ Results. The overall study included 66,118 OLT recipients. The majority were Caucasian (78%), followed by Hispanics (13%) and African-Americans (9%). Hispanic and African-American adults were more likely to be female, have Hepatitis C, to be in the intensive care unit (ICU) or ventilated at time of OLT, to have a MELD score ≥23, to have a lower education level, and to have public insurance when compared to Caucasian adults (all p-values < 0.05). Hispanic and African-American pediatric recipients were more likely have public insurance and less likely to receive a living donor OLT than were Caucasian pediatric OLT recipients (p <0.05). There was no difference in the likelihood of having a PELD score ≥21 among racial groups (p >0.40). African-American adults in Era I and Era II had worse patient survival rates than both Caucasians and Hispanic (pair-wise p-values <0.05). This same disparity was seen for pediatric recipients in Era I, but not in Era II. Multivariate analysis of African-American recipients revealed no unique predictors of patient death. ^ Conclusions. African-American race is still a predictor of poor outcome after adult OLT, even after adjustment for multiple clinical, demographic, and liver disease severity variables. Although African-American and Hispanic subgroups share many characteristics previously thought to increase risk of post-OLT death, only African-American patients have poor survival rates when compared to Caucasians. ^

Is family medicine meeting the HIV/AIDS challenge? A national survey of family physicians' beliefs, clinical competence, and experience regarding HIV disease

A national sample of family physicians was surveyed to (1) assess family physicians' beliefs about the human immunodeficiency virus (HIV) and individuals at risk for infection, their clinical competence regarding HIV-related issues, and their experiences with HIV disease; (2) present conclusions to the American Academy of Family Physicians (AAFP) to effect the development of an early clinical care protocol and a continuing medical education curriculum; and (3) collect base-line data for use in the evaluation of an early clinical care protocol and a continuing medical education curriculum, in the case that such programs are developed and disseminated. After considering retired or deceased respondents, of the 2,660 physicians surveyed, 1,678 (63.7%) responded. The resulting sample was representative of the active members of the AAFP. About 77% of the respondents were unable to accurately identify the universal precautions for blood and body fluids to prevent occupational transmission of HIV or hepatitis B virus (HBV). Residency trained and board certified physicians expressed fewer "external constraints," such as fear of losing patients, obviating them from providing treatment to individuals with HIV disease (p =.004 and p $<$.001, respectively). These physicians also manifested fewer "internal constraints" to the provision of HIV treatment, such as fear of becoming infected (p $<$.001 and p =.012, respectively). Residency trained physicians also expressed a greater comfort with discussing sexually-related topics with their patients than did non-residency trained physicians (p $<$.001). There were 67.1% of the physicians surveyed who reported never providing treatment to an individual with HIV disease. Residency trained and board certified physicians expressed a greater likelihood to provide treatment to HIV-infected patients (p $<$.001) than non-residency trained and non-board certified physicians.^ Among the various primary care specialties, family medicine is especially vulnerable to the current challenges of HIV/AIDS. These challenges are augmented by the epidemiologic pattern that characterizes AIDS. For the past several years, we have seen AIDS in this country assume a similar pattern to that seen in most other countries; HIV is becoming increasingly prevalent in the heterosexual population as well as in locations removed from metropolitan centers. This current phase of the epidemic generates greater pressures upon primary care physicians, particularly family physicians, to become better acquainted with the means to provide early care to HIV/AIDS patients and to prevent HIV/AIDS among their patients. Family medicine is especially appropriate for providing care to HIV patients because family medicine involves treatment to all age groups and conditions; other primary care specialties focus on limited patient populations or specific conditions. Family physicians should be armed with the expertise to confront HIV/AIDS. However, family physicians' clinical competence and experience with HIV is not known. The data collected in this survey describes their competencies, attitudes, and experiences. ^

Identification of eukaryotic mRNAs that are translated at reduced cap binding complex eIF4F concentrations using a cDNA microarray

Although most eukaryotic mRNAs need a functional cap binding complex eIF4F for efficient 5′ end- dependent scanning to initiate translation, picornaviral, hepatitis C viral, and a few cellular RNAs have been shown to be translated by internal ribosome entry, a mechanism that can operate in the presence of low levels of functional eIF4F. To identify cellular mRNAs that can be translated when eIF4F is depleted or in low abundance and that, therefore, may contain internal ribosome entry sites, mRNAs that remained associated with polysomes were isolated from human cells after infection with poliovirus and were identified by using a cDNA microarray. Approximately 200 of the 7000 mRNAs analyzed remained associated with polysomes under these conditions. Among the gene products encoded by these polysome-associated mRNAs were immediate-early transcription factors, kinases, and phosphatases of the mitogen-activated protein kinase pathways and several protooncogenes, including c-myc and Pim-1. In addition, the mRNA encoding Cyr61, a secreted factor that can promote angiogenesis and tumor growth, was selectively mobilized into polysomes when eIF4F concentrations were reduced, although its overall abundance changed only slightly. Subsequent tests confirmed the presence of internal ribosome entry sites in the 5′ noncoding regions of both Cyr61 and Pim-1 mRNAs. Overall, this study suggests that diverse mRNAs whose gene products have been implicated in a variety of stress responses, including inflammation, angiogenesis, and the response to serum, can use translational initiation mechanisms that require little or no intact cap binding protein complex eIF4F.

Perturbation of the T cell repertoire in rheumatoid arthritis

Aberrations in the T cell repertoire with the emergence of oligoclonal populations have been described in patients with rheumatoid arthritis (RA). However, the extent of the repertoire perturbations as well as the underlying mechanisms are not known. We now have examined the diversity of the peripheral CD4 T cell repertoire by determining the frequencies of arbitrarily selected T cell receptor (TCR) β-chain sequences. Healthy individuals displayed a highly diverse repertoire, with a median frequency of individual TCR β-chain sequences of 1 in 2.4 × 107 CD4 T cells. In RA patients, the median TCR β-chain frequency was increased 10-fold, indicating marked contraction of the repertoire (P < 0.001). The loss in TCR diversity was not limited to CD4 memory T cells but also involved the compartment of naive T cells, suggesting that it reflected an abnormality in T cell repertoire formation and not a consequence of antigen recognition in the synovium. Also, control patients with chronic inflammatory disease such as hepatitis C expressed a diverse repertoire indistinguishable from that of normals. Telomere length studies indicated an increased replicative history of peripheral CD4 T cells in RA patients, suggesting an enhanced turnover within the CD4 compartment. Compared with age-matched controls, terminal restriction fragment sizes were 1.7 kilobases shorter (P < 0.001). These data demonstrate an altered CD4 T cell homeostasis in RA that may contribute to the autoimmune response as well as to the immunodeficiency in these patients.

Involvement of a cytosine side chain in proton transfer in the rate-determining step of ribozyme self-cleavage

Ribozymes of hepatitis delta virus have been proposed to use an active-site cytosine as an acid-base catalyst in the self-cleavage reaction. In this study, we have examined the role of cytosine in more detail with the antigenomic ribozyme. Evidence that proton transfer in the rate-determining step involved cytosine 76 (C76) was obtained from examining cleavage activity of the wild-type and imidazole buffer-rescued C76-deleted (C76Δ) ribozymes in D2O and H2O. In both reactions, a similar kinetic isotope effect and shift in the apparent pKa indicate that the buffer is functionally substituting for the side chain in proton transfer. Proton inventory of the wild-type reaction supported a mechanism of a single proton transfer at the transition state. This proton transfer step was further characterized by exogenous base rescue of a C76Δ mutant with cytosine and imidazole analogues. For the imidazole analogues that rescued activity, the apparent pKa of the rescue reaction, measured under kcat/KM conditions, correlated with the pKa of the base. From these data a Brønsted coefficient (β) of 0.51 was determined for the base-rescued reaction of C76Δ. This value is consistent with that expected for proton transfer in the transition state. Together, these data provide strong support for a mechanism where an RNA side chain participates directly in general acid or general base catalysis of the wild-type ribozyme to facilitate RNA cleavage.

SURVEY AND SUMMARY: Recent advances in the elucidation of the mechanisms of action of ribozymes

The cleavage of RNA can be accelerated by a number of factors. These factors include an acidic group (Lewis acid) or a basic group that aids in the deprotonation of the attacking nucleophile, in effect enhancing the nucleophilicity of the nucleophile; an acidic group that can neutralize and stabilize the leaving group; and any environment that can stabilize the pentavalent species that is either a transition state or a short-lived intermediate. The catalytic properties of ribozymes are due to factors that are derived from the complicated and specific structure of the ribozyme–substrate complex. It was postulated initially that nature had adopted a rather narrowly defined mechanism for the cleavage of RNA. However, recent findings have clearly demonstrated the diversity of the mechanisms of ribozyme-catalyzed reactions. Such mechanisms include the metal-independent cleavage that occurs in reactions catalyzed by hairpin ribozymes and the general double-metal-ion mechanism of catalysis in reactions catalyzed by the Tetrahymena group I ribozyme. Furthermore, the architecture of the complex between the substrate and the hepatitis delta virus ribozyme allows perturbation of the pKa of ring nitrogens of cytosine and adenine. The resultant perturbed ring nitrogens appear to be directly involved in acid/base catalysis. Moreover, while high concentrations of monovalent metal ions or polyamines can facilitate cleavage by hammerhead ribozymes, divalent metal ions are the most effective acid/base catalysts under physiological conditions.

A secondary-structure model for the self-cleaving region of Neurospora VS RNA.

Neurospora VS RNA performs an RNA-mediated self-cleavage reaction whose products contain 2',3'-cyclic phosphate and 5'-hydroxyl termini. This reaction is similar to those of hammerhead, hairpin, and hepatitis delta virus ribozymes; however, VS RNA is not similar in sequence to these other self-cleaving motifs. Here we propose a model for the secondary structure of the self-cleaving region of VS RNA, supported by site-directed mutagenesis and chemical modification structure probing data. The secondary structure of VS RNA is distinct from those of the other naturally occurring RNA self-cleaving domains. In addition to a unique secondary structure, several Mg-dependent interactions occur during the folding of VS RNA into its active tertiary conformation.

Avaliação de fatores virológicos associados ao desenvolvimento de carcinoma hepatocelular (CHC) em pacientes com hepatite B crônica

O objetivo principal deste estudo foi avaliar fatores virais associados com a evolução para o carcinoma hepatocelular (CHC) em pacientes com hepatite B crônica. Para tanto caracterizamos os subgenótipos do HBV, investigamos a ocorrência de mutações nos genes pré-core/core do HBV associadas à presença de CHC avaliamos por análise filogenética a associação de linhagens virais com a ocorrência de CHC e por fim a associação de outros fatores de risco com o desenvolvimento de CHC. Foram incluídos 119 amostras de soro de pacientes com infecção crônica pelo HBV, destas amostras 60 pertencem ao grupo 1 (CHC), que são pacientes com diagnóstico confirmado de carcinoma hepatocelular e 59 amostras pertencem ao grupo 2 (sem CHC) que são pacientes com hepatite crônica sem detecção prévia de nódulos hepáticos. Foram obtidas informações acerca da idade, sexo e naturalidade. Além disso, os pacientes responderam a um questionário sobre fatores de riscos associados ao desenvolvimento de CHC. Foram realizados exames bioquímicos, sorológicos, determinação da carga viral, e amplificação por nested PCR e sequenciamento das regiões S/polimerase e pré-core/core do genoma viral para posterior caracterização dos genótipos/subgenótipos do HBV e pesquisa de mutações associadas com evolução da doença hepática. Em relação à idade e sexo não houve grande variação entre os grupos. Quanto à naturalidade a maioria era procedente da região sudeste, seguido pela região nordeste; e por fim seis pacientes eram procedentes de outros países. Com base no sobrenome dos pacientes avaliou-se também a frequência de etnia oriental na casuística estudada, que foi similar nos 2 grupos. O perfil sorológico HBeAg negativo foi o mais frequente nos dois grupos de pacientes, assim como níveis de carga viral abaixo de 2.000 UI/mL. Em relação aos exames bioquímicos foram observadas diferenças estatisticamente significantes nos níveis séricos de AFP (p= 0,0013), FA (p= 0,0003) e GGT (p= 0,005). Dentre os fatores de risco analisados neste estudo, o consumo de amendoim foi o único que apresentou significância estatística (p= 0,003). A região S/pol foi amplificada e sequenciada com sucesso em 58 amostras (28 do grupo 1 e 30 do grupo 2). Entre as 58 amostras analisadas 4 genótipos e 8 subgenótipos do HBV foram identificados, sendo o subgenótipo A1 o mais frequente nos dois grupos. Não se observou diferença estatisticamente significante na distribuição dos subgenótipos entre os dois grupos de pacientes. Na topologia da árvore filogenética construída com sequências do HBV isoladas dos pacientes incluídos neste estudo e sequências disponíveis no GenBank não se observou padrões de agrupamento associados com o perfil clinico do paciente (com e sem CHC). Foram obtidas sequências de boa qualidade da região précore/ core em 44 amostras, sendo 20 amostras do grupo 1 e 24 do grupo 2. Diversas das mutações investigadas foram identificadas na região précore/ core, as quais foram avaliadas estatisticamente para verificar a existência de diferença na frequência das mesmas entre os grupos de pacientes estudados. Entre as mutações identificadas se destacaram com significância estatística as seguintes mutações: T1768A (p= 0,006), a combinação das mutações C1766T + T1768A (p= 0,043) e G1888H (p= 0,05). Na análise de regressão logística simples foi possível identificar que a chance de um paciente do grupo 2 desenvolver CHC aumenta 14,7 vezes na presença de infecção por cepas do HBV com a mutação T1768A, enquanto que a infecção com cepas do HBV que albergam a mutação G1888H reduz tal chance 2,5 vezes

Heterogeneity in testing practices for infections during pregnancy: national survey across Switzerland.

QUESTION Detection and treatment of infections during pregnancy are important for both maternal and child health. The objective of this study was to describe testing practices and adherence to current national guidelines in Switzerland. METHODS We invited all registered practicing obstetricians and gynaecologists in Switzerland to complete an anonymous web-based questionnaire about strategies for testing for 14 infections during pregnancy. We conducted a descriptive analysis according to demographic characteristics. RESULTS Of 1138 invited clinicians, 537 (47.2%) responded and 520 (45.6%) were eligible as they are currently caring for pregnant women. Nearly all eligible respondents tested all pregnant women for group B streptococcus (98.0%), hepatitis B virus (HBV) (96.5%) and human immunodeficiency virus (HIV) (94.7%), in accordance with national guidelines. Although testing for toxoplasmosis is not recommended, 24.1% of respondents tested all women and 32.9% tested at the request of the patient. Hospital doctors were more likely not to test for toxoplasmosis than doctors working in private practice (odds ratio [OR] 2.52, 95% confidence interval [CI] 1.04-6.13, p = 0.04). Only 80.4% of respondents tested all women for syphilis. There were regional differences in testing for some infections. The proportion of clinicians testing all women for HIV, HBV and syphilis was lower in Eastern Switzerland and the Zurich region (69.4% and 61.2%, respectively) than in other regions (range 77.1-88.1%, p <0.001). Most respondents (74.5%) said they would appreciate national guidelines about testing for infections during pregnancy. CONCLUSIONS Testing practices for infections in pregnant women vary widely in Switzerland. More extensive national guidelines could improve consistency of testing practices.

CCR5-Delta 32 mutation is strongly associated with primary sclerosing cholangitis

CCR5 plays a key role in the distribution of CD45RO+ T cells and contributes to generation of a T helper 1 immune response. CCR5-Delta32 is a 32-bp deletion associated with significant reduction in cell surface expression of the receptor. We investigated the role of CCR5-Delta32 on susceptibility to ulcerative colitis (UC), Crohn's disease ( CD) and primary sclerosing cholangitis (PSC). Genotype and allelic association analyses were performed in 162 patients with UC, 131 with CD, 71 with PSC and 419 matched controls. There was a significant difference in CCR5 genotype (OR 2.27, P = 0.003) between patients with sclerosing cholangitis and controls. Similarly, CCR5-Delta32 allele frequency was significantly higher in sclerosing cholangitis (17.6%) compared to controls (9.9%, OR 2.47, P = 0.007) and inflammatory bowel disease patients without sclerosing cholangitis ( 11.3%, OR 1.9, P = 0.027). There were no significant differences in CCR5 genotype or allele frequency between those with either UC or CD and controls. Genotypes with the CCR5-Delta32 variant were increased in patients with severe liver disease defined by portal hypertension and/or transplantation (45%) compared to those with mild liver disease (21%, OR 3.17, P = 0.03). The CCR5-Delta32 mutation may influence disease susceptibility and severity in patients with PSC.

Modest weight loss and physical activity in overweight patients with chronic liver disease results in sustained improvements in alanine aminotransferase, fasting insulin, and quality of life

Background and aim: Obesity is a risk factor for progression of fibrosis in chronic liver diseases such as non-alcoholic fatty liver disease and hepatitis C. The aim of this study was to investigate the longer term effect of weight loss on liver biochemistry, serum insulin levels, and quality of life in overweight patients with liver disease and the effect of subsequent weight maintenance or regain. Patients: Thirty one patients completed a 15 month diet and exercise intervention. Results: On completion of the intervention, 21 patients (68%) had achieved and maintained weight loss with a mean reduction of 9.4 (4.0)% body weight. Improvements in serum alanine aminotransferase (ALT) levels were correlated with the amount of weight loss (r=0.35, p=0.04). In patients who maintained weight loss, mean ALT levels at 15 months remained significantly lower than values at enrolment (p=0.004), while in regainers (n=10), mean ALT levels at 15 months were no different to values at enrolment (p=0.79). Improvements in fasting serum insulin levels were also correlated with weight loss (r=0.46, p=0.04), and subsequent weight maintenance sustained this improvement. Quality of life was significantly improved after weight loss. Weight maintainers sustained recommended levels of physical activity and had higher fasting insulin levels (p=0.03) at enrolment than weight regainers. Conclusion: In summary, these findings demonstrate that maintenance of weight loss and exercise in overweight patients with liver disease results in a sustained improvement in liver enzymes, serum insulin levels, and quality of life. Treatment of overweight patients should form an important component of the management of those with chronic liver disease.