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At least 145 records · Page 8Linked to original sources
PubMed2002

Rationale and design of TeraViC-4 study: a phase III, randomized clinical trial to evaluate the effects of treatment duration with peginterferon alfa-2a (40-kDa) and ribavirin in naïve patients with chronic hepatitis C virus infection without early virological response at week 4.

Several studies are available on the efficacy and safety of 40 kDa branched peginterferon alfa-2a (40-kDa) combined with ribavirin in the treatment of chronic hepatitis C patients. The TeraViC-4 study is a phase III, randomized, parallel group, multicenter study that includes two additional open arms. The main objective is to investigate if extended therapy over 72 weeks increases the rate of sustained virological response induced by a standard 48-week treatment period in naïve patients with chronic hepatitis C who do not show an early virological response. All patients will be treated with peginterferon alfa-2a (40-kDa), 180 micrograms subcutaneous (s.c.) once-weekly, and ribavirin, 400 mg b.i.d. Virological response will be assessed by a hepatitis C virus ribonucleic acid (HCV-RNA) qualitative polymerase chain reaction (PCR) test. Non-early responders (HCV-RNA still detectable after 4 weeks of therapy) will be randomly separated to receive combination therapy for 44 or 68 additional weeks. Early responders (undetectable HCV-RNA at week 4) will be allocated into two open arms according to HCV genotype and basal viral load, and they will be treated for 20 or 44 additional weeks. All patients will be followed for 24 weeks on no therapy. A total of 504 patients are planned to be included in the study in order to reach the required sample size in the two randomized groups. Efficacy of treatment will be assessed by determination of HCV-RNA and the primary efficacy variable is the rate of sustained virological response (after 24 weeks of treatment-free follow-up) in patients without early virological response. Secondary efficacy variables are the rate of sustained biochemical response, the rate of response in function of HCV genotype, viral load and treatment duration. Safety data will also be recorded and analyzed.

Antiviral Agents↗
PubMed2004

Predictive value of HIV-1 protease genotype and virtual phenotype on the virological response to lopinavir/ritonavir-containing salvage regimens.

The predictive values of HIV-1 protease genotype and virtual phenotype (vPhenotype) results on the HIV-1 RNA response to lopinavir/ritonavir (LPV/r)-containing salvage regimens were assessed. Data were evaluated from patients with antiretroviral (ARV) resistance testing prior to initiating an LPV/r-containing salvage ARV regimen, from two independent cohorts from Toronto, Ontario and British Columbia, Canada. Multivariate logistic regression models controlling for previous non-nucleoside reverse transcriptase inhibitor use, baseline viral load and AIDS-defining illness were used to assess the impact of different protease genotypic mutations (individual and in combination) and lopinavir vPhenotyping on virological suppression to <50 copies/ml by 12 months. We confirmed that the 11-mutation 'lopinavir mutation score' (LMS) was significantly inversely associated with the probability of virological suppression within 12 months [odds ratio (OR)=0.91; P=0.02]. The only single specific protease mutation found to predict virological response in multivariate analyses was 461 (OR=0.55; P=0.02). The most predictive three-mutation combination was 10F/I/R/V, 461, 82A/F/T (OR=0.18; P=0.0004). We confirmed that a 10-fold increase of lopinavir IC50 is an appropriate clinical cut-off for lopinavir vPhenotype. In univariate analyses, a cut-off of the LMS as low as 3 was significantly associated with a lack of virological suppression (P=0.04). This finding, which is in contrast to those of other studies, may be due to the high degree of ARV experience of our population and lack of active agents in the salvage regimen. Selecting the 11 specific mutations to make the LMS is potentially arbitrary; we determined that when different combinations of 11 protease mutations were chosen randomly from a set of 30, similar associations with virological response were found, probably due to the co-linearity of these mutations.

Adult↗
PubMed2004

Variability in the interpretation of transmitted genotypic HIV-1 drug resistance and prediction of virological outcomes of the initial HAART by distinct systems.

High level HIV-1 drug resistance in recently infected treatment-naive individuals correlates with sub-optimal virological responses to highly active antiretroviral therapy (HAART). To determine whether genotypic HIV-1 drug resistance in chronic naive patients, as interpreted by various systems, could predict the virological outcomes of HAART, isolates from patients enrolled in a prospective observational cohort (ICoNA) prior to treatment start were genotyped. Genotypic susceptibility scores (GSS) assigned to the initial HAART regimens using the interpretations of pre-therapy resistance mutations by 13 systems were related to virological outcomes. Of 415 patients, 42 (10%) had at least one major resistance mutation. According to the different interpretations, 1.9-20.5% of patients had some level of resistance to at least one drug in the initial regimen. In multivariable analysis, GSS from two systems significantly predicted the time to virological success: Rega 5.5, for each unit increase in GSS adjusted relative hazard (RH) 1.86 [95% confidence intervals (95% CI): 1.15-3.02] and hivresistanceWeb v3, RH 1.87 (95% CI: 1.00-3.48). With three other systems, GSS showed a trend towards a significant prediction of success: Retrogram 1.6, RH 2.33 (95% CI: 0.98-5.53), Menéndez 2002, RH 2.36 (95% CI: 0.97-5.72) and Stanford hivdb, RH 2.06 (95% CI: 0.94-4.49). Genotypic resistance testing coupled with adequate interpretation in chronic naive patients can usefully identify those at risk of sub-optimal virological response to HAART. This work was presented in part at the First European Workshop on HIV Drug Resistance. Luxembourg, 4-6 March 2003 (Abstract 44); and at the 9th European Conference on CIinical AIDS Therapy. Warsaw, 25-28 October 2003 (Abstract F6/7).

Adult↗
PubMed2006

[Virological response of chronic hepatitis C management with peg-interferon alpha-2b and ribavirin].

OBJECTIVE: To evaluate the virological response of managing chronic hepatitis C (CHC) with peg-interferon alpha-2b (PEG-IFN alpha-2b) and ribavirin. METHODS: We retrospectively analyzed the virological response of 40 patients with different genotypes of hepatitis C virus (HCV) infection after anti-HCV management. Patients were given different dosages of PEG-IFN alpha-2b and ribavirin based on their weights. The duration of treatment was 48 weeks for patients infected by HCV genotype 1, and was 24 weeks for the others. HCV RNA was tested before treatment, 12 weeks post management, end of treatment, and 24 weeks after treatment stopped. RESULTS: Data from 40 patients were collected. Among them, 24 cases experienced HCV genotype 1 infection, and 16 cases were infected with other genotypes. Between these two groups, the early virological responses were 75.0% (18/24) and 87.5% (14/16), the end-of-treatment virological responses were 80.0% (16/20) and 85.7% (12/14), and the sustained virological responses were 56.2% (9/16) and 78.5% (11/14), respectively. CONCLUSION: Body weight-based customized PEG-IFN alpha-2b in combination with ribavirin can effectively treat patients with different genotypes of CHC.

Adult↗
PubMed2005

Estimates of global research productivity in virology.

The quantity and quality of published research in the field of Virology by different world regions was estimated in this study. Using the PubMed database, articles from journals included in the "Virology" category of the "Journal Citation Reports" database of the Institute for Scientific Information for the period 1995-2003 were retrieved. The world was divided into nine regions based on geographic, economic, and scientific criteria. Data on the country of origin of the research was available for 33,425 out of 33,712 articles (99.2% of all articles from the included journals). USA exceeds all other world regions in research production for the period studied (42% of total articles), with Western Europe ranking second (35.7%). The mean impact factor in articles published in Virology journals was highest for the USA (4.60), while it was 3.90 for Western Europe and 3.22 for the rest of the world (seven regions combined). USA and Canada ranked first in research productivity when both gross national income per capita (GNIPC) and population were taken into account. The results of this analysis show a distressing fact; the absolute and relative production of research in the field of Virology by the developing regions is very low, although viral diseases cause considerable morbidity and mortality in these areas. It is evident from this study that developing regions need more help from the developed regions to enhance research infrastructure.

Bibliometrics↗
PubMed2005

United States Pharmacopeia activities in the area of vaccines, virology and immunology.

The United States Pharmacopeia (USP) develops public standards for medical products that are enforceable by FDA. USP general information chapters have been providing industrial and academic researchers alike with crucial guidance especially in areas where there is absence of regulatory guidance. In an effort to meet the challenge of rapid advances in vaccine research and manufacturing, the Council of Experts Committee for Vaccines, Virology, and Immunology of the US Pharmacopeia has recently initiated two new general chapters to provide advice for researchers and manufacturers in the vaccine and virology fields and beyond. Chapter 1235 Vaccines and Vaccine Test Methods will focus on manufacturing and analytical requirements for the different types of vaccines currently in manufacture and development. Chapter 1237 Virology Test Methods will discuss modern diagnostic virology techniques and a variety of tests as applicable to vaccine and biologics manufacturing.

Allergy and Immunology↗
PubMed2002

Clinical virology in real time.

The ability to detect nucleic acids has had and still has a major impact on diagnostics in clinical virology. Both quantitative and qualitative techniques, whether signal or target amplification based systems, are currently used routinely in most if not all virology laboratories. Technological improvements, from automated sample isolation to real time amplification technology, have given the ability to develop and introduce systems for most viruses of clinical interest, and to obtain clinical relevant information needed for optimal antiviral treatment options. Both polymerase chain reaction (PCR) and nucleic acid sequence-based amplification (NASBA) can currently be used together with real time detection to generate results in a short turn-around time and to determine whether variants relevant for antiviral resistance are present. These new technologies enable the introduction of an individual patient disease management concept. Within our clinical setting, we have introduced this e.g. for quantitative detection of Epstein-Barr Virus (EBV) in T-dell depleted allogeneic stem cell transplant patients. This enabled us to develop models for pre-emptive anti B-cell immunotherapy for EBV reactivation, thereby effectively reducing not the incidence of EBV-lymphoproliferative disease but the virus related mortality. Furthermore, additional clinically relevant viruses can now easily be detected simultaneously. It also becomes more feasible to introduce molecular testing for those viruses that can easily be detected using classical virological methods, like culture techniques or antigen detection. Prospective studies are needed to evaluate the clinical importance of the additional positive samples detected. It should however be made clear that a complete exchange of technologies is unlikely to occur, and that some complementary technologies should stay operational enabling the discovery of new viruses. The implementation of these molecular diagnostic technologies furthermore warrants the use and introduction of standardized materials as well as participation in international quality control programs. Finally, the use of an internal control throughout the whole procedure not only ensures the accuracy of the results generated, but also is necessary to enable precise quantification of these results and to determine detection thresholds more accurately. Since so many targets do have clinical implications, laboratories might prefer to use universal internal controls before the in-house developed assays should be introduced in clinical virology.

Disease Management↗
PubMed1992

Standardization of sensitive human immunodeficiency virus coculture procedures and establishment of a multicenter quality assurance program for the AIDS Clinical Trials Group. The NIH/NIAID/DAIDS/ACTG Virology Laboratories.

An independent quality assurance program has been established by the Division of AIDS, National Institute of Allergy and Infectious Diseases, for monitoring virologic assays performed by nearly 40 laboratories participating in multicenter clinical trials in the United States. Since virologic endpoints are important in evaluating the timing and efficacy of therapeutic interventions, it is imperative that virologic measurements be accurate and uniform. When the quality assurance program was initially created, fewer than 40% of the laboratories could consistently recover human immunodeficiency virus (HIV) from peripheral blood mononuclear cells (PBMCs) of HIV-infected patients. By comparing coculture procedures in the more competent laboratories with those in laboratories who were struggling to isolate virus, optimal conditions were established and nonessential reagents and practices were eliminated. Changes were rapidly introduced into a laboratory when experience dictated that such modifications would result in a favorable outcome. Isolation of HIV was enhanced by optimizing the numbers and ratios of patient and donor cells used in cultures, by standardizing PBMC separation procedures, by using fresh rather than frozen donor PBMCs, by processing whole blood within 24 h, and by using natural delectinated interleukin 2 instead of recombinant interleukin 2 products in existence at that time. Delays of more than 8 h in the addition of phytohemagglutinin-stimulated donor cells to freshly separated patient PBMCs reduced recovery. Phytohemagglutinin in cocultures and the addition of Polybrene and anti-human alpha interferon to media were not important in HIV isolation. The introduction of a consensus protocol based on this information brought most laboratories quickly into compliance. In addition, monthly monitoring has successfully maintained proficiency among the laboratories, a process that is critical for the scientific integrity of collaborative multicenter trials. Problems which might not be appreciated for months are now being resolved early, before data can be compromised unknowingly. This consensus protocol is recommended for any laboratory attempting to isolate HIV for the purpose of standardizing recovery and for accessing virologic endpoints in clinical trials.

Culture Media↗
PubMed2002

The origin of modern plant virology.

Plant virology, born with Mayer's work, saw a first (embryonic) phase of development during two decades (1900-1920) with outstanding contributions from Dimitri Ivanovski, Martinus Beijerinck, Erwin Baur and Harry Allard. Between 1920 and 1930 a second phase saw the elaboration of surprising hypotheses concerning the enigmatic nature of viruses and experimental evidence of great stress was obtained. Revolutionary renewal began from the mid-1930s on the basis of a body of knowledge which was organically assembled into the first textbook of plant virology published by Kenneth Smith in 1933. In 1922, the geneticist Hermann Muller put forward the hypothesis that considered viruses as possible genes. The theory was resumed in an apparently independent way by Benjamin Duggar and Joanne Karrer Armstrong in 1923, who considered TMV a biocolloidal self-reproducing protein, like genes appeared to be. This hypothesis, even if neglected by virologists, anticipated by some decades the functional nature of viruses and represented the first conceptual response to virus enigma. Considerable experimental results were obtained by James Johnson, who showed that plants could be infected by different viruses and who introduced a first rational system of plant virus classification. Harold McKinney showed that TMV could mutate. Harold Storey, Kenneth Smith and Harry Severin demonstrated that several viruses could be transmitted by insects and supplied the first interpretation of the relationship between virus and insect. Mayme Dvorak and Helen Purdy obtained the first experimental evidence of the antigenic power of plant viruses. Virus purification, first tentatively accomplished with physical methods, was brilliantly performed by chemical means. Finally, Francis Holmes elaborated the first suitable test to estimate virus infectivity. The evolution of plant virology from an empirical discipline to a biological science took place thanks to the work of one group of American and English scientists who must be regarded as the fathers of modern plant virology.

History, 20th Century↗
PubMed2005

[Venezuelan Virology Network].

In November 2004, sponsored by the World Bank, the Venezuelan Foundation of Science, Technology and Innovation (Fonacit) and the Venezuelan Institute of Scientific Research (IVIC), delegates from the different virology research groups of the country, met in Caracas-Venezuela, with the aim to establish the "Venezuelan Virology Network". The symposium entitled "Molecular biology applied to virus of health importance in Venezuela", was divided into three areas, including human and animals viruses related to public health: 1) Dengue, others arboviruses and Hemorrhagic Fevers; 2) diarrhea-related and others veterinary viruses and 3) Hepatitis, HIV and others sexually transmitted viruses. This symposium allowed the delegates to evaluate the current strengths, weaknesses and needs of the different laboratories, becoming evident the necessity of developing collaborative work between the groups that share the same interests or lines of research; and also their need to exchange technical resources, human and bibliographical material and consequently, avoiding the duplication of efforts and the unnecessary cost of resources. One of the main strengths of Venezuelan virology is the presence, in most laboratories, of researchers with studies of fourth level and multidisciplinary teams of work. We aspire to achieve the raised objectives in the event, to the benefit of our virology and even more important, of our people.

Computer Communication Networks↗
PubMed2002

Virological and immunological effects of salvage therapy following treatment interruption and a shift in HIV-1 resistance genotype.

The circulating human immunodeficiency virus type 1 (HIV-1) population of patients in whom many prior therapy regimens have failed often undergo a shift from a drug-resistant virus to a wild-type virus following interruption of treatment. This study analyses the virological and immunological effects of salvage therapy following treatment interruption and a shift from a drug-resistance genotype. Twenty-one HIV-1 infected patients who had genotype reversion by population-based sequencing after 3 months of treatment interruption were given a new salvage regimen consisting of 3-5 drugs selected according to their treatment history. Seven (33%) of 21 patients who had fewer than 200 HIV-1 RNA copies/ml until month 12 were defined as virological responders. Four patients were transient responders and 10 were nonresponders. The virological responders were more frequently CDC group A and had higher CD4 + T lymphocyte counts at the time of treatment resumption. The peripheral blood T CD4 + and T CD8 + lymphocyte populations of the patients declined significantly during treatment interruption. Only virological responders showed significant increases in their CD4 + T lymphocyte count 12 months after treatment resumption and these counts rapidly returned to pre-interruption baseline values in most of these patients. Treatment interruption could be useful for optimising salvage therapy for patients previously given many failing regimens. However, controlled trials are needed to assess the clinical benefit of this strategy.

Adult↗
PubMed1998

Virological importance of the protease-cleavage site in human immunodeficiency virus type 1 Nef is independent of both intravirion processing and CD4 down-regulation.

The HIV-1 Nef protein is present within the virion and is processed there by the viral protease. Mutational analysis indicated that residues 54-60 in HIV-1 Nef were required for intravirion cleavage. When viruses were produced using T cell lines or primary lymphoblasts, these residues were also required for optimal viral infectivity. However, substitution of native Nef residues with those of a functional Gag cleavage site demonstrated that intravirion cleavage was insufficient for the virological function of this domain. Furthermore, the importance of certain cleavage site residues to infectivity was conditional on the producer cell type. In particular, a mutant containing a deletion of residues 54-57 was phenotypically nef defective when produced using T cells (CEM, A2.01, or primary lymphoblasts) but was minimally impaired when produced from 293 or HeLa cells. This mutant was cleavage resistant, indicating that proteolytic processing of Nef was dispensable for infectivity enhancement when virions were assembled in certain non-T cells. Residues 54-61 of the cleavage site, including 54-57, were also required for Nef-mediated down-regulation of CD4. However, the surface expression of CD4 on HeLa cells in amounts comparable to that on the surface of primary T lymphoblasts did not create a producer cell environment in which residues 54-57 acquired greater virological importance. Furthermore, these residues were required for optimal infectivity even during virion assembly in T cells (A2. 01) that expressed a CD4 molecule that is unable to respond to Nef. These data suggested that in producer T cells, certain cleavage site residues (54-57) contribute to a Nef-mediated virological effect that is unlikely to be linked causally to CD4 down-regulation. Conversely, in the context of 293 cells as viral producers, the Delta54-57 mutant separated genetically down-regulation of CD4 (for which it was defective) from enhancement of infectivity (for which it was functional). Together, these data indicate that the virological function of the cleavage site domain is both independent of intravirion proteolytic processing of Nef and independent of CD4 down-regulation.

Amino Acid Sequence↗
PubMed2005

Prospective study on early virologic response to treatment with interferon alpha-2b plus ribavirin in patients with chronic hepatitis C genotype 1b.

To evaluate the predictive value of early virologic response (EVR) of achieving a sustained virologic response (SVR), an open, prospective trial including 42 patients with chronic hepatitis C genotype 1b was performed with directly observed 24-week treatment with interferon alpha-2b plus ribavirin. We assessed the predictive values of EVR at days 3, 7, 14, and weeks 4, 8, and 12 of the SVR. The SVR in an intention-to-treat analysis was 19.0%. Patients who reached SVR presented a significantly faster reduction in plasma viral load. Stepwise multiple logistic regression analysis of the factors (gender, age, IFN dosage, ribavirin dosage, HCV RNA, ISDR, and loss of HCV RNA at week 4) revealed that loss of HCV RNA at week 4 was the only independent variable of treatment outcome (P=0.0039). A viral load at treatment day 3 above 100kIU/ml, at day 7 above 50kIU/ml, and at day 14 above 10kIU/ml was 100% predictive for virologic non-response in all except 1 patient. The cutoff levels for HCV RNA at days 3 and 14 of treatment were associated with an algorithm of the failure to detect HCV RNA after 12 weeks of treatment. In conclusions, a very early virologic response assessment could be useful for prediction of later outcome of combination therapy in chronic hepatitis C genotype 1b.

Journal Article↗
PubMed2006

Virological response to HIV-1 nucleoside/nucleotide reverse transcriptase inhibitors-based, tenofovir DF-including regimens in the ANRS Aquitaine Cohort.

BACKGROUND: HIV-1 nucleoside/tide reverse transcriptase inhibitors (NRTI)-only based, comprising tenofovir DF(TDF) have been shown to lead to high rates of virological failures (VF), mainly in patients on first-line combination therapy. We wished to investigate the virological response to these regimens in a large cohort of antiretroviral (ARV)-treated patients. METHODS: Patients followed-up in the Aquitaine Cohort in 2001-2003 and who had received NRTI-based, TDF-including regimens for at least 3 months were included. The VF was defined as: (i) a decrease in plasma HIV-1 RNA <0.5 log(10)copies/ml between M0 and M3; or (ii) a plasma HIV-1 RNA >50 copies/ml at M3 in patients with plasma HIV-1 RNA <50 copies/ml at M0. The baseline RT genotype was determined in a subgroup of patients. RESULTS: Within 121 patients (95% ARV-experienced) who received either lamivudine (3TC)/didanosine (DDI)/TDF (n=48), or abacavir (ABC)/3TC/TDF (n=14), or 3TC/zidovudine (ZDV)/TDF (n=27), or 3TC/ZDV/ABC/TDF (n=20), or DDI/ABC/TDF (n=12), the ABC/3TC/TDF and DDI/ABC/TDF combinations were associated with the highest frequencies of VF. In contrast the use of ZDV was related to a better virological response. The baseline RT genotype was also predictive of the virological outcome. CONCLUSION: NRTI-based, TDF-including therapies can lead to high rates of VF both in ARV-naïve and in ARV-experienced patients. Our data strongly suggest the interest of associating ZDV and TDF in these regimens.

Adenine↗
PubMed2004

Association of serum interleukin-8 with virologic response to antiviral therapy in patients with chronic hepatitis C.

BACKGROUND/AIMS: Upregulation of interleukin-8 by the hepatitis C virus non-structural-5A-protein leads to inhibition of the antiviral activity of interferon-alpha in vitro. The clinical significance of interleukin-8 levels for virologic response to interferon-alpha-based treatment in patients with chronic hepatitis C is unknown. METHODS: We investigated serum interleukin-8 in 59 healthy controls and 214 patients with chronic hepatitis C (genotype 1, n=152; genotype 2, 3, n=62) and different outcome to interferon-alpha-based therapy. RESULTS: In patients with chronic hepatitis C higher interleukin-8 levels were observed compared with healthy controls (P<0.0001). Hepatitis C genotype 1-infected patients with early and overall virologic response to interferon-alpha-based therapy showed lower interleukin-8 levels than non-responders (P=0.025 and P=0.035, respectively). In all patients, elevated interleukin-8 levels were associated with cirrhosis (genotype 1, P=0.0003; genotype 2, 3, P=0.009). Interleukin-8 levels in sustained virologic responders were still higher 24 weeks after the end-of-therapy compared with healthy controls (P<0.0001). CONCLUSIONS: In genotype 1 infected patients, low pretreatment serum interleukin-8 is associated with virologic response to interferon-alpha-based therapy. Thus, the conclusion from in vitro studies that the upregulation of interleukin-8 by the hepatitis C virus contributes to the inhibition of the antiviral actions of interferon-alpha may also be applicable in vivo.

Adult↗
PubMed2005

Predicting sustained virological responses in chronic hepatitis C patients treated with peginterferon alfa-2a (40 KD)/ribavirin.

BACKGROUND/AIMS: Prediction of sustained virological response (SVR) during treatment would allow clinicians to identify patients most likely to benefit from therapy. METHODS: Retrospective analysis of data from 1121 adults with chronic hepatitis C treated for 48 weeks with peginterferon alfa-2a (40 KD) 180 microg/week plus placebo or ribavirin (1000/1200 mg/day), or interferon alfa-2b 3 MIU three times/week plus ribavirin in a randomized, multinational, study. RESULTS: 67% of patients treated with peginterferon alfa-2a (40 KD)/ribavirin with early virological responses (HCV RNA negative or > or = 2 log10 decrease) at week 12 had SVRs at week 72 (HCV RNA < 50 IU/mL). The negative predictive value (NPV) was 97%. The probability of an SVR increased with the rapidity of HCV RNA suppression. The highest SVR rates were achieved in patients with rapid virological responses at week 4, but the corresponding NPV (74%) is too low for a decision criterion. In patients with early virological responses by week 12, the SVR rate was approximately 20% lower in those who received <80% compared with patients who received > or = 80% of the planned ribavirin dose. CONCLUSIONS: Early, sustained suppression of HCV replication portends an SVR. Cessation of treatment may be contemplated in patients without a > or = 2 log10 reduction in HCV RNA after 12 weeks.

Antiviral Agents↗
PubMed2006

Sustained virological response to antiviral therapy reduces mortality in HCV reinfection after liver transplantation.

BACKGROUND/AIMS: HCV infection recurs almost in all HCV-positive patients receiving liver transplantation and carries a poor prognosis. Aim of this study was to analyze efficacy and effect on survival of antiviral therapy in this clinical setting. METHODS: Pegylated-interferon alpha-2b and ribavirin were administered at a dose of 1 microg/kg of bwt weekly and 600-800 mg/day. Planned duration of treatment was 24 or 48 weeks according to HCV genotype. Patients who failed to respond at week 24 were considered as non-responders. RESULTS: 61 patients were enrolled. According to intention-to-treat analysis, 44 (72%) patients were considered as treatment failure (31 non-responders, 4 relapsers, 9 dropout). Sustained virological response was achieved in 17 cases (28%). Genotype 2, higher doses of antivirals and absence of histological cirrhosis were predictors of sustained virological response. In the follow up, patients with sustained virological response had a significantly lower mortality compared to patients with treatment failure (chi2=6.9; P<0.01). CONCLUSIONS: Response rate to antiviral therapy in HCV reinfection after liver transplantation is higher if a full dose of antiviral drugs is administered and if treatment starts before histological cirrhosis has developed. Sustained virological response improves patient survival.

Adult↗
PubMed2003

Change to abacavir-lamivudine-tenofovir combination treatment in patients with HIV-1 who had complete virological suppression.

Patients who have not received previous antiretroviral treatment (ART) have a high failure rate on the combination treatment of abacavir, lamivudine, and tenovir. We assessed the virological failure rate in eight patients with HIV-1 who switched to this combination after having complete virological suppression from their previous long-term ART (median 8.0 months, range 7.5-18.0). Five of the eight patients showed virological failure. Four of these five patients had either the K65R mutation, the M184V/I mutation, or both. This combination of drugs cannot therefore be recommended as alternative treatment in patients with HIV-1 who are fully virologically suppressed.

Adenine↗