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PubMed2003

Superior virological efficacy of ritonavir-boosted protease inhibitor regimens compared to single protease inhibitor therapy.

Low dose-ritonavir boosted protease inhibitors are increasingly being used for the first-line antiretroviral treatment, though their virological efficacy has just poorly been compared to alternative antiretroviral therapies. Here, we retrospectively investigated the virological responses of 316 protease inhibitor-naive HIV patients receiving highly active antiretroviral treatment based on a single (n = 256) or a ritonavir-boosted protease inhibitor (n = 60), both in the background of two nucleoside analogues. - By intent-to-treat analysis, a complete initial virological response was achieved in 71.8% of all patients in the single protease inhibitor group (indinavir: 76%, ritonavir: 67.5%, nelfinavir: 70.6%) and in 88.3% (p = 0.008) of patients treated with a boosted protease inhibitor (saquinavir/r: 71.4%, indinavir/r: 92.1%, lopinavir/r: 86.6%). The multivariate risk analysis identified boosted PI treatment as an independent predictor of a complete virological response (OR = 2.8, p=0.02). Viral rebound after an initial complete virological response was observed in 28% and 17% (p = 0.06) of patients receiving a single or a dual protease inhibitor, respectively. The rate of durable viral suppression over 12 months was 44.5% and 56.7% (p = 0.09) in the respective study cohorts. Ritonavir-boosted protease inhibitors therefore seem to induce a superior virological response rate and a higher degree of sustained virological suppression.

Adult↗
PubMed2003

The effect of number of mutations and of drug-class sparing on virological response to salvage genotype-guided antiretroviral therapy.

OBJECTIVE: To assess on longitudinal data the impact of number of drug-associated mutations at genotype resistance testing (GRT) and history of previous exposure to antiretrovirals on the virological response to genotype-guided antiretroviral therapy. METHODS: Subjects that failed HAART who underwent GRT between June 1999 and March 2002 were enrolled. GRT was performed by Viroseq-2 with expert advice offered to physicians. Main outcome was reaching undetectable (< 80 copies/ml) HIV-1 RNA level after GRT and maintaining undetectable viraemia for at least 6 months. The number of mutations conferring resistance to each class of antiretrovirals was categorized and their effect on virological outcome investigated. Mutations considered in the analysis were those reported by the IAS-USA in 2002. Multivariate analysis was performed by Cox proportional hazard model. RESULTS: Four-hundred-and-seventy consecutive subjects were enrolled and followed-up for a median of 14 (IQR 9-19) months after GRT. Sustained undetectable viraemia was reached by 80 of 449 subjects (18%). Using as end-point reaching and maintaining for at least 6 months < 400 copies/ml after GRT, 103 out of 447 subjects (23%) reached the outcome. For each single protease inhibitor (PI)-, nucleoside reverse transcriptase inhibitor (NRTI)-and non-nucleoside reverse transcriptase inhibitor (NNRTI)-associated mutation, there was a reduction of, respectively, 11% (P = 0.008), 12% (P = 0.001) and 39% (P = 0.005) in the likelihood of reaching virological outcome. Subjects carrying > or = 6 mutations to NRTIs, > or = 7 mutations to PIs and > or = 2 mutations to NNRTIs were less likely to reach the virological success compared with those carrying 0-1 (NRTI and PI) or 0 (NNRTI) mutations [HR = 0.25 (95% CI: 0.10-0.65); HR = 0.33 (950% CI: 0.16-0.67); HR = 0.33 (95% CI: 0.14-0.77)], respectively. However, at multivariate analysis the probability of reaching a favourable virological outcome in patients with > or = 7 mutations to PIs, if naive for NNRTIs [HR = 1.74 (0.69-4.36)], and in subjects with > or = 2 mutations for NNRTIs if naive for PIs [HR = 1.23 (0.22-6.80)], was comparable to those observed in patients with none or one mutation. CONCLUSIONS: Our data showed a non-linear association between resistance-conferring mutations and virological outcome. GRT-guided therapy still provided remarkable chances of durable virological success even in subjects with > or = 7 mutations to PIs and in subjects with > or = 2 mutations to NNRTIs, when the subjects did not have a three-class exposure or if GRT showed no evidence of mutations for a drug class. GRT and as-long-as-possible sparing of a drug class could be a convenient strategy for long-term management of drug-failing patients.

Anti-HIV Agents↗
PubMed2007

Repeated measures analyses of dose timing of antiretroviral medication and its relationship to HIV virologic outcomes.

Medication adherence is a critical predictor of the effectiveness of antiretroviral medications in the treatment of HIV/AIDS. Studies of adherence, however, have focused primarily on the per cent of prescribed doses taken (per cent adherence). In the Adherence and Efficacy of Protease Inhibitor Therapy study, we collected detailed adherence data including dose timing information as well as data regarding patients' virologic responses. For 48 weeks, adherence data and virologic outcomes were collected every 4 weeks, and demographics and other measures were collected at baseline and at weeks 8, 24, and 48. We constructed eight different dose timing error (DTE) measures and evaluated their associations with virologic outcomes using longitudinal analyses. Repeated measures mixed effect models were fitted to evaluate the predicting power of each of the DTE measures. Among 52 036 electronically measured doses obtained from 122 patients, DTE measures significantly predicted virologic outcomes. Of the eight different DTE measures, the six DTE measures were significantly predictive of virologic outcomes even after controlling for per cent adherence. In conclusion, we identified several measures of DTE that explain HIV virologic outcomes not captured by traditional adherence measures. Investigations of adherence to antiretrovirals would benefit from measuring not only per cent adherence but dose timing adherence.

Adult↗
PubMed2002

Impact of adherence on duration of virological suppression among patients receiving combination antiretroviral therapy.

OBJECTIVE: To assess the effect of adherence to antiretroviral therapy on the duration of virological suppression after controlling for whether or not the patient ever attained a plasma viral load below the limit of detection of sensitive HIV-1 RNA assays. METHODS: Data were combined from three randomized, blinded clinical trials (INCAS, AVANTI-2, and AVANTI-3) that compared the antiviral effects of two- and three-drug antiretroviral regimens. Virological suppression was defined as maintaining a plasma viral load below 1000 copies/mL. Adherence was defined prospectively and measured by patient self-report. RESULTS: Adherence did not have a major impact on the probability of achieving virological suppression for patients receiving dual therapy. However, for patients receiving triple therapy, adherence increased the probability of virological suppression, whether the plasma viral load nadir was above or below the lower limit of quantification. Compared to adherent patients with a plasma viral load nadir below the lower limit of quantification, the relative risk of virological failure was 3.0 for non-adherent patients with a nadir below the limit, 18.1 for adherent patients with a nadir above the limit, and 32.1 for non-adherent patients with a nadir above the limit. CONCLUSION: For patients receiving current three-drug antiretroviral regimens, adherence to therapy and plasma viral load nadir are important factors determining the duration of virological suppression.

Anti-HIV Agents↗
PubMed2004

Targeting virological core groups: a new paradigm for controlling herpes simplex virus type 2 epidemics.

BACKGROUND: Classic modeling of sexually transmitted diseases has focused on modeling behavioral heterogeneity and designing epidemic control strategies targeted at behavioral core groups. METHODS: We analyzed a new mathematical model of herpes simplex virus type 2 (HSV-2) epidemics that includes virological core groups (i.e., groups of individuals with high rates of viral reactivation) and suggest a new paradigm for epidemic control. We used our model, in conjunction with virological data, to determine the potential role of virological core groups in contributing to transmission and the effect that daily antiviral therapy (DAT) could have on reducing transmission if virological core groups were targeted. RESULTS: We estimated that a virological core group (11% of infected individuals) can cause a disproportionately large percentage (44%) of new infections and that a median of only 6.4 person-years of DAT would be necessary to prevent 1 HSV-2 infection. We determined that relatively few individuals would need to receive DAT to substantially reduce the incidence of HSV-2 infection. CONCLUSION: Identifying and targeting individuals in the virological core group could be an effective and practical public health strategy for reducing transmission. Treating individuals who are high-frequency viral shedders should be evaluated as a strategy for reducing HSV-2 transmission.

Antiviral Agents↗
PubMed2004

Prediction of virological response to lopinavir/ritonavir using the genotypic inhibitory quotient.

The predictive value of virological response to lopinavir (LPV)/ritonavir (r) was assessed in 126 HIV-infected patients who failed antiretroviral therapy and had begun a rescue intervention based on LPV/r. At 3 months, subjects with < or =6 protease (PRO) resistance mutations showed a higher rate of virological response (HIV-RNA drop > 1 log or to <50 copies/ml) than patients with >6 PRO resistance mutations (77% versus 48%; p = 0.01). On the other hand, virological responders had greater mean LPV plasma trough levels than nonresponders (6.4 versus 3.9 microg/ml; p = 0.02). A positive correlation was found between LPV trough concentration and viral load reductions at 3 months under LPV/r (r = 0.23; p = 0.017). Overall, virological response was seen in 80.8% of patients with LPV trough levels >4.8 microg/ml while in only 52.5% of patients with lower LPV trough concentrations (p = 0.002). In the multivariate analysis, both < or =6 PRO resistance mutations and LPV trough levels >4.8 microg/ml were independent predictors of virological response to salvage therapy with LPV/r. A genotypic inhibitory quotient (GIQ) was estimated for each patient based on the ratio between LPV trough levels and the number of PRO resistance mutations. A positive strong correlation was found between GIQ and viral load reductions (r = 0.42; p = 0.002). Virological response was seen in 78% of patients with a GIQ >0.7 but only in 41.6% of those with lower GIQ (p = 0.004). When LPV trough levels >4.8 microg/ml, PRO resistance mutations < or =6, and GIQ >0.7 were all included in a stepwise multivariate analysis, GIQ remained as the main independent predictor of response to LPV/r.

Adult↗
PubMed2006

Immune reconstitution and predictors of virologic failure in adolescents infected through risk behaviors and initiating HAART: week 60 results from the PACTG 381 cohort.

The responses to HAART in HIV-infected adolescents infected through risk behaviors are not well defined. PACTG 381 collected intensive immunologic and virologic data on youth naive to or with minimal exposure to antiretroviral therapy who began HAART. Subjects were evaluated according to their weeks 16-24 virologic response. Comparisons with a cohort of HIV-uninfected adolescents from the REACH cohort were performed. Cox proportional hazards models were used to identify baseline and week 24 predictors of virologic failure. Only 69 of 120 subjects (58%) achieved virologic suppression by weeks 16-24, whereas 55 of 69 (80%) demonstrated control to week 60. Higher CD4+ naive T cells (CD4+/62L+/RA+: hazard ratio [HR], 2.13; p = 0.018), higher CD8+ activated T cells (CD8+/CD38+/DR+: HR, 1.40, p = 0.028 per 100 cells/mm3) and higher CD8+ naive T cells (CD8+/62L+/RA+: HR, 1.72; p = 0.005) at weeks 16-24 in subjects with early viral success were predictive of subsequent failure. By week 60, total CD4+ T cells remained significantly lower than in uninfected controls. Adolescents beginning HAART achieve moderate rates of viral suppression by weeks 16-24. In those who do achieve early virologic control, suppression to week 60 is high although total CD4+ T cells remain significantly lower than in uninfected controls. Several T cell markers were predictive of subsequent virologic failure in subjects achieving short-term success. Further study is warranted to determine whether these predictors provide any benefit to clinical management.

Adolescent↗
PubMed2002

Effect of zidovudine resistance mutations on virologic response to treatment with zidovudine or stavudine, each in combination with lamivudine and indinavir.

The authors studied the effect of zidovudine (ZDV) resistance mutation on virologic response to treatment with ZDV or stavudine (d4T) each in combination with lamivudine and indinavir. Viral genotyping was performed on plasma HIV-1 RNA at study entry and concerned 155 patients previously treated with ZDV, didanosine, or zalcitabine and enrolled in the NOVAVIR (Agence National de Recherche sur le SIDA [ANRS] 073) trial. Three virologic responses were investigated: early response (<50 copies/mL at week 24), late response (<500 copies/mL at week 80), and virologic failure (two HIV-1 RNA >5000 copies/mL). Patients were classified as resistant or susceptible to ZDV according to the ANRS algorithm. Plasma viral RNA from 123 of 155 patients had two or more ZDV resistance mutations. The number of ZDV resistance mutations was positively correlated with the duration of prior antiviral therapy (p <.001). At week 24, 74% and 77% of patients with virus classified as resistant were responders in the d4T and ZDV arm, respectively. Similar results were found at week 80. Virologic failure was reached in 7 of 24 patients with virus classified as susceptible and in 26 of 131 patients with resistant virus (p =.29). In the ZDV arm, patients classified as resistant had longer times to virologic failure than those classified as susceptible (p =.003). In conclusion, sustained virologic response despite presence of ZDV resistance mutations implies that these mutations do not preclude an early and durable response to treatment with a potent three-drug regimen in these patients. Patients susceptible to ZDV had lower median mean corpuscular volumes and lower random indinavir levels, suggesting that adherence was the main reason for failure.

Anti-HIV Agents↗
PubMed2004

A randomized controlled trial of amantadine plus interferon-alpha2a vs. interferon-alpha2a alone in naive patients with chronic hepatitis C randomized according to the early virological response to interferon-alpha2a monotherapy.

BACKGROUND: An early virological response to interferon-alpha treatment is a strong predictor of sustained response, but it has never been exploited to stratify patients in clinical trials. AIM: To evaluate the efficacy of amantadine plus interferon-alpha compared with interferon-alpha alone in naive patients with chronic hepatitis C who were randomized on the basis of the early virological response to interferon-alpha. METHODS: One hundred and eighty-one patients received recombinant interferon-alpha2a (3 MU three times weekly) for 2 months and 164 were evaluated for early (i.e. month 2) virological response. Hepatitis C virus (HCV) RNA-negative patients (n = 66) were randomized to receive 3 MU of interferon-alpha three times weekly, with or without amantadine (200 mg/day); HCV RNA-positive patients (n = 98) were randomized to receive 6 MU of interferon-alpha three times weekly, with or without amantadine (200 mg/day). HCV RNA-positive patients at 6 months discontinued treatment, and all others completed 12 months. RESULTS: At month 6, HCV RNA-negative patients made up 54.2% of the interferon + amantadine group and 42.0% of the monotherapy group (P = 0.07). At month 12, HCV RNA-negative patients made up 38.5% of the interferon + amantadine group and 28.4% of the monotherapy group (N.S.). The sustained virological response rates were 21.6% and 20.9%, respectively (N.S.). CONCLUSION: The addition of amantadine does not enhance the sustained virological response to interferon-alpha in naive patients with chronic hepatitis C; however, an additive effect of amantadine occurs in the first 6 months, mainly in patients without an early response to monotherapy. Early response to interferon-alpha is a strong predictor of sustained virological response.

Adolescent↗
PubMed2006

Long-term follow-up of chronic hepatitis C patients with sustained virological response to various forms of interferon-based anti-viral therapy.

BACKGROUND: Combination anti-viral therapy achieves a sustained virological response (defined as HCV-RNA negativity 6 months after the end of therapy) of 56% of patients with chronic hepatitis C. Little is known about long-term durability of HCV-RNA negativity in patient treated with pegylated interferon. AIM: To evaluate the durability of virologic response in patients with sustained virological response to anti-viral therapy treated at our centre. METHODS: A total of 187 sustained virological responses (50% genotype 1, 42% genotype 2 or 3 and 8% genotype 4; 20% with cirrhosis) with a follow-up of >12 months post-therapy were studied. Twelve patients received monotherapy with interferon-alpha2a or -2b. One hundred and seventy-five received combination therapy with ribavirin and standard interferon-alpha (n = 73) or pegylated interferon-alpha2a or 2b (n = 102). Qualitative serum HCV-RNA was tested by COBAS AMPLICOR HCV test, v2.0. RESULTS: Median follow-up time was 29 months (range 12-172). Recurrence of HCV infection was not observed in any of the 187 sustained virological responders. Alanine aminotransferase values were normal in 90% and two patients showed minimal elevation of alpha-fetoprotein levels. CONCLUSIONS: No recurrence of HCV infection was seen in any patient. Thus, long-term prognosis in chronic hepatitis C patients with a sustained virological response to therapy with pegylated interferon +/- ribavirin is promising, but long-term studies need to continue.

Adult↗
PubMed2006

Persistent low-level viraemia and virological failure in HIV-1-infected patients treated with highly active antiretroviral therapy.

OBJECTIVE: To assess the prognostic significance of persistent low-level viraemia (PLV, defined as persistent plasma viral loads of 51-1000 HIV-1 RNA copies/mL for at least 3 months) in patients who had achieved viral suppression on antiretroviral therapy (ART). METHODS: A retrospective cohort of HIV-infected patients who received ART, were followed-up for > or =12 months, made regular visits to the clinic during which blood tests were performed for an ultrasensitive HIV RNA assay every 3 months, and achieved viral loads <50 copies/mL were evaluated. Virological failure was defined as two consecutive viral load measurements >1000 copies/mL. RESULTS: Of 362 patients, 78 (27.5%) experienced PLV. The demographics of patients with and without PLV were similar. PLV occurred at a mean (+/-standard deviation) of 22.6+/-16.9 months after ART initiation and lasted for 6.4+/-3.4 months. During a median follow-up of 29.5 months, patients with PLV had a higher rate of virological failure (39.7% vs 9.2%; P < 0.001). The median time to failure was 68.4 months [95% confidence interval (CI) 37.0-99.7] for patients with PLV and >72 months for patients without PLV (log rank test, P < 0.001). By Cox regression, patients with PLV had a greater risk of virological failure [hazard ratio (HR) 3.8; 95% CI 2.2-6.4; P < 0.001]. Among patients with PLV, a PLV of >400 copies/mL (HR 3.3; 95% CI 1.5-7.1; P = 0.003) and a history of ART (HR 2.4; 95% CI 1.0-5.7; P = 0.042) predicted virological failure. CONCLUSIONS: PLV is associated with virological failure. Patients with a PLV >400 copies/mL and a history of ART experience are more likely to experience virological failure. Patients with PLV should be considered for treatment optimization and interventional studies.

Adult↗
PubMed2001

Assessment, by transcription-mediated amplification, of virologic response in patients with chronic hepatitis C virus treated with peginterferon alpha-2a.

Transcription-mediated amplification (TMA) is an isothermal, autocatalytic target amplification method which has the potential to detect less than 50 hepatitis C virus (HCV) RNA copies/ml (10 IU/ml). The TMA assay was used to assess the presence of residual HCV RNA in plasma from patients treated with polyethylene glycol-modified interferon alpha-2a (peginterferon alpha-2a) who showed a virologic relapse after the end of therapy. Stored end-of-treatment and end-of-follow-up plasma samples from 177 of 267 patients treated with peginterferon alpha-2a (S. Zeuzem et al., N. Engl. J. Med. 343:1666--1672, 2000) were available for retesting by TMA. Plasma samples from patients in the same study who exhibited virologic relapse after treatment with standard interferon alpha-2a served as controls. Virologic response during the trial was defined as HCV RNA that was undetectable using a PCR-based test system with a sensitivity of 50 IU/mL (Cobas Amplicor HCV version 2.0) and was compared with TMA-based retesting results (VERSANT HCV RNA Qualitative Assay). Residual HCV RNA was detected in 4 of 60 cases (7%) by the TMA technology in end-of-treatment plasma samples from patients who relapsed after receiving peginterferon alpha-2a and in 6 of 18 patients (33%) following therapy with standard interferon alpha-2a. For peginterferon alpha-2a-treated patients with sustained virologic response, HCV RNA was detectable by TMA in end-of-treatment samples in 3 of 78 cases but in none of the end-of-follow-up samples. For all end-of-treatment and end-of-follow-up plasma samples of virologic nonresponders, a complete concordance between the PCR-based assay and TMA was observed. In conclusion, in patients with virologic relapse after the end of therapy, according to PCR, who were treated with peginterferon alpha-2a or standard interferon alpha-2a, residual HCV RNA was detectable in end-of-treatment samples by the TMA-based assay in 7 or 33% of cases, respectively. The lower rate of residual HCV RNA detection by TMA for patients treated with peginterferon alpha-2a than that for patients treated with standard interferon alpha-2a may be due to the maintained antiviral pressure of the long-acting peginterferon alpha-2a at the end-of-treatment visit.

Antiviral Agents↗
PubMed2005

Association of amino acid substitution pattern in core protein of hepatitis C virus genotype 1b high viral load and non-virological response to interferon-ribavirin combination therapy.

OBJECTIVE: Patients with high titer (>/=100 kIU/ml) of hepatitis C virus (HCV) genotype 1b do not achieve highly sustained virological response rates to combination therapy with interferon plus ribavirin. Non-virological responders (NVRs, namely ultimate resistant cases) who do not achieve HCV-RNA negativity during treatment are also encountered. We investigated the pretreatment virological features of NVRs. METHODS: We evaluated 50 consecutive Japanese adults with high titer of HCV genotype 1b who received combination therapy for 48 weeks. We investigated the pretreatment substitution patterns in amino acids 1-191 of the core region and amino acids 2209-2248 of NS5A, and early viral kinetics. RESULTS: Overall, a non-virological response was noted in 12 (24%) patients. Multivariate analysis identified serum albumin <3.9 g/dl, substitutions of amino acid 70 in the core region, and substitutions of amino acid 91 as independent and significant factors associated with a non-virological response. Especially, substitutions of arginine (R) by glutamine (Q) at amino acid 70, and/or leucine (L) by methionine (M) at amino acid 91 were significantly more common in NVRs. The falls in HCV-RNA levels during treatment in patients with specific substitutions in the core region were significantly less than in those without such substitutions. CONCLUSIONS: Our results suggest that serum albumin and amino acid substitution patterns in the core region in patients with high titers of HCV genotype 1b may have an effect on combination therapy in NVRs. Further large-scale studies are required to examine the role of amino acid substitutions specific to a non-virological response to combination therapy.

Adult↗
PubMedDate not supplied

Determinants of sustained virological suppression in indigent, HIV-infected patients: is single protease inhibitor-based antiretroviral therapy truly highly active?

BACKGROUND: Effective virological suppression with HAART is dependent on strict adherence to therapy. Compliance with therapy is influenced by clinical and psychosocial factors. METHOD: We performed a retrospective study investigating determinants of effective virological suppression, defined as <400 RNA at 11-13 months of HAART, in an urban indigent population. The study included 366 new patients presenting for care to the Thomas Street Clinic, Houston, Texas, between April and December 1998. Median age, CD4 count, and viral load (VL) of the study population were 37.5 years, 189 cells/mm(3), and 53,000, respectively. Thirty-nine percent had AIDS, 20% had cocaine-positive drug screens, and 64% were antiretroviral naïve. Two hundred and sixty-seven patients were started on HAART. Thirty-four percent showed virological suppression. RESULTS: In multivariate analysis, adherence to HAART, care by experienced primary provider, baseline VL <100,000 copies/mL, age >35 years, and no active substance use were associated with virological suppression. Rates of virological suppression with HAART are unacceptably low in this urban indigent population. CONCLUSION: Low rates of virological suppression are primarily due to lack of adherence rather than late utilization of care among ethnic minorities. Single protease-inhibitor-based antiretroviral therapy does not appear to be highly active in this patient population.

Adult↗
PubMed2002

Analysis of virological efficacy in trials of antiretroviral regimens: drawbacks of not including viral load measurements after premature discontinuation of therapy.

OBJECTIVES: To compare two analytic approaches to assess the virological effect of HAART according to the intention-to-treat (ITT) principle. MATERIAL: Data from 2318 patients enrolled in 10 randomised clinical trials (RCTs) and from 3091 patients followed in an observation cohort (EuroSIDA) starting their first HAART regimen. METHODS: Two classifications of defining virological response 48 weeks after starting the therapy to be evaluated were compared: 1) only patients remaining on the therapy and having a plasma viral load (pVL) below a given cut-off level at week 48 were classified as responders (ITT/s=f); and 2) patients with a pVL below a given cut-off at week 48 whether they remained on initial assigned therapy or switched therapy were responders (ITT/s incl). In both analyses, patients with missing data at week 48 were classified as failures (i.e., non-responders). RESULTS: According to ITT/s=f, 22-70% of the patients starting a HAART regimen in a RCT experienced a virological response at week 48. Only two RCTs had complete follow-up data (n=424): between 29 and 62% achieved a virological response at week 48 in the six treatment arms evaluated in the studies according to ITT/s=f, and 41-72% according to ITT/s incl. Among those who discontinued the therapy to be evaluated in these two trials, 13-45% (cohort: 39-74%) subsequently experienced a virological response at week 48. The subsequent response rates were associated with the reason for discontinuation (toxicity versus confirmed virological failure: 63 vs 33%), varied largely across regimens and were not associated with the discontinuation rate. CONCLUSIONS: Discontinuation of follow-up at switch from the therapy to be evaluated remains common in antiretroviral treatment trials, but leads to an imprecise and incomplete assessment of the intrinsic effect of a given regimen. Complete follow-up of all patients should be encouraged strongly as this will allow for several complementary analytic approaches and a focus on optimal treatment strategies rather than specific regimens.

Antiretroviral Therapy, Highly Active↗
PubMed2003

[Immunological, virological and clinical response in patients infected with HIV after highly active antiviral therapy with nelfinavir: prospective cohort study].

INTRODUCTION: To assess the long-term effectiveness, safety and response-related factors in a cohort of HIV-infected persons receiving antiretroviral therapy containing nelfinavir. Design and setting. Prospective, non-randomized multicenter study. METHOD: A total of 792 patients were included: 254 (32.1%) treatment-naive patients and 538 (67.9%) patients previously treated with protease inhibitors who were switched to a nelfinavir-containing regimen due to virological failure or intolerance. Factors related to virological response and to treatment failure were assessed by standard survival techniques and Cox proportional risk models. RESULTS: Nelfinavir was well tolerated; treatment had to be interrupted in only 57 patients (7.1%) because of toxicity. During a median follow-up of 12 months, 31 patients (3.9%) experienced a new AIDS-defining event or death, and 463 (58.4%) showed immunological response. Overall, 52% patients achieved plasma HIV-1 RNA levels below 500 copies/mL (57% of naive and 49% of previously treated patients), but a high rate of virological rebound (24% and 49%, respectively) was observed. Low baseline viral load and few prior treatments were factors related to virological response. Naive treatment status and a high increase in CD4 cell count were predictive of longer viral response. CONCLUSIONS: Highly active antiretroviral therapy with a nelfinavir-containing regimen was associated with favorable virological response in nearly half of previously treated patients, and most experienced clinical and immunological benefits. Nevertheless, the limited duration of virological response indicates the need for new alternative drugs.

Adult↗
PubMed2004

Interferon alpha-2b in combination with ribavirin for the treatment of chronic hepatitis C: assessment of virological, biochemical and histological treatment response.

UNLABELLED: Aim of the study is to establish the efficacy of treatment of chronic hepatitis C with interferon alpha-2b and ribavirin in treatment-naive patients, in non-responders to interferon monotherapy, in relapsers after interferon monotherapy, and to evaluate the possible predictors of treatment response. MATERIAL AND METHODS: One hundred thirty one patients with chronic hepatitis C were included and assigned to 24-week course of interferon alpha-2b with ribavirin. At the end of 24-week combination therapy biochemical, histological, virological and complete end-of-treatment responses were evaluated. Patients with virological end-of-treatment response were treated with interferon alpha-2b and ribavirin for further 24 weeks and followed-up for the next 6 months after stopping therapy. RESULTS: End-of-treatment response was assessed in 119 patients: 57.1% were treatment-naive, 28.6% were non-responders, and 14.3%--relapsers. Overall virological end-of-treatment response rate was 35.3%, biochemical--64.7%, histological--80.9% and complete--33.3%. Treatment-naive patients have better end-of-treatment response than non-naive patients in all dimensions, but statistical significance is reached only evaluating histological end-of-treatment response. Sustained virological response of overall 119 patients was in 23.6%. There was no statistically significant difference in sustained virological response rate among all patient groups. None of pre-treatment demographic, clinical, biochemical and morphological parameters was found as possible response predicting factors. Hepatitis C virus genotype was assessed in 40 patients. Hepatitis C virus genotype 1 was found in 34 (85%), genotype 2 in 3 (7.5%), and genotype 3 in 3 (7.5%) patients. In conclusion, in our studied population with high prevalence of hepatitis C virus genotype 1 (85%), there is low sustained virological response rate (23.6%) to interferon alpha-2b in combination with ribavirin therapy.

Adult↗
PubMed1980

Pregnancy abnormalities among personnel at a virological laboratory.

Observations on an increased spontaneous abortion rate initiated a study among personnel working at a laboratory for diagnostic virology. Personnel at a bacteriological laboratory and at another virological laboratory served as controls. Seventy-seven female employees at the laboratory for virology were interviewed, as well as 91 at the bacteriology laboratory and 45 women at another virological laboratory. A significantly increased perinatal death rate was found among the virology personnel, with no apparent clustering over the time period studied. A higher serum titer against common viruses was found among employees actively working with patient sera. A model experiment demonstrated the risk for aerosolization of serum samples during processing. No evidence of a relationship between chemical work environment factors and the increased perinatal death rate was found. It is concluded that the factor in the working environment most closely related to the increased perinatal death rate was exposure to viral aerosols.

Abortion, Spontaneous↗