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Maraviroc belongs to the family of chemokine (C-C motif) receptor 5 (CCR5) antagonists that prevent the entry of human immunodeficiency virus (HIV) into host CD4+ T cells by blocking the CCR5 co-receptor R5. Maraviroc is currently the only CC5R co-receptor inhibitor that has been approved for clinical use in HIV-1-infected patients carrying the CCR5 tropism who are antiretroviral-naïve or have experienced therapeutic failure following traditional antiretroviral therapies. This article is a review of the main characteristics of maraviroc and the latest data regarding its clinical application. Maraviroc is effective and well tolerated in pre-treated and antiretroviral-naïve patients with HIV-1 infections carrying the CCR5 tropism. Data from the phase III programme of maraviroc, which includes the MOTIVATE 1 and 2 studies and the MERIT study, indicate that maraviroc significantly (p < 0.001) increases CD4+ cell counts compared with placebo in pre-treated patients and to a similar extent as efavirenz in antiretroviral-naïve patients. Even in cases where viral load is not completely suppressed, maraviroc improves immunological response compared with placebo. In addition, promising research suggests that maraviroc has favourable pharmacokinetic and safety profiles in patients with high cardiovascular risk or those co-infected with tuberculosis or hepatitis and could be considered an option for treatment of HIV-infected patients with these co-morbidities. Resistance to maraviroc is low and mainly related to the presence of chemokine (C-X-C motif) receptor 4 (CXCR4) tropism HIV-1-infections or to mutations in the V3 region of glycoprotein (gp) 120; however, the exact mechanisms by which resistance is acquired and their genotypic and phenotypic pattern have not yet been established. It is recommended that a tropism test should be performed when considering maraviroc as an alternate drug in HIV-1-infected patients. Current tropism assays have increased sensitivity to reliably detect CXCR4 HIV with rapid turn-around and at a low cost. Improved detection together with positive data on the drug's efficacy and safety profiles should help physicians to identify more accurately the appropriate candidates for commencement of treatment with maraviroc. In summary, maraviroc improves immunological response and has shown favourable pharmacokinetic and safety profiles in patients with high cardiovascular risk or in those co-infected with tuberculosis or hepatitis. Long-term studies are needed to confirm whether therapeutic expectations resulting from clinical trials with maraviroc translate into a real benefit for HIV-1-infected patients for whom traditional antiretroviral therapies have failed or are not suitable.

Objective: To compare the incidence of severe hepatitis in HIV-infected patients receiving rifampicin plus pyrazinamide (RZ) for antituberculosis prophylaxis with that of patients receiving a conventional isoniazid-based regime for 6 to 12 months (6-12H)., Methods: Meta-analysis of randomized controlled trials, in which RZ was compared with 6-12H, the standard regimen for latent tuberculosis infection in HIV-infected patients. A systematic search of studies published between 1986 and 2007 was carried out, and 5 randomized clinical trials conducted in Spain (2), the USA (1), Haiti (1), and Zambia (1) were identified. The absence or presence of severe hepatoxicity, which was defined as toxicity causing the death of the patient or requiring treatment withdrawal, was assessed as a binary response, and the outcome measure was the difference in the risk of hepatotoxicity between patients receiving RZ and those receiving 6-12H (controls)., Results: Among the 5 trials retrieved, 1 was excluded from the final analysis because of incomplete data on the development of hepatotoxicity. A final total of 2657 patients were included (1324 patients receiving RZ and 1333 receiving 6-12H). The development of severe hepatotoxicity was lower in the RZ group than in the 6-12H group (1.208% vs. 2.851%; P=0.0042, 95% CI: -0.028 to -0.005). The meta-analysis showed no statistical evidence of heterogeneity between the studies or publication bias. The difference in the risk of severe hepatotoxicity favored the RZ regimen in both the fixed effects model (-0.0119, 95% CI: -0.0206 to -0.0033) and random effects model (-0.0147, 95% CI: -0.0289 to -0.0006)., Conclusions: The meta-analysis did not demonstrate an increased risk of severe hepatoxicity in HIV-infected patients receiving tuberculosis prophylaxis with the rifampicin/pyrazinamide combination compared to the conventional 6- or 12-month isoniazid-based regimen., (Copyright 2009 Elsevier España, S.L. All rights reserved.)

Impairment of the response of HIV-specific CD8(+) T cells, in spite of the high frequency of occurrence of these cells even in the advanced phase of HIV-1 infection, has been demonstrated. It is also known that new antiretroviral treatments are able to reduce the viral load and partially repair the immunological damage caused by HIV-1, but it is not clear whether the extent of these changes affects the functional profile of HIV-specific CD8(+) T cells. We evaluated, in HIV-1(+) patients undergoing antiretroviral therapy, the HIV-specific CD8(+) subset distribution and their functional capacity as intracellular expression of IFN-gamma, TNF-alpha, and perforin after PMA stimulation. Our results indicate that HIV-1(+)-treated individuals show distributions of HIV-specific CD8 subsets similar to nontreated patients, while the frequency of HIV-specific CD8 cells expressing IFN-gamma and perforin after stimulation is lower in HAART-treated patients. This indicates that HAART, which controls viral replication, may impair the HIV-specific CD8(+) response.

Objective: To evaluate the adherence to, and safety of three chemoprophylaxis regimens for latent tuberculosis (TB) infection in HIV-infected patients with a positive tuberculin skin test., Patients and Methods: A randomized, comparative, open clinical assay was carried out in 316 HIV-infected patients in 12 Spanish hospitals. Patients were randomly assigned to one of three regimens, 108 to isoniazid for six months (6H), 103 to rifampin and isoniazid for three months (3RH), and 105 to rifampin and pyrazinamide for two months (2RZ). After completion of treatment, patients were followed-up for two years., Results: The period of observation following completion of treatment was 115, 108 and 101 person-years for 6H, 3RH and 2RZ, respectively. Twenty-seven percent of patients voluntarily abandoned chemoprophylaxis and 9.7% were withdrawn due to adverse side-effects or interactions. Seven patients were withdrawn due to hepatotoxicity (5 in 6H, 2 in 3RH and 0 in 2RZ). No appreciable differences were found among the three regimens. There were 11 cases of tuberculosis during follow-up. The TB rates (cases per 100 person-years) in the three treatment groups were 3.48 in 6H, 4.63 in 3RH and 1.98 in 2RZ. With respect to 2RZ, the relative risk for TB in the 6H and 3RH regimens was 1.76 and 2.34, respectively., Conclusions: The safety of the 2RZ regimen for prophylaxis of latent TB infection in HIV patients was similar to that of the 6H and 3RH regimens. The incidence of hepatotoxicity was not higher in patients who received 2RZ.

In order to better understand the possible beneficial effects of intermittent IL-2 treatment as complement of antiretroviral therapy in HIV-1+ patients, we have measured the levels of RANTES in the supernatants and the CD25 expression in cultured PBMCs obtained from HIV-1+ individuals in presence of IL-2. The results showed a significant increases in RANTES production and in the expression of CD25+ in the cultures with IL-2 of PBMC obtained from HIV-1+ patients with a detectable viral load in comparison with both, HIV-1+ patients with no detectable viral loads and with healthy individuals. These results suggest that therapeutic IL-2 administered in addition to highly active anti-retroviral therapy (HAART) may contribute to increase the effect of this therapy by rising both RANTES production and CD25 expression only in HIV-1+ patients with detectable viral loads.

Background: Administration of antiretroviral therapy (ART) once daily is creating extraordinary interest among the members of the scientific community and also among those who receive the therapy. However, in clinical practice, some doubts remain about its use., Objectives: This document examines the characteristics and possibilities of treatment administered once daily., Methods: Consensus of 248 Spanish experts in the field., Results: Once-daily dosing is considered an added value which could favour adherence and, therefore, efficacy, as well as the quality of life of certain patients, however, the objective of adequate adherence in the long term is often difficult to achieve regardless of the treatment used. In theory, any patient can receive once-daily therapy, although some patients could particularly benefit from it, e.g. those with unfavourable social or personal circumstances, including drug users, patients whose treatment must be supervised, patients receiving multiple medications, or those who need rescue therapy after multiple treatment failures. At present, it is possible to design once-daily ART using some of the combinations of drugs considered as first-choice in national and international recommendations for antiretroviral therapy, but the options are still limited. The marketing of new drugs with this characteristic could allow us to increase the number and types of patient who can benefit from once-daily regimens, including those patients who need rescue therapy., Conclusions: Once-daily ART is a good alternative to regimens administered several times each day when a potent combination of active drugs is available.

Antiretroviral treatment has modified the course of human immunodeficiency virus (HIV) infection transforming it into a chronic disease. However, as treatment is conceived "for life", more effective and safety drugs, overcoming the growing resistance of the virus are required. New molecules may block the known viral targets or other new ones. The mechanism of the virus union and entrance to the cell includes the new therapeutic targets that are studied more frequently. Although studies with substances that efficiently block the virus-CD4 receptors union are in very early phases, other studies of molecules capable to block the entrance co-receptors are in more advanced phases (II or III), and enfuvirtide, a substance that blocks membrane fusion, the last phase of virus entrance, has been recently marketed. Another very promising pharmacological target is the integration of the proviral DNA as we know some substances that in vitro block HIV integrase. Besides this, new drugs are increasing the three classic antiretroviral families. Among nucleoside analogs emtricitabine (recently marketed) and amdoxovir are the more prominent. Capravirine and TMC-125 are the non-nucleoside analogs whose studies are more advanced. And atazanavir, fos-amprenavir, tipranavir and TMC-114 are the new protease inhibitors recently marketed or near to be.

Objective: This consensus document is an update of antiretroviral therapy (ART) recommendations for adult patients infected with the human immunodeficiency virus (HIV)., Methods: To formulate these recommendations, a panel composed of members of the Grupo de Estudio de Sida (GESIDA; AIDS Study Group) and the Plan Nacional sobre el Sida (PNS; Spanish AIDS Plan) reviewed the advances in current understanding of the pathophysiology of HIV, the safety and efficacy findings from clinical trials, and the results from cohort and pharmacokinetic studies published in biomedical journals or presented at scientific meetings over the last years. Three levels of evidence were defined according to the source of the data: randomized studies (level A), cohort or case-control studies (level B), and expert opinion (level C). The decision to recommend, consider or not recommend ART was established in each of these situations., Results: ART consisting of at least three drugs is currently the initial treatment of choice for chronic HIV infection. These regimens should include 2 NRTI + 1 NNRTI or 2 NRTI + 1 PI. Initiation of ART is recommended in patients with symptomatic HIV infection. In asymptomatic patients, initiation of ART is recommended on the basis of CD4+ lymphocyte counts per L and plasma viral load, as follows: 1) Therapy should be started in patients with CD4+ counts of < 200 cells/microL; 2) Therapy should be started in most patients with CD4+ counts of 200-350 cells/microL, although it can be delayed when CD4+ count persists at around 350 cells/microL and viral load is low; and 3) Initiation of therapy can be delayed in patients with CD4+ counts of > 350 cells/microL. The initial objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining the antiviral response. Because of the development of cross resistance, therapeutic options are limited when ART fails. Genotype studies are useful in these cases. Toxicity is a limiting factor in the use of ART, although the benefits outweigh the risks. In addition, the criteria for the use of ART are discussed in situations of acute infection, pregnancy, and post-exposure prophylaxis, and in the management of co-infection of HIV with HCV or HBV., Conclusions: CD4+ lymphocyte count is the most important reference factor for initiating ART in asymptomatic patients. The large number of available drugs, the increased sensitivity of tests to monitor viral load, and the possibility to determine viral resistance is leading to a more individualized approach to therapy.

The aim of this work is to analyze if the highly active antiretroviral therapy (HAART) has any effect in the number of peripheral monocytes expressing the tolerogenic molecule human leukocyte antigen G (HLA-G) in HIV-1 infected individuals. In this sense, expression of HLA-G was measured by flow cytometry on peripheral monocytes from HIV-1 antiretroviral-receiving and antiretroviral naïve patients and in HIV-1 patients at different times after the antiretroviral treatments were removed. It was found an increment of monocytes expressing HLA-G in HIV-1 infected individuals receiving HAART, whereas monocytes from untreated HIV-1 patients did not change. When the HLA-G was measured on monocytes after antiretroviral treatment was removed, the number of peripheral monocytes expressing HLA-G was progressively decreasing. These data suggest that antiretroviral therapy is able to induce the expression of the tolerogenic molecule HLA-G on peripheral monocytes from HIV-1 seropositive individuals.

Introduction: To evaluate the efficacy of three regimens of prophylactic therapy for tuberculosis in HIV-infected patients with anergy., Methods: Prospective, multi-center, randomized, comparative, and open clinical trial. Anergy was defined as absence of induration in response to three antigens (PPD, Candida albicans and parotiditis antigen) applied by the Mantoux method. Patients were randomized into one of the following prophylactic treatment groups: isoniazid for six months (6H), rifampin plus isoniazid for three months (3RH), rifampin plus pyrazinamide for two months (2RZ) or no treatment (NT). After completion of treatment, patients were followed up for two years., Result: A total of 319 patients were included in the study, 83 in the 6H regimen, 82 in 3RH, 77 in 2RZ and 77 in NT. The observation period following treatment was 88, 96, 81 and 126 person-years, respectively, for 6H, 3RH, 2RZ and NT. There were 11 cases of tuberculosis during the follow-up period. The tuberculosis rates (cases per 100 person-years) were 3.4, 3.1, 1.2 and 3.1 for 6H, 3RH, 2RZ and NT respectively, with relative risks in regimens 6H, 3RH and 2RZ with respect to NT of 1.07 (0.24-4.80), 0.98 (0.22-4.4) and 0.39 (0.04-3.48), all statistically non-significant. Twenty-nine patients died during the follow-up period, none due to tuberculosis, and no appreciable differences were found among the groups., Conclusions: The results showed no significant decrease in the risk of developing tuberculosis with any of the evaluated regimens and, therefore, do not support the use of antituberculosis chemoprophylaxis in anergic HIV-infected patients.

Objective: To study the expression of HLA-G on peripheral blood mononuclear cells (PBMC) from HIV-1-infected individuals in order to determine whether this molecule is induced as a consequence of HIV-1 infection., Design: A total of 23 HIV-positive individuals in different stages of the disease were studied., Methods: Flow cytometric analysis and Western blot were used to measure HLA-G expression on PBMC obtained from HIV-positive and control individuals., Results: Most of the monocytes obtained from HIV-1-infected individuals express HLA-G, whereas only a very low proportion of monocytes from healthy individuals express this molecule. When T lymphocytes from HIV-1 infections were studied, it was found that 30% of them express HLA-G, whereas only 1% were HLA-G-positive in healthy individuals. HLA-G expression was also confirmed by Western blot using specific anti-HLA-G monoclonal antibodies., Conclusion: The synthesis of HLA-G is increased in monocytes and certain T lymphocytes from HIV-1-infected individuals.

Objective: To examine if peripheral T lymphocytes from HIV-infected individuals show abnormalities in the surface expression of CD43, the major sialoglycoprotein of leukocytes., Design: A series of 86 HIV-positive individuals was studied. The subjects, grouped by their peripheral CD4 cell count, were in different stages of the disease as defined by the Centers for Disease Control and Prevention (CDC)., Methods: Peripheral leukocytes and isolated lymphocytes were examined by double and triple immunofluorescence flow cytometric and Western blot analyses with monoclonal antibodies, which discriminate between CD43 isoforms., Results: We found elevated percentages of the surface expression of CD43-hexasaccharide isoform on T lymphocytes from 82 out of 86 individuals tested. Increasing percentages are progressively found in CDC groups 1, 2 and 3 patients. The expression of the molecule is remarkably biased towards the CD8 cell subpopulation. The percentage of cells bearing human leukocyte antigen-DR locus molecules (HLA-DR) is also augmented. Two subsets expressing T305 have been identified: a minor subset that co-expresses HLA-DR and T305; and a second population formed by the majority of T305-positive cells, which lack surface HLA-DR. Finally, we found CD43 bands with altered electrophoretic mobility in lysates from peripheral lymphocytes from all HIV-positive individuals tested., Conclusion: The augmented expression of CD43-hexasaccharides and the observed cellular distribution suggest an important regulatory role for this molecule in HIV-specific responses.

Background: To analyze the frequency of HIV primary mutations to nucleosides analogues in Andalusia., Patients and Method: Genotype study (LiPA) of mutations in codons M41L, T69D, K70R, L74V, M184V, T215Y/F and RT75G-S was performed in 106 HIV-naive patients from 12 Andalusian hospitals, with viral load over 5000 copies of RNA/ml., Results: Reliable results were obtained in 96 patients; 11 of them (11.45%) showed 12 mutations: two in codon 41, four in codon 70, three in codon 184 and three in codon 215. One patient showed two mutations (41 and 215). The presence of mutations only was related to having sex partner and sexual transmission of HIV infection., Conclusions: a) The primary mutations to nucleosides in HIV patients from Andalusia was 11.45%; b) mainly involved drugs were AZT and 3Tc, and c) mutations regarding resistance to ddC, ddI o D4T were not found.