[Recommendations from the GESIDA/Spanish AIDS Plan regarding antiretroviral treatment in adults with human immunodeficiency virus infection (update January 2007)]

Safe Reduction in CD4 Cell Count Monitoring in Stable, Virally Suppressed Patients With HIV Infection or HIV/Hepatitis C Virus Coinfection

BACKGROUND

It has been suggested that routine CD4 cell count monitoring in human immunodeficiency virus (HIV)-monoinfected patients with suppressed viral loads and CD4 cell counts >300 cell/μL could be reduced to annual. HIV/hepatitis C virus (HCV) coinfection is frequent, but evidence supporting similar reductions in CD4 cell count monitoring is lacking for this population. We determined whether CD4 cell count monitoring could be reduced in monoinfected and coinfected patients by estimating the probability of maintaining CD4 cell counts ≥200 cells/µL during continuous HIV suppression.

METHODS

The PISCIS Cohort study included data from 14 539 patients aged ≥16 years from 10 hospitals in Catalonia and 2 in the Balearic Islands (Spain) since January 1998. All patients who had at least one period of 6 months of continuous HIV suppression were included in this analysis. Cumulative probabilities with 95% confidence intervals were calculated using the Kaplan-Meier estimator stratified by the initial CD4 cell count at the period of continuous suppression initiation.

RESULTS

A total of 8695 patients were included. CD4 cell counts fell to <200 cells/µL in 7.4% patients, and the proportion was lower in patients with an initial count >350 cells/µL (1.8%) and higher in those with an initial count of 200-249 cells/µL (23.1%). CD4 cell counts fell to <200 cells/µL in 5.7% of monoinfected and 11.1% of coinfected patients. Of monoinfected patients with an initial CD4 cell count of 300-349 cells/µL, 95.6% maintained counts ≥200 cells/µL. In the coinfected group with the same initial count, this rate was lower, but 97.6% of coinfected patients with initial counts >350 cells/µL maintained counts ≥200 cells/µL.

CONCLUSIONS

From our data, it can be inferred that CD4 cell count monitoring can be safely performed annually in HIV-monoinfected patients with CD4 cell counts >300 cells/µL and HIV/HCV-coinfected patients with counts >350 cells/µL.

Observational study to evaluate clinical outcomes after first-line efavirenz-or lopinavir-ritonavir-based HAART in treatment-naive patients

PURPOSE

To evaluate clinical, immunological, and virological outcomes after first-line highly active antiretroviral therapy (HAART) with a regimen including either efavirenz (EFV) or lopinavir/ritonavir (LPV/r) in treatment-naive adult patients in routine clinical care.

METHOD

An ongoing prospective, observational follow-up study included all patients starting their first antiretroviral therapy (ART) with any of the studied regimens from July 1998 to July 2004. The follow-up period was finalized in September 2006, when all patients completed an observation of at least 96 weeks. Mortality rates, CD4 counts, viral suppression (HIV RNA below 50 copies/mL), and discontinuation of any component of the regimen were compared at 48 and 96 weeks.

RESULTS

Despite the worst immunological status of the LPV/r group patients at baseline, this regimen was at least as effective as the one based on EFV not only in terms of treatment durability but also in terms of virological responses, nevertheless with an apparently quicker immune recovery. In general terms, both regimens present similar tolerability and safety outcomes except for the higher risk of increasing triglyceride (TG) levels in the LPV/r group. Low durability was observed in both regimens.

CONCLUSION

In a routine clinical care setting, initial HAART containing LPV/r seems to present an effectiveness, tolerability, and toxicity similar to the one containing EFV.

[Lopinavir/ritonavir monotherapy as a simplification strategy in the treatment of HIV-1 infection]

Simplification of triple antiretroviral therapy to lopinavir/ritonavir (LPV/r) monotherapy in patients with well-controlled viremia for prolonged periods (more than 6 months) without prior failure with a protease inhibitor has been proposed as a strategy that could reduce the toxicity and costs of antiretroviral therapy in the long term while also preserving other therapeutic options. The results of several studies are currently available, some of which had a large number of patients and follow-up of up to 4 years. These studies indicate that this strategy is safe and efficacious, thus allowing its clinical use when indicated. This strategy may be especially useful in reducing the costs of treatment in countries with scarce economic resources. The role of LPV/r monotherapy in the prevention and management of lipodystrophy and in improving the selection of patients with an optimal risk-benefit ratio remains to be defined.

[Lopinavir/ritonavir monotherapy as a simplification strategy in antiretroviral therapy in clinical practice]

Although guidelines for the treatment of HIV-infected patients recommend triple drug antiretroviral therapy, because of the toxicity of these regimens, the complexity of treatment and its costs, other therapeutic options are desirable. Several clinical trials have shown that lopinavir/ritonavir (LPV/r) as a simplification strategy in antiretroviral therapy in HIV-infected patients who maintain suppression of viral replication while receiving conventional treatment regimens is safe and is associated with less toxicity than that due to prolonged exposure to protease inhibitors and nucleoside analogs. The present review summarizes the main results of the various retrospective studies on LPV/r as a simplification strategy of antiretroviral therapy in daily clinical practice.

A simplification trial switching from nucleoside reverse transcriptase inhibitors to once-daily fixed-dose abacavir/lamivudine or tenofovir/emtricitabine in HIV-1-infected patients with virological suppression

BACKGROUND

Data comparing abacavir/lamivudine versus tenofovir/emtricitabine in antiretroviral-naive patients are controversial. We compared 48-week efficacy and safety of these combinations as substitutes of nucleosides in patients with virological suppression.

METHODS

We randomly assigned 333 HIV-1-infected patients on lamivudine-containing triple regimens with <200 copies per milliliter for at least 6 months to switch their nucleosides to either abacavir/lamivudine (n = 167) or tenofovir/emtricitabine (n = 166). The primary outcome was treatment failure ["switching = failure" intention to treat (ITT) analysis, noninferiority margin 12.5%]. Secondary outcomes were time to treatment failure, virological failure, adverse events, and changes in CD4 count, fasting plasma lipids, lipodystrophy, body fat, bone mineral density, and renal function.

RESULTS

Treatment failure occurred in 32 patients (19%) on abacavir/lamivudine and 22 patients (13%) on tenofovir/emtricitabine [difference 5.9%; (95% confidence interval -2.1% to 14.0%), P = 0.06]. Four patients in the abacavir/lamivudine group versus none in the tenofovir/emtricitabine group developed virological failure [difference 2.4; (95% confidence interval 0.05 to 6.0), P = 0.04]. Twenty-three patients (14%) assigned to abacavir/lamivudine and 10 (6%) to tenofovir/lamivudine experienced grade 3 or 4 adverse effects (P = 0.03). CD4 counts and plasma lipids showed higher increments in the abacavir/lamivudine group than in the tenofovir/emtricitabine group.

CONCLUSIONS

In HIV-1-infected patients with virological suppression, abacavir/lamivudine did not meet the noninferiority outcome for treatment efficacy compared with tenofovir/emtricitabine.

[Interpreting methodological and statistical considerations in studies of rescue therapy]

The methodology used in studies of rescue therapy is sometimes complex. This is because of the heterogeneity of objectives and options. Firstly, the definition of failure has multiple interpretations and subtle distinctions. Secondly, the aim of treatment in these patients has varied according to the available treatment options in each case and at each moment of time. Lastly, the methodology used to develop these studies of rescue therapy has varied over time in line with changes in their aims and options. Currently, a new change can be expected to adjust to the current situation, since the number of therapeutic options for rescue therapy has substantially increased in the last year. The present review discusses changes in the design of these studies, the main methodological issues to be taken into account and the recommendations on this subject.

[Monotherapy in treatment-naïve patients]

The development of antiretroviral therapy (ART) with current triple drug combinations has dramatically reduced morbidity and mortality in HIV-infected patients. However, there is a need for less toxic treatments without sacrificing efficacy, as well as for less expensive drugs to facilitate universal access to this therapy. The protease inhibitors (PI) administered with ritonavir have a favorable pharmacokinetic profile and high genetic barrier and consequently are ideal candidates for use in monotherapy, thus avoiding the toxicity and cost associated with nucleoside analogs, as well as preserving drugs for future options. The promising results of studies performed with lopinavir/ritonavir (LPV/r) in induction-maintenance regimens in patients without prior failure to PIs encourage research into the cost-effectiveness of LPV/r in monotherapy from the beginning of ART. The few studies performed in this context seem to indicate the following: a) LPV/r monotherapy achieves undetectable viral loads in a large proportion of treatment-naïve patients, b) future treatment options are not compromised in patients not achieving undetectable viral loads since the likelihood of resistance mutations is low and treatment intensification achieves suppression of viral replication, and c) strategies for early detection can probably be considered in patients who will not achieve complete suppression with LPV/r monotherapy. Nevertheless, before LPV/r monotherapy can be considered a first-line option, new studies with larger samples and longer follow-up are required. These studies should pay particular attention to viral replication in areas where PI show less penetration.

Clinicoepidemiological characteristics of HIV-infected immigrants attended at a tropical medicine referral unit

BACKGROUND

Migration is a growing phenomenon with a well-known impact in infectious diseases epidemiology. Currently, immigrants represent almost 10% of the Spanish population. The majority come from countries where the prevalence of chronic viral illnesses is higher than in Spain.

METHODS

To describe clinicoepidemiological features of human immunodeficiency virus (HIV)-infected immigrants attending our Unit and to compare differential characteristics depending on geographical origin, information from all new immigrants from January 1997 to December 2006 was collected.

STUDY DESIGN

noninterventional retrospective chart review.

RESULTS

We screened 1,609 patients of whom 77 (4.8%) were HIV antibody (Ab) positive. Of these, 80% were sub-Saharan Africans (SSAFR) and 20% were South-Central Americans (SCA). HIV prevalence was higher in SSAFR (5.6% vs 3.2%; p= 0.04). Overall, of those who were HIV Ab positive, 70% were male (median age 30 years), 59% heterosexuals, 9% hepatitis C virus coinfected, 8.6% hepatitis B virus coinfected, and 34% showed a positive tuberculin skin test. Median CD4 cell count was 263 cells/microL, median HIV-ribonucleic acid viral load 4.6 Log/mL, and 48% had a late diagnosis [acquired immunodeficiency syndrome (AIDS)-defining illness or <200 CD4 microL at the time of diagnosis]. Only 68% of patients for whom antiretroviral therapy was indicated actually started therapy and 22% were lost to follow-up just after diagnosis. SCA had lower CD4 cell counts (26 vs 168 cells/microL; p= 0.016), higher viral loads (5.3 vs 4.8 Log; p= 0.001), and were more likely to have an AIDS-defining illness (53% vs 21%; p= 0.04) compared to SSAFR. Tuberculin skin test reactivity was more common among SSAFR versus SCA [adjusted by CD4 count, odds ratio (OR) 6.3 and 95% confidence interval (CI): 0.65-60.5]. The main risk factor for late diagnosis was geographical origin: OR 4.6 (95% CI: 1.11-19.3) (SCA vs SSAFR; adjusted by the interval between the date of arrival in Spain and the date of HIV diagnosis).

CONCLUSIONS

Almost half the HIV-infected immigrants were diagnosed in late stages. Patients were frequently lost to follow-up, and a significant minority did not start highly active antiretroviral therapy when indicated. SCA seem to have more severe immunosuppression at the time of diagnosis than SSAFR. Early voluntary routine HIV screening should be promoted.

[Darunavir in patients with advanced HIV and multiresistance. The POWER, DUET and BENCHMRK studies]

Darunavir is a new protease inhibitor. This drug is highly active against wild-type and multiresistant HIV strains, binds strongly to the HIV-1 protease, has extremely high affinity for the protease and, when enhanced by subtherapeutic doses of ritonavir, has a favorable resistance profile differing from that of current protease inhibitors (PIs). After determining the optimal dose, phase IIb clinical trials (POWER studies 1 and 2) observed much higher virological and immunological efficacy with darunavir than with the comparator PIs. The results of a phase III clinical trial (POWER 3) provide further support for the safety and efficacy of darunavir, and the three POWER studies demonstrate the high genetic barrier of this drug against mutations conferring resistance to other PIs, although the baseline sensitivity of darunavir and the specific mutations to this PI influence the virological response. Better therapeutic responses have been obtained when there are two or more antiretroviral drugs active against multiresistant HIV strains. The phase III trials (DUET 1 and 2), in which darunavir was administered with the new nonnucleoside reverse transcriptase inhibitor, etravirine, found that if these two drugs were administered in highly treatment-experienced patients, a large percentage showed suppression of plasma viremia and immunological recovery. These data have been supported by the results of the BENCHMARK studies, in which darunavir was included in an optimized regimen in a substantial number of patients. In these trials, when darunavir was administered with the integrase inhibitor, raltegravir, undetectable viral loads both in the raltegravir arm and in the control group were substantially improved with respect to the overall results obtained in the control group.

[Lipid profile of atazanavir]

It is currently known that exposure to antiretroviral treatment, particularly to the classic protease inhibitors, is associated with an increased risk of suffering from cardiovascular disease, although stopping antiretroviral treatment can cause an even greater risk. Recommendations have been made on how to deal with dyslipaemia and cardiovascular risk in seropositive patients. These recommendations are similar to those for the general population, but include the particular feature of considering including benign treatment with lipids wherever possible. Atazanavir has different characteristics from other protease inhibitors as regards its effects on adipose tissue and metabolism in general. Atazanavir is not associated with increases in total cholesterol, LDL-cholesterol or triglycerides as with other PI in initial, rescue or simplification therapy. The results of in vitro studies and clinical studies are clear and convincing. These characteristics give it a particular role that is very attractive when deciding the most suitable antiretroviral treatment for a proportion of HIV-infected patients in whom the reduction in cardiovascular risk is seen as a priority.

[Treatment of opportunistic infections in adolescent and adult patients infected with the human immunodeficiency virus during the era of highly active antiretroviral therapy. AIDS Study Group (GESIDA) and National AIDS Plan Expert Committee]

Despite the huge advance that highly active antiretroviral therapy has represented for the prognosis of infection by human immunodeficiency virus (HIV), opportunistic infections continue to be a cause of morbidity and mortality in HIV-infected patients. This is often the case because of severe immunodepression, poor adherence to antiretroviral therapy, failure of therapy, or the fact that patients are unaware of their HIV-positive status and debut with an opportunistic infection. This article updates the guidelines on treatment of acute episodes of various opportunistic infections in HIV-infected patients, including infections due to parasites, fungi, viruses, mycobacteria, and bacteria. This edition has a new chapter on imported parasite infections as well as additional information on endemic mycoses in the chapter on fungal infections, taking into account the growing number of immigrants in our setting. Lastly, the chapter on the immune reconstitution syndrome has also been updated, providing relevant data on a phenomenon that has clinical and diagnostic repercussions in patients who start antiretroviral therapy while they are severely immunodepressed (English version available at http://www.gesida.seimc.org).

[Longitudinal study on adherence, treatment satisfaction, and effectiveness of once-daily versus twice-daily antiretroviral therapy in a Spanish cohort of HIV-infected patients (CUVA study)]

INTRODUCTION

Adherence is essential for successful antiretroviral therapy (ART), but complex dosing schedules compromise the adherence to and efficacy of this treatment. Once-daily (QD) ART simplifies treatment by lowering the dosing frequency and pill burden. The aim of this study, performed when QD regimens were still limited, was to determine the degree of adherence and patient satisfaction of QD dosing versus twice-daily dosing (BID) of ART.

METHODS

Non-interventional, multicenter, longitudinal study, including initial (I), simplification (S), and rescue (R) therapies. Medical visits were performed at baseline, and at 3 and 6 months. A validated, structured questionnaire was used to assess adherence, and a visual analogical scale applied by independent observers was used to assess satisfaction.

RESULTS

From May to December 2002, 978 patients were recruited. Average pill burden was 5 in QD vs. 6.1 in BID regimens. Undetectable viral load was achieved at 6 months in 83.7% (I), 87.5% (S), and 57.4% (R) of patients, with no significant differences between QD and BID. Adherence and satisfaction with ART were both significantly better in QD vs. BID regimens: 61.4% vs. 53.2% (P < .05) and 54.4% vs. 41.2% (P < .05), respectively. Multivariate analysis revealed the following variables to account for 1) Adherence to ART (OR; 95% CI): treatment satisfaction (1.53, 1.30-1.80), family support (1.25, 0.98-1.61), years of HIV infection (0.97, 0.94-1.003) and intravenous drug use (0.83, 0.70-0.99); 2) Satisfaction with ART: simplification group (1.70, 1.22-2.34), QD therapy (1.33, 1.13-1.56), years of HIV infection (0.95, 0.93-0.98), and CDC stage C (0.85, 0.73-1.01); and 3) Undetectable viral load: naive group (5.08, 3.14-8.22) and adherence (1.57, 1.13-2.17).

CONCLUSION

QD antiretroviral schedules appear to be as effective as BID regimens, with better adherence and treatment satisfaction. This may positively affect treatment efficacy at long-term.

Short communication: oral lesions in HIV/AIDS patients undergoing HAART including efavirenz

Oral lesions (OL) have an important prognostic value for HIV/AIDS patients. However, the behavior of OL in HIV/AIDS patients undergoing highly active antiretroviral therapy including efavirenz (HAART/EFV) has not been documented. Our objective was to establish the prevalence of OL in HIV/AIDS patients undergoing HAART/EFV and to compare it with the prevalence of OL in patients undergoing antiretroviral therapy including a protease inhibitor (HAART/PI). Seventy-three HIV/AIDS patients undergoing antiretroviral treatment for at least for 6 months at "La Raza" Medical Center's Internal Medicine Unit (IMSS, Mexico City) were included. To detect OL, a detailed examination of oral soft tissues was performed in each patient. Patient records recorded gender, seropositivity time, route of contagion, antiretroviral therapy type and duration, CD4 lymphocyte count/ml, and viral load. Two groups were formed: 38 patients receiving HAART/EFV [two nucleoside analogue reverse transcriptase inhibitors (NARTI) plus efavirenz] and 35 patients receiving HAART/PI (two NARTIs plus one PI). OL prevalence was established in each study group. The Chi-square test was applied (p < 0.05(IC95%)). OL prevalence in the HAART/EFV group (32%) was lower (p < 0.007) than in the HAART/PI group (63%). Candidosis was the most prevalent OL in both groups. Herpes labialis, HIV-associated necrotizing periodontitis, xerostomia, hairy leukoplakia, and nonspecific oral sores were identified. The highest prevalence for all OL was found in the HAART/PI group. These findings suggest that HIV/AIDS patients undergoing HAART/EFV show a lower prevalence of oral lesions than patients undergoing HAART/PI.

[Preferences, satisfaction and compliance with antiretroviral treatment: ARPAS study (II)]

OBJECTIVE

To describe the ARPAS study and analyse the sociodemographic and clinical characteristics and patient preferences with regards the antiretroviral treatment (ART), as well as the relationship between compliance and satisfaction with the ART and quality of life.

METHOD

The ARPAS study has looked at adult patients diagnosed with HIV and on ART, using a protocol including sociodemographic, clinical, therapeutic and quality of life variables. Compliance was estimated using the SMAQ questionnaire; satisfaction was measured using the ESTAR questionnaire, as was quality of life with the MOS-HIV Health Survey, and treatment preferences were determined using a questionnaire prepared based on the consensus of an expert team in the field of therapeutic monitoring of these patients. A stratified univariate analysis according to compliance and a logistic regression analysis were carried out to study the association of the independent variables with compliance.

RESULTS

A total of 234 patients were evaluated (73.7% male; 43.2+/-7.8 years of age). The average time since diagnosis and from the initiation of ART was 10.1+/-5.7 and 7.4+/-4.4 years respectively. The therapeutic regime of twice-daily doses (bid) was applied to 71% of the patients, and once daily (qd) in 21%. A total of 43% of the patients fulfilled compliance criteria according to the SMAQ. The percentage of the patients with qd complying with the ART was greater than the remaining dosing schedules (55.3 vs. 45.1%), although not significantly (p=0.251). No differences were observed in the sociodemographic and clinical variables in terms of compliance. An elective preference was observed for the simplest of the therapeutic regimes which contrasts with the evaluation of the ART characteristics, where power is given preference over durability, tolerance and lastly, the convenience of taking the ART. The univariate analysis showed the highest score on the satisfaction scales (50.4+/-7.8 vs. 46.5+/-9.7, p=0.001) and quality of life (81.6+/-10.7 vs. 75.7+/-11.8, p<0.001) in compliant patients with respect to non-compliers. The multivariate models confirm the existence of a significant association between compliance and satisfaction, and between compliance and quality of life.

CONCLUSIONS

Patients consider treatment with a powerful, long-lasting and well-tolerated ART a priority and among their preferences for different treatment regimes, once-daily dosing regimes are highlighted. The ARPAS study showed a direct relationship between compliance and satisfaction with ART, and between compliance and quality of life, in a manner that the strategies improving compliance must necessarily include aspects that allow them to improve patient satisfaction with treatment and quality of life.

[Psychometric characteristics of the antiretroviral treatment satisfaction scale (ESTAR): ARPAS study (I)]

OBJECTIVE

To evaluate the psychometric characteristics, convergent validity and reliability of the antiretroviral treatment satisfaction scale (ESTAR, escala de satisfacción con el tratamiento antirretroviral).

METHOD

Patient satisfaction with ART was determined using the ESTAR questionnaire, developed in Spanish based on the English language version of the HIV-Treatment-Satisfaction Questionnaire (HIVTSQ). In order to evaluate this, internal consistency and test-retest reliability were measured. The construct analysis was performed by studying the covariance and correlation of the questions, and the convergent validity was assessed by using the MOS-HIV (Medical Outcomes Study HIV Health Survey) questionnaire as the standard, as was the content validity by the correlation between the ESTAR and the clinical and therapeutic variables.

RESULTS

The ESTAR is structured in two dimensions (clinical satisfaction and satisfaction with lifestyle) with slight modifications to the original version; question 4, discarded in the original version, has been reworded in the Spanish version, and question 9 was deleted because of low communality. As regards the test-retest reliability, all the questions show significant intraclass correlation coefficients (p<0.001). The internal consistency shows higher values than the original version in the lifestyle dimension (a=0.81 vs. a=0.74) and in the total score (a=0.84 vs. a=0.82). With regard to convergent validity, the ESTAR presents significant correlations with the MOS-HIV as a whole and with different dimensions of it, especially the association with mental health, health distress and cognitive functioning dimensions.

CONCLUSIONS

The ESTAR turns out to be a suitable, reliable instrument for evaluating satisfaction with ART by HIV+ patients.

[Analysis of the causes and predictive factors for discontinuing treatment with tenofovir in pretreated HIV patients]

OBJECTIVE

To determine the frequency and causes for discontinuing treatment with tenofovir and analyse possible predictive factors for changing this therapy in pretreated HIV patients.

METHOD

A multi-centre, observational and retrospective study of all HIV patients undergoing treatment with tenofovir between July 2002 and December 2005. Data were obtained from databases for outpatients attending the three pharmacy departments participating in the study, and by reviewing clinical histories. The main sociodemographic, clinical and analytical variables at the start of treatment with tenofovir were collected. The causes for discontinuing treatment were classified as follows: adverse effects, virological failure, death and "other causes". A survival analysis was performed using the Kaplan-Meier method to analyse the possible predictive factors for discontinuing treatment.

RESULTS

A total of 733 patients were included in the study and the median treatment period was 34.7 months. A total of 23.8% of patients discontinued treatment for the following reasons: adverse effects (43.2%), death (17.7%), virological failure (14.8%) and "other causes" (24.4%). There were 99 cases of lost to follow-up. In the survival analysis an association was found between normal serum creatinine values (p = 0.0042) at the start of treatment and the statistically significant probability of discontinuing treatment.

CONCLUSIONS

Almost a quarter of the patients discontinued treatment with tenofovir during the study. The main cause for this was adverse effects. No association was found between any abnormal basal analytical parameter and a greater probability of discontinuing treatment.

Antiretroviral therapy : optimal sequencing of therapy to avoid resistance

In the second decade of highly active antiretroviral therapy, drug regimens offer more potent, less toxic and more durable choices. However, strategies addressing convenient sequential use of active antiretroviral combinations are rarely presented in the literature. Studies have seldom directly addressed this issue, despite it being a matter of daily use in clinical practice. This is, in part, because of the complexity of HIV-1 resistance information as well as the complexity of designing these types of studies. Nevertheless, several principles can effectively assist the planning of antiretroviral drug sequencing. The introduction of tenofovir disoproxil fumarate, abacavir and emtricitabine into current nucleoside backbone options, with each of them selecting for an individual pattern of resistance mutations, now permits sequencing in the context of previously popular thymidine analogues (zidovudine and stavudine). Similarly, newer ritonavir-boosted protease inhibitors could potentially be sequenced in a manner that uses the least cross-resistance prone protease inhibitor at the start of therapy, while leaving the most cross-resistance prone drugs for later, as long as there is rationale to employ such a compound because of its utility against commonly observed drug-resistant forms of HIV-1.

[New therapeutic options in protracted HIV-infected patients with virological failure]

Once patients have a triple class virological failure, their treatment options are limited and there is an increased risk of death. In order to construct active treatment regimens, new potent antiretroviral agents are available for these patients. The virological target in patients with treatment failure is now plasma HIV RNA level below 50 copies/ml when 2 or more potent drugs are identified. If at least two active drugs cannot be identified, the current regimen should be maintained until new drugs become available, assuming that there is an immunological and clinical stability, in order to avoid the use of a single-active drug that usually leads to rapid development of resistance, further limiting the future treatment options. In this article, the current state of knowledge about these new agents available and the guidelines of main societies are reviewed.

Lopinavir-ritonavir monotherapy versus lopinavir-ritonavir and two nucleosides for maintenance therapy of HIV

BACKGROUND

Prior attempts to reduce the number of drugs needed to maintain viral suppression in patients with suppressed HIV replication while receiving three antiretroviral drugs have been unsuccessful.

METHODS

In 205 patients with suppressed HIV replication on lopinavir-ritonavir and two nucleosides, this randomized, open-label, non-inferiority clinical trial compared the strategies of continuation of triple therapy versus lopinavir-ritonavir monotherapy followed by reinduction with two nucleosides if virological rebound occurred without genotypic resistance to lopinavir-ritonavir. The primary endpoint was proportion of patients without therapeutic failure, defined as confirmed HIV RNA higher than 500 copies/mL (with exclusion of patients receiving monotherapy who resuppressed to < 50 copies/mL after resuming baseline nucleosides), or loss to follow-up, or change of randomized therapy other than reinduction.

RESULTS

At week 48, the percentage of patients without therapeutic failure was 94% in the monotherapy group versus 90% in the triple therapy group (difference,-4%; upper limit of 95% confidence interval for difference, 3.4%). The percentage of patients with HIV RNA 50 copies/mL at 48 weeks by intention-to-treat, missing data or reinductions considered as failures, were 85% in the monotherapy group versus 90% in the triple therapy group (P = 0.31; 95% upper limit of 95% confidence interval for difference, 14%).

CONCLUSION

In this trial, 48 weeks of lopinavir-ritonavir monotherapy with reintroduction of nucleosides as needed was non-inferior to continuation of two nucleosides and lopinavir-ritonavir in patients with prior stable suppression. However, episodes of low level viremia were more common in patients receiving monotherapy.

[Microbiological diagnosis of HIV infection]

Currently, there are around 150,000 HIV-infected patients in Spain. This number, together with the fact that this disease is now a chronic condition since the introduction of antiretroviral therapy, has generated an increasing demand on the clinical microbiology laboratories in our hospitals. This increase has occurred not only in the diagnosis and treatment of opportunistic diseases, but also in tests related to the diagnosis and therapeutic management of HIV infection. To meet this demand, the Sociedad de Enfermedades Infecciosas y Microbiología Clinica (Spanish Society of Infectious Diseases and Clinical Microbiology) has updated its standard Procedure for the microbiological diagnosis of HIV infection. The main advances related to serological diagnosis, plasma viral load, and detection of resistance to antiretroviral drugs are reviewed in this version of the Procedure.

Strategies for the optimal sequencing of antiretroviral drugs toward overcoming and preventing drug resistance

Drug regimens now offer more potent, less toxic and more durable choices in the treatment of HIV disease than ever before. This has led to a need to consider the convenient, sequential use of active antiretroviral combinations. Ritonavir-boosted protease inhibitors (PIs) can now be potentially sequenced in a manner that uses the least cross-resistance-prone PI at the start of therapy while leaving the most cross-resistance-prone drug for later, if the latter retains activity against commonly observed drug-resistant forms. Similarly, such new drugs as tenofovir, abacavir and emtricitabine, which make up current nucleoside backbone options, can be potentially sequenced, since each of them selects for an individual pattern of resistance mutations that are generally distinct from those selected by previously popular thymidine analogs such as zidovudine and stavudine.