Short- versus long-duration levofloxacin plus rifampicin for acute staphylococcal prosthetic joint infection managed with implant retention: a randomised clinical trial

Levofloxacin plus rifampicin (L+R) is the treatment of choice for acute staphylococcal prosthetic joint infection (PJI) managed with debridement and implant retention (DAIR). Long courses have been empirically recommended, but some studies have suggested that shorter treatments could be as effective. Our aim was to prove that a short treatment schedule was non-inferior to the standard long schedule. An open-label, multicentre, randomised clinical trial (RCT) was performed. Patients with an early post-surgical or haematogenous staphylococcal PJI, managed with DAIR and initiated on L+R were randomised to receive 8 weeks of treatment (short schedule) versus a long schedule (3 months or 6 months for hip or knee prostheses, respectively). The primary endpoint was cure rate. From 175 eligible patients, 63 were included (52% women; median age, 72 years): 33 patients (52%) received the long schedule and 30 (48%) received the short schedule. There were no differences between the two groups except for a higher rate of polymicrobial infection in the long-schedule group (27% vs. 7%; P = 0.031). Median follow-up was 540 days. In the intention-to-treat analysis, cure rates were 58% and 73% in patients receiving the long and short schedules, respectively (difference -15.7%, 95% CI -39.2% to 7.8%). Forty-four patients (70%) were evaluable per-protocol: cure rates were 95.0% and 91.7% for the long and short schedules, respectively (difference 3.3%, 95% CI -11.7% to 18.3%). This is the first RCT suggesting that 8 weeks of L+R could be non-inferior to longer standard treatments for acute staphylococcal PJI managed with DAIR.

Costs and cost-efficacy analysis of the 2016 GESIDA/Spanish AIDS National Plan recommended guidelines for initial antiretroviral therapy in HIV-infected adults

INTRODUCTION

GESIDA and the AIDS National Plan panel of experts suggest preferred (PR), alternative (AR), and other regimens (OR) for antiretroviral treatment (ART) as initial therapy in HIV-infected patients for the year 2016. The objective of this study is to evaluate the costs and the efficacy of initiating treatment with these regimens.

METHODS

Economic assessment of costs and efficiency (cost/efficacy) based on decision tree analyses. Efficacy was defined as the probability of reporting a viral load <50copies/mL at week 48 in an intention-to-treat analysis. Cost of initiating treatment with an ART regimen was defined as the costs of ART and its consequences (adverse effects, changes of ART regimen, and drug resistance studies) during the first 48 weeks. The payer perspective (National Health System) was applied, only taking into account differential direct costs: ART (official prices), management of adverse effects, studies of resistance, and HLA B*5701 testing. The setting is Spain and the costs correspond to those of 2016. A sensitivity deterministic analysis was conducted, building three scenarios for each regimen: base case, most favourable, and least favourable.

RESULTS

In the base case scenario, the cost of initiating treatment ranges from 4663 Euros for 3TC+LPV/r (OR) to 10,894 Euros for TDF/FTC+RAL (PR). The efficacy varies from 0.66 for ABC/3TC+ATV/r (AR) and ABC/3TC+LPV/r (OR), to 0.89 for TDF/FTC+DTG (PR) and TDF/FTC/EVG/COBI (AR). The efficiency, in terms of cost/efficacy, ranges from 5280 to 12,836 Euros per responder at 48 weeks, for 3TC+LPV/r (OR), and RAL+DRV/r (OR), respectively.

CONCLUSION

Despite the overall most efficient regimen being 3TC+LPV/r (OR), among the PR and AR, the most efficient regimen was ABC/3TC/DTG (PR). Among the AR regimes, the most efficient was TDF/FTC/RPV.

Clinical outcomes of patients infected with HIV through use of injected drugs compared to patients infected through sexual transmission: late presentation, delayed anti-retroviral treatment and higher mortality

AIMS

To compare patients who acquired HIV infection through use of injected drugs (HIV-IDU) with patients who acquired HIV by sexual transmission (HIV-ST) in terms of late presentation (LP), delay in anti-retroviral treatment (ART) initiation, virological and immunological response to ART, mortality and progression to AIDS.

DESIGN

Prospective multi-centre cohort study of HIV-infected subjects naive to ART at entry (Cohort of the Spanish HIV Research Network: CoRIS).

SETTING

Thirty-one centres from the Spanish public health-care system.

PARTICIPANTS

A total of 9355 patients were included (1064 HIV-IDU and 8291 HIV-ST) during 2004-13.

MEASUREMENTS

We compared LP (defined as presentation for care with a CD4 cell count < 350/μl and/or AIDS-defining illness), delayed ART initiation (defined as initiating treatment more than 6 months after the date when treatment was indicated by the guidelines, or not initiating treatment at all when it was indicated), virological and immunological response to ART (defined as viral load < 50 HIV-1 RNA copies/ml and a CD4 count increase of at least 100 cells/μl, respectively, after 1 year of treatment), mortality and progression to AIDS in HIV-IDU and HIV-ST.

FINDINGS

Compared with HIV-ST, HIV-IDU had higher risk of LP [odds ratio (OR) = 1.76; 95% confidence interval (CI) = 1.41-2.18], delayed ART initiation (OR 1.87; 95% CI = 1.46-2.40) and higher mortality [hazard ratio (HR) = 1.43; 95% CI = 1.03-2.01] and risk of progression to AIDS [subhazard ratio (SHR) = 1.68; 95% CI = 1.29-2.18]. Virological suppression due to ART was lower in HIV-IDU than in patients with HIV-ST only among patients without hepatitis C virus (HCV) infection [adjusted OR (aOR) = 0.59; 95% CI = 0.36-0.95]; among patients with HCV infection, virological suppression due to ART did not show significant differences between HIV-IDU and HIV-ST. There were no significant differences in immunological response after adjusting by HCV (aOR = 0.74; 95% CI = 0.52-1.06).

CONCLUSIONS

In Spain, patients who acquire HIV infection through use of injected drugs appear to have a higher risk of late presentation, delayed initiation of anti-retroviral treatment and progression to AIDS and death than patients who acquire HIV by sexual transmission.

Executive summary: Prevention and treatment of opportunistic infections and other coinfections in HIV-infected patients: May 2015

Opportunistic infections continue to be a cause of morbidity and mortality in HIV-infected patients. They often arise because of severe immunosuppression resulting from poor adherence to antiretroviral therapy, failure of antiretroviral therapy, or unawareness of HIV infection by patients whose first clinical manifestation of AIDS is an opportunistic infection. The present article is an executive summary of the document that updates the previous recommendations on the prevention and treatment of opportunistic infections in HIV-infected patients, namely, infections by parasites, fungi, viruses, mycobacteria, and bacteria, as well as imported infections. The article also addresses immune reconstitution inflammatory syndrome. This document is intended for all professionals who work in clinical practice in the field of HIV infection.

Prevention and treatment of opportunistic infections and other coinfections in HIV-infected patients: May 2015

Despite the huge advance that antiretroviral therapy represents for the prognosis of infection by the human immunodeficiency virus (HIV), opportunistic infections (OIs) continue to be a cause of morbidity and mortality in HIV-infected patients. OIs often arise because of severe immunosuppression resulting from poor adherence to antiretroviral therapy, failure of antiretroviral therapy, or unawareness of HIV infection by patients whose first clinical manifestation of AIDS is an OI. The present article updates our previous guidelines on the prevention and treatment of various OIs in HIV-infected patients, namely, infections by parasites, fungi, viruses, mycobacteria, and bacteria, as well as imported infections. The article also addresses immune reconstitution inflammatory syndrome.

Transmission of HIV Drug Resistance and the Predicted Effect on Current First-line Regimens in Europe

Transmitted human immunodeficiency virus drug resistance in Europe is stable at around 8%. The impact of baseline mutation patterns on susceptibility to antiretroviral drugs should be addressed using clinical guidelines. The impact on baseline susceptibility is largest for nonnucleoside reverse transcriptase inhibitors.

Background. Numerous studies have shown that baseline drug resistance patterns may influence the outcome of antiretroviral therapy. Therefore, guidelines recommend drug resistance testing to guide the choice of initial regimen. In addition to optimizing individual patient management, these baseline resistance data enable transmitted drug resistance (TDR) to be surveyed for public health purposes. The SPREAD program systematically collects data to gain insight into TDR occurring in Europe since 2001.

Methods. Demographic, clinical, and virological data from 4140 antiretroviral-naive human immunodeficiency virus (HIV)–infected individuals from 26 countries who were newly diagnosed between 2008 and 2010 were analyzed. Evidence of TDR was defined using the WHO list for surveillance of drug resistance mutations. Prevalence of TDR was assessed over time by comparing the results to SPREAD data from 2002 to 2007. Baseline susceptibility to antiretroviral drugs was predicted using the Stanford HIVdb program version 7.0.

Results. The overall prevalence of TDR did not change significantly over time and was 8.3% (95% confidence interval, 7.2%–9.5%) in 2008–2010. The most frequent indicators of TDR were nucleoside reverse transcriptase inhibitor (NRTI) mutations (4.5%), followed by nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations (2.9%) and protease inhibitor mutations (2.0%). Baseline mutations were most predictive of reduced susceptibility to initial NNRTI-based regimens: 4.5% and 6.5% of patient isolates were predicted to have resistance to regimens containing efavirenz or rilpivirine, respectively, independent of current NRTI backbones.

Conclusions. Although TDR was highest for NRTIs, the impact of baseline drug resistance patterns on susceptibility was largest for NNRTIs. The prevalence of TDR assessed by epidemiological surveys does not clearly indicate to what degree susceptibility to different drug classes is affected.

Virological failure to raltegravir in Spain: incidence, prevalence and clinical consequences

OBJECTIVES

The objective of this study was to evaluate the incidence, prevalence and clinical consequences of virological failure (VF) to raltegravir-based regimens in Spain.

METHODS

A multicentre, retrospective, observational study was performed in 10 tertiary hospitals (January 2006 to June 2013). The study included HIV-1-infected patients with loss of virological suppression (LVS; two consecutive HIV-1 RNA ≥50 copies/mL) while receiving raltegravir. VF and low-level viraemia (LLV) were defined as two consecutive HIV-1 RNA ≥200 copies/mL and 50 to <200 copies/mL, respectively. Integrase strand-transfer inhibitor resistance was investigated at LVS. During the 48 weeks following LVS, recorded data included clinical characteristics, treatment discontinuations, AIDS-associated events and deaths. Effectiveness of therapy following LVS was evaluated by ITT and PP. Multivariate regression was used to assess predictors of efficacy.

RESULTS

Of the 15 009 HIV-infected patients in participating centres, 2782 (18.5%) had received raltegravir-based regimens. Of those, 192 (6.9%), 125 (4.5%) and 67 (2.4%) experienced LVS, VF and LLV, respectively. The incidence of VF was 1.8 (95% CI, 1.5-2.1) per 100 patients/year. The prevalence of VF was 4.5% (95% CI, 3.8%-5.3%). Integrase-associated mutations were found in 78.8% of patients with integrase genotyping results available. High-level resistance to dolutegravir was not observed. Salvage therapy failed in 34.1% of patients; progression to AIDS/death occurred in 8.3% during the first year following LVS. The latter was associated with intravenous drug use, time on raltegravir and lower CD4+ count nadir in patients who started raltegravir-based treatments as salvage regimens.

CONCLUSIONS

VF with raltegravir is infrequent, but often associated with major clinical complications in treatment-experienced patients.

Increased risk of non-AIDS-related events in HIV subjects with persistent low CD4 counts despite cART in the CoRIS cohort

The aim was to analyze clinical complications in HIV-infected subjects who persistently maintain low CD4 levels despite virological response to cART in the Spanish CoRIS cohort. The main inclusion criteria were CD4 counts <200cells/mm(3) at cART-initiation and at least 2years under cART achieving a viral load <500copies/mL. Those patients with CD4 counts <250cells/mm(3) 2years after cART were classified as the Low-CD4 group, and clinical events were collected from this time-point. Poisson regression models were used to calculate incidence rate ratios of death, AIDS-defining events, serious non-AIDS-defining events (NAE) and of each specific NAE category (non-AIDS-defining malignancies (non-ADM), cardiovascular, kidney- and liver-related events). Of 9667 patients in the cohort, a total of 1128 met the criteria and 287 (25.4%) were classified in the Low-CD4 group. A higher risk of death (aIRR: 4.71; 95% CI: 1.88-11.82; p-value=0.001) and of non-ADM were observed in this group (aIRR: 2.23; 95% CI: 1.07-4.63; p=0.03). Our results stress the need to control accelerated aging in this population to counter their increased risk of non-AIDS-defining diseases, particularly cancer, and are consistent with the concept that clinical complications are potentially affected by genetics and lifestyle.

Tuberculosis in a cohort of HIV-positive patients: epidemiology, clinical practice and treatment outcomes

OBJECTIVE

To describe tuberculosis (TB) incidence, risk factors, clinical presentation, disease management and outcomes in human immunodeficiency virus (HIV) infected patients from the CoRIS cohort, Spain, 2004-2010.

DESIGN

Open multicentre cohort of antiretroviral treatment (ART) naïve patients at entry. Incidence and risk factors were evaluated using multivariate Poisson regression.

RESULTS

Among 6811 patients, 271 were eligible for the study and 198 for the estimation of the incidence rate; TB incidence ranged from 12.1 to 14.1/1000 person-years. TB was associated with low education level (rate ratio [RR] 2.65, 95%CI 1.73-4.07), being sub-Saharan African (RR 3.14, 95%CI 1.81-5.45), heterosexual (RR 2.01, 95%CI 1.22-3.29) or an injecting drug user (RR 2.11, 95%CI 1.20-3.69), not undergoing ART (RR 3.33, 95%CI 2.22-4.76), CD4 <200 cells/mm(3) (RR 5.20, 95%CI 3.25-8.33) and log-viral load of 4-5 (RR 5.44, 95%CI 3.28-9.02) or >5 (RR 13.10, 95%CI 8.27-20.76). Overall, 87% were new cases and 13% were previously treated cases; 175 (65%) were bacteriologically confirmed. Drug susceptibility testing was performed in 146 (83%) patients: resistance to first-line drugs was 11.1% in new and 36.4% in previously treated cases. Standard anti-tuberculosis treatment with four or three drugs was prescribed in respectively 55% and 36% of cases. Treatment default was 11%, and was higher among previously treated cases; 80% received ART during anti-tuberculosis treatment, 80% of new and 50% of previously treated cases were cured or completed treatment, and 18 (6.6%) died.

CONCLUSION

TB incidence in HIV-infected patients remains high. Interventions should include early HIV diagnosis and access to ART, enhanced bacteriological confirmation, wider use of four-drug regimens and reduction in treatment default.

Cardiovascular risk factors and lifetime risk estimation in HIV-infected patients under antiretroviral treatment in Spain

BACKGROUND AND OBJECTIVES

Cardiovascular disease is a major concern in HIV-infected patients. Lifetime risk estimations use the risk of developing it over the course of remaining lifetime, and are useful in communicating this risk to young patients. We aim to describe the prevalence of cardiovascular risk factors among a representative sample of HIV-infected subjects under antiretroviral therapy in Spain, and to estimate their lifetime risk of cardiovascular disease.

METHODS

Cross-sectional survey about cardiovascular risk factors in 10 HIV units across Spain. Lifetime risk assessed according to Barry was classified in two major categories: low and high lifetime risk.

RESULTS

We included 895 subjects, 72% men, median age 45.7 years; median CD4 lymphocyte count 598 cells/μl, median time since HIV diagnosis 11 years, median time on antiretroviral treatment 6.3 years, 87% had undetectable HIV viral load. Tobacco smoking was the most frequent risk factor (54%), followed by dyslipidemia (48.6%) and hypertension (38.6%). Estimated 10-year coronary risk (Framingham/Regicor Risk Score) risk was low ( < 5%) in 78% of the patients, and intermediate (5-10%) in 20%. Lifetime risk estimation showed a high risk profile for 71.4% of the population studied, which was associated with increasing age, prolonged antiretroviral therapy and patient's place of origin.

CONCLUSIONS

Modifiable cardiovascular risk factors in this population are very common. There are significant disparities between the low 10-year risk estimated with the Framingham/Regicor score and the higher lifetime risk in HIV patients on antiretroviral therapy. A more aggressive management of modifiable cardiovascular risk factors in these patients seems advisable.

Gram-negative prosthetic joint infection: outcome of a debridement, antibiotics and implant retention approach. A large multicentre study

We aim to evaluate the epidemiology and outcome of gram-negative prosthetic joint infection (GN-PJI) treated with debridement, antibiotics and implant retention (DAIR), identify factors predictive of failure, and determine the impact of ciprofloxacin use on prognosis. We performed a retrospective, multicentre, observational study of GN-PJI diagnosed from 2003 through to 2010 in 16 Spanish hospitals. We define failure as persistence or reappearance of the inflammatory joint signs during follow-up, leading to unplanned surgery or repeat debridement>30 days from the index surgery related death, or suppressive antimicrobial therapy. Parameters predicting failure were analysed with a Cox regression model. A total of 242 patients (33% men; median age 76 years, interquartile range (IQR) 68-81) with 242 episodes of GN-PJI were studied. The implants included 150 (62%) hip, 85 (35%) knee, five (2%) shoulder and two (1%) elbow prostheses. There were 189 (78%) acute infections. Causative microorganisms were Enterobacteriaceae in 78%, Pseudomonas spp. in 20%, and other gram-negative bacilli in 2%. Overall, 19% of isolates were ciprofloxacin resistant. DAIR was used in 174 (72%) cases, with an overall success rate of 68%, which increased to 79% after a median of 25 months' follow-up in ciprofloxacin-susceptible GN-PJIs treated with ciprofloxacin. Ciprofloxacin treatment exhibited an independent protective effect (adjusted hazard ratio (aHR) 0.23; 95% CI, 0.13-0.40; p<0.001), whereas chronic renal impairment predicted failure (aHR, 2.56; 95% CI, 1.14-5.77; p 0.0232). Our results confirm a 79% success rate in ciprofloxacin-susceptible GN-PJI treated with debridement, ciprofloxacin and implant retention. New therapeutic strategies are needed for ciprofloxacin-resistant PJI.

Use of cohort data to estimate national prevalence of transmitted drug resistance to antiretroviral drugs in Spain (2007-2012)

Prevalence of transmitted drug resistance (pTDR) to antiretroviral drugs in Spain (2007-2012) was estimated using the CoRIS cohort, adjusting its territorial distribution and transmission route to the reference population from the Spanish Information System on New human immunodeficiency virus diagnoses. A total of 2702 patients from ten autonomous communities and with naive FASTA sequence within 6 months of human immunodeficiency virus diagnosis were selected. Weighted pTDR, estimated using the inverse probability of selection in the sample by autonomous communities and transmission group, was 8.12% (95% CI 6.44-9.80), not significantly different from unweighted pTDR. We illustrate how proportional weighting can maximize representativeness of cohort-based data, and its value to monitor pTDR at country level.

Executive summary of the Consensus Statement on monitoring HIV: pregnancy, birth, and prevention of mother-to-child transmission

The main objective in the management of HIV-infected pregnant women is prevention of mother-to-child transmission; therefore, it is essential to provide universal antiretroviral treatment, regardless of CD4 count. All pregnant women must receive adequate information and undergo HIV serology testing at the first visit. If the serological status is unknown at the time of delivery, or in the immediate postpartum, HIV serology testing has to be performed as soon as possible. In this document, recommendations are made regarding the health of the mother and from the perspective of minimizing mother-to-child transmission.

A large multicenter study of methicillin-susceptible and methicillin-resistant Staphylococcus aureus prosthetic joint infections managed with implant retention

BACKGROUND

Several series predicting the prognosis of staphylococcal prosthetic joint infection (PJI) managed with debridement, antibiotics, and implant retention (DAIR) have been published, but some of their conclusions are controversial. At present, little is known regarding the efficacy of the different antibiotics that are used or their ability to eliminate methicillin-resistant S. aureus (MRSA) infection.

METHODS

This was a retrospective, multicenter, observational study of cases of PJI by S. aureus that were managed with DAIR (2003-2010). Cases were classified as failures when infection persistence/relapse, death, need for salvage therapy, or prosthesis removal occurred. The parameters that predicted failure were analyzed with logistic and Cox regression.

RESULTS

Out of 345 episodes (41% men, 73 years), 81 episodes were caused by MRSA. Fifty-two were hematogenous, with poorer prognoses, and 88% were caused by methicillin-susceptible S. aureus (MSSA). Antibiotics were used for a median of 93 days, with similar use of rifampin-based combinations in MSSA- and MRSA-PJI. Failure occurred in 45% of episodes, often early after debridement. The median survival time was 1257 days. There were no overall prognostic differences between MSSA- and MRSA-PJI, but there was a higher incidence of MRSA-PJI treatment failure during the period of treatment (HR 2.34), while there was a higher incidence of MSSA-PJI treatment failure after therapy. Rifampin-based combinations exhibited an independent protective effect. Other independent predictors of outcome were polymicrobial, inflammatory, and bacteremic infections requiring more than 1 debridement, immunosuppressive therapy, and the exchange of removable components of the prosthesis.

CONCLUSIONS

This is the largest series of PJI by S. aureus managed with DAIR reported to date. The success rate was 55%. The use of rifampin may have contributed to homogenizing MSSA and MRSA prognoses, although the specific rifampin combinations may have had different efficacies.

Clinical, virological and biochemical evidence supporting the association of HIV-1 reverse transcriptase polymorphism R284K and thymidine analogue resistance mutations M41L, L210W and T215Y in patients failing tenofovir/emtricitabine therapy

Background

Thymidine analogue resistance mutations (TAMs) selected under treatment with nucleoside analogues generate two distinct genotypic profiles in the HIV-1 reverse transcriptase (RT): (i) TAM1: M41L, L210W and T215Y, and (ii) TAM2: D67N, K70R and K219E/Q, and sometimes T215F. Secondary mutations, including thumb subdomain polymorphisms (e.g. R284K) have been identified in association with TAMs. We have identified mutational clusters associated with virological failure during salvage therapy with tenofovir/emtricitabine-based regimens. In this context, we have studied the role of R284K as a secondary mutation associated with mutations of the TAM1 complex.

Results

The cross-sectional study carried out with >200 HIV-1 genotypes showed that virological failure to tenofovir/emtricitabine was strongly associated with the presence of M184V (P < 10^-10) and TAMs (P < 10^-3), while K65R was relatively uncommon in previously-treated patients failing antiretroviral therapy. Clusters of mutations were identified, and among them, the TAM1 complex showed the highest correlation coefficients. Covariation of TAM1 mutations and V118I, V179I, M184V and R284K was observed. Virological studies showed that the combination of R284K with TAM1 mutations confers a fitness advantage in the presence of zidovudine or tenofovir. Studies with recombinant HIV-1 RTs showed that when associated with TAM1 mutations, R284K had a minimal impact on zidovudine or tenofovir inhibition, and in their ability to excise the inhibitors from blocked DNA primers. However, the mutant RT M41L/L210W/T215Y/R284K showed an increased catalytic rate for nucleotide incorporation and a higher RNase H activity in comparison with WT and mutant M41L/L210W/T215Y RTs. These effects were consistent with its enhanced chain-terminated primer rescue on DNA/DNA template-primers, but not on RNA/DNA complexes, and can explain the higher fitness of HIV-1 having TAM1/R284K mutations.

Conclusions

Our study shows the association of R284K and TAM1 mutations in individuals failing therapy with tenofovir/emtricitabine, and unveils a novel mechanism by which secondary mutations are selected in the context of drug-resistance mutations.

Short-term and long-term clinical and immunological consequences of stopping antiretroviral therapy in HIV-infected patients with preserved immune function

BACKGROUND

The aim of this study was to assess the short-term and long-term consequences of stopping antiretroviral therapy (ART) in patients with preserved immune function.

METHODS

This was a randomized 144-week follow-up CD4⁺ T-cell-count-guided treatment-interruption trial. HIV-1-infected adults with plasma HIV-1 RNA<50 copies/ml, CD4⁺ T-cell count >500 cells/μl and nadir CD4⁺ T-cell count >100 cells/μl were randomized to continuous treatment (CT) or treatment interruption (TI) until CD4⁺ T-cell count decreased to <350 cells/μl. The primary end points were AIDS-defining illnesses, death, CD4⁺ T-cell count <200 cells/μl, or virological failure after restarting ART.

RESULTS

A total of 106 patients were included, 50 in the CT arm and 56 in the TI arm. A trend to a higher rate of primary end points was observed in the TI group (26.8% versus 14%, difference 12.8%, 95% CI -2.3, 27.8; P=0.105). In addition, 10 patients presented clinical events related with HIV rebound, including 8 cases of thrombocytopaenia. The CD4⁺ T-cell count significantly decreased in the TI group (even in patients with persistently high CD4⁺ T-cell counts and no clinical events) versus the CT group (median change -408 cells/μl versus -21.5 cells/μl; P<0.001), whereas a significant increase in CD8⁺ T-cell count was observed (256 cells/μl versus -59 cells/μl; P<0.001). The time to ART re-initiation was significantly associated with nadir and baseline CD4⁺ T-cell counts.

CONCLUSIONS

Discontinuation of ART in patients with preserved immune function is followed by significant immunological impairment even in those with no clinical events, and may be associated with an increased risk of HIV-related complications. Hence, patients who stop ART voluntarily should be closely monitored, regardless of their CD4⁺ T-cell count.

Update on clinical and methodological recommendations for genotypic determination of HIV tropism to guide the usage of CCR5 antagonists

The genotypic determination of HIV tropism to guide the use of maraviroc, the first CCR5 antagonist with specific antiviral activity against CCR5 (R5)-tropic HIV variants, has been widespread in the last two years. Retrospective analyses from maraviroc clinical trials (MOTIVATE and MERIT) demonstrated that specific genotypic tools and the phenotypic assay TrofileTM are comparable in predicting virologic response to maraviroc. Moreover, recent studies performed in cohorts of patients outside clinical trials have reported overall rates of virologic response to maraviroc up to 82% in patients harboring HIV R5-tropic variants according to genotypic tools. Specific technical requirements as well as recommendations for proper HIV tropism determination in the clinical setting have been improving, according to new data reported in several studies related with this issue. This review updates clinical and methodological recommendations for genotypic determination of HIV tropism to guide therapeutic decisions using CCR5 antagonists, considering the most recently reported data.

[Prevention of HIV transmission (vertical, occupational and non-occupational)]

In these almost thirty years since the epidemic of HIV infection strategies have been developed to decrease the transmission risk when a non-infected person comes into contact with HIV. One of the key landmarks was the use zidovudine was shown to reduce the risk of HIV infection by vertical transmission from 25% to 8% when given from the second trimester of pregnancy, during partum and for several weeks in the newborn. These strategies have been subsequently perfected until achieving vertical transmission rates less than 1%. Almost at the same time, strategies have been developed in an attempt to reduce the risk of transmission of infection after occupational accidents and, in the last few years prophylaxis after non-occupational exposure has been a field of particular concern. Even in this past year several experiments on pre-exposure prophylaxis have been published, which are generating an intense debate on is applicability. In this article, we analyse the state of the art in the prevention of vertical transmission and occupational and non-occupational prophylaxis, from a perspective of applying this in the developed world. We also review the published data on pre-exposure prophylaxis.

HIV infection and aging

The median age of HIV-infected patients is increasing all over the world. Age has a significant impact on some aspects of HIV-infection when compared to younger patients. Diagnostic delay and late presentation are more frequent in older patients because some of the initial symptoms are masked by age and because older people are not considered to be a risk group for HIV infection. Despite the clinical, immunological, and virologic benefits of HAART, most studies suggest that older patients have a poorer immunological and clinical response to HAART than younger patients, despite a similar virologic response. Other problems include the frequent presence of comorbid conditions and medications that can affect the efficacy and safety of HAART as well as its pharmacokinetics and pharmacodynamics. Because no guidelines recommend a specific HAART regimen for older people, specific clinical trials and pharmacological studies should be designed to optimize HAART in these patients.

Identification of a new HIV type 1 circulating BF intersubtype recombinant form (CRF47_BF) in Spain

We report the identification of a new HIV-1 circulating recombinant form (CRF47_BF) derived from subtypes B and F. It was initially identified in protease-reverse transcriptase sequences from nine individuals from three separate regions of Spain who acquired HIV-1 infection via sexual contact. All nine sequences formed a strongly supported phylogenetic cluster, branching apart from all known CRFs, and in bootscan analyses were BF mosaics with two coincident breakpoints. Two epidemiologically unlinked viruses were sequenced in near full-length genomes, which exhibited identical mosaic structures, with 16 intersubtype breakpoints in a genome predominantly of subtype B. Subtype F segments of the new CRF failed to cluster with any of the near full-length genome subtype F sequences available in public databases. Recent dates of HIV-1 diagnoses and short genetic distances suggest a recent origin of this CRF. This is the tenth reported CRF_BF, the first apparently having originated outside of South America.