Management of incidental durotomies in an integrated Orthopaedic and Neurosurgical Spinal Unit.

Introduction: Incidental durotomy (ID) is an intraoperative event associated to prolonged bed rest and hospital stay, antibiotic use, higher patient dissatisfaction, and leg pain among other complications of its postoperative course. Several repair techniques and postsurgical care have been proposed for its management. This study was designed to develop an agreed protocol in cases of ID among Orthopaedic Surgeons (OS) and Neurosurgeons (NS) integrated into a Spinal Surgery Unit. Research question: Incidental durotomies management protocol. Materials and methods: From 997 eligible cases operated in Hospital del Mar (Barcelona, Spain) from April 2018 to March 2022, demographic, clinical, surgical and postoperative data was collected for statistical analysis from the morbidity and mortality database, with 79 identified IDs. Redo procedures were significantly associated to OS, and cervical and anterior/lateral approaches to NS, both groups were not comparable. Results: ID occurred in 7.9% of cases, more frequently after the lockdown (p=0.03), in females (p=0.04), during posterior approaches (p=0.003), and less frequently in the cervical spine (p=0.009). IDs were linked to postoperative infections (p< 0.001) and nerve root damage (p< 0.001). Patients without ID evolved more satisfactorily during the postoperative period (p=0.002), and those with CSF leak (20/79) spent on bed rest more than twice the time as those without (p<0.001). Multivariable logistic regression showed strong association between posterior approaches and ID, between complicated postoperative courses and ID. Discussion and conclusions: ID is linked to an adverse postoperative recovery, and it should be primarily repaired under microscope, with early mobilization of patients after surgery.

Safety and Efficacy of Prolonged Use of Dalbavancin in Bone and Joint Infections.

Dalbavancin is a lipoglycopeptide with potent activity against Gram-positive microorganisms, a long half-life, a favorable safety profile, and a high concentration in bone, which makes it an interesting alternative for treatment of osteoarticular infections. We performed a multicentric retrospective study of all patients with an osteoarticular infection (septic arthritis, spondylodiscitis, osteomyelitis, or orthopedic implant-related infection) treated with at least one dose of dalbavancin between 2016 and 2017 in 30 institutions in Spain. In order to evaluate the response, patients with or without an orthopedic implant were separated. A total of 64 patients were included. Staphylococcus epidermidis and Staphylococcus aureus were the most frequent microorganisms. The reasons for switching to dalbavancin were simplification (53.1%), adverse events (25%), or failure (21.9%). There were 7 adverse events, and no patient had to discontinue dalbavancin. In 45 cases, infection was related to an orthopedic implant. The implant material was retained in 23 cases, including that in 15 (65.2%) patients that were classified as cured and 8 (34.8%) that presented improvement. In 21 cases, the implants were removed, including those in 16 (76.2%) cases that were considered successes, 4 (19%) cases were considered improved, and 1 (4.8%) case that was considered a failure. Among the 19 cases without implants, 14 (73.7%) were considered cured, 3 (15.8%) were considered improved, and 2 (10.5%) were considered failures. The results show that dalbavancin is a well-tolerated antibiotic, even when >2 doses are administered, and is associated with a high cure rate. These are preliminary data with a short follow-up; therefore, it is necessary to gain more experience and, in the future, to establish the most appropriate dose and frequency.

Do magnetic phosphorus adsorbents used for lake restoration impact on zooplankton community?

Magnetic microparticles (MPs) have been recently proposed as innovative and promising dissolved inorganic phosphorus (DIP) adsorbents. However, before using them in a whole-lake restoration project, it is essential to assess their toxicological effects (direct and indirect) on aquatic biota. In the present study we hypothesized that zooplankton community is affected by MPs used for lake restoration. To test our hypothesis we designed a microcosms experiment (n = 15) containing lake water and surface sediment from a hypertrophic lake. Temporal changes (70 days) on physico-chemical conditions and on zooplankton structure (rotifers, copepods and branchiopods) were monitored under different scenarios. In particular, three different treatments were considered: no addition of MPs (control) and MPs addition (1.4 g MPs L-1) on the surface water layer (T-W) and on the sediment (T-S). After 24 h of contact time, MPs were removed with a magnetic rake. A total of 15 zooplankton species (12 rotifers, 1 branchiopod and 2 copepods) were recorded and a high abundance of zooplankton was registered during the experiment for all treatments. No significant differences (RM-ANOVA test; p > 0.05) in total abundance, species richness and species diversity among treatments were found. The absence of any effect of MPs on zooplankton can be explained because MPs did not significantly alter any of its physico-chemical (e.g. temperature, pH, O2) or biological (e.g. food quantity and quality) drivers. These results confirm the suitability of MPs as a promising tool for removing DIP in eutrophic aquatic ecosystems.

Results of an early intervention programme for patients with bacteraemia: analysis of prognostic factors and mortality.

BACKGROUND: Bacteraemia is a common cause of morbidity and mortality in patients admitted to hospital. The aim of this study is to analyse the results of a two-year programme for the early optimisation of antibiotic treatment in patients admitted to the Costa del Sol Hospital (Marbella. Spain). METHODS: A prospective two-year cohort study was conducted, evaluating all episodes of bacteraemia at the Costa del Sol Hospital. Epidemiological and microbiological characteristics, any modification of the initial antibiotic treatment, prognostic risk stratification, early mortality related to the episode of bacteraemia, and mortality after the seventh day, were included in the analysis. RESULTS: Seven hundred seventy-three episodes of bacteraemia were treated, 61.6% males and 38.4% females. The mean age was 65.2 years. The condition was most commonly acquired in the community (41.4%). The bacteraemia was most frequently urological in nature (30.5%), and E coli was the microorganism most frequently isolated (31.6%). In 51.1% of the episodes, a modification was made to optimise the treatment. In the first week, 8.2% died from bacteraemia, and 4.5% had died when they were located. The highest rates of death were associated with older patients, nosocomial acquisition, no source, McCabe score rapidly fatal, Charlson index ≥3, Pitt index ≥3 and treatment remained unmodified. CONCLUSION: The existence of bacteraemia control programmes and teams composed of clinicians who are experienced in the treatment of infectious diseases, can improve the disease outcome by enabling more severe episodes of bacteraemia to be recognised and their empirical treatment optimised.

A microcosm experiment to determine the consequences of magnetic microparticles application on water quality and sediment phosphorus pools.

This study used microcosms to evaluate the effects of adding iron (Fe) magnetic microparticles (MPs) on water quality, focusing on P concentrations in the water column and sediment. Two treatments were considered for a constant 85:1 MP:PMobile molar ratio: T-W, applying MPs on the surface water layer; and T-S, applying MPs on the sediment. MP addition reduced P concentrations in lake water and sediment, with both treatments producing a mean reduction of 68±6% in dissolved inorganic P concentration (DIP) over a 70-day oxic period and reductions of 80±8% (T-W) and 80±4% (T-S) over a 5-day anoxic period. MPs also decreased reactive silicate (Si) concentrations by around 50% in both periods, but dissolved organic carbon (DOC) was reduced by only 15% at 24h after MP addition. Despite the marked decrease in DIP concentration due to MP addition, there was no reduction in chlorophyll a (Chla), because post-treatment total P concentrations (>200µgL-1vs. >700µgL-1 before treatments) remained higher than required for changes in the biological community (0.05-0.1mgL-1). With T-S treatment, there was a reduction of 15% in P bound to Al oxides, clay minerals, and humic substances (P→NaOH) and of 12% in labile organic P (Org-PLabile) versus controls. P bound to humic substances (P→NaOH, Humic) was reduced by 11-22% in both treatments. Finally, T-W rather than T-S treatments are recommended for future whole-lake applications to achieve more effective P removal from water and sediment and a higher percentage MP recovery.

Clinical, virological and phylogenetic characterization of a multiresistant HIV-1 strain outbreak in naive patients in southern Spain.

BACKGROUND: We describe the characteristics of an HIV-1 strain with six viral reverse transcriptase mutations (D67N, T69N/D, V118I, V179D, T215S and K219Q), which we have called the Malaga strain. This strain was detected in treatment-naive patients from southern Spain. METHODS: The study was undertaken at the Virgen de la Victoria Hospital, Malaga, a reference centre for the study of HIV-1 genotype resistance in Andalusia (the 'Costa del Sol'), Spain. Genotypic resistance testing was done in an automated sequencer. Phylogenetic analysis was performed using a 630 bp region of the reverse transcriptase with the mutations mentioned. RESULTS: Between 2007 and 2014, we detected the Malaga strain in 30 treatment-naive patients. All were MSM, seen at five hospitals on the Costa del Sol. In all cases, the HIV-1 was subtype B with viral tropism R5. Phylogenetic analysis based on the reverse transcriptase sequence showed consistent grouping (with a bootstrap value of the common node of 100%) of the isolates that shared the mutation pattern mentioned. This strain has not been detected elsewhere or in previously treated patients. All of the patients treated with first-line combination ART responded. CONCLUSIONS: We report a cluster of an HIV-1 strain with multiple resistance mutations that was transmitted over a period of >8 years, affecting 30 naive patients from the same geographical area. The strain was susceptible to first-line combination ART.

The impact of an antimicrobial stewardship programme on the use of antimicrobials and the evolution of drug resistance.

Misuse of antibiotics can provoke increased bacterial resistance. There are no immediate prospects of any new broad-spectrum antibiotics, especially any with activity against enterobacteria, coming onto the market. Therefore, programmes should be implemented to optimise antimicrobial therapy. In a quasi-experimental study, the results for the pre-intervention year were compared with those for the 3 years following the application of an antimicrobial stewardship programme. We describe 862 interventions carried out as part of the stewardship programme at the Hospital Costa del Sol from 2009 to 2011. We examined the compliance of the empirical antimicrobial treatment with the programme recommendations and the treatment optimisation achieved by reducing the antibiotic spectrum and adjusting the dose, dosing interval and duration of treatment. In addition, we analysed the evolution of the sensitivity profile of the principal microorganisms and the financial savings achieved. 93 % of the treatment recommendations were accepted. The treatment actions taken were to corroborate the empirical treatment (46 % in 2009 and 31 % in 2011) and to reduce the antimicrobial spectrum taking into account the antibiogram results (37 % in 2009 and 58 % in 2011). The main drugs assessed were imipenem/meropenem, used in 38.6 % of the cases, and cefepime (20.1 %). The sensitivity profile of imipenem against Pseudomonas aeruginosa increased by 10 % in 2011. Savings in annual drug spending (direct costs) of 30,000 Euros were obtained. Stewardship programmes are useful tools for optimising antimicrobial therapy. They may contribute to preventing increased bacterial resistance and to reducing the long-term financial cost of antibiotic treatment.

Are hip hemiarthroplasty and total hip arthroplasty infections different entities? The importance of hip fractures.

Hip hemiarthroplasty (HHA) and total hip arthroplasty (THA) infections are usually considered as one entity; however, they may show important differences. We analyze these differences, as well as predictors of treatment failure (TF) and poor functional status among patients with prosthetic hip infections (PHIs). A multicenter cohort study of consecutive patients with PHIs was performed. The main outcome variable was TF after the first surgical treatment performed to treat the infection. Multivariate analysis was used to identify predictors of TF. A total of 127 patients with PHI were included (43 HHA, 84 THA). Patients with HHA infections were more frequently women (88% vs. 54%; p < 0.001), had comorbidities (86% vs. 67%, p = 0.02), and were older (median age 79 vs. 65 years, p < 0.001), and the reason for arthroplasty was more frequently a fracture (100% vs. 18%, p < 0.001). Failure of initial treatment and crude mortality were more frequent among HHA patients (44% vs. 23%, p = 0.01 and 28% vs. 7%, p = 0.001, respectively). However, HHA was not associated with TF in the multivariate analysis when hip fracture was considered; thus, variables independently associated with TF were hip fracture, inadequate surgical management, prosthesis retention, and higher C-reactive protein level. Failure of the first surgical treatment was associated with poorer functional status. HHA and THA infections showed significant differences in epidemiology, clinical features, and outcome. Although patients with HHA infections had a higher risk of TF, this was related to the reason for hip implant: a hip fracture. Success of the initial management of infection is a predictor of better clinical and functional outcome.

Left ventricular mass in HIV-infected patients.

BACKGROUND: The HIV infection has been associated with an increased incidence of vascular events. Left ventricular mass (LVM) is independently associated with greater overall mortality. Various studies have shown that patients with HIV infection have higher LVM than the uninfected population. We aim to describe the distribution of LVM in an extensive series of patients with HIV infection, and the factors associated with its increase. PATIENTS AND METHODS: A cross-sectional study was performed in HIV-infected patients followed in our center from 1 December 2009 to 28 February 2011. A transthoracic echocardiography (TTE) was performed in all patients who gave their consent. Demographic variables, viroimmunological status, cardiovascular risk factors, vascular risk at 10 years (VR10) and history of exposure to antiretroviral drugs were collected. LVM was considered to be the quantitative dependent variable. A univariate analysis was performed, including in the multivariate analysis those variables with P<,05. RESULTS: A TTE was performed in 400 patients, and the LVM was calculated in 388. Mean age was 45 years, 75.5 males. Mean LVM was 39.54g/m(2.7)(95% CI: 38.35-40.73). Age, height, body mass index, VR10, hypertension, dyslipidemia, different medications within the cardiovascular area and having taken nevirapine have been used in the history of the patient were associated to greater LVM. In the multivariate analysis, use of nevirapine in the history of the patient and VR10 remained in the model. CONCLUSIONS: VR10 may be associated with greater LVM. The relationship with nevirapine may respond to an indication bias.

Left ventricular mass in HIV-infected patients. / Masa ventricular izquierda en pacientes con infección VIH.

BACKGROUND: The HIV infection has been associated with an increased incidence of vascular events. Left ventricular mass (LVM) is independently associated with greater overall mortality. Various studies have shown that patients with HIV infection have higher LVM than the uninfected population. We aim to describe the distribution of LVM in an extensive series of patients with HIV infection, and the factors associated with its increase. PATIENTS AND METHODS: A cross-sectional study was performed in HIV-infected patients followed in our center from 1 December 2009 to 28 February 2011. A transthoracic echocardiography (TTE) was performed in all patients who gave their consent. Demographic variables, viroimmunological status, cardiovascular risk factors, vascular risk at 10 years (VR10) and history of exposure to antiretroviral drugs were collected. LVM was considered to be the quantitative dependent variable. A univariate analysis was performed, including in the multivariate analysis those variables with P<,05. RESULTS: A TTE was performed in 400 patients, and the LVM was calculated in 388. Mean age was 45 years, 75.5 males. Mean LVM was 39.54g/m(2.7)(95% CI: 38.35-40.73). Age, height, body mass index, VR10, hypertension, dyslipidemia, different medications within the cardiovascular area and having taken nevirapine have been used in the history of the patient were associated to greater LVM. In the multivariate analysis, use of nevirapine in the history of the patient and VR10 remained in the model. CONCLUSIONS: VR10 may be associated with greater LVM. The relationship with nevirapine may respond to an indication bias.

Differential effects of environmental enrichment and isolation housing on the hormonal and neurochemical responses to stress in the prefrontal cortex of the adult rat: relationship to working and emotional memories.

The present study was designed to investigate the modulation of the stress responses by the environmental conditions and its putative neurobiological mechanisms. For that an integrative study on the effects of environmental enrichment and isolation housing on (1) the corticosterone, dopamine and acetylcholine responses to acute restraint stress in the prefrontal cortex (PFC) of the awake rat; (2) the mRNA levels of glucocorticoid receptors (GRs) in the PFC, and (3) the behavioral responses to stress, related to the PFC (habituation to a novel environment, spatial-working memory and inhibitory avoidance response) was performed. Male Wistar rats were maintained from 3 to 6 months of age in two different conditions: enriched (EC) or impoverished (IC). Animals were stereotaxically implanted with bilateral guide cannulae in the PFC to perform microdialysis experiments to evaluate the concentrations of corticosterone, dopamine and acetylcholine. EC animals showed lower increases of corticosterone and dopamine but not of acetylcholine than IC animals in the PFC in response to acute restraint stress (20 min). In the PFC, GR mRNA levels showed a trend towards an enhancement in EC animals. EC reduced the days to learn the spatial working memory task (radial-water maze). Spatial working memory, however, was not different between groups in either basal or stress conditions. Inhibitory avoidance response was reduced in EC rats. The changes produced by EC in the neurochemical, neuroendocrine and behavioral parameters evaluated suggest that EC rats could show a better coping during an acute stress challenge.

SCaMC-1 promotes cancer cell survival by desensitizing mitochondrial permeability transition via ATP/ADP-mediated matrix Ca(2+) buffering.

Ca(2+)-mediated mitochondrial permeability transition (mPT) is the final common pathway of stress-induced cell death in many major pathologies, but its regulation in intact cells is poorly understood. Here we report that the mitochondrial carrier SCaMC-1/SLC25A24 mediates ATP-Mg(2-)/Pi(2-) and/or HADP(2-)/Pi(2-) uptake into the mitochondria after an increase in cytosolic [Ca(2+)]. ATP and ADP contribute to Ca(2+) buffering in the mitochondrial matrix, resulting in desensitization of the mPT. Comprehensive gene expression analysis showed that SCaMC-1 overexpression is a general feature of transformed and cancer cells. Knockdown of the transporter led to vast reduction of mitochondrial Ca(2+) buffering capacity and sensitized cells to mPT-mediated necrotic death triggered by oxidative stress and Ca(2+) overload. These findings revealed that SCaMC-1 exerts a negative feedback control between cellular Ca(2+) overload and mPT-dependent cell death, suggesting that the carrier might represent a novel target for cancer therapy.

Late initiation of HAART among HIV-infected patients in Spain is frequent and related to a higher rate of virological failure but not to immigrant status.

PURPOSE: To determine whether immigrant status is associated with late initiation of highly active antiretroviral treatment (HAART) and/or poor response to antiretrovirals. METHODS: GESIDA 5808 is a multicenter, retrospective cohort study (inclusion period January 2005 through December 2006) of treatment-naïve patients initiating HAART that compares HIV-infected patients who are immigrants with Spanish-born patients. A late starter (LS) was defined as any patient starting HAART with a CD4+ lymphocyte count <200 cells/µL and/or diagnosis of an AIDS-defining illness before or at the start of therapy. The primary endpoint was time to treatment failure (TTF), defined as virological failure (VF), death, opportunistic infection, treatment discontinuation/switch (D/S), or missing patient. Secondary endpoints were time to treatment failure as observed data (TTO; censoring missing patients) and time to virological failure (TVF; censoring missing patients and D/S not due to VF). RESULTS: LS accounted for 56% of the patients. Lower educational and socioeconomic level and intravenous drug use (IVDU) were associated with categorization as LS, but immigrant status was not. Cox regression analysis (hazard ratio [HR]; 95% CI) between LS and non-LS patients showed no differences in TTF (0.97; 0.78-1.20) or TTO (1.18; 0.88-1.58), although it did reveal a difference in TVF (1.97; 1.18-3.29). CD4+ lymphocyte recovery was equivalent for both LS and non-LS patients (159 vs 173). CONCLUSIONS: In our cohort, immigrant status was not shown to be related to late initiation of HAART. Although LS patients did not have a longer TTF for any reason, TVF was significantly shorter. Despite universal free access to HAART in Spain, measures to ensure early diagnosis and treatment of HIV infection are necessary.

Similar antiviral efficacy and tolerability between efavirenz and lopinavir/ritonavir, administered with abacavir/lamivudine (Kivexa), in antiretroviral-naïve patients: a 48-week, multicentre, randomized study (Lake Study).

BACKGROUND: Although efavirenz and lopinavir/ritonavir(r) are both recommended antiretroviral agents in antiretroviral-naïve HIV-infected patients, there are few randomized comparisons of their efficacy and tolerability. METHODS: A multicenter and randomized study was performed including 126 antiretroviral-naïve patients, randomly assigned to efavirenz+Kivexa (n=63) or lopinavir/r+Kivexa (n=63). Efficacy endpoints were the percentage of patients with HIV-RNA < or =50 copies/mL at week 48 and CD4 recovery. Safety was assessed by comparing toxicity and discontinuations. Statistical analyses were performed on an intention-to-treat (ITT) basis (Missing=Failure). RESULTS: At week 48, 56.7% of patients in the efavirenz and 63.2% in the lopinavir/r groups showed HIV-1 RNA <50 copies/mL (P=0.770) (intention-to-treat analysis; Missing=Failure). Only 1 (1.53%) patient from each group experienced virological failure. CD4 values increased in both groups (298 cells in the efavirenz group, P=0.001; 249 cells in the lopinavir/r group, P=0.002; P=0.126 between groups). HDL-cholesterol only increased in the efavirenz group (from 39+/-12 mg/dL to 49+/-11; P=0.001). Discontinuations were more frequent in the lopinavir/r group (36.5% versus 28.5%; P=0.193), but more patients with efavirenz interrupted due to toxicity (11.1% versus 6.3%); most of them were attributed to hypersensitivity reaction. CONCLUSIONS: Similar virological efficacy was observed for efavirenz and lopinavir/r, when administered with Kivexa in antiretroviral-naïve patients, while immunological improvement was slightly superior for efavirenz. The higher rate of discontinuation due to toxicity in the efavirenz group was related to a higher incidence of hypersensitivity reaction. Nowadays, the use of the new formulation of lopinavir/r and the HLA-B*5701 genotype test before starting abacavir should improve the safety profiles of these regimens.

Epidemiology and clinical features of community-acquired, healthcare-associated and nosocomial bloodstream infections in tertiary-care and community hospitals.

Classification of bloodstream infections (BSIs) as community-acquired (CA), healthcare-associated (HCA) and hospital-acquired (HA) has been proposed. The epidemiology and clinical features of BSI according to that classification in tertiary-care (TH) and community (CH) hospitals were investigated in a prospective cohort of 821 BSI episodes from 15 hospitals (ten TH and five CH hospitals) in Andalucía, Spain. Eighteen percent were CA, 24% were HCA and 58% were HA. The incidence of CA and HCA BSI was higher in CH than in TH (CA: 3.9 episodes per 1000 admissions vs. 2.2, p <0.01; HCA: 5.0 vs. 2.9, p <0.01), whereas the incidence of HA BSI was lower (7.7 vs. 8.7, p <0.01). In CA and HCA BSI, the respiratory tract was more frequently the source in CH than in TH (CA: 30% vs. 15%; HCA: 20% vs. 9%, p ≤0.03). In HCA BSI, chronic renal insufficiency and tunnelled catheters were less frequent in CH than in TH (11% vs. 26% and 7% vs. 19%, p ≤0.03), although chronic ulcers were more frequent (22% vs. 8%, p 0.008). BSIs as a result of methicillin-resistant Staphylococcus aureus or Pseudomonas aeruginosa were very rare in CA episodes, although extended-spectrum b-lactamase-producing Escherichia coli (ESBLEC) caused a similar proportion of all BSIs in CA, HCA and HA episodes. Multivariate analysis revealed no significant difference in mortality rates in CH and TH. HCA infections should be considered as a separate class of BSI in both TH and CH, although differences between hospitals must be considered. CA BSIs were not caused by multidrug-resistant pathogens, except for ESBLEC.

Ankle-branch index and HIV: the role of antiretrovirals.

OBJECTIVE: To study the relationship between antiretroviral (ARV) treatment and abnormal ankle-branch index (ABI) and to compare the risk factors for altered ABI. METHODS: Patients coming to the office from April 2007 until July 2007 were offered the chance to take part in the study. ABI was obtained by the standard technique. Those < or = 0.9 or > or = 1.3 were considered altered ABI. Clinical reports were reviewed to examine traditional vascular risk factors, coinfection with hepatitis C virus and/or hepatitis B virus, tobacco use, highly active antiretroviral therapy use and its components and length of use of each ARV drug. RESULTS: ABI was measured in 147 patients, 82.3% males. Thirty-three patients (22.45%) had an altered ABI, and it was related to CD4 cell nadir, dyslipidaemia and protease inhibitor (PI) use. When logistic regression was carried out, only dyslipidaemia (OR 2.68, CI 95%: 1.06-6.91) and PI use (OR 2.79, CI 95%: 1.15-6.54) remained in the model. CONCLUSIONS: Altered ABI is associated with PI use independently of dyslipidaemia. Probably, it marks patients with high vascular risk not identified with traditional scales.

Effectiveness and safety of simplification from tenofovir-lamivudine (TDF-3TC) to tenofovir-emtricitabine (TDF-FTC) co-formulation (Truvada) in virologically suppressed HIV-infected patients on HAART.

The objective was to evaluate the effectiveness and safety of simplification from tenofovir-lamivudine (TDF-3TC) to Truvada (TVD) in virologically suppressed HIV patients. We carried out an open-label, multicentre, non-controlled study of HIV patients on a stable regimen including TDF-3TC who switched from TDF-3TC to TVD. Viral load responses at 24 and 48 weeks were evaluated. Changes in the calculated glomerular filtration rates (cGFR; Cockcroft-Gault equation) were analysed at baseline and at 24 and 48 weeks. Patients with drug-related nephrotoxicity (cGFR < 60 mL/min at 48 weeks or interruption of TVD because of renal toxicity) were analysed in detail. Two hundred and ninety-five patients with a mean time on TDF-3TC of 19.9 months (range 8.8-29.8) were enrolled. The third drug was a non-nucleoside reverse transcriptase inhibitor, which was administered to 187 patients (76.4% efavirenz) and a protease inhibitor was administered to 108 (43.5% lopinavir/ritonavir). At 48 weeks, 85.7% of the patients were still taking the same regimen, all with an undetectable viral load. The cGFR (mL/min) decreased from baseline (111 [89-130]) to 48 weeks (105 [84-121]); p < 0.0001. The percentage of patients with a cGFR <60 mL/min at 48 weeks was 3.5. Six patients ceased TVD because of drug-related nephrotoxicity. The only factors associated with nephrotoxicity were age, baseline weight and cGFR. Simplification from TDF-3TC to TVD was associated with a decrease in cGFR, with a low prevalence of nephrotoxicity at 48 weeks.