Modulation of TCR avidity of primary HIV-1-specific CD8 T-cell responses by early and potent antiviral therapy responses

Background: CD8 T-cells play a critical role in antiviral immunity. However, mechanisms of virus control and immune correlates of protection are still not fully understood. Among other factors, TCR avidity (antigen sensitivity) is thought to play a critical role. Whereas there is a large consensus that high TCR avidity T-cell responses are correlated to higher efficacy against cancer and acute viral infections, it may be not the case in chronic persistent viral infections. Methods: TCR avidity (measured by the effect concentration 50% [EC50]) of HIV-1-specific CD8 T-cell responses directed against optimal epitopes was investigated in different cohorts of HIV-1- infected subjects (n¼114) including early acute and chronic (progressive and non-progressive) HIV-1-infection. Overall, TCR avidity was investigated in 245 HIV-1-specific CD8 T-cell responses. The relationships between TCR avidity, T-cell differentiation and functional profile including cytokine secretion, proliferation and cytotoxic potential (determined by polychromatic flow cytometry) were analyzed. Results: HIV-1-specific CD8 T-cell responses from patients with acute infection had significantly lower TCR avidity as compared to patients with chronic (progressive or non-progressive) HIVinfection (P¼0.03 and 0.003, respectively). These differences remained significant when the analyses were restricted to common epitopes (same epitopes restricted by the same class I HLA). Interestingly, some patients treated during acute infection underwent spontaneous treatment interruption. Re-exposure to high viral load induced two major effects: a) the increase in TCR avidity of pre-existing high avidity (EC50<0.01) T-cell responses (P<0.02) and b) the generation of new T-cell responses with higher TCR avidity as compared to the average pre-existing T-cell responses. Conclusion: These results suggest that high TCR avidity T-cell responses are selected during the course of HIV-1 infection and that one of the potential driving mechanisms is continuous exposure to HIV-1 antigens. These results advance our understanding of the relationship between TCR avidity and Ag exposure of antiviral memory CD8 T-cells.

Intrauterine exposure to carbamazepine and specific congenital malformations: systematic review and case-control study.

OBJECTIVE: To identify specific major congenital malformations associated with use of carbamazepine in the first trimester of pregnancy. DESIGN: A review of all published cohort studies to identify key indications and a population based case-control study to test these indications. SETTING: Review of PubMed, Web of Science, and Embase for papers about carbamazepine exposure in the first trimester of pregnancy and specific malformations, and the EUROCAT Antiepileptic Study Database, including data from 19 European population based congenital anomaly registries, 1995-2005. PARTICIPANTS: The literature review covered eight cohort studies of 2680 pregnancies with carbamazepine monotherapy exposure, and the EUROCAT dataset included 98 075 registrations of malformations covering over 3.8 million births. MAIN OUTCOME MEASURES: Overall prevalence for a major congenital malformation after exposure to carbamazepine monotherapy in the first trimester. Odds ratios for malformations with exposure to carbamazepine among cases (five types of malformation identified in the literature review) compared with two groups of controls: other non-chromosomal registrations of malformations and chromosomal syndromes. RESULTS: The literature review yielded an overall prevalence for a major congenital malformation of 3.3% (95% confidence interval 2.7 to 4.2) after exposure to carbamazepine monotherapy in the first trimester. In 131 registrations of malformations, the fetus had been exposed to carbamazepine monotherapy. Spina bifida was the only specific major congenital malformation significantly associated with exposure to carbamazepine monotherapy (odds ratio 2.6 (95% confidence interval 1.2 to 5.3) compared with no antiepileptic drug), but the risk was smaller for carbamazepine than for valproic acid (0.2, 0.1 to 0.6). There was no evidence for an association with total anomalous pulmonary venous return (no cases with carbamazepine exposure), cleft lip (with or without palate) (0.2, 0.0 to 1.3), diaphragmatic hernia (0.9, 0.1 to 6.6), or hypospadias (0.7, 0.3 to 1.6) compared with no exposure to antiepileptic drugs. Further exploratory analysis suggested a higher risk of single ventricle and atrioventricular septal defect. CONCLUSION: Carbamazepine teratogenicity is relatively specific to spina bifida, though the risk is less than with valproic acid. Despite the large dataset, there was not enough power to detect moderate risks for some rare major congenital malformations.

Procalcitonin for reduced antibiotic exposure in ventilator-associated pneumonia: a randomised study.

In patients with ventilator-associated pneumonia (VAP), guidelines recommend antibiotic therapy adjustment according to microbiology results after 72 h. Circulating procalcitonin levels may provide evidence that facilitates the reduction of antibiotic therapy. In a multicentre, randomised, controlled trial, 101 patients with VAP were assigned to an antibiotic discontinuation strategy according to guidelines (control group) or to serum procalcitonin concentrations (procalcitonin group) with an antibiotic regimen selected by the treating physician. The primary end-point was antibiotic-free days alive assessed 28 days after VAP onset and analysed on an intent-to-treat basis. Procalcitonin determination significantly increased the number of antibiotic free-days alive 28 days after VAP onset (13 (2-21) days versus 9.5 (1.5-17) days). This translated into a reduction in the overall duration of antibiotic therapy of 27% in the procalcitonin group (p = 0.038). After adjustment for age, microbiology and centre effect, the rate of antibiotic discontinuation on day 28 remained higher in the procalcitonin group compared with patients treated according to guidelines (hazard rate 1.6, 95% CI 1.02-2.71). The number of mechanical ventilation-free days alive, intensive care unit-free days alive, length of hospital stay and mortality rate on day 28 for the two groups were similar. Serum procalcitonin reduces antibiotic therapy exposure in patients with ventilator associated pneumonia.

Active intravenous drug use during chronic hepatitis C therapy does not reduce sustained virological response rates in adherent patients.

SUMMARY: Reluctance has been expressed about treating chronic hepatitis C in active intravenous (IV) drug users (IDUs), and this is found in both international guidelines and routine clinical practice. However, the medical literature provides no evidence for an unequivocal treatment deferral of this risk group. We retrospectively analyzed the direct effect of IV drug use on treatment outcome in 500 chronic hepatitis C patients enrolled in the Swiss Hepatitis C Cohort Study. Patients were eligible for the study if they had their serum hepatitis C virus (HCV) RNA tested 6 months after the end of treatment and at least one visit during the antiviral therapy, documenting the drug use status. Five hundred patients fulfilled the inclusion criteria (199 were IDU and 301 controls). A minimum exposure to 80% of the scheduled cumulative dose of antivirals was reached in 66.0% of IDU and 60.5% of controls (P = NS). The overall sustained virological response (SVR) rate was 63.6%. Active IDU reached a SVR of 69.3%, statistically not significantly different from controls (59.8%). A multivariate analysis for treatment success showed no significant negative influence of active IV drug use. In conclusion, our study shows no relevant direct influence of IV drugs on the efficacy of anti-HCV therapy among adherent patients.

Exposition de l'enfant a des violences domestiques. Un modèle pluridisciplinaire de détection, d'evaluation et de prise en charge [Children's exposure to domestic violence. A multidisciplinary model of detection, assessment and management].

Children psychological abuse is difficult to identify. However, its consequences on child development can be as serious as physical and sexual abuses. It is therefore essential, to implement in our hospitals, structures whose missions are successively to detect victims, evaluate them on somatic and psychological levels, and elaborate a therapy. We propose a model for the achievement of these objectives through collaboration between the Medical Unit of Violence, the Pediatric CAN Team and the Unit of Les Boréales.

Small dense lipoproteins, apolipoprotein B, and risk of coronary events in HIV-infected patients on antiretroviral therapy: the Swiss HIV Cohort Study.

OBJECTIVES: HIV infection and exposure to certain antiretroviral drugs is associated with dyslipidemia and increased risk for coronary events. Whether this risk is mediated by highly atherogenic lipoproteins is unclear. We investigated the association of highly atherogenic small dense low-density lipoproteins (LDLs) and apolipoprotein B and coronary events in HIV-infected individuals receiving antiretroviral therapy. METHODS: We conducted a case-control study nested into the Swiss HIV Cohort Study to investigate the association of small dense LDL and apolipoprotein B and coronary events in 98 antiretroviral drug-treated patients with a first coronary event (19 fatal and 79 nonfatal coronary events with 53 definite and 15 possible myocardial infarctions, 11 angioplasties or bypasses) and 393 treated controls matched for age, gender, and smoking status. Lipids were measured by ultracentrifugation. RESULTS: In models including cholesterol, triglycerides, high-density lipoprotein cholesterol, blood pressure, central obesity, diabetes, and family history, there was an independent association between small dense LDL and coronary events [odds ratio (OR) for 1 mg/dL increase: 1.06, 95% confidence interval (CI): 1.00 to 1.11] and apolipoprotein B (OR for 10 mg/dL increase: 1.16, 95% CI: 1.02 to 1.32). When adding HIV and antiretroviral therapy-related variables, ORs were 1.04 (95% CI: 0.99 to 1.10) for small dense LDL and 1.13 (95% CI: 0.99 to 1.30) for apolipoprotein B. In both models, blood pressure and HIV viral load was independently associated with the odds for coronary events. CONCLUSIONS: HIV-infected patients receiving antiretroviral therapy with elevate small dense LDL and apolipoprotein B are at increased risk for coronary events as are patients without sustained HIV suppression.

Spare non-occupational HIV post-exposure prophylaxis by active contacting and testing of the source person.

OBJECTIVE: HIV-1 post-exposure prophylaxis (PEP) is frequently prescribed after exposure to source persons with an undetermined HIV serostatus. To reduce unnecessary use of PEP, we implemented a policy including active contacting of source persons and the availability of free, anonymous HIV testing ('PEP policy'). METHODS: All consultations for potential non-occupational HIV exposures i.e. outside the medical environment) were prospectively recorded. The impact of the PEP policy on PEP prescription and costs was analysed and modelled. RESULTS: Among 146 putative exposures, 47 involved a source person already known to be HIV positive and 23 had no indication for PEP. The remaining 76 exposures involved a source person of unknown HIV serostatus. Of 33 (43.4%) exposures for which the source person could be contacted and tested, PEP was avoided in 24 (72.7%), initiated and discontinued in seven (21.2%), and prescribed and completed in two (6.1%). In contrast, of 43 (56.6%) exposures for which the source person could not be tested, PEP was prescribed in 35 (81.4%), P &lt; 0.001. Upon modelling, the PEP policy allowed a 31% reduction of cost for management of exposures to source persons of unknown HIV serostatus. The policy was cost-saving for HIV prevalence of up to 70% in the source population. The availability of all the source persons for testing would have reduced cost by 64%. CONCLUSION: In the management of non-occupational HIV exposures, active contacting and free, anonymous testing of source persons proved feasible. This policy resulted in a decrease in prescription of PEP, proved to be cost-saving, and presumably helped to avoid unnecessary toxicity and psychological stress.

Disposition of oral valganciclovir during continuous renal replacement therapy in two lung transplant recipients

Background: Oral valganciclovir (VGC) is hydrolysed into active ganciclovir (GCV) which is eliminated in the kidney by filtration and secretion. VGC dosage has to be adapted in renal failure with continuous renal replacement therapy (CRRT), a condition sometimes encountered early after solid organ transplantation. This investigation aimed to determine whether VGC 450 mg every 48 hours provides appropriate GCV exposure for cytomegalovirus (CMV) prophylaxis during CRRT. Methods: GCV pharmacokinetics were extensively studied during CRRT in two lung transplant recipients with acute renal failure receiving VGC 450 mg every 48 hours trough a nasogastric tube. In vitro experiments using blank whole blood spiked with GCV further investigated exchanges between plasma and erythrocytes. Results: GCV disposition was characterised by an area under the curve (AUC) of 98.0 and 55.4 mg h/L, resulting in trough concentrations of 0.7 and 0.2 mg/L, an apparent total body clearance of 3.3 and 5.8 L/h, a terminal half-life of 16.9 and 14.1 h, and an apparent volume of distribution of 60.3 and 104.9 L. The observed sieving coefficient (filtrate/plasma) was 1.05 and 0.96, and the hemofiltration clearance 3.3 and 3.1 L/h, respectively. High sieving values could be explained by an efflux of GCV from erythrocytes. In vitro experiments confirmed that erythrocytes are loaded with significant GCV amount and release it quickly into plasma, thus contributing to the apparent efficacy of hemofiltration. Conclusion: These results indicate that a VGC dosage of 450 mg every 48 hours was adequate for CMV prophylaxis during CRRT, providing GCV levels similar to those reported using 900 mg qd in transplant recipients with normal renal function.

High prevalence of severe vitamin D deficiency in combined antiretroviral therapy-naive and successfully treated Swiss HIV patients.

OBJECTIVES: To evaluate the prevalence of 25-hydroxyvitamin D [25(OH)D] deficiency in HIV-positive patients, a population at risk for osteoporosis. DESIGN: Retrospective assessment of vitamin D levels by season and initiation of combined antiretroviral therapy (cART). METHODS: 25(OH)D was measured in 211 HIV-positive patients: samples were taken before initiation of cART from February to April or from August to October as well as 12 (same season) and 18 months (alternate season) after starting cART. 1,25-Dihydroxyvitamin D [1,25(OH)2D] was measured in a subset of 74 patients. Multivariable analyses included season, sex, age, ethnicity, BMI, intravenous drug use (IDU), renal function, time since HIV diagnosis, previous AIDS, CD4 cell count and cART, in particular nonnucleoside reverse transcriptase inhibitor (NNRTI) and tenofovir (TDF) use. RESULTS: At baseline, median 25(OH)D levels were 37 (interquartile range 20-49) nmol/l in spring and 57 (39-74) nmol/l in the fall; 25(OH)D deficiency less than 30 nmol/l was more prevalent in spring (42%) than in fall (14%), but remained unchanged regardless of cART exposure. In multivariable analysis, 25(OH)D levels were higher in white patients and those with a longer time since HIV diagnosis and lower in springtime measurements and in those with active IDU and NNRTI use. 1-Hydroxylation rates were significantly higher in patients with low 25(OH)D. Hepatitis C seropositivity, previous AIDS and higher CD4 cell counts correlated with lower 1,25(OH)2D levels, whereas BMI and TDF use were associated with higher levels. In TDF-treated patients, higher 1,25(OH)2D correlated with increases in serum alkaline phosphatase. CONCLUSION: Based on the high rate of vitamin D deficiency in HIV-positive patients, systematic screening with consideration of seasonality is warranted. The impact of NNRTIs on 25(OH)D and TDF on 1,25(OH)2D needs further attention.

Recommendations to reduce hand exposure for standard nuclear medicine procedures

The optimization of the extremity dosimetry of medical staff in nuclear medicine was the aim of the Work Package 4 (WP4) of the ORAMED project, a Collaborative Project (2008-2011) supported by the European Commission within its 7th Framework Programme. Hand doses and dose distributions across the hands of medical staff working in nuclear medicine departments were evaluated through an extensive measurement program involving 32 hospitals in Europe and 139 monitored workers. The study included the most frequently used radionuclides, (99m)Tc- and (18)F-labelled radiopharmaceuticals for diagnostic and (90)Y-labelled Zevalin (R) and DOTATOC for therapy. Furthermore, Monte Carlo simulations were performed in different predefined scenarios to evaluate separately the efficacy of different radiation protection measures by comparing hand dose distributions according to various parameters. The present work gives recommendations based on results obtained with both measurements and simulations. This results in nine practical recommendations regarding the positioning of the dosemeters for an appropriate skin dose monitoring and the best protection means to reduce the personnel exposure.

VEGF is a mediator of retinal pigment epithelium permeability leading to photoreceptor cell death in light-induced retinal degeneration : gene therapy strategy to prevent AMD-disorders

ABSTRACTIn normal tissues, a balance between pro- and anti-angiogenic factors tightly controls angiogenesis. Alterations of this balance may have pathological consequences. For instance, concerning the retina, the vascular endothelial growth factor (VEGF) is a potent pro-angiogenic factor, and has been identified has a key player during ocular neovascularization implicated in a variety of retinal diseases. In the exudative form (wet-form) of age-related macular degeneration (AMD), neovascularizations occurring from the choroidal vessels are responsible for a quick and dramatic loss of visual acuity. In diabetic retinopathy and retinopathy of prematurity, sprouting from the retinal vessels leads to vision loss. Furthermore, the aging of the population, the increased- prevalence of diabetes and the better survival rate of premature infants will lead to an increasing rate of these conditions. In this way, anti-VEGF strategy represents an important therapeutic target to treat ocular neovascular disorders.In addition, the administration of Pigmented Epithelial growth factor, a neurotrophic and an anti- angiogenic factor, prevents photoreceptor cell death in a model of retinal degeneration induced by light. Previous results analyzing end point morphology reveal that the light damage (LD) model is used to mimic retinal degenerations arising from environmental insult, as well as aging and genetic disease such as advanced atrophic AMD. Moreover, light has been identified as a co-factor in a number of retinal diseases, speeding up the degeneration process. This protecting effect of PEDF in the LD retina raises the possibility of involvement of the balance between pro- and anti-angiogenic factors not only for angiogenesis, but also in cell survival and maintenance.The aim of the work presented here was to evaluate the importance of this balance in neurodegenerative processes. To this aim, a model of light-induced retinal degeneration was used and characterized, mainly focusing on factors simultaneously controlling neuron survival and angiogenesis, such as PEDF and VEGF.In most species, prolonged intense light exposure can lead to photoreceptor cell damage that can progress to cell death and vision loss. A protocol previously described to induce retinal degeneration in Balb/c mice was used. Retinas were characterized at different time points after light injury through several methods at the functional and molecular levels. Data obtained confirmed that toxic level of light induce PR cell death. Variations were observed in VEGF pathway players in both the neural retina and the eye-cup containing the retinal pigment epithelium (RPE), suggesting a flux of VEGF from the RPE towards the neuroretina. Concomitantly, the integrity of the outer blood-retinal-barrier (BRB) was altered, leading to extravascular albumin leakage from the choroid throughout the photoreceptor layer.To evaluate the importance of VEGF during light-induced retinal degeneration process, a lentiviral vector encoding the cDNA of a single chain antibody directed against all VEGF-A isoforms was developed (LV-V65). The bioactivity of this vector to block VEGF was validated in a mouse model of laser-induced choroidal neovascularization mediated by VEGF upregulation. The vector was then used in the LD model. The administration of the LV-V65 contributed to the maintenance of functional photoreceptors, which was assessed by ERG recording, visual acuity measurement and histological analyses. At the RPE level, the BRB integrity was preserved as shown by the absence of albumin leakage and the maintenance of RPE cell cohesion.These results taken together indicate that the VEGF is a mediator of light induced PR degeneration process and confirm the crucial role of the balance between pro- and anti-angiogenic factors in the PR cell survival. This work also highlights the prime importance of BRB integrity and functional coupling between RPE and PR cells to maintain the PR survival. VEGF dysregulation was already shown to be involved in wet AMD forms and our study suggests that VEGF dysregulation may also occur at early stages of AMD and could thus be a potential therapeutic target for several RPE related diseases.RESUMEDans les différents tissues de l'organisme, l'angiogenèse est strictement contrôlée par une balance entre les facteurs pro- et anti-angiogéniques. Des modifications survenant dans cette balance peuvent engendrer des conséquences pathologiques. Par exemple, concernant la rétine, le facteur de croissance de l'endothélium vasculaire (VEGF) est un facteur pro-angiogénique important. Ce facteur a été identifié comme un acteur majeur dans les néovascularisations oculaires et les processus pathologiques angiogéniques survenant dans l'oeil et responsables d'une grande variété de maladies rétiniennes. Dans la forme humide de la dégénérescence maculaire liée à l'âge (DMLA), la néovascularisation choroïdienne est responsable de la perte rapide et brutale de l'acuité visuelle chez les patients affectés. Dans la rétinopathie diabétique et celle lié à la prématurité, l'émergence de néovaisseaux rétiniens est la cause de la perte de la vision. Les néovascularisations oculaires représentent la principale cause de cécité dans les pays développés. De plus, l'âge croissant de la population, la progression de la prévalence du diabète et la meilleure survie des enfants prématurés mèneront sans doute à l'augmentation de ces pathologies dans les années futures. Dans ces conditions, les thérapies anti- angiogéniques visant à inhiber le VEGF représentent une importante cible thérapeutique pour le traitement de ces pathologies.Plusieurs facteurs anti-angiogéniques ont été identifiés. Parmi eux, le facteur de l'épithélium pigmentaire (PEDF) est à la fois un facteur neuro-trophique et anti-angiogénique, et l'administration de ce facteur au niveau de la rétine dans un modèle de dégénérescence rétinienne induite par la lumière protège les photorécepteurs de la mort cellulaire. Des études antérieures basées sur l'analyse morphologique ont révélé que les modifications survenant lors de la dégénération induite suite à l'exposition à des doses toxiques de lumière représente un remarquable modèle pour l'étude des dégénérations rétiniennes suite à des lésions environnementales, à l'âge ou encore aux maladies génétiques telle que la forme atrophique avancée de la DMLA. De plus, la lumière a été identifiée comme un co-facteur impliqué dans un grand nombre de maladies rétiniennes, accélérant le processus de dégénération. L'effet protecteur du PEDF dans les rétines lésées suite à l'exposition de des doses toxiques de lumière suscite la possibilité que la balance entre les facteurs pro- et anti-angiogéniques soit impliquée non seulement dans les processus angiogéniques, mais également dans le maintient et la survie des cellules.Le but de ce projet consiste donc à évaluer l'implication de cette balance lors des processus neurodégénératifs. Pour cela, un modèle de dégénération induite par la lumière à été utilisé et caractérisé, avec un intérêt particulier pour les facteurs comme le PEDF et le VEGF contrôlant simultanément la survie des neurones et l'angiogenèse.Dans la plupart des espèces, l'exposition prolongée à une lumière intense peut provoquer des dommages au niveau des cellules photoréceptrices de l'oeil, qui peut mener à leur mort, et par conséquent à la perte de la vision. Un protocole préalablement décrit a été utilisé pour induire la dégénération rétinienne dans les souris albinos Balb/c. Les rétines ont été analysées à différents moments après la lésion par différentes techniques, aussi bien au niveau moléculaire que fonctionnel. Les résultats obtenus ont confirmé que des doses toxiques de lumière induisent la mort des photorécepteurs, mais altèrent également la voie de signalisation du VEGF, aussi bien dans la neuro-rétine que dans le reste de l'oeil, contenant l'épithélium pigmentaire (EP), et suggérant un flux de VEGF provenant de ΙΈΡ en direction de la neuro-rétine. Simultanément, il se produit une altération de l'intégrité de la barrière hémato-rétinienne externe, menant à la fuite de protéine telle que l'albumine, provenant de la choroïde et retrouvée dans les compartiments extravasculaires de la rétine, telle que dans la couche des photorécepteurs.Pour déterminer l'importance et le rôle du VEGF, un vecteur lentiviral codant pour un anticorps neutralisant dirigée contre tous les isoformes du VEGF a été développé (LV-V65). La bio-activité de ce vecteur a été testé et validée dans un modèle de laser, connu pour induire des néovascularisations choroïdiennes chez la souris suite à l'augmentation du VEGF. Ce vecteur a ensuite été utilisé dans le modèle de dégénération induite par la lumière. Les résultats des électrorétinogrammes, les mesures de l'acuité visuelle et les analyses histologiques ont montré que l'injection du LV-V65 contribue à la maintenance de photorécepteurs fonctionnels. Au niveau de l'EP, l'absence d'albumine et la maintenance des jonctions cellulaires des cellules de l'EP ont démontré que l'intégrité de la barrière hémato-rétinienne externe est préservée suite au traitement.Par conséquent, tous les résultats obtenus indiquent que le VEGF est un médiateur important impliquée dans le processus de dégénération induit par la lumière et confirme le rôle cruciale de la balance entre les facteurs pro- et anti-angiogéniques dans la survie des photorécepteurs. Cette étude révèle également l'importance de l'intégrité de la barrière hémato-rétinienne et l'importance du lien fonctionnel et structurel entre l'EP et les photorécepteurs, essentiel pour la survie de ces derniers. Par ailleurs, Cette étude suggère que des dérèglements au niveau de l'équilibre du VEGF ne sont pas seulement impliqués dans la forme humide de la DMLA, comme déjà démontré dans des études antérieures, mais pourraient également contribuer et survenir dans des formes précoces de la DMLA, et par conséquent le VEGF représente une cible thérapeutique potentielle pour les maladies associées à des anomalies au niveau de l'EP.

Tobramycin exposure from active calcium sulfate bone graft substitute.

BACKGROUND: Bone graft substitute such as calcium sulfate are frequently used as carrier material for local antimicrobial therapy in orthopedic surgery. This study aimed to assess the systemic absorption and disposition of tobramycin in patients treated with a tobramycin-laden bone graft substitute (Osteoset® T). METHODS: Nine blood samples were taken from 12 patients over 10 days after Osteoset® T surgical implantation. Tobramycin concentration was measured by fluorescence polarization. Population pharmacokinetic analysis was performed using NONMEM to assess the average value and variability (CV) of pharmacokinetic parameters. Bioavailability (F) was assessed by equating clearance (CL) with creatinine clearance (Cockcroft CLCr). Based on the final model, simulations with various doses and renal function levels were performed. (ClinicalTrials.gov number, NCT01938417). RESULTS: The patients were 52 +/- 20 years old, their mean body weight was 73 +/- 17 kg and their mean CLCr was 119 +/- 55 mL/min. Either 10 g or 20 g Osteoset® T with 4% tobramycin sulfate was implanted in various sites. Concentration profiles remained low and consistent with absorption rate-limited first-order release, while showing important variability. With CL equated to CLCr, mean absorption rate constant (ka) was 0.06 h-1, F was 63% or 32% (CV 74%) for 10 and 20 g Osteoset® T respectively, and volume of distribution (V) was 16.6 L (CV 89%). Simulations predicted sustained high, potentially toxic concentrations with 10 g, 30 g and 50 g Osteoset® T for CLCr values below 10, 20 and 30 mL/min, respectively. CONCLUSIONS: Osteoset® T does not raise toxicity concerns in subjects without significant renal failure. The risk/benefit ratio might turn unfavorable in case of severe renal failure, even after standard dose implantation.

Exposition aux immunosuppresseurs in utero [Exposure in utero to immunosuppressives]

The number of pregnant women receiving immunosuppressive therapy is increasing. Use of immunosuppressants during pregnancy is indicated for anti-rejection therapy in transplantation patients and treatment of autoimmune diseases. Despite the maternal and fetal risks of these pregnancies, the proportion of surviving infants is improving and the possibility that a pregnancy could occur in these women during their childbearing years should be considered. All immunosuppressant drugs and their metabolites cross the placenta, raising questions about the long-term outcome of the children exposed to these agents in utera. There is no increased risk of congenital anomalies. However, there is an elevated incidence of prematurity, intrauterine growth retardation (IUGR) and therefore low birthweight, as well as maternal hypertension and preeclampsia. The most frequent neonatal complications are those associated with prematurity and IUGR, as well as adrenal insufficiency with corticosteroids, immunological disturbances with azathioprine and cyclosporin, and hyperkalemia with tacrolimus. The long-term follow-up of infants exposed to immunosuppressants in utero is still limited and experimental studies raise the question whether there could be an increased incidence at adult age of some pathologies including renal insufficiency, hypertension and diabetes. The follow-up of these infants should be carefully organized and multidisciplinary, taking the perinatal context into account.

Efficacy, tolerability and risk factors for virological failure of darunavir-based therapy for treatment-experienced HIV-infected patients: the Swiss HIV Cohort Study.

OBJECTIVES: Darunavir was designed for activity against HIV resistant to other protease inhibitors (PIs). We assessed the efficacy, tolerability and risk factors for virological failure of darunavir for treatment-experienced patients seen in clinical practice. METHODS: We included all patients in the Swiss HIV Cohort Study starting darunavir after recording a viral load above 1000 HIV-1 RNA copies/mL given prior exposure to both PIs and nonnucleoside reverse transcriptase inhibitors. We followed these patients for up to 72 weeks, assessed virological failure using different loss of virological response algorithms and evaluated risk factors for virological failure using a Bayesian method to fit discrete Cox proportional hazard models. RESULTS: Among 130 treatment-experienced patients starting darunavir, the median age was 47 years, the median duration of HIV infection was 16 years, and 82% received mono or dual antiretroviral therapy before starting highly active antiretroviral therapy. During a median patient follow-up period of 45 weeks, 17% of patients stopped taking darunavir after a median exposure of 20 weeks. In patients followed beyond 48 weeks, the rate of virological failure at 48 weeks was at most 20%. Virological failure was more likely where patients had previously failed on both amprenavir and saquinavir and as the number of previously failed PI regimens increased. CONCLUSIONS: As a component of therapy for treatment-experienced patients, darunavir can achieve a similar efficacy and tolerability in clinical practice to that seen in clinical trials. Clinicians should consider whether a patient has failed on both amprenavir and saquinavir and the number of failed PI regimens before prescribing darunavir.

The effect of three or six years of denosumab exposure in women with postmenopausal osteoporosis: results from the FREEDOM extension.

CONTEXT: The Fracture Reduction Evaluation of Denosumab in Osteoporosis Every 6 Months (FREEDOM) extension is evaluating the long-term efficacy and safety of denosumab for up to 10 years. OBJECTIVE: The objective of the study was to report results from the first 3 years of the extension, representing up to 6 years of denosumab exposure. DESIGN, SETTING, AND PARTICIPANTS: This was a multicenter, international, open-label study of 4550 women. INTERVENTION: Women from the FREEDOM denosumab group received 3 more years of denosumab for a total of 6 years (long-term) and women from the FREEDOM placebo group received 3 years of denosumab (crossover). MAIN OUTCOME MEASURES: Bone turnover markers (BTMs), bone mineral density (BMD), fracture, and safety data are reported. RESULTS: Reductions in BTMs were maintained (long-term) or achieved rapidly (crossover) after denosumab administration. In the long-term group, BMD further increased for cumulative 6-year gains of 15.2% (lumbar spine) and 7.5% (total hip). During the first 3 years of denosumab treatment, the crossover group had significant gains in lumbar spine (9.4%) and total hip (4.8%) BMD, similar to the long-term group during the 3-year FREEDOM trial. In the long-term group, fracture incidences remained low and below the rates projected for a virtual placebo cohort. In the crossover group, 3-year incidences of new vertebral and nonvertebral fractures were similar to those of the FREEDOM denosumab group. Incidence rates of adverse events did not increase over time. Six participants had events of osteonecrosis of the jaw confirmed by adjudication. One participant had a fracture adjudicated as consistent with atypical femoral fracture. CONCLUSION: Denosumab treatment for 6 years remained well tolerated, maintained reduced bone turnover, and continued to increase BMD. Fracture incidence remained low.