[Safety update on vaccination during pregnancy]. / Point sur les vaccinations à risque pendant la grossesse.

During influenza A pandemia, the vaccination on pregnant women has raised many questions. Pandemia, easiness of travelling, and insufficient vaccinal coverage, expose these patients to infection which may have serious consequences on their pregnancy and on the child to born. On pregnant women, the precautionary principle is a priority and the evaluation of epidemiological risk is essential, in order to prevent adverses events. Prophylactic vaccinal administration against infections should be assessed with caution due to the little amount of available data. Its use will depend on the vaccine's composition and known side effects, the stage of pregnancy, as well as the benefit for the mother and the child to born, and her clinical history. Whatever the vaccine's nature, its administration never justifies a therapeutic abortion; its evolution must be closely followed to cover the occurrence of complication.

Pravastatin reverses the membrane cholesterol reorganization induced by myocardial infarction within lipid rafts in CD14(+)/CD16(-) circulating monocytes.

Large numbers of monocytes are recruited in the infarcted myocardium. Their cell membranes contain cholesterol-rich microdomains called lipids rafts, which participate in numerous signaling cascades. In addition to its cholesterol-lowering effect, pravastatin has several pleiotropic effects and is widely used as secondary prevention treatment after myocardial infarction (MI). The aim of this study was to investigate the effects of pravastatin on the organization of cholesterol within monocyte membrane rafts from patients who had suffered myocardial infarction. Monocytes from healthy donors and acute MI patients were cultured with or without 4µM pravastatin. Lipid rafts were extracted by Lubrol WX, caveolae and flat rafts were separated using a modified sucrose gradient. Cholesterol level and caveolin-1 expression in lipid rafts were determined. In healthy donors, cholesterol was concentrated in flat rafts (63±3 vs 13±1%, p<0.001). While monocytes from MI patients presented similar cholesterol distribution in both caveolae and flat rafts. Cholesterol distribution was higher in flat rafts in healthy donors, compared to MI patients (63±3 vs 41±2%, p<0.001), with less distribution in caveolae (13±1 vs 34±2%, p<0.001). Pravastatin reversed the cholesterol distribution in MI patients cells between flat rafts (41±2 vs 66±3%, p<0.001) and caveolae (34±2 vs 18±1%, p<0.001). In conclusion, MI redistributes cholesterol from flat rafts to caveolae indicating monocyte membrane reorganization. In vitro pravastatin treatment restored basal conditions in MI monocytes, suggesting another effect of statins.

The number of circulating CD14(+) cells is related to infarct size and postinfarct volumes in ST segment elevation myocardial infarction but not non-ST segment elevation myocardial infarction.

OBJECTIVE: To determine the relationship between the number of CD14(+) cells, myocardial infarct (MI) size and left ventricular (LV) volumes in ST segment elevation MI (STEMI) and non-ST segment elevation MI (NSTEMI) patients. METHODS: A total of 62 patients with STEMI (n=34) or NSTEMI (n=28) were enrolled. The number of CD14(+) cells was assessed at admission. Infarct size, left ventricular ejection fraction (LVEF) and LV volumes were measured using magnetic resonance imaging five days after MI and six months after MI. RESULTS: In STEMI patients, the number of CD14(+) cells was positively and significantly correlated with infarct size at day 5 (r=0.40; P=0.016) and after six months (r=0.34; P=0.047), negatively correlated with LVEF at day 5 (r=-0.50; P=0.002) and after six months (r=-0.46; P=0.005) and positively correlated with end-diastolic (r=0.38; P=0.02) and end-systolic (r=0.49; P=0.002) volumes after six months. In NSTEMI patients, no significant correlation was found between the number of CD14(+) cells and infarct size, LVEF or LV volumes at day 5 or after six months. CONCLUSIONS: The number of CD14(+) cells at admission was associated with infarct size and LV remodelling in STEMI patients with large infarct size, whereas in NSTEMI patients, no relationship was observed between numbers of CD14(+) cells and LV remodelling.

Relative impact of ribavirin monitoring and HIV coinfection on sustained virological response in patients with chronic hepatitis C.

BACKGROUND: In chronic hepatitis C, higher ribavirin (RBV) concentrations are associated with sustained virological response (SVR); target concentration cutoffs have been proposed. As RBV displays interindividual variability, monitoring of RBV plasma levels appears relevant. The impact of RBV therapeutic drug monitoring (TDM(RBV)) on SVR has not been explored in current practice. Our study aimed to assess this impact. METHODS: Three patient groups were defined as RBV cutoffs achieved at week 12 (group A1), not achieved (group A2), and one without RBV concentration assessment (group B). A predictive model assessed the group impact on SVR in multivariate analysis, while adjusting for additional predictive factors. A specific evaluation of HIV-HCV-coinfected patients was performed. RESULTS: A total of 122 patients were included. In group A1 (n=30, HIV-positive =18), SVR, relapse and non-response rates were 60%, 17% and 23%, respectively; in group A2 (n=32, HIV-positive =18), 25%, 19% and 56%, respectively; and in group B (n=60, HIV-positive =3), 52%, 33% and 15%, respectively (P=0.0004). The patient group was an independent predictor of SVR (P=0.01), along with baseline viral load and HCV genotype. HIV coinfection did not impede the SVR rate. The cutoffs were achieved in 62% and 28% (P=0.008) of patients, when TDM(RBV) was performed or not, respectively. CONCLUSIONS: The achievement of RBV cutoffs is a predictive factor of SVR independent of HIV coinfection. It makes it possible to reach high SVR rates, avoid relapse and obtain the same SVR rates in HIV-HCV-coinfected as in HCV-monoinfected patients. TDM(RBV) enables RBV concentration cutoffs to be reached more frequently and could thus be a useful tool to optimize hepatitis C treatment.

Presence of endothelial colony-forming cells is associated with reduced microvascular obstruction limiting infarct size and left ventricular remodelling in patients with acute myocardial infarction.

Endothelial colony-forming cells (ECFCs) are known to increase after acute myocardial infarction (AMI). We examined whether the presence of ECFCs is associated with preserved microvascular integrity in the myocardium at risk by reducing microvascular obstruction (MVO). We enrolled 88 patients with a first ST elevation AMI. ECFC colonies and circulating progenitor cells were characterized at admission. MVO was evaluated at 5 days and infarct size at 5 days and at 6-month follow-up by magnetic resonance imaging. ECFC colonies were detected in 40 patients (ECFC(pos) patients). At 5 days, MVO was of greater magnitude in ECFC(neg) versus ECFC(pos) patients (7.7 ± 5.3 vs. 3.2 ± 5%, p = 0.0002). At 6 months, in ECFC(pos) patients, there was a greater reduction in infarct size (-32.4 ± 33 vs. -12.8 ± 24%; p = 0.003) and a significant improvement in left ventricular (LV) volumes and ejection fraction. Level of circulating CD34+/VEGF-R2+ cells was correlated with the number of ECFC colonies (r = 0.54, p < 0.001) and relative change in infarct size (r = 0.71, p < 0.0001). The results showed that the presence of ECFC colonies is associated with reduced MVO after AMI, leading to reduced infarct size and less LV remodelling and can be considered a marker of preserved microvascular integrity in AMI patients.

Presence of circulating endothelial progenitor cells and levels of stromal-derived factor-1α are associated with ascending aorta aneurysm size.

OBJECTIVE: Circulating endothelial progenitor cells (EPCs) are a specialized subset of stem/progenitor cells found in bone marrow. They participate in neo-vascularization of injured vessels and predict cardiovascular outcome in patient at risk. Several factors influence their migration and proliferation, among which is the widely studied stromal-derived factor-1α (SDF-1α). In cardiovascular disease, regarding thoracic aortic aneurysms (TAAs), few studies have investigated the levels of EPC and SDF-1α. As rupture, acute dissection and hematoma are acute complications of idiopathic ascending thoracic aortic aneurysm (iATAA) that increase with the size of aneurysm, we aimed to evaluate a potential relationship between circulating EPC and SDF-1α and iATAA size. METHODS: The aneurysm size of 27 consecutive patients suffering from iATAA and scheduled for surgery was assessed by computed tomography scan. In all patients, we measured levels of circulating EPCs by flow cytometer, and plasma levels of SDF-1α the day before surgery. RESULTS: The median aneurysm size was 54 mm (interquartile range (IQR): 50.0-58.8]. The EPC levels of CD34+/CD144+/CD14- and CD34+/VEGF-R2+/CD14- were inversely correlated to aneurysm diameter (p = 0.038, r = -0.424 and p = 0.0046, r = -0.65, respectively) before surgery. Conversely, plasma levels of SDF-1α were positively correlated to aneurysm size (p = 0.042; r = 0.47). CONCLUSIONS: Our findings indicate that EPC levels may be useful for monitoring ascending aorta aneurysms and that SDF-1α could be a biomarker of iATAA expansion.

An APCI LC-MS/MS method for routine determination of capecitabine and its metabolites in human plasma.

The anticancer drug capecitabine and its metabolites [including the active metabolite 5-fluorouracil (5-FU)] display high pharmacokinetic inter-patient variability. Such variability, which may lead to treatment failure or toxicity, could need drug concentration measurement to individualize dosing regimen. However, usual assay methods are often long and fastidious. A simultaneous and cost-effective method was thus developed for the determination of the concentrations of these compounds in human plasma. Compounds were extracted via a classic liquid-liquid extraction. Chromatographic analysis was performed on a C18 reverse phase column with detection by atmosphere pressure chemical ionization LC-MS/MS. Our method allows a good chromatographic separation of the compounds and was fully validated following Food and Drug Administration (FDA) recommendations (good selectivity, no carry-over, linearity of the calibration curves without weighting, deviations from nominal concentrations of standard samples lower than 15%, intra- and inter-assay precision and accuracy lower than 15%). Recovery and stability were also acceptable following the FDA guidelines. A matrix effect impairing the determination of 5-FU was avoided by using a stable isotopic derivative of 5-FU as internal standard. Interestingly, this method allows detection of TetraHydroUridine, an inhibitor of ex vivo degradation of metabolites, which is essential for the stability, the adequate conditioning of blood samples and for good laboratory practice, essential in routine determination. This method seems usable to routinely determine concentrations of capecitabine and its metabolites in blood and may be helpful in further studies aiming at performing therapeutic drug monitoring.

Pharmacokinetic modelling and development of Bayesian estimators for therapeutic drug monitoring of mycophenolate mofetil in reduced-intensity haematopoietic stem cell transplantation.

BACKGROUND: Mycophenolate mofetil, a prodrug of mycophenolic acid (MPA), is used during non-myeloablative and reduced-intensity conditioning haematopoetic stem cell transplantation (HCT) to improve engraftment and reduce graft-versus-host disease (GVHD). However, information about MPA pharmacokinetics is sparse in this context and its use is still empirical. OBJECTIVES: To perform a pilot pharmacokinetic study and to develop maximum a posteriori Bayesian estimators (MAP-BEs) for the estimation of MPA exposure in HCT. PATIENTS AND METHODS: Fourteen patients administered oral mycophenolate mofetil 15 g/kg three times daily were included. Two consecutive 8-hour pharmacokinetic profiles were performed on the same day, 3 days before and 4 days after the HCT. One 8-hour pharmacokinetic profile was performed on day 27 after transplantation. For these 8-hour pharmacokinetic profiles, blood samples were collected predose and 20, 40, 60, 90 minutes and 2, 4, 6 and 8 hours post-dose. Using the iterative two-stage (ITS) method, two different one-compartment open pharmacokinetic models with first-order elimination were developed to describe the data: one with two gamma laws and one with three gamma laws to describe the absorption phase. For each pharmacokinetic profile, the Akaike information criterion (AIC) was calculated to evaluate model fitting. On the basis of the population pharmacokinetic parameters, MAP-BEs were developed for the estimation of MPA pharmacokinetics and area under the plasma concentration-time curve (AUC) from 0 to 8 hours at the different studied periods using a limited-sampling strategy. These MAP-BEs were then validated using a data-splitting method. RESULTS: The ITS approach allowed the development of MAP-BEs based either on 'double-gamma' or 'triple-gamma' models, the combination of which allowed correct estimation of MPA pharmacokinetics and AUC on the basis of a 20 minute-90 minute-240 minute sampling schedule. The mean bias of the Bayesian versus reference (trapezoidal) AUCs was <5% with <16% of the patients with absolute bias on AUC >20%. AIC was systematically calculated for the choice of the most appropriate model fitting the data. CONCLUSION: Pharmacokinetic models and MAP-BEs for mycophenolate mofetil when administered to HCT patients have been developed. In the studied population, they allowed the estimation of MPA exposure based on three blood samples, which could be helpful in conducting clinical trials for the optimization of MPA in reduced-intensity HCT. However, prior studies will be needed to validate them in larger populations.

Pharmacokinetics of mycophenolic acid administered 3 times daily after hematopoietic stem cell transplantation with reduced-intensity regimen.

Mycophenolate mofetil (MMF) is an immunosuppressive drug used as a prophylactic agent to prevent acute graft-versus-host disease (aGVHD) after hematopoietic stem cell transplantation (HSCT). After reduced-intensity conditioning (RIC) regimen, administration of MMF orally 3 times a day (tid) seems to be more beneficial than twice a day (bid). However, information regarding the pharmacokinetic (PK) parameters of mycophenolic acid (MPA), the active metabolite of MMF, administered in this regimen are very limited. We performed a prospective study in 15 patients for whom 3 sets of sampling were performed: at the beginning of the treatment, after 1 week, and after 1 month. Two consecutive 8-hour sets of sampling were performed at day 0 (D0) and D7. Plasma concentrations of MPA were quantified and areas under the curve for 8hours (AUC(0-8)), and maximal and through concentrations were calculated. The results show that AUC(0-8) increases between the beginning of treatment and the end of the first week, but remains stable thereafter. Moreover, a trend to lower AUC(0-8) was observed for the patients who experienced GVHD > or =2 compared to those patients who did not. The other PK parameters are not associated with pharmacodynamic events. A limited sampling strategy with Bayesian estimators is currently under investigation to confirm these data and the role of D7 AUC(0-8) as a potential target of therapeutic drug monitoring (TDM).

Population pharmacokinetics and dosing recommendations for cisplatin during intraperitoneal peroperative administration: development of a limited sampling strategy for toxicity risk assessment.

BACKGROUND: Ovarian cancer is the leading cause of gynaecological cancer-related death in Western countries. Intraperitoneal (IP) peroperative chemotherapy is an interesting therapeutic option. However, very few data are available regarding pharmacokinetics and especially population pharmacokinetics. PATIENTS AND METHODS: Thirty-one patients with advanced epithelial cancer classified as International Federation of Gynecology and Obstetrics stage IIIC were included in the study. Blood and IP samples were taken over a 24-hour period during and after IP treatment. Both total and ultrafiltered (Uf) platinum (Pt) concentrations were analysed using a population approach with nonlinear mixed-effects modelling (NONMEM) software. Improvement of the model with covariates was performed as well as assessment of the model using bootstrap and posterior visual predictive methods. RESULTS: Both IP fluid and serum pharmacokinetics were satisfactorily described with a three-compartment model for both Uf Pt and total Pt concentrations. The covariates were bodyweight for the IP volume of distribution in the Uf Pt model, and both IP and serum protein concentrations for the clearance from the central compartment in the total Pt model. A nomogram, based on the results of the Monte Carlo simulations, displays a dose recommendation regarding both the risk of renal toxicity and the potent efficacy of the treatment. A limited sampling strategy (LSS) allowing the estimation of potential risk of renal toxicity is also described. CONCLUSION: The pharmacokinetics of cisplatin during peroperative IP chemotherapy could be successfully fitted with the present model, which allowed a dosing strategy accompanied by an LSS to facilitate the follow-up of patients.

Interindividual variability of methadone response: impact of genetic polymorphism.

Methadone, an opioid analgesic, is used clinically in pain therapy as well as for substitution therapy in opioid addiction. It has a large interindividual variability in response and a narrow therapeutic index. Genetic polymorphisms in genes coding for methadone-metabolizing enzymes, transporter proteins (p-glycoprotein; P-gp), and mu-opioid receptors may explain part of the observed interindividual variation in the pharmacokinetics and pharmacodynamics of methadone. Cytochrome P450 (CYP) 3A4 and 2B6 have been identified as the main CYP isoforms involved in methadone metabolism. Methadone is a P-gp substrate, and, although there are inconsistent reports, ABCB1 genetic polymorphisms also contribute slightly to the interindividual variability of methadone kinetics and influence dose requirements. Genetic polymorphism is the cause of high interindividual variability of methadone blood concentrations for a given dose; for example, in order to obtain methadone plasma concentrations of 250 ng/mL, doses of racemic methadone as low as 55 mg/day or as high as 921 mg/day can be required in a 70-kg patient without any co-medication. The clinician must be aware of the pharmacokinetic properties and pharmacological interactions of methadone in order to personalize methadone administration. In the future, pharmacogenetics, at a limited level, can also be expected to facilitate individualized methadone therapy.

Improvement in intraperitoneal intraoperative cisplatin exposure based on pharmacokinetic analysis in patients with ovarian cancer.

Ovarian cancer is the leading cause of gynecological cancer-related death in Western countries. The present treatment standards for ovarian cancer are based on the association of debulking surgery with platinum-based chemotherapy. Another strategy that could be further investigated is intraperitoneal chemotherapy (IP). We previously described that the 2-h administration of intraoperative IP cisplatin did not reach satisfactory concentrations. In the present study, we present the results of a pharmacokinetic analysis performed after two consecutive 1-h IP 30 mg/l cisplatin administrations. Twenty-seven patients with advanced epithelial cancer classified FIGO stage IIIC were included in the study. Blood and IP samples were taken over a 24-h period, during and after IP treatment. Both total and ultrafiltered (Uf) platinum (Pt) concentration levels were analyzed. Biological and clinical toxicities were also recorded. With this strategy, IP Pt concentrations stayed above the target concentration (10 mg/l) for a satisfactory length of time. The serum Pt concentrations were higher than those observed with the "one-bath" protocol and they induced the occurrence of recoverable renal toxicities (3 grade 1, 7 grade 2 and 4 grade 3). The best predictive parameter for renal failure was the total Pt 24-h Area Under the Curve (AUC) with a threshold value of 25 mg h/l RR = 0.31 (95% CI 0.13 - 0.49, P < 0.01). Administration of an increased amount of cisplatin is feasible and a satisfactory level of IP Pt concentrations is obtained. However, this improvement is associated with an increase in serum Pt levels and resulting renal toxicities. An attractive solution would be to decrease Pt transfer from peritoneum to bloodstream. A phase 1 study using intraoperative IP epinephrine in order to decrease this transfer is presently being carried out.

Two types of circulating endothelial progenitor cells in patients receiving long term therapy by HMG-CoA reductase inhibitors.

3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are widely used to decrease cholesterol synthesis and are well established to reduce vascular diseases. Recently, it has been proposed that statins mobilize endothelial progenitor cells from bone marrow during the first four weeks, which could help to prevent vascular diseases. However, in humans there are few data concerning the long term effects of statin treatment on these endothelial progenitor cells. We investigated whether endothelial progenitor cells can be detected and characterized in patients receiving long term statin therapy. Mononuclear cells from patients receiving or not receiving statin therapy were assessed for progenitor cell content by flow cytometry and were cultured in specific conditions to determine the number and the type of progenitors. Our results showed there were significantly more CD34(+), CD34(+)/CD144(+) circulating progenitor cells in the statin(pos) group than in the statin(neg) group. In culture two types of endothelial progenitor cells were detected. Early endothelial progenitor cells gave colonies at day 5 comprising elongated cells whereas late endothelial progenitor cells generated cobblestone-like colonies with strong proliferation capacities. The number of circulating early endothelial progenitor cells was significantly higher in the statin(neg) group, while only late endothelial progenitor cells were detected in the statin(pos) group. Moreover, cells from cobblestones clearly had an endothelial phenotype CD31(+), VEGF-R2(+), CD34(+), CD146(+) in contrast to cells from colonies from early endothelial progenitor cells, which were VEGF-R2(low), CD34(-). These results strongly suggest that long term statin treatment specifically maintains late endothelial progenitor cells in circulation with a CD34(+)/CD144(+) phenotype.

Serum and intraperitoneal pharmacokinetics of cisplatin within intraoperative intraperitoneal chemotherapy: influence of protein binding.

Intraperitoneal (i.p.) chemotherapy is a promising therapeutic method to improve the effectiveness of cisplatin in patients with ovarian cancer and peritoneum involvement. Intraperitoneal treatment can be intraoperatively performed just after a complete surgical resection of peritoneal tumor nodules. However, little is known regarding the pharmacokinetics of platinum during intraoperative i.p. chemotherapy (IIC). Serum and i.p. measurements of total and ultrafilterable platinum were performed to determined pharmacokinetic parameters in 11 consecutive patients who received a 2-h IIC with 50 mg/m cisplatin. Protein concentrations were determined in serum and peritoneal liquid at the same times. The cisplatin concentration required to kill OVCAR-3 human ovarian cancer cells and evaluation of cisplatin binding to proteins were determined in vitro. Platinum i.p. concentration decreased rapidly and quickly came under the cytotoxicity threshold (10 mg for 2 h). About 85% of i.p. and serum cisplatin was ultrafilterable during IIC. Platinum concentrations were closely related to protein concentrations. Due to the very low level of serum protein (almost 25 g/l), serum cisplatin binding during chemotherapy was very low (almost 25%), but increased with protein concentration recovery. These pharmacokinetic data show that a sufficient concentration to kill human ovarian cancer is not reached with a single i.p. bath containing 50 mg/m cisplatin for 2 h. A new protocol with a renewed bath and a higher cisplatin concentration is under investigation.

Evaluation of a sunscreen photoprotective effect by ascorbic acid assessment in human dermis using microdialysis and gas chromatography mass spectrometry.

Ultraviolet irradiation causes adverse effects like sunburn, photosensitivity reactions or immunologic suppression. The aim of this study was to evaluate the photo-protective outcome of a sunscreen cream (SPF8) by the determination of erythema indexes and the assessment of ascorbic acid and its metabolites in human dermis. These substances were used as markers of oxidative effect. Eight healthy female subjects were enrolled in this study. Two abdominal areas were exposed to solar simulated irradiation with three minimal erythema dose, one with SPF8 application and the other site without SPF8 application. Two other areas were used as control, one without SPF8 application and the other site after SPF8 application. Ascorbic acid and its metabolites (dehydroascorbic acid, threonic acid, oxalic acid and xylose) were collected from human dermis by microdialysis and assessed by gas chromatography mass spectrometry. Irradiated site without sunscreen application had significantly demonstrated lower dermis ascorbic acid concentrations and a higher erythema index than the three other sites (P < 0.05). Threonic acid, oxalic acid and xylose dermis concentrations were significantly higher in site III than in the control site I (P < 0.05). The protected-irradiated site did not show erythema formation and there was stability of ascorbic acid dermis concentrations with non-variation in its metabolites. The assessment of ascorbic acid and its metabolites in human dermis could be an efficient tool to demonstrate the oxidative process and consequently to control the efficiency of sunscreen creams against undesirable UV effects.