Arrhythmogenic cardiomyopathy as a myogenic disease: highlights from cardiomyocytes derived from human induced pluripotent stem cells.

Arrhythmogenic cardiomyopathy (ACM) is an inherited cardiomyopathy characterized by the replacement of myocardium by fibro-fatty infiltration and cardiomyocyte loss. ACM predisposes to a high risk for ventricular arrhythmias. ACM has initially been defined as a desmosomal disease because most of the known variants causing the disease concern genes encoding desmosomal proteins. Studying this pathology is complex, in particular because human samples are rare and, when available, reflect the most advanced stages of the disease. Usual cellular and animal models cannot reproduce all the hallmarks of human pathology. In the last decade, human-induced pluripotent stem cells (hiPSC) have been proposed as an innovative human cellular model. The differentiation of hiPSCs into cardiomyocytes (hiPSC-CM) is now well-controlled and widely used in many laboratories. This hiPSC-CM model recapitulates critical features of the pathology and enables a cardiomyocyte-centered comprehensive approach to the disease and the screening of anti-arrhythmic drugs (AAD) prescribed sometimes empirically to the patient. In this regard, this model provides unique opportunities to explore and develop new therapeutic approaches. The use of hiPSC-CMs will undoubtedly help the development of precision medicine to better cure patients suffering from ACM. This review aims to summarize the recent advances allowing the use of hiPSCs in the ACM context.

Visual and Hearing Sensitivity Affect Robot-Based Training for Children Diagnosed With Autism Spectrum Disorder.

In this paper, we investigate the impact of sensory sensitivity during robot-assisted training for children diagnosed with Autism Spectrum Disorder (ASD). Indeed, user-adaptation for robot-based therapies could help users to focus on the training, and thus improve the benefits of the interactions. Children diagnosed with ASD often suffer from sensory sensitivity, and can show hyper or hypo-reactivity to sensory events, such as reacting strongly or not at all to sounds, movements, or touch. Considering it during robot therapies may improve the overall interaction. In the present study, thirty-four children diagnosed with ASD underwent a joint attention training with the robot Cozmo. The eight session training was embedded in the standard therapy. The children were screened for their sensory sensitivity with the Sensory Profile Checklist Revised. Their social skills were screened before and after the training with the Early Social Communication Scale. We recorded their performance and the amount of feedback they were receiving from the therapist through animations of happy and sad emotions played on the robot. Our results showed that visual and hearing sensitivity influenced the improvements of the skill to initiate joint attention. Also, the therapists of individuals with a high sensitivity to hearing chose to play fewer animations of the robot during the training phase of the robot activity. The animations did not include sounds, but the robot was producing motor noise. These results are supporting the idea that sensory sensitivity of children diagnosed with ASD should be screened prior to engaging the children in robot-assisted therapy.

New insights into the haemo- and coelo-microbiota with antimicrobial activities from Echinodermata and Mollusca.

AIMS: The aim of this study was to investigate the diversity of bacteria with antimicrobial activity present in the coelomic fluid and haemolymph of wild and healthy echinodermata and mollusca. METHODS AND RESULTS: Collection expeditions of healthy marine molluscs and echinoderms were conducted in the Glenan archipelago in spring 2014. Members of the culturable microbiota present in the haemolymph, (haemo-microbiota) of Haliotis tuberculata (gastropoda, abalone) and Mytilus edulis (bivalvia, mussel), as well as in the coelomic fluid (coelo-microbiota) of Echinus esculentus (echinoidea, sea urchin) and Holothuria forskali (Holothuroidea, holothurian) were screened for antimicrobial activity, and further identified using 16S rRNA sequencing. Except for E. esculentus, culturable bacteria in the internal fluids of all studied organisms (mussel, abalone and holothurian) were more abundant than in seawater. The haemo- and coelo-microbiota with antimicrobial activity differed significantly between host species, in terms of abundance and diversity. Indeed, higher numbers were isolated from mussel than from abalone haemolymph. Moreover, in mussels and holothurians, bacteria with antimicrobial activities were predominantly Vibrio spp. (respectively 55 and 45%), while Pseudoalteromonas spp. were the most abundant (50%) in abalone haemolymph. Nevertheless, the activity spectra of these bacteria mainly included marine pathogens affiliated to the Vibrio genus. CONCLUSION: The haemo- and coelo-microbiota with antimicrobial activities were significantly related to their host species and differed in terms of abundance and diversity. These bacteria may play a key role in host homeostasis against pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: This study brings new knowledge on the diversity of bacteria present in the internal fluids of two marine molluscs and two echinoderms and their antimicrobial activities towards marine pathogens.

Direct thermo-optical tuning of silicon microresonators for the mid-infrared.

We use light from a visible laser diode to directly tune silicon-on-chip microresonators by thermo-optical effect. We show that this direct tuning is local, non invasive and has a much smaller time constant than global temperature tuning methods. Such an approach could prove to be highly effective for Kerr comb generation in microresonators pumped by quantum cascade lasers, which cannot be easily tuned to achieve comb generation and soliton-mode locked states.

Truncating mutations on myofibrillar myopathies causing genes as prevalent molecular explanations on patients with dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is one of the leading causes of heart failure with high morbidity and mortality. More than 40 genes have been reported to cause DCM. To provide new insights into the pathophysiology of dilated cardiomyopathy, a next-generation sequencing (NGS) workflow based on a panel of 48 cardiomyopathies-causing genes was used to analyze a cohort of 222 DCM patients. Truncating variants were detected on 63 unrelated DCM cases (28.4%). Most of them were identified, as expected, on TTN (29 DCM probands), but truncating variants were also identified on myofibrillar myopathies causing genes in 17 DCM patients (7.7% of the DCM cohort): 10 variations on FLNC and 7 variations on BAG3 . This study confirms that truncating variants on myofibrillar myopathies causing genes are frequently associated with dilated cardiomyopathies and also suggest that FLNC mutations could be considered as a common cause of dilated cardiomyopathy. Molecular approaches that would allow to detect systematically truncating variants in FLNC and BAG3 into genetic testing should significantly increase test sensitivity, thereby allowing earlier diagnosis and therapeutic intervention for many patients with dilated cardiomyopathy.

Prevalence of drug-related problems associated with direct oral anticoagulants in hospitalized patients: a multicenter, cross-sectional study.

WHAT IS KNOWN AND OBJECTIVE: The complex dose regimens of the direct-acting oral anticoagulants (DOAC) make their appropriate prescribing highly challenging. Inappropriate prescribing of the DOAC remains poorly addressed. We studied the patterns of DOAC prescription and estimated the prevalence of drug-related problems (DRPs) associated with their use. METHODS: A cross-sectional study was conducted using data from medical records system of the Lyon teaching hospitals. DRPs, identified among patients who received a DOAC, between 1 January 2010 and 31 July 2013, were categorized according to the Pharmaceutical Care Network Europe Classification System. The prevalence of hospital stays with a DRP was estimated, and a subgroup analysis according to DOAC and their indication for use was provided. Clinical outcomes were not assessed. RESULTS: Of the 4154 hospital stays with at least one DOAC administration [3412 patients; median age (range): 71 years (14-98), 57% female], 70·8% were excluded from the analysis mainly due to missing information for renal function and/or patient weight. Of the 1188 hospital stays that were screened, 100 DRPs were identified (prevalence 8·4%; 95% CI, 6·8-10·0). The highest prevalence was found among patients who received rivaroxaban for atrial fibrillation (14·6%; 95% CI, 10·7-18·5). A too low drug dose was the most frequent DRP (n = 56; 4·7%), followed by a too high drug dose (n = 37; 3·1%), contraindication (n = 5; 0·4%), and pharmacokinetic problem requiring dose adjustment (n = 2; 0·2%). WHAT IS NEW AND CONCLUSION: Drug-related problems associated with the DOACs occur quite commonly among hospitalized patients. Although these DRPs were considered to be of minor severity, prescribing protocols to support better prescribing should be disseminated to reduce the risk to patients. Renal function and body weight data should be mandatory on prescriptions to allow cross-checking.

Cost and co-morbidities associated with hypoglycemic inpatients in Belgium.

BACKGROUND AND OBJECTIVES: Little is known about the economic burden of hypoglycemia in Belgium, or its related co-morbidities. This study aimed at estimating the cost and length of stay associated with hypoglycemia-related hospitalizations in diabetic patients in Belgium and the association between hypoglycemia and in-hospital all-cause mortality, incidence of traumatic fractures, depression, and cardiovascular diseases (myocardial infarction or unstable angina), using retrospective data from 2011. METHODS: Patient data were retrieved from the IMS Hospital Disease Database, including longitudinal (per calendar year) information on diagnoses, procedures, and drugs prescribed in ∼20% of all Belgian hospital beds. The eligible population included all adult (<19 year) diabetic (both types) patients, further split between those with/without a history of hypoglycemia-related hospitalizations. Diabetes, hypoglycemia, and co-morbidities of interest were identified based on International Classification of Diseases and Related Health Problems Version 9 (ICD-9) diagnosis codes. All costs were extrapolated to 2014 using progression in hospitalization costs since 2001. RESULTS: A total of 43,410 diabetes-related hospitalizations were retrieved, corresponding to 30,710 distinct patients. The average hospitalization cost was €10,258 when hypoglycemia was documented (n = 2625), vs €7173 in other diabetic hospitalized patients (n = 40,785). When controlling for age and sex, a higher mortality risk (OR = 1.59; p-value <0.001), a higher incidence of traumatic fractures (OR = 1.25; p-value = 0.009), and a higher probability of depression-related hospitalizations (OR = 1.90; p-value <0.001) were observed in hypoglycemic patients. A similar risk of cardiovascular event was observed in both groups, but hypoglycemic patients were more at risk of experiencing multiple events. CONCLUSION: Hospitalizations for hypoglycemia are expensive and associated with an increased risk of depression and traumatic fractures as well as increased in-hospital mortality. Interventions that can help reduce the risk of hypoglycemia, and consequently the burden on hospitals and society, without compromising glycemic control, will help to further improve diabetes management.

90Y-ibritumomab tiuxetan, fludarabine, busulfan and antithymocyte globulin reduced-intensity allogeneic transplant conditioning for patients with advanced and high-risk B-cell lymphomas.

BACKGROUND: Patients with advanced B-cell non-Hodgkin's lymphoma (NHL) refractory to initial chemotherapy or relapsing after autologous stem-cell transplantation have a poor prognosis. Allogeneic stem-cell transplantation after reduced-intensity conditioning (RIC) regimen can be a therapeutic option. However, the high incidence of relapse remains a challenging issue. We speculated that the incorporation of (90)Y-Ibritumomab tiuxetan into a fludarabine-based RIC regimen would improve the lymphoma control without overwhelming toxicity. Our aim was to evaluate the safety of (90)Y-Ibritumomab tiuxetan in association with such a regimen in a prospective multicenter phase II trial. PATIENTS AND METHODS: Thirty-one patients with advanced lymphoma from five distinct institutions were included between February 2008 and October 2010. Thirty patients in complete or partial response after failure of a median of 3 (range, 2-4) previous chemotherapy regimens including autologous transplant in 29 were evaluable for nonrelapse mortality (NRM) at day 100 post-transplant that was the primary end point. RESULTS: With a median follow-up of 32 months (range, 29-60 months), the 2-year event-free and overall survivals of the whole study group were both 80% [95 confidence interval (CI) 60.8% to 90.5%). The 100-day and 2-year post-transplant cumulative incidences of NRM were 3.3% (95% CI 0.2% to 14.9%) and 13.3% (95% CI 5.4% to 33.2%), respectively. The 2-year cumulative incidence of relapse was 6.7% (95% CI 1.7% to 25.4%). The cumulative incidences of grade II-IV and extensive chronic graft-versus-host disease were 27% and 14%, respectively. CONCLUSIONS: For chemosensitive advanced high-risk B-cell lymphoma, the addition of (90)Y-Ibritumomab tiuxetan to a RIC regimen based on fludarabine, busulfan and antithymocyte globulin followed by allogeneic transplant is safe and highly effective. clinicaltrials.gov: NCT00607854.

Pre-transplantation risk factors to develop sclerotic chronic GvHD after allogeneic HSCT: a multicenter retrospective study from the Société Française de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC).

Sclerotic chronic GvHD (cGvHD) is one of the most severe complications after allo-hematopoietic stem cell transplantation (HSCT). Risk factors associated with this complication remain not very well defined. With the aim to define a pre-transplantation risk profile, we have conducted a French retrospective analysis in 705 consecutive patients between 2005 and 2010. Analyses to determine pre-transplantation risk factors included as variables: patient and donor age, kind of donor, HLA matching, ABO matching, sex-matching, diagnosis, stem cell source, gender, GvHD prophylaxis and antithymocyte globulin (ATG) in the conditioning regimen. The cumulative incidence of sclerotic cGvHD was 18% (95% CI, 16.6-19.6) 3 years after onset of cGvHD. In univariate analysis, we found a significantly lower number of sclerotic cGvHD form in patients transplanted from cord blood cells (P=0.0021), in patients with a one mismatched donor (P=0.041) and in patients who had received ATG in the conditioning regimen (P=0.002). In multivariate analysis, factors associated with an increased risk of sclerotic cGvHD were young patient age, multiple myeloma and PBSC as the stem cell source. ATG in conditioning regimen and cord blood unit as the stem cell source were associated with a lower risk.

In-hospital costs associated with chronic constipation in Belgium: a retrospective database study.

BACKGROUND: Real-life data on the economic burden of chronic idiopathic constipation are scarce. The objectives of this study were to assess hospitalization resource use and costs associated with chronic constipation and its complications in Belgium. METHODS: This was a single country, retrospective study using the IMS Hospital Disease Database (2008), which comprises data on 34% of acute hospital beds in Belgium and contains information on patient demographics, length of stay (LOS), billed costs, drug use, diagnoses, and procedures. Stays with a primary diagnosis of constipation, or a secondary diagnosis of constipation and a concomitant diagnosis of a constipation-related complication, were selected. Patients with diagnoses of colorectal cancer, ulcerative colitis or Crohn's disease, or who had stays involving potentially constipation-inducing procedures, were excluded as having secondary constipation. Patients receiving opioids, calcium-antagonists, antipsychotics or antidepressants were excluded as having drug-induced constipation. KEY RESULTS: In total, 1541 eligible patients were identified. The average unadjusted cost per day in hospital for idiopathic constipation was €441 (€311 ± 1.4 in day clinic visits without overnight stays; €711 ± 14.0 in full hospitalizations with complications). The average LOS in a full hospitalization setting was 7.0 and 4.0 days in stays with and without complications, respectively. The most frequent drug and procedural treatments were osmotically acting laxatives (with complications: 42.61%; without complications: 35.69%), and transanal enema (2.32% and 2.03%), respectively. CONCLUSIONS & INFERENCES: The burden of constipation is often underestimated; it is a condition reflected by hospital-related costs comparable to such indications as migraine, which increase when associated with complications.

Risk of infectious gastroenteritis in young children living in Québec rural areas with intensive animal farming: results of a case-control study (2004-2007).

This study was designed to evaluate the epidemiology of severe gastroenteritis in children living in Québec rural areas with intensive livestock activities. From September 2005 through June 2007, 165 cases of gastroenteritis in children aged from 6 months to 5 years, hospitalized or notified to the public health department were enrolled, and 326 eligible controls participated. The parents of cases and controls were asked questions about different gastroenteritis risk factors. The quality of the drinking water used by the participants was investigated for microbial indicators as well as for four zoonotic bacterial pathogens (Campylobacter spp, Escherichia coli, Salmonella spp and Yersinia spp) and two enteric parasites (Cryptosporidium spp and Giardia spp). From 134 stool specimen analysed, viruses were detected in 82 cases (61%), while 28 (21%) were found with at least one of the bacteria investigated, and five cases were infected by parasites. Campylobacteriosis was the main bacterial infection (n = 15), followed by Salmonella sp (n = 7) and E. coli O157:H7 (n = 5) among cases with bacterial gastroenteritis. No significant difference was found between cases and controls regarding the quality of water consumed; the frequency of faecal contamination of private wells was also similar between cases and controls. Considering the total cases (including those with a virus), no link was found between severe gastroenteritis and either being in contact with animals or living in a municipality with the highest animal density (4th quartile). However, when considering only cases with a bacterial or parasite infection (n = 32), there was a weak association with pig density that was not statistically significant after adjusting for potential confounders. Contact with domestic, zoo or farm animals were the only environmental factor associated with the disease.

Clinical validation of the planar radionuclide ventriculography in patients with right ventricular dysfunction.

OBJECTIVES: Gated radionuclide ventriculography (RNV) may be used for the evaluation of the right ventricular function. However, the accuracy of the method should be clinically validated in patients suffering from diseases with specific pathology of the right ventricle (RV) and with possible left ventricular (LV) interaction. METHODS: Three groups of 15 patients each, diagnosed with arrhythmogenic right ventricular dysplasia (ARVD), pulmonary artery hypertension (PAH) or atrial septal defect (ASD) were compared to a group of normal subjects. The parameters for both ventricles were evaluated separately (ejection fractions: LVEF and RVEF, and intraventricular synchronism quantified as phase standard deviation: LVPSD and RVPSD) as well as the relation or interdependence of the right to left ventricle (RV/LV volume ratio, LV/RV ejection fraction and stroke volume ratios, and interventricular synchronism). All the variables as a whole were analyzed to identify groups of patients according to their functional behaviour. RESULTS: Significant differences were found between the patients and control group for the RV function while the LV function remained mostly within normal limits. When the RV function was considered, the control group and ASD patient group showed differences regarding the ARVD and PAH patients. On evaluating the RV/LV ratios, differences were found between the control group and the ASD group. In the PAH patients, LV function showed differences in relation to the rest of the groups. CONCLUSION: RNV is a reliable clinical tool to evaluate RV function in patients with RV abnormality.

Left atrial endocardial fibrosis and intra-atrial thrombosis - landmarks of left atrial remodeling in rats with spontaneous atrial tachyarrhythmias.

INTRODUCTION: Histological abnormalities are common findings in the left atria (LA) of atrial fibrillation (AF) patients. We aimed to assess LA histological abnormalities in our model of spontaneous atrial tachyarrhythmias in rats. MATERIALS AND METHODS: LA sampling was performed in 12 spontaneously hypertensive rats (SHRs) and eight age-matched Wistar-Kyoto (WKY) rats. Tissue sections were stained with Masson's trichrome and Hematoxylin-Eosin-Safran and examined with a light microscope. A 0 to 3 scoring system was used to quantify the severity of LA structural abnormalities. LA von Willebrand factor (vWF) content was also assessed using immunohistochemical staining. RESULTS: In six of the eight SHRs, LA fibrosis, inflammatory infiltrates, and myocyte necrosis of varying grades of severity were observed. The most frequent feature was endocardial fibrosis, which was observed in six SHRs and in none of the WKY rats. Intra-atrial thrombosis was found in three SHRs and in none of the WKY rats. The intensity of vWF-related fluorescence was higher in the atrial endocardium of SHRs compared to age-matched WKY rats. CONCLUSIONS: Our findings reinforce the role of LA structural abnormalities in atrial arrhythmogenicity. However, two SHRs did not present LA histological abnormalities despite the presence of arrhythmias. This finding suggests that the LA remodeling-atrial tachyarrhythmia relationship could be highly nonlinear and that atrial fibrosis is more likely to be a facilitator of atrial arrhythmogenicity, rather than a prerequisite. We also provide evidence that intra-atrial thrombosis accompanies LA structural remodeling in arrhythmic rats. Increased endocardial platelet adhesion molecule vWF could contribute to this increased thrombogenicity.

Molecular characterization of a large MYBPC3 rearrangement in a cohort of 100 unrelated patients with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM), a common and clinically heterogeneous disease characterized by unexplained ventricular myocardial hypertrophy and a high risk of sudden cardiac death, is mostly caused by mutations in MYH7 and MYBPC3 genes. As 70% of MYBPC3 mutations introduce a premature termination codon, the purpose of the current study was to report the prevalence of large MYBPC3 rearrangements. A large French cohort of 100 HCM patients, for whom no putatively causative point mutations were identified previously in the most prevalent HCM-causing genes, was investigated using an MLPA methodology. One HCM patient was identified to carry a large MYBPC3 rearrangement (<1%). This patient presents a 3505-bp deletion, which begins in the intron 27 and ends 485 bp after the MYBPC3 stop codon (g.47309385_47312889del). It was originated by recombination of a 296 bp AluSz sequence located in intron 27 and a 300 bp AluSx sequence located immediately downstream of exon 35. This study allowed the characterization of the first large MYBPC3 deletion reported in the literature. However, it appears that MLPA strategy, that moderates the identification of large MYBPC3 rearrangements, might confirm a clinical diagnosis only in a small number of patients (<1%).

Agroenvironmental determinants associated with the presence of antimicrobial-resistant Escherichia coli in beach waters in Quebec, Canada.

Exposure to microorganisms resistant to antimicrobials may constitute a health risk to human populations. It is believed that one route of exposure occurs when people engage in recreational activities in water contaminated with these microorganisms. The main objective of this study was to explore population-level and environmental determinants specifically associated with the presence of antimicrobial resistant (AMR) generic Escherichia coli isolated from recreational waters sampled from beaches located in southern Quebec, Canada. Water samples originated from the Quebec provincial beach surveillance program for the summers of 2004 and 2005. This study focused on three classes of determinants, namely: agricultural, population-level and beach characteristics for a total of 19 specific factors. The study was designed as a retrospective observational analysis and factors were assessed using logistic regression methods. From the multivariable analysis, the data suggested that the percentage of land used for spreading liquid manure was a significant factor associated with the presence of AMR E. coli (OR=27.73). Conceptually, broad factors potentially influencing the presence of AMR bacteria in water must be assessed specifically in addition to factors associated with general microbial contamination. Presence of AMR E. coli in recreational waters from beaches in southern Quebec may represent a risk for people engaging in water activities and this study provides preliminary evidence that agricultural practices, specifically spreading liquid manure in agricultural lands nearby beaches, may be linked to the contamination of these waters by AMR E. coli.

Valganciclovir prophylaxis for cytomegalovirus infection in thoracic transplant patients: retrospective study of efficacy, safety, and drug exposure.

Oral ganciclovir (GCV) was replaced by prodrug valganciclovir (vGCV) for cytomegalovirus (CMV) prophylaxis. We assessed retrospectively (2005-2007) vGCV effectiveness and safety during prophylaxis and 4 months after, in heart (HTx) and lung transplantation (LTx), including lung transplant for cystic fibrosis (CFTx). Patients with stable renal function received vGCV 900 mg daily during 3-6 and 8-12 months in HTx and LTx. Effectiveness was assessed by antigenemia (pp65Ag) and a GCV therapeutic drug monitoring to document exposure. A total of 32 patients (11 HTx, 7 LTx, and 14 CFTx) received vGCV for 106+/-67 days in HTx versus 270+/-85 days in LTx and CFTx. Doses were 700+/-225, 915+/-60, and 820+/-150 mg/24 h in HTx, LTx, and CFTx showing acceptable mean trough GCV 0.75+/-0.5 mg/L. Two of 9 cases of neutropenia were attributable to vGCV. Three CMV donor-positive/recipient-negative CFTx patients presented positive pp65Ag; 2 developed CMV disease (6%). We found that vGCV 900 mg, adapted to renal function, was effective and safe for long CMV prophylaxis together with efficient exposure in thoracic transplantation.

[How to improve the continuity of pharmacotherapy at hospital admission and discharge]. / Comment optimiser la continuité du traitement médicamenteux entre l'hôpital et le domicile?

The continuity of pharmacotherapy is of vital importance when patients move from one health care setting to another. Unfortunately, this continuity is not always guaranteed. The aim of this study is to propose solutions to enhance the continuity of pharmacotherapy at hospital admission and discharge. The study consists of a systematic review of the international literature and an analysis of seamless care initiatives in seven selected countries; a summary of Belgian data on problems as well as solutions with regard to continuity of care; a quantification of the extent of medication changes as a result of a hospital stay in Belgium; and a qualitative analysis of the perception of Belgian health care professionals (HCPs) on approaches to improve seamless care. The literature review yielded 15 papers of sufficient quality. However, this review did not generate definitive conclusions on the clinical impact and the cost-effectiveness of interventions aiming to enhance the continuity of pharmacotherapy. The most important initiatives that have been put in practice in foreign countries include the development and implementation of guidelines for HCPs; national information campaigns; education of HCPs; and the development of information technologies as to share patient and prescription data between settings of care. For Belgium, 66 seamless care initiatives were identified. The high number and variety of projects show the interest for this topic as well as the involvement of various HCPs from diverse settings in the development of solutions. Based on this research, and the solutions discussed in the focus groups, the following elements are proposed to enhance the continuity of pharmacotherapy: a national guideline governing the continuity of pharmacotherapy; a national campaign to sensitize HCPs and patients in this area; the availability of a comprehensive and up to date medication list for each patient; and electronic healthcare infrastructure that facilitates sharing of information.

Voriconazole pharmacokinetic variability in cystic fibrosis lung transplant patients.

BACKGROUND: Aspergillosis is a high-risk complication in cystic fibrosis (CF) lung transplant patients. Azole antifungal drugs inhibit CYP3A4, resulting in significant metabolic drug-drug interactions. Voriconazole (VRZ) was marketed without therapeutic drug monitoring (TDM) recommendations, consistent with favorable pharmacokinetics, but regular determinations of plasma VRZ concentration were introduced in our center to manage interactions with calcineurin inhibitors and to document the achievement of therapeutic levels. METHODS: VRZ TDM data analysis for trough concentration (C0) and peak concentration (C2) was carried out, using validated liquid chromatography assay with ultraviolet detection, for 35 CF lung transplant patients (mean age 25 years, mean weight 47 kg, balanced sex ratio) since 2003. Therapeutic range (C0: 1.5 +/- 0.5 - C2 : 4.0 +/- 1.0 mg/L) was expressed relative to pivotal pharmacokinetic trial data. RESULTS: The duration of VRZ treatment ranged from 9 days to 22 months. The recommended standard dose of VRZ (200 mg twice a day, following the loading dose) resulted in significant plasma concentrations (>0.5 mg/L) in 20% of CF lung transplant patients. Therapeutic concentrations were obtained using higher doses (average 570 +/- 160 mg/day, +43%, P<0.01). Despite adaptation, C0 remained <0.5 mg/L (11%), even when the drug was administered intravenously, highlighting the variability of VRZ pharmacokinetics, possibly enhanced by CYP2C19 polymorphism. The risk of inefficacy during periods of underdosage was overcome by treatment with antifungal drug combinations (caspofungin, n=10). The therapeutic index was limited by neurologic effects (14%) and hepatic abnormalities (30%). VRZ concentrations correlated significantly (P<0.01) with aspartate aminotransferase levels but not with bilirubin levels. VRZ acted as a metabolic inhibitor of tacrolimus (C0 to dose ratio 5.8 +/- 2.6, n=31/VRZ versus 1.7 +/- 0.9 alone, P<0.001). Large changes in azole concentration affected the magnitude of the drug-drug interactions and adjustment requirements. CONCLUSIONS: TDM is required because VRZ levels are often undetectable in treated CF lung transplant patients, supporting the use of antifungal drug combinations until achievement of VRZ C0 at a steady state between 1 and 2 mg/L. Plasma VRZ concentrations should be determined for the quantitative, individualized management of drug-drug interactions in lung transplant patients, in particular immunosuppressant such as tacrolimus, considering VRZ to be both a target and an inhibitor of CYP3A4.