[Repetition of blood testing : which risks for the patient?] / Prises de sang répétées :quels risques pour le patient?

Numerous tests are performed in the hospital, often on a daily basis. These tests should answer a specific scientific question and be performed only if their results can have an impact on patient care. In addition to causing anemia, overutilization of tests, such as useless blood testing, can have a deleterious impact on the patients because they carry the risk of false positive results, which can trigger downstream unnecessary investigations and costs.

De nombreuses investigations diagnostiques sont pratiquées à intervalles réguliers en milieu hospitalier. Ces examens devraient répondre à une question clinique spécifique et ne devraient être réalisés que si leur résultat peut influencer la prise en charge du patient. Outre le risque de générer une anémie, la surutilisation de ces tests, comme des prises de sang inutiles, peut avoir un impact délétère sur la prise en charge du patient. En effet, cette surutilisation comporte également le risque de générer des résultats « faux positifs ¼ et ainsi de devoir suivre et potentiellement traiter des patients qui n'en ont pas besoin. Finalement, cette pratique augmente de façon conséquente les coûts de la santé.

METHYLATION OF SEROTONIN RECEPTOR 3A IN ADHD, BORDERLINE PERSONALITY, AND BIPOLAR DISORDERS: LINK WITH SEVERITY OF THE DISORDERS AND CHILDHOOD MALTREATMENT.

BACKGROUND: Serotonin 3A receptor (5-HT3A R) is associated at the genetic and epigenetic levels with a variety of psychiatric disorders and interacts with early-life stress such as childhood maltreatment. We studied the impact of childhood maltreatment on the methylation status of the 5-HT3A R and its association with clinical severity outcomes in relation with a functional genetic polymorphism. METHODS: Clinical severity indexes of 346 bipolar, borderline personality, and adult attention deficit hyperactivity disorders patients were tested for association with the DNA methylation status of eight 5-HT3A R gene CpGs. Relationship between the functional variant rs1062613 (C > T) and methylation status on severity of the disorders were also assessed. RESULTS: Childhood maltreatment was associated with higher severity of the disease (higher number of mood episodes, history of suicide attempts, hospitalization, and younger age at onset) across disorders and within each individual disorder. This effect was mediated by two 5-HT3A R CpGs. Compared to T allele carriers, CC carriers had higher methylation status at one CpG located 1 bp upstream of this variant. CONCLUSIONS: This study shows that epigenetic modification of the 5-HT3A R is involved in the mechanism underlying the relationship between maltreatment in childhood and the severity of several psychiatric disorders in adulthood.

What are the bottlenecks to health data sharing in Switzerland? An interview study.

BACKGROUND: While health data sharing for research purposes is strongly supported in principle, it can be challenging to implement in practice. Little is known about the actual bottlenecks to health data sharing in Switzerland. AIMS OF THE STUDY: This study aimed to assess the obstacles to Swiss health data sharing, including legal, ethical and logistical bottlenecks. METHODS: We identified 37 key stakeholders in data sharing via the Swiss Personalised Health Network ecosystem, defined as being an expert on sharing sensitive health data for research purposes at a Swiss university hospital (or a Swiss disease cohort) or being a stakeholder in data sharing at a public or private institution that uses such data. We conducted semi-structured interviews, which were transcribed, translated when necessary, and de-identified. The entire research team discussed the transcripts and notes taken during each interview before an inductive coding process occurred. RESULTS: Eleven semi-structured interviews were conducted (primarily in English) with 17 individuals representing lawyers, data protection officers, ethics committee members, scientists, project managers, bioinformaticians, clinical trials unit members, and biobank stakeholders. Most respondents felt that it was not the actual data transfer that was the bottleneck but rather the processes and systems around it, which were considered time-intensive and confusing. The templates developed by the Swiss Personalised Health Network and the Swiss General Consent process were generally felt to have streamlined processes significantly. However, these logistics and data quality issues remain practical bottlenecks in Swiss health data sharing. Areas of legal uncertainty include privacy laws when sharing data internationally, questions of "who owns the data", inconsistencies created because the Swiss general consent is perceived as being implemented differently across different institutions, and definitions and operationalisation of anonymisation and pseudo-anonymisation. Many participants desired to create a "culture of data sharing" and to recognise that data sharing is a process with many steps, not an event, that requires sustainability efforts and personnel. Some participants also stressed a desire to move away from data sharing and the current privacy focus towards processes that facilitate data access. CONCLUSIONS: Facilitating a data access culture in Switzerland may require legal clarifications, further education about the process and resources to support data sharing, and further investment in sustainable infrastructureby funders and institutions.

Clinical, behavioral and biomarker predictors of PCSK9 levels in HIV-infected patients naïve of statin therapy: A cross-sectional analysis from the Swiss HIV cohort.

BACKGROUND AND AIMS: Better characterization of Proprotein Convertase Subtilisin/Kexin 9 (PCSK9) profile is currently needed to tailor appropriate lipid-lowering strategies in HIV patients. METHODS: HIV-infected individuals aged ≥ 40 years and naive of statin therapy included in the Swiss HIV cohort study were screened for PCSK9 levels with a routine blood sample collection in 2014 at the Geneva University Hospitals. An exploratory linear regression model was built including clinical (age, sex, ethnicity, cardiovascular risk factors, body mass index, low CD4 defined as ≤200 cells/µl, leucocytes, lymphocytes, platelet, antiretroviral therapy), behavioral (tobacco and marijuana smoking, alcohol use and physical activity) and biomarker (CRP, TNF-α, IL-8, Il-10 and MCP-1) to investigate association with continuous PCSK9 levels. RESULTS: We studied 239 HIV-infected individuals who met inclusion criteria and available PCSK9 levels with a mean age of 49 years. 35 subjects (14.6%) reported marijuana consumption, of whom 20 (57.1%) reported daily consumption and 15 (6.3%) occasional use. PCSK9 levels were correlated with low-density lipoprotein-cholesterol (LDL-C). Our exploratory model identified marijuana consumption (p=0.023) and low CD4 values (p=0.020) as significantly associated factors with higher PCSK9 levels. No association was found with Framingham risk score. Patients with marijuana consumption had significantly higher levels of PCSK9 with a dose-response effect (p < 0.001); the association persisted after adjustment for the calculated Framingham risk score (p=0.003) and additional adjustment for clinical variables (p=0.027). CONCLUSIONS: In HIV-infected individuals naïve of statin treatment, marijuana consumption and low CD4 values are associated with higher PCSK9 levels independently of clinically relevant confounding factors.

Involvement of gap junctional communication in secretion.

Glands were the first type of tissues in which the permissive role of gap junctions in the cell-to-cell transfer of membrane-impermeant molecules was shown. During the 40 years that have followed this seminal finding, gap junctions have been documented in all types of multicellular secretory systems, whether of the exocrine, endocrine or pheromonal nature. Also, compelling evidence now indicates that gap junction-mediated coupling, and/or the connexin proteins per se, play significant regulatory roles in various aspects of gland functions, ranging from the biosynthesis, storage and release of a variety of secretory products, to the control of the growth and differentiation of secretory cells, and to the regulation of gland morphogenesis. This review summarizes this evidence in the light of recent reports.

Connexin36 and pancreatic beta-cell functions.

Most cell types are functionally coupled by connexin (Cx) channels, i.e. exchange cytoplasmic ions and small metabolites through gap junction domains of their membrane. This form of direct cell-to-cell communication occurs in all existing animals, whatever their position in the phylogenetic scale, and up to humans. Pancreatic beta-cells are no exception, and normally cross-talk with their neighbors via channels made of Cx36. These exchanges importantly contribute to coordinate and synchronize the function of individual cells within pancreatic islets, particularly in the context of glucose-induced insulin secretion. Compelling evidence now indicates that Cx36-mediated coupling, and/or the Cx36 protein per se, play significant regulatory roles in various beta-cell functions, ranging from the biosynthesis, storage and release of insulin. Recent preliminary data further suggest that the protein may also be implicated in the balance of beta-cell growth versus necrosis and apoptosis, and in the regulated expression of specific genes. Here, we review this evidence, discuss the possible involvement of Cx36 in the pathophysiology of diabetes, and evaluate the relevance of this connexin in the therapeutic approaches to the disease.

The intercellular synchronization of Ca2+ oscillations evaluates Cx36-dependent coupling.

Connexin36 (Cx36) plays an important role in insulin secretion by controlling the intercellular synchronization of Ca(2+) transients induced during stimulation. The lack of drugs acting on Cx36 channels is a major limitation in further unraveling the molecular mechanism underlying this effect. To screen for such drugs, we have developed an assay allowing for a semi-automatic, fluorimetric quantification of Ca(2+) transients in large populations of MIN6 cells. Here, we show that (1) compared to control cells, MIN6 cells with reduced Cx36 expression or function showed decreased synchrony of glucose-induced Ca(2+) oscillations; (2) glibenclamide, a sulphonylurea which promotes Cx36 junctions and coupling, increased the number of synchronous MIN6 cells, whereas quinine, an antimalarial drug which inhibits Cx36-dependent coupling, decreased this proportion; (3) several drugs were identified that altered the intercellular Ca(2+) synchronization, cell coupling and distribution of Cx36; (4) some of them also affected insulin content. The data indicate that the intercellular synchronization of Ca(2+) oscillations provides a reliable and non-invasive measurement of Cx36-dependent coupling, which is useful to identify novel drugs affecting the function of ß-cells, neurons, and neuron-related cells that express Cx36.

Lack of "hemichannel" activity in insulin-producing cells.

Connexins and pannexins have been implicated in the formation of "hemichannels," which may account for the uptake and release of membrane-impermeant molecules in single cells. The in vivo existence of "hemichannels" and their protein composition is still debated. Investigations on these matters are complicated by the lack of adequate negative controls. In search for such essential controls, the authors have investigated transformed (MIN6 line) and primary insulin-producing cells. Here, the authors report that these cells, which express Cx36 and pannexin 1, cannot be shown to display functional "hemichannels," as evaluated by (1) uptake of the membrane-impermeant tracer ethidium bromide, whether in the presence or absence of extracellular Ca(2+), following stimulation of P2X(7) receptors, and after exposure to hypotonic medium; and (2) lack of exocytosis-independent release of endogenous ATP. Moreover, electrophysiological recordings indicated the absence of carbenoxolone-sensitive pannexin 1 currents evoked by membrane potentials above +30 mV. Thus, insulin-producing cells are expected to provide a useful tool in the further characterization of hemichannel composition, properties, and physiological relevance.