Cancer du sein : la pathologie, pierre angulaire de la décision therapeutique [Breast cancer: pathology, the cornerstone of therapeutic decision]

Tailoring adjuvant therapy in breast cancer patients relies on prognostic and predictive factors, most of which are currently established by histopathological analysis of tumors. The quality of the assessment of the former (i.e.: tumor size, lymph node status, tumor grade, HER2 status, and lymphovascular invasion) and the latter (estrogen and progesteron receptors expression, HER2 overexpression or amplification) is an essential prerequisite for an optimal therapeutic decision. If the prognostic and predictive values of multigenes signatures are confirmed by on-going clinical studies, this approach could enter the clinical practice in the coming years and result in improved accuracy of adjuvant therapies in breast cancer patients. This approach might especially allow avoiding overtreatment in patients at low risk of recurrence.

Epithelial to mesenchymal transition in the pathogenesis of uterine malignant mixed Müllerian tumours: the role of ubiquitin proteasome system and therapeutic opportunities.

Malignant mixed Müllerian tumours (malignant mixed mesodermal tumours, MMMT) of the uterus are metaplastic carcinomas with a sarcomatous component and thus they are also called carcinosarcomas. It has now been accepted that the sarcomatous component is derived from epithelial elements that have undergone metaplasia. The process that produces this metaplasia is epithelial to mesenchymal transition (EMT), which has recently been described as a neoplasia-associated programme shared with embryonic development and enabling neoplastic cells to move and metastasise. The ubiquitin proteasome system (UPS) regulates the turnover and functions of hundreds of cellular proteins. It plays important roles in EMT by being involved in the regulation of several pathways participating in the execution of this metastasis-associated programme. In this review the specifi c role of UPS in EMT of MMMT is discussed and therapeutic opportunities from UPS manipulations are proposed.

Therapeutic Drug Monitoring (TDM) of Imatinib: Effectiveness of Bayesian dose adjustment for CML patients enrolled in the Imatinib Concentration Monitoring (I-COME) study

Introduction: As imatinib pharmacokinetics are highly variable, plasma levels differ largely between patients under the same dosage. Retrospective studies in chronic myeloid leukemia (CML) patients showed significant correlations between low levels and suboptimal response, as well as between high levels and poor tolerability. Monitoring of trough plasma levels, targeting 1000 μg/L and above, is thus increasingly advised. Our study was launched to assess prospectively the clinical usefulness of systematic imatinib TDM in CML patients. This preliminary analysis addresses the appropriateness of the dosage adjustment approach applied in this study, which targets the recommended trough level and allows an interval of 4-24 h after last drug intake for blood sampling. Methods: Blood samples from the first 15 patients undergoing 1st TDM were obtained 1.5-25 h after last dose. Imatinib plasma levels were measured by LC-MS/MS and the concentrations were extrapolated to trough based on a Bayesian approach using a population pharmacokinetic model. Trough levels were predicted to differ significantly from the target in 12 patients (10 <750 μg/L; 2 >1500 μg/L along with poor tolerance) and individual dose adjustments were proposed. 8 patients underwent a 2nd TDM cycle. Trough levels of 1st and 2nd TDM were compared, the sample drawn 1.5 h after last dose (during distribution phase) was excluded from the analysis. Results: Individual dose adjustments were applied in 6 patients. Observed concentrations extrapolated to trough ranged from 360 to 1832 μg/L (median 725; mean 810, CV 52%) on 1st TDM and from 720 to 1187 μg/L (median 950; mean 940, CV 18%) on 2nd TDM cycle. Conclusions: These preliminary results suggest that TDM of imatinib using a Bayesian interpretation is able to target the recommended trough level of 1000 μg/L and to reduce the considerable differences in trough level exposure between patients (with CV decreasing from 52% to 18%). While this may simplify blood collection in daily practice, as samples do not have to be drawn exactly at trough, the largest possible interval to last drug intake yet remains preferable to avoid sampling during distribution phase leading to biased extrapolation. This encourages the evaluation of the clinical benefit of a routine TDM intervention in CML patients, which the randomized Swiss I-COME trial aims to.

Automated analysis of background EEG and reactivity during therapeutic hypothermia in comatose patients after cardiac arrest.

Visual analysis of electroencephalography (EEG) background and reactivity during therapeutic hypothermia provides important outcome information, but is time-consuming and not always consistent between reviewers. Automated EEG analysis may help quantify the brain damage. Forty-six comatose patients in therapeutic hypothermia, after cardiac arrest, were included in the study. EEG background was quantified with burst-suppression ratio (BSR) and approximate entropy, both used to monitor anesthesia. Reactivity was detected through change in the power spectrum of signal before and after stimulation. Automatic results obtained almost perfect agreement (discontinuity) to substantial agreement (background reactivity) with a visual score from EEG-certified neurologists. Burst-suppression ratio was more suited to distinguish continuous EEG background from burst-suppression than approximate entropy in this specific population. Automatic EEG background and reactivity measures were significantly related to good and poor outcome. We conclude that quantitative EEG measurements can provide promising information regarding current state of the patient and clinical outcome, but further work is needed before routine application in a clinical setting.

Pyoderma gangrenosum: défi diagnostique et thérapeutique [Pyoderma gangrenosum: diagnostic and therapeutic challenge]

Pyoderma gangrenosum is a rare ulcerative disease associated with inflammatory bowel disease, arthritis or haematological malignancies. The diagnosis of Pyoderma gangrenosum is often delayed while consideration is given to the more likely diagnoses of wound breakdown or bacterial infection. The outcome depends on early diagnosis and on excellent collaboration between the surgical team and the infectious disease specialist. We present two puzzling cases of Pyoderma gangrenosum and discuss the physiopathology, the diagnosis strategy and the management. Le Pyoderma gangrenosum constitue une entité clinique méconnue, se présentant classiquement par des ulcérations cutanées inflammatoires et douloureuses. Le contexte clinique retrouve fréquemment une pathologie inflammatoire digestive, une néoplasie ou une atteinte rhumatologique concomitante. Le diagnostic est trop souvent tardif, après de multiples traitements antibiotiques et chirurgicaux, et nécessite une excellente coordination entre le médecin traitant, les équipes chirurgicales et les spécialistes des maladies infectieuses. Au travers de deux cas spectaculaires, nous rappelons quelques notions de base sur la physiopathologie, la présentation clinique et la prise en charge du Pyoderma gangrenosum.

Immunothérapie: une nouvelle arme contre le cancer de la prostate [Immunotherapy: a therapeutic revolution against prostate cancer?].

The interaction between the immune system and cancer was an area of research interest for several decades. The recent U.S. Food and Drug Administration approval of sipuleucel-T and ipilimumab stimulated broader interest in manipulating immunity to fight cancer. In the context of prostate cancer, the immunotherapy strategies under development are therapeutic vaccination strategies, such as sipuleucel-T and PROSTVAC-VF, or immune checkpoint blockade of CTLA-4. Improved understanding of the immune responses generated by the development of predictive biomarkers for patient selection will guide rational combinations of these treatments and provide new treatment options in prostate cancer.

A qui administrer le vaccin anti-pneumococcique? [We should received and pneumococcal immunization?]

Alors que l'immunisation active contre l'influenza semble être actuellement largement entrée dans la pratique médicale, force est de constater que c'est loin d'être le cas pour les infections à pneumocoque. La vaccination anti-pneumocoque. La vaccination anti-pneumococcique, qui est incluse dans les schémas d'immunisation de nombreux pays, ne fait actuellement pas l'objet de recommendations particulières en Suisse et son utilisation y reste marginale. Compte tenu du nombre élevé d'infections sévères et de décès potentiellement évitables, sa généralisation à tous les groupes à risque doit être encouragée. De plus, cette stratégie pourrait se révéler utile face à la progression inexorable de la proportion de souches résistantes à la pénicilline et aux autres microbes.

Rôle des molécules de co-stimulations et de CD93 dans la différenciation en plasmocytes

Le développement des cellules B est constitué d'une première phase qui se déroule dans la moelle en absence d'antigène et d'une deuxième phase qui se déroule dans les organes lymphoïdes secondaires et qui débute uniquement en présence d'antigène. Cette deuxième partie est extrêmement importante et doit être très bien régulée pour lutter efficacement contre les pathogènes, ainsi que pour éviter de nombreuses maladies de type auto-immunes. Ce travail est basé à l'origine sur l'étude de souris mutantes dans lesquelles une protéine des cellules T est modifiée, impliquant une très forte activation des cellules B en absence d'antigène et de manière non spécifique. Ces souris constituent donc un outil de travail très intéressant pour étudier tout d'abord le mécanisme aboutissant à l'activation des cellules B dans ce contexte particulier. De plus comme ces souris contiennent énormément de cellules sécrétant des anticorps, à savoir les plasmocytes, il est facile d'étudier leur phénotype. Cela nous a permis de démontrer qu'un récepteur membranaire, CD93 est exprimé à leur surface. Cette observation a ensuite été confirmée dans des souris normales, de type sauvage. L'utilisation de ce marqueur de surface nous a permis de caractériser plus en détail les étapes du développement des plasmocytes. De plus nous avons tenté de trouver la fonction jouée par cette molécule à la surface de ces cellules, en utilisant des souris dans lesquelles ce récepteur a été supprimé. Si les premières étapes de l'activation des cellules B étaient normales, ces souris n'étaient par contre pas capables de produire des anticorps à long-terme dans le sang. Nous avons pu montrer que la survie des plasmocytes en l'absence de CD93 est moins efficace dans la moelle, probablement du au fait qu'en absence de cette molécule, les plasmocytes ont plus de difficultés à adhérer dans ce que l'on appelle des niches de survie. Nous avons essayé ensuite de déterminer si CD93 peut être utilisé comme cible thérapeutique dans le cadre de maladies auto-immunes ou de lymphomes. Bien que CD93 soit exprimé à la surface des cellules d'intérêt dans les souris souffrant de lupus, il n'a pas été possible de les éliminer avec un anticorps dirigé contre CD93. De plus nous n'avons pas pu mettre en évidence l'expression de CD93 à la surface des plasmocytes humains induits in vitro. SUMMARY : Antigen dependent B cell activation is a key aspect of the adaptive immunity which is involved in the efficient response against pathogens, but also in vaccination and in numerous pathologies. The aim of this project was to investigate two key aspects of the late B cell development, namely the role of costimulatory molecules in the immunological synapse between T and B cells and the characterization of a new plasma cell marker, CD93. This work was initially based on the study of the LatY136F mutant mouse. The latter harbors a point mutation in the LAT adaptor protein which is involved in T cell receptor signaling. As a consequence of this mutation, CD4 T cells in the periphery expand strongly and are polarized in a TH2 manner leading to a normal but exaggerated B cell response. For this reason, these mice provide a useful tool to investigate different aspects of the late B cell development. The first part of the project was focused on the role played by costimulatory molecules in LotY136F CD4 T cell mediated B cell activation. In vitro studies showed that CD80/CD86, IL-4 and LFA-1 were required for LatY136FT cells to activate B cells whereas CD40 and IcosL were not necessary. In vivo we showed that CD80/CD86 was required for initial T cell expansion whereas CD40 and IcosL deficiency led to a less efficient B cell activation. The large amount of plasma cells present in LatY136F mice allows investigating in more details their phenotype and CD93 was found to be expressed on their surface, This observation was confirmed in wild type B cells activated either in vivo or in vitro with T-independent or T-dependent antigens. Moreover we found that CD93 expression can occur either before CD138/Blimp-1 induction or after, showing that two independent pathways can lead to the formation of CD93/CD138 double positive population, which was shown to be the more mature. Indeed, their phenotype correlated with modified transcriptional network, high isotype switched antibody secretion and cell cycle arrest. Analysis of CD93 deficient mice demonstrated that the initial B cell activation after immunization was normal, but also showed that these mice failed to maintain a high antibody secretion level at later time points both after primary and boost immunization. This was shown to be due to a less efficient survival of the long-lived plasma cells in the bone marrow niches, most likely related with a defective adhesion process in absence of CD93. We investigated the possibility to use CD93 as a target to treat plasma cell pathologies, but even if this molecule is expressed on cells of interest in the bone marrow of lupus mice, it was not possible to deplete them using anti-CD93 antibodies. Moreover we were not able to show its expression on the surface of in vitro activated B cells and multiple myeloma cell lines of human origin. In conclusion, our data helped understand both the mechanisms leading to the polyclonal B cell activation occurring in the LatY136F KI mouse and the role played by CD93 on the surface of plasma cells, which could potentially open the way to therapeutic application.

Between Cultures: The Dyadic and Triadic Therapeutic Alliance in Multicultural Setting

Many researchers have identified the therapeutic alliance (TA) as the main factor that predicts psychotherapeutic success regardless the type of approach or treatment. In a multicultural setting, the construction of the therapeutic alliance is accompanied by elements that specially influence the flow of the interaction. Some examples of these elements are language, cultural beliefs, and traditions. For Hispanic-American clients in Lausanne (Switzerland), this encounter could take place in a dyadic setting, in the presence of a therapist who speaks Spanish and shares or not the client's culture of origin. On the other hand, it can take place in a triadic setting, in the presence of a therapist who does not speak Spanish and an interpreter that serves as a communication bridge. This present project has the purpose of studying the TA between different health professionals and the Hispanic- American clients who are assisted with and without an interpreter in Lausanne's health system. My goal is to study this relationship in the clients' context (many of them are clandestine) and based on their perception and subjective experience through a quantitative and qualitative complementary methodology. Because this project is in progress, this communication will focus on presenting the population's socio-demographic characteristics, the research questionings, methodology, and preliminary results.This project can enhance our knowledge about relationships between two cultures in a therapeutic encounter (psychological/psychiatric or medical). At the same time, it can bring us a better understanding about the migration movements of Hispanic-Americans in Switzerland.

Multiplex liquid chromatography-tandem mass spectrometry assay for simultaneous therapeutic drug monitoring of ribavirin, boceprevir, and telaprevir.

New directly acting antivirals (DAAs) that inhibit hepatitis C virus (HCV) replication are increasingly used for the treatment of chronic hepatitis C. A marked pharmacokinetic variability and a high potential for drug-drug interactions between DAAs and numerous drug classes have been identified. In addition, ribavirin (RBV), commonly associated with hemolytic anemia, often requires dose adjustment, advocating for therapeutic drug monitoring (TDM) in patients under combined antiviral therapy. However, an assay for the simultaneous analysis of RBV and DAAs constitutes an analytical challenge because of the large differences in polarity among these drugs, ranging from hydrophilic (RBV) to highly lipophilic (telaprevir [TVR]). Moreover, TVR is characterized by erratic behavior on standard octadecyl-based reversed-phase column chromatography and must be separated from VRT-127394, its inactive C-21 epimer metabolite. We have developed a convenient assay employing simple plasma protein precipitation, followed by high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) for the simultaneous determination of levels of RBV, boceprevir, and TVR, as well as its metabolite VRT-127394, in plasma. This new, simple, rapid, and robust HPLC-MS/MS assay offers an efficient method of real-time TDM aimed at maximizing efficacy while minimizing the toxicity of antiviral therapy.