Hemoglobin curves during pregnancy before and after fortification of flours with iron

Objective: To assess the level of hemoglobin-Hb during pregnancy before and after fortification of flours with iron. Method: A cross-sectional study with data from 12,119 pregnant women attended at a public prenatal from five macro regions of Brazil. The sample was divided into two groups: Before-fortification (birth before June/2004) and After-fortification (last menstruation after June/2005). Hb curves were compared with national and international references. Polynomial regression models were built, with a significance level of 5%. Results: Although the higher levels of Hb in all gestational months after-fortification, the polynomial regression did not show the fortification effect (p=0.3). Curves in the two groups were above the references in the first trimester, with following decrease and stabilization at the end of pregnancy. Conclusion: Although the fortification effect was not confirmed, the study presents variation of Hb levels during pregnancy, which is important for assistencial practice and evaluation of public policies.


Segundo Inquérito Demográfico e de Saúde Reprodutiva

O Inquérito Demográfico e de Saúde Reprodutiva (IDSR-II) é o segundo inquérito do género realizado em Cabo Verde. Trata-se de uma pesquisa por sondagem, executada pelo INE e pelo Ministério da Saúde. Tem como objectivo fornecer informações sobre a fecundidade, a mortalidade das crianças menores de cinco anos, o planeamento familiar, a saúde materna e infantil, as IST, o VIH/SIDA, e a violência doméstica. A inovação em relação ao primeiro IDSR, realizado em 1998, provém do facto de permitir, através da introdução do teste do VIH e da análise da hemoglobina, medir a prevalência do VIH e da anemia. Durante o inquérito, realizado de Julho a Novembro de 2005, foram entrevistados com sucesso 5 712 agregados familiares, 5 505 mulheres dos 15-49 anos e 2 644 homens dos 15-59 anos, seleccionados na metade dos agregados. Foi nestes agregados que se realizou o teste do VIH e a análise de hemoglobina. A violência doméstica contemplou um terço dos agregados, nos quais foram entrevistadas 1 333 mulheres. As informações recolhidas são significativas a nível nacional, por meio de residência urbano e rural e a nível dos 11 domínios de estudo: a cidade da Praia, Santiago Norte, o Resto de Santiago e as 8 restantes ilhas constituem cada,um domínio de estudo.

Parameters for successful monthly extended dosing of darbepoetin-alpha in patients undergoing hemodialysis.

AIM: To document the feasibility and report the results of dosing darbepoetin-alpha at extended intervals up to once monthly (QM) in a large dialysis patient population. MATERIAL: 175 adult patients treated, at 23 Swiss hemodialysis centres, with stable doses of any erythropoiesis-stimulating agent who were switched by their physicians to darbepoetin-alpha treatment at prolonged dosing intervals (every 2 weeks [Q2W] or QM). METHOD: Multicentre, prospective, observational study. Patients' hemoglobin (Hb) levels and other data were recorded 1 month before conversion (baseline) to an extended darbepoetin-alpha dosing interval, at the time of conversion, and once monthly thereafter up to the evaluation point (maximum of 12 months or until loss to follow-up). RESULTS: Data for 161 evaluable patients from 23 sites were included in the final analysis. At 1 month prior to conversion, 73% of these patients were receiving darbepoetin-alpha weekly (QW) and 27% of the patients biweekly (Q2W). After a mean follow-up of 9.5 months, 34% received a monthly (QM) dosing regimen, 52% of the patients were receiving darbepoetin-alpha Q2W, and 14% QW. The mean (SD) Hb concentration at baseline was 12.3 +/- 1.2 g/dl, compared to 11.9 +/- 1.2 g/dl at the evaluation point. The corresponding mean weekly darbepoetin-alpha dose was 44.3 +/- 33.4 microg at baseline and 37.7 +/- 30.8 microg at the evaluation point. CONCLUSIONS: Conversion to extended darbepoetin-alpha dosing intervals of up to QM, with maintenance of initial Hb concentrations, was successful for the majority of stable dialysis patients.

A Multi-Center Phase II Study (SAKK 36/06) of Single Agent Everolimus (RAD001) In Patients with Relapsed or Refractory Mantle Cell Lymphoma

Introduction: Mantle cell lymphoma (MCL) accounts for 6% of all B-cell lymphomas and remains incurable for most patients. Those who relapse after first line therapy or hematopoietic stem cell transplantation have a dismal prognosis with short response duration after salvage therapy. On a molecular level, MCL is characterised by the translocation t[11;14] leading to Cyclin D1 overexpression. Cyclin D1 is downstream of the mammalian target of rapamycin (mTOR) kinase and can be effectively blocked by mTOR inhibitors such as temsirolimus. We set out to define the single agent activity of the orally available mTOR inhibitor everolimus (RAD001) in a prospective, multi-centre trial in patients with relapsed or refractory MCL (NCT00516412). The study was performed in collaboration with the EU-MCL network. Methods: Eligible patients with histologically/cytologically confirmed relapsed (not more than 3 prior lines of systemic treatment) or refractory MCL received everolimus 10 mg orally daily on day 1 - 28 of each cycle (4 weeks) for 6 cycles or until disease progression. The primary endpoint was the best objective response with adverse reactions, time to progression (TTP), time to treatment failure, response duration and molecular response as secondary endpoints. A response rate of ≤ 10% was considered uninteresting and, conversely, promising if ≥ 30%. The required sample size was 35 pts using the Simon's optimal two-stage design with 90% power and 5% significance. Results: A total of 36 patients with 35 evaluable patients from 19 centers were enrolled between August 2007 and January 2010. The median age was 69.4 years (range 40.1 to 84.9 years), with 22 males and 13 females. Thirty patients presented with relapsed and 5 with refractory MCL with a median of two prior therapies. Treatment was generally well tolerated with anemia (11%), thrombocytopenia (11%), neutropenia (8%), diarrhea (3%) and fatigue (3%) being the most frequent complications of CTC grade III or higher. Eighteen patients received 6 or more cycles of everolimus treatment. The objective response rate was 20% (95% CI: 8-37%) with 2 CR, 5 PR, 17 SD, and 11 PD. At a median follow-up of 6 months, TTP was 5.45 months (95% CI: 2.8-8.2 months) for the entire population and 10.6 months for the 18 patients receiving 6 or more cycles of treatment. Conclusion: This study demonstrates that single agent everolimus 10 mg once daily orally is well tolerated. The null hypothesis of inactivity could be rejected indicating a moderate anti-lymphoma activity in relapsed/refractory MCL. Further studies of either everolimus in combination with chemotherapy or as single agent for maintenance treatment are warranted in MCL.

Epigenetic deregulation of DNA repair and its potential for therapy.

Epigenetic silencing of essential components of DNA repair pathways is a common event in many tumor types, and comprise O6-methylguanine-DNA methyltransferase (MGMT), human mut L homolog 1 (hMLH1), Werner syndrome gene (WRN), breast cancer susceptibility gene 1 (BRCA1), and genes of the Fanconi anemia pathway. Most interestingly, some of these alterations become the Achilles heel of the affected tumors upon treatment with certain classes of anticancer agents. That is, patients whose tumors carry such defects can be stratified for respective therapy rendering some classic DNA damaging agents, such as alkylators or DNA crosslinking agents, into "targeted therapies." Here we review some of the affected repair pathways that, when inactivated, sensitize the tumors to specific drugs and are thus exploitable for individualized therapy.

A multicenter phase II study (SAKK 36/06) of single-agent everolimus (RAD001) in patients with relapsed or refractory mantle cell lymphoma

Introduction: Mantle cell lymphoma (MCL) accounts for 6% of all B-cell lymphomas and is in most cases an incurable disease. It is characterized by the translocation t(11;14) leading to Cyclin D1 over-expression. Cyclin D1 is downstream of the mammalian target of rapamycin (mTOR) threonine kinase and can be effectively blocked by mTOR inhibitors. We set out to define the single agent activity of the orally available mTOR inhibitor everolimus in a prospective, multicentre trial in patients with relapsed or refractory MCL (NCT00516412).Methods: Eligible patients with confirmed relapsed or refractory MCL received everolimus 10 mg for 28 days (one cycle) for a total of 6 cycles or until disease progression. The primary endpoint was the best objective response (OR) with adverse reactions, time to progression (TTP), time to treatment failure, response duration and molecular response as secondary endpoints.Results: A total of 36 patients with 35 evaluable patients at a median age of 69 years (range 40 to 85 years) from 19 centers were enrolled between August 2007 and January 2010. Treatment was generally well tolerated with anemia (11%), thrombocytopenia (11%), neutropenia (8%), diarrhea (3%) and fatigue (3%) being the most frequent complications of CTC grade 3 or higher. The OR rate was 20% (95% CI: 8-37%) with 2 complete remissions (CR) and 5 partial response (PR), stable disease (SD) 48% and progression disease (PD) 28%. At a median follow-up of 6 months, TTP was 5.45 months (95% CI: 2.8-8.2 months) for the entire population and 10.6 months for the 18 patients receiving 6 or more cycles of treatment. Three patients achieved a lasting complete molecular response when assessed in the peripheral blood.Conclusion: This study demonstrates that single agent everolimus is well tolerated and has anti-lymphoma activity including lasting molecular responses. Further studies of everolimus either in combination with chemotherapy or as single agent for maintenance treatment are warranted in MCL.

Clinical evaluation of iron treatment efficiency among non-anemic but iron-deficient female blood donors: a randomized controlled trial.

ABSTRACT: Iron deficiency without anemia (IDWA) is related to adverse symptoms that can be relieved by supplementation. Since a blood donation can induce such an iron deficiency, we investigated the clinical impact of an iron treatment after blood donation. METHODS: One week after donation, we randomly assigned 154 female donors with IDWA aged <50 years to a 4-week oral treatment of ferrous sulfate vs. placebo. The main outcome was the change in the level of fatigue before and after the intervention. Also evaluated were aerobic capacity, mood disorder, quality of life, compliance and adverse events. Biological markers were hemoglobin and ferritin. RESULTS: Treatment effect from baseline to 4 weeks for hemoglobin and ferritin were 5.2 g/L (p < 0.01) and 14.8 ng/mL (p < 0.01) respectively. No significant clinical effect was observed for fatigue (-0.15 points, 95% confidence interval -0.9 to 0.6, p = 0.697) or for other outcomes. Compliance and interruption for side effects was similar in both groups. Additionally, blood donation did not induce overt symptoms of fatigue in spite of the significant biological changes it produces. CONCLUSIONS: These data are valuable as they enable us to conclude that donors with IDWA after a blood donation would not clinically benefit from iron supplementation. Trial registration: NCT00689793.

Une dyspnée pas comme les autres, ou quand on parle du loup.. [Unusual cause for a dyspnea.].

We report the case of a patient presenting with late onset systemic lupus erythematosus presenting as a haemolytic anemia and pleuritis. We describe the clinical features, diagnosis, prognosis and treatment of the disease with special focus on haematological and pulmonary involvement.

Estudo de Prevalência de Parasitas Intestinais nas crianças dos 2 a 12 anos da Comunidade de Rincão – Santa Catarina.

As parasitoses intestinais constituem um grave problema de saúde pública, sobretudo nos países em desenvolvimento, sendo uma das principais causas de morbimortalidade no Mundo ( NEVES, 2005) . Segundo a Organização Mundial da Saúde ( OMS/WHO ) , mais de 2 bilhões de pessoas são infetados por protozoários intestinais e helmintos no mundo ( OMS, 2010) . Estima-se que mais de 10% da população mundial esteja infetada por E. histolytica E. dispar, sendo a ocorrência estimada em 50 milhões de casos invasivos/ano. Amebas como Entamoeba coli, Endolimax nana e Iodamoeba butschilii, são encontradas nas fezes com frequência em todos os países do mundo, apesar de não serem consideraras patogénicas ao homem em condições normais, devem ser identificadas nas análises parasitológico das fezes por serem indicadores do nível de saneamento ( OMS, 2010) .Dos helmintos intestinais mais frequentes no mundo e que causam maiores problemas de saúde pública, destacam-se Ascaris lumbricoides ( 1 bilhão ) , Trichuris trichiura ( 795 milhões) e Ancylostoma sp. ( 740 milhões) . As maiores taxas de infeção e transmissão por helmintos ocorrem na África subsaariana, América Latina, China e leste da Ásia ( OMS, 2010) . Os parasitas intestinais correspondem a uma das principais causas de má nutrição infantil, podendo levar ao retardamento no desenvolvimento físico e mental das crianças que na idade pré-escolar e escolar estão mais sujeitas às infeções parasitárias, por não possuírem ainda consciência dos hábitos corretos de higiene e por terem o sistema imune ainda em formação ( GRAY et al., 1994) . Este trabalho teve como objetivo determinar a prevalência das parasitoses intestinais que afetam as crianças da comunidade de Rincão/Santa Catarina, Ilha de Santiago, Cabo Verde.

Estudo de Prevalência de Parasitas Intestinais nas crianças dos 2 a 12 anos da Comunidade de Rincão – Santa Catarina.

Os parasitas intestinais continuam a ser um problema de saúde pública em Cabo Verde, principalmente nas comunidades onde as condições sócio-económicos e ambientais favorecem o desenvolvimento destes. Segundo a Organização Mundial da Saúde (OMS/WHO), mais de 2 bilhões de pessoas são infectados por protozoários intestinais e helmintos no mundo (OMS, 2010). Estima-se que mais de 10% da população mundial esteja infectada por E. histolytica/ E. dispar, e as amebas não patogénicas mais encontradas em fezes humanas em todo mundo destcam-se Entamoeba coli, Endolimax nana e Iodamoeba butschilii. Dos helmintos intestinais mais frequentes no mundo destacam-se Ascaris lumbricoides (1 bilhão), Trichuris trichiura (795 milhões) e Ancylostoma sp. (740 milhões), com maiores taxas de infecção e transmissão na África sub-saariana, América Latina, China e leste da Ásia (OMS, 2010). O presente trabalho teve como objectivo, determinar a prevalência das parasitoses intestinais que afectam as crianças dos 2 a 12 anos da comunidade de Rincão/Santa Catarina, na ilha de Santiago, Cabo Verde e aprovado pelo Comité Nacional de Ética para Pesquisa em Saúde (CNEPS). Os trabalhos de campo decorreram entre Junho a Outubro de 2011. As amostras foram analisadas na Unidade Sanitária Base de Rincão e no Laboratório análises Clínica do Hospital Regional Santiago Norte. De acordo com os resultados obtidos nesse estudo, existe uma alta prevalência de parasitas intestinais nas crianças da comunidade em estudo, havendo necessidade de expandir estudos do género à outras comunidades do país, apostando na educação sanitária e campanhas de desparasitação. A alta taxa de anemia encontrada, é um aspecto que deverá ser continuamente estudada, de forma a determinar as causas relacionadas com a alta prevalência de anemia no país, que segundo a classificação da magnitude da anemia da OMS é grave.

A critical review of the molecular pathophysiology of lenalidomide sensitivity in 5q - myelodysplastic syndromes.

Abstract The 5q deletion is a chromosomal abnormality that is observed in a subset of myelodysplastic syndromes (MDS). When isolated, this abnormality defines a specific clinical syndrome termed MDS associated with isolated deletion 5q, presenting with macrocytic anemia, normal platelet count or slight thrombocytosis, hypolobated megakaryocytes and fewer than 5% blasts in the bone marrow. MDS with the 5q deletion have a particular sensitivity to treatment with lenalidomide, a thalidomide analog. In this article, molecular changes in 5q- MDS derived from haploinsufficiency of genes encoded from the deleted region in 5q are reviewed, and mechanisms that link these molecular lesions with lenalidomide sensitivity are proposed.

Iron supplementation in a large Swiss cohort of IBD patients demonstrates a shift from oral to intravenous iron over time

Background: The 2007 European Crohn's and Colitis Organization guidelines on anemia in inflammatory bowel disease (IBD) favour intravenous (iv) over oral (po) iron supplementation due to better effectiveness and tolerance. We aimed to determine the percentage of IBD patients under iron supplementation therapy and the dynamics of prescription habits (iv versus po) over time. Methods: Helsana, a leading Swiss health insurance company provides coverage for approximately 18% of the Swiss population, corresponding to about 1.2 million enrollees. Patients with Crohn's disease (CD) and ulcerative colitis (UC) were analyzed from the anonymised Helsana database. Results: In total, 629 CD (61% female) and 398 UC (57% female) patients were identified, mean observation time was 31.8 months for CD and 31.0 months for UC patients. Of the entire study population, 27.1% were prescribed iron (21.1% in males and 31.1% in females). Patients treated with IBDspecific drugs (steroids, immunomodulators, anti-TNF agents) were more frequently treated with iron compared to patients without any medication (35.0% vs. 20.9%, OR 1.91, 95%- CI 1.41 2.61). The prescription of iv iron increased from 2006/2007 (48.8% of all patients receiving any iron priscription) to 65.2% in 2008/2009 by a factor of 1.89. Conclusions: One third of the IBD population was treated with iron supplementation. A gradual shift from oral to iv iron was observed over time. This switch in prescription habits goes along with the implementation of the ECCO consensus guidelines on anemia in IBD.

5-Azacytidine to Treat Acute Myeloid Leukemia In Elderly or Frail Patients: A Phase II Study (SAKK 30/07).

Background: Acute Myeloid Leukemia (AML) in the elderly is notoriously difficult to treat and has a low remission rate with very few long term survivors when using standard treatment approaches. Azacytidine, a hypomethylating agent, has been shown to induce remission and prolong survival in patients with myelodysplastic syndromes; studying this approach to patients with AML is therefore warranted. We present results of an ongoing phase II trial treating elderly or frail AML patients with Azacytidine. Methods: AML elderly or frail patients, and therefore unfit for an intensive chemotherapy regimens, with a WHO performance status 3 were considered for this trial. Trial therapy consisted of 100mg/m2 of Azacytidine injected subcutaneously on 5 consecutive days every 28 days up to 6 cycles, stopping at 6 months if no hematological improvement achieved, or earlier in the case of progression or complications. Treatment was continued beyond 6 months in responding patients. Trial therapy was considered uninteresting if the response rate (CR + PR) within 6 months of therapy initiation was 15% or less and promising if 34% or more. Using the exact single-stage phase II design by A'Hern with a 5% significance level and 90% power, 43 patients were required: If 10 or fewer achieved a response within 6 months the trial therapy should not be considered for further investigation in its current format for this indication and patient population. Results: Between September 2008 and January 2010, 45 evaluable patients across 10 Swiss centers were accrued with a median follow-up of 7 months (range: 0 - 13). 27 (60%) were male, median age was 74 (range: 55 - 86) years and 35 (78.8%) had performance status 0-1. Patients had been excluded from more intensive chemotherapy regimens because of age (n = 37) or due to comorbidities or patient refusal (n=8). Five patients had therapy related AML. Patients received a median of 3 (range: 1 - 10) cycles. Treatment was stopped for not achieving a response by the 6th cycle in 2 patients and earlier in 26 patients (for disease progression in 5, toxicity in 3, patient refusal in 2, recurrent infections in 1, and death in 8). Seventeen patients remain on therapy. The median time spent in the hospital was 12 days (1 - 30) in 24/38 patients hospitalized during the first treatment cycle and 13 days (2 - 28) in 15/31 patients hospitalized during subsequent cycles. Adverse events of grade III or higher most frequently reported were constitutional or hematologic, i.e. fatigue in 5, febrile neutropenia in 8, infections in 6, dyspnea in 6, anemia in 3, neutropenia in 12 and thrombocytopenia in 10, hemorrhage in 2 and retinal detachment in 5. Based on available data on 38 patients, CR/CRi or hematologic improvement or stable disease within 6 months of trial registration was observed in a proportion of patients. Final and mature data, determining whether the predefined proportion of responding patients has been reached or not, will be presented at the conference. Up to now there were a total of 26 deaths. Median overall survival time was 5.7 months (95% CI: 3.1, 8.7). Conclusions: The current results of this slightly modified Azacytidine schedule demonstrate a feasible new therapy option for elderly or frail AML patients in an outpatient setting with moderate, mainly hematologic toxicity.

A cell therapy approach for erythropoietin delivery using encapsulated human primary fibroblasts

Summary Cell therapy has emerged as a strategy for the treatment of various human diseases. Cells can be transplanted considering their morphological and functional properties to restore a tissue damage, as represented by blood transfusion, bone marrow or pancreatic islet cells transplantation. With the advent of the gene therapy, cells also were used as biological supports for the production of therapeutic molecules that can act either locally or at distance. This strategy represents the basis of ex vivo gene therapy characterized by the removal of cells from an organism, their genetic modification and their implantation into the same or another individual in a physiologically suitable location. The tissue or biological function damage dictates the type of cells chosen for implantation and the required function of the implanted cells. The general aim of this work was to develop an ex vivo gene therapy approach for the secretion of erythropoietin (Epo) in patients suffering from Epo-responsive anemia, thus extending to humans, studies previously performed with mouse cells transplanted in mice and rats. Considering the potential clinical application, allogeneic primary human cells were chosen for practical and safety reasons. In contrast to autologous cells, the use of allogeneic cells allows to characterize a cell lineage that can be further transplanted in many individuals. Furthermore allogeneic cells avoid the potential risk of zoonosis encountered with xenogeneic cells. Accordingly, the immune reaction against this allogeneic source was prevented by cell macro- encapsulation that prevents cell-to-cell contact with the host immune system and allows to easy retrieve the implanted device. The first step consisted in testing the survival of various human primary cells that were encapsulated and implanted for one month in the subcutaneous tissue of immunocompetent and naturally or therapeutically immunodepressed mice, assuming that xenogeneic applications constitute a stringent and representative screening before human transplantation. A fibroblast lineage from the foreskin of a young donor, DARC 3.1 cells, showed the highest mean survival score. We have then performed studies to optimize the manufacturing procedures of the encapsulation device for successful engraftment. The development of calcifications on the polyvinyl alcohol (PVA) matrix serving as a scaffold for enclosed cells into the hollow fiber devices was reported after one month in vivo. Various parameters, including matrix rinsing solutions, batches of PVA and cell lineages were assessed for their respective role in the development of the phenomenon. We observed that the calcifications could be totally prevented by using ultra-pure sterile water instead of phosphate buffer saline solution in the rinsing procedure of the PVA matrix. Moreover, a higher lactate dehydrogenase activity of the cells was found to decrease calcium depositions due to more acidic microenvironment, inhibiting the calcium precipitation. After the selection of the appropriate cell lineage and the optimization of encapsulation conditions, a retroviral-based approach was applied to DARC 3.1 fibroblasts for the transduction of the human Epo cDNA. Various modifications of the retroviral vector and the infection conditions were performed to obtain clinically relevant levels of human Epo. The insertion of a post-transcriptional regulatory element from the woodchuck hepatitis virus as well as of a Kozak consensus sequence led to a 7.5-fold increase in transgene expression. Human Epo production was further optimized by increasing the multiplicity of infection and by selecting high producer cells allowing to reach 200 IU hEpo/10E6 cells /day. These modified cells were encapsulated and implanted in vivo in the same conditions as previously described. All the mouse strains showed a sustained increase in their hematocrit and a high proportion of viable cells were observed after retrieval of the capsules. Finally, in the perspective of human application, a syngeneic model using encapsulated murine myoblasts transplanted in mice was realized to investigate the roles of both the host immune response and the cells metabolic requirements. Various loading densities and anti-inflammatory as well as immunosuppressive drugs were studied. The results showed that an immune process is responsible of cell death in capsules loaded at high cell density. A supporting matrix of PVA was shown to limit the cell density and to avoid early metabolic cell death, preventing therefore the immune reaction. This study has led to the development of encapsulated cells of human origin producing clinically relevant amounts of human EPO. This work resulted also to the optimization of cell encapsulation technical parameters allowing to begin a clinical application in end-stage renal failure patients. Résumé La thérapie cellulaire s'est imposée comme une stratégie de traitement potentiel pour diverses maladies. Si l'on considère leur morphologie et leur fonction, les cellules peuvent être transplantées dans le but de remplacer une perte tissulaire comme c'est le cas pour les transfusions sanguines ou les greffes de moelle osseuse ou de cellules pancréatiques. Avec le développement de la thérapie génique, les cellules sont également devenues des supports biologiques pour la production de molécules thérapeutiques. Cette stratégie représente le fondement de la thérapie génique ex vivo, caractérisée par le prélèvement de cellules d'un organisme, leur modification génétique et leur implantation dans le même individu ou dans un autre organisme. Le choix du type de cellule et la fonction qu'elle doit remplir pour un traitement spécifique dépend du tissu ou de la fonction biologique atteintes. Le but général de ce travail est de développer .une approche par thérapie génique ex vivo de sécrétion d'érythropoïétine (Epo) chez des patients souffrant d'anémie, prolongeant ainsi des travaux réalisés avec des cellules murines implantées chez des souris et des rats. Dans cette perpective, notre choix s'est porté sur des cellules humaines primaires allogéniques. En effet, contrairement aux cellules autologues, une caractérisation unique de cellules allogéniques peut déboucher sur de nombreuses applications. Par ailleurs, l'emploi de cellules allogéniques permet d'éviter les riques de zoonose que l'on peut rencontrer avec des cellules xénogéniques. Afin de protéger les cellules allogéniques soumises à une réaction immunitaire, leur confinement dans des macro-capsules cylindriques avant leur implantation permet d'éviter leur contact avec les cellules immunitaires de l'hôte, et de les retrouver sans difficulté en cas d'intolérance ou d'effet secondaire. Dans un premier temps, nous avons évalué la survie de différentes lignées cellulaires humaines primaires, une fois encapsulées et implantées dans le tissu sous-cutané de souris, soit immunocompétentes, soit immunodéprimées naturellement ou par l'intermédiaire d'un immunosuppresseur. Ce modèle in vivo correspond à des conditions xénogéniques et représente par conséquent un environnement de loin plus hostile pour les cellules qu'une transplantation allogénique. Une lignée fibroblastique issue du prépuce d'un jeune enfant, nommée DARC 3 .1, a montré une remarquable résistance avec un score de survie moyen le plus élevé parmi les lignées testées. Par la suite, nous nous sommes intéressés aux paramètres intervenant dans la réalisation du système d'implantation afin d'optimaliser les conditions pour une meilleure adaptation des cellules à ce nouvel environnement. En effet, en raison de l'apparition, après un mois in vivo, de calcifications au niveau de la matrice de polyvinyl alcohol (PVA) servant de support aux cellules encapsulées, différents paramètres ont été étudiés, tels que les procédures de fabrication, les lots de PVA ou encore les lignées cellulaires encapsulées, afin de mettre en évidence leur rôle respectif dans la survenue de ce processus. Nous avons montré que l'apparition des calcifications peut être totalement prévenue par l'utilisation d'eau pure au lieu de tampon phosphaté lors du rinçage des matrices de PVA. De plus, nous avons observe qu'un taux de lactate déshydrogénase cellulaire élevé était corrélé avec une diminution des dépôts de calcium au sein de la matrice en raison d'un micro-environnement plus acide inhibant la précipitation du calcium. Après sélection de la lignée cellulaire appropriée et de l'optimisation des conditions d'encapsulation, une modification génétique des fibroblastes DARC 3.1 a été réalisée par une approche rétrovirale, permettant l'insertion de l'ADN du gène de l'Epo dans le génome cellulaire. Diverses modifications, tant au niveau génétique qu'au niveau des conditions d'infection, ont été entreprises afin d'obtenir des taux de sécrétion d'Epo cliniquement appropriés. L'insertion dans la séquence d'ADN d'un élément de régulation post¬transcriptionnelle dérivé du virus de l'hépatite du rongeur (« woodchuck ») ainsi que d'une séquence consensus appelée « Kozak » ont abouti à une augmentation de sécrétion d'Epo 7.5 fois plus importante. De même, l'optimisation de la multiplicité d'infection et la sélection plus drastique des cellules hautement productrices ont permis finalement d'obtenir une sécrétion correspondant à 200 IU d'Epo/10E6 cells/jour. Ces cellules génétiquement modifiées ont été encapsulées et implantées in vivo dans les mêmes conditions que celles décrites plus haut. Toutes les souris transplantées ont montré une augmentation significative de leur hématocrite et une proportion importante de cellules présentait une survie conservée au moment de l'explantation des capsules. Finalement, dans la perspective d'une application humaine, un modèle syngénique a été proposé, basé sur l'implantation de myoblastes murins encapsulés dans des souris, afin d'investiguer les rôles respectifs de la réponse immunitaire du receveur et des besoins métaboliques cellulaires sur leur survie à long terme. Les cellules ont été encapsulées à différentes densités et les animaux transplantés se sont vus administrer des injections de molécules anti-inflammatoires ou immunosuppressives. Les résultats ont démontré qu'une réaction immunologique péri-capsulaire était à la base du rejet cellulaire dans le cas de capsules à haute densité cellulaire. Une matrice de PVA peut limiter cette densité et éviter une mort cellulaire précoce due à une insuffisance métabolique et par conséquent prévenir la réaction immunitaire. Ce travail a permis le développement de cellules encapsulées d'origine humaine sécrétant des taux d'Epo humaine adaptés à des traitements cliniques. De pair avec l'optimalisation des paramètres d'encapsulation, ces résultats ont abouti à l'initiation d'une application clinique destinée à des patients en insuffisance rénale terminale.

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.