Is Less Chemotherapy Detrimental in Adults with Philadelphia Chromosome (Ph)-Positive Acute Lymphoblastic Leukemia (ALL) Treated with High-Dose Imatinib? Results of the Prospective Randomized Graaph-2005 Study

Aim: To compare a less intensive regimen based on high-dose imatinib (IM) to an intensive IM/HyperCVAD regimen in adults with Ph+ ALL, in terms of early response and outcome after stem cell transplantation (SCT). Methods: Patients aged 18-60 years with previously untreated Ph+ ALL not evolving from chronic myeloid leukemia were eligible if no contra-indication to chemotherapy and SCT (ClinicalTrials.gov ID, NCT00327678). After a steroid prephase allowing Ph and/or BCR-ABL diagnosis, cycle 1 differed between randomization arms. In arm A (IM-based), IM was given at 800 mg on day 1-28, combined with vincristine (2 mg, day 1, 8, 15, 22) and dexamethasone (40 mg, day 1-2, 8-9, 15-16, and 22-23) only. In arm B (IM/HyperCVAD), IM was given at 800 mg on day 1-14, combined with adriamycin (50 mg/m2, day 4), cyclophosphamide (300 mg/m2/12h, day 1, 2, 3), vincristine (2 mg, day 4 and 11), and dexamethasone (40 mg, day 1-4 and 11-14). All patients received a cycle 2 combining high-dose methotrexate (1 g/m2, day 1) and AraC (3 g/m2/12h, day 2 and 3) with IM at 800 mg on day 1-14, whatever their response. Four intrathecal infusions were given during this induction/consolidation period. Minimal residual disease (MRD) was centrally evaluated by quantitative RQ-PCR after cycle 1 (MRD1) and cycle 2 (MRD2). Major MRD response was defined as BCR-ABL/ABL ratio <0.1%. Then, all patients were to receive allogeneic SCT using related or unrelated matched donor stem cells or autologous SCT if no donor and a major MRD2 response. IM/chemotherapy maintenance was planned after autologous SCT. In the absence of SCT, patients received alternating cycles 1 (as in arm B) and cycles 2 followed by maintenance, like in the published IM/HyperCVAD regimen. The primary objective was non-inferiority of arm A in term of major MRD2 response. Secondary objectives were CR rate, SCT rate, treatment- and transplant-related mortality, relapse-free (RFS), event-free (EFS) and overall (OS) survival. Results: Among the 270 patients randomized between May 2006 and August 2011, 265 patients were evaluable for this analysis (133 arm A, 132 arm B; median age, 47 years; median follow-up, 40 months). Main patient characteristics were well-balanced between both arms. Due to higher induction mortality in arm B (9 versus 1 deaths; P=0.01), CR rate was higher in the less intensive arm A (98% versus 89% after cycle 1 and 98% versus 91% after cycle 2; P= 0.003 and 0.006, respectively). A total of 213 and 205 patients were evaluated for bone marrow MRD1 and MRD2. The rates of patients reaching major MRD response and undetectable MRD were 45% (44% arm A, 46% arm B; P=0.79) and 10% (in both arms) at MRD1 and 66% (68% arm A, 63.5% arm B; P=0.56) and 25% (28% arm A, 22% arm B; P=0.33) at MRD2, respectively. The non-inferiority primary endpoint was thus demonstrated (P= 0.002). Overall, EFS was estimated at 42% (95% CI, 35-49) and OS at 51% (95% CI, 44-57) at 3 years, with no difference between arm A and B (46% versus 38% and 53% versus 49%; P=0.25 and 0.61, respectively). Of the 251 CR patients, 157 (80 arm A, 77 arm B) and 34 (17 in both arms) received allogeneic and autologous SCT in first CR, respectively. Allogeneic transplant-related mortality was similar in both arms (31.5% versus 22% at 3 years; P=0.51). Of the 157 allografted patients, 133 had MRD2 evaluation and 89 had MRD2 <0.1%. In these patients, MRD2 did not significantly influence post-transplant RFS and OS, either when tested with the 0.1% cutoff or as a continuous log covariate. Of the 34 autografted patients, 31 had MRD2 evaluation and, according to the protocol, 28 had MRD2 <0.1%. When restricting the comparison to patients achieving major MRD2 response and with the current follow-up, a trend for better results was observed after autologous as compared to allogeneic SCT (RFS, 63% versus 49.5% and OS, 69% versus 58% at 3 years; P=0.35 and P=0.08, respectively). Conclusions: In adults, the use of TK inhibitors (TKI) has markedly improved the results of Ph+ ALL therapy, now close to those observed in Ph-negative ALL. We demonstrated here that chemotherapy intensity may be safely reduced when associated with high-dose IM. We will further explore this TKI-based strategy using nilotinib prior to SCT in our next GRAAPH-2013 trial. The trend towards a better outcome after autologous compared to allogeneic SCT observed in MRD responders validates MRD as an important early surrogate endpoint for treatment stratification and new drug investigation in this disease.

Pansements bioactifs [Bioactive dressings]

Wound healing is a complex process involving several cell types (keratinocytes, fibroblasts, endothelial cells, etc.) as well as many growth factors (PDGF, TGF-betas, FGFs, VEGF, etc.). It can be challenging when wounds are deep or very large (third degree burn, ulceration after cutaneous tumor resection) or in presence of peripheral vascular disease, metabolic disturbances or peripheral neuropathy (chronic vascular or diabetic wounds). In order to promote skin regeneration, numerous bioactive dressings combining cells, matrices and growth factors are available on the market. This article provides a general overview of the various product categories and presents their main indications. The principal axes of the biomedical research in this area are also discussed.

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.

Challenges in lung transplantation.

Lung transplantation is an established therapy for end-stage pulmonary disorders in selected patients without significant comorbidities. The particular constraints associated with organ transplantation from deceased donors involve specific allocation rules in order to optimise the medical efficacy of the procedure. Comparison of different policies adopted by national transplant agencies reveals that an optimal and unique allocation system is an elusive goal, and that practical, geographical and logistic parameters must be taken into account. A solution to attenuate the imbalance between the number of lung transplant candidates and the limited availability of organs is to consider marginal donors. In particular, assessment and restoration of gas exchange capacity ex vivo in explanted lungs is a new and promising approach that some lung transplant programmes have started to apply in clinical practice. Chronic lung allograft dysfunction, and especially bronchiolitis obliterans, remains the major medium- and long-term problem in lung transplantation with a major impact on survival. Although there is to date no cure for established bronchiolitis obliterans, new preventive strategies have the potential to limit the burden of this feared complication. Unfortunately, randomised prospective studies are infrequent in the field of lung transplantation, and data obtained from larger studies involving kidney or liver recipients are not always relevant for this purpose.

Transformed and nontransformed human T lymphocytes migrate to skin in a chimeric human skin/SCID mouse model.

To study human T cell migration to human skin in vivo, we grafted severe combined immunodeficient mice with 500-microm thick human skin. Two weeks after grafting, epidermal and dermal structures in the grafts were of human origin. When we intraperitoneally injected grafted mice with clones of the human HUT-78 T cell line derived from a patient with cutaneous T cell lymphoma and Sézary syndrome, we detected in the grafts the rare Vbeta23-Jbeta1.2 T cell receptor transcripts characteristic for the HUT-78 clones. These signals were found 2-6 d after cell injection in about 40% of the grafted and HUT-78 cell injected mice but not in grafts from mice that received no exogenous T cells. In contrast to HUT-78 cells, which only accumulate in low number, grafts topically challenged with nickel sufate in vaseline from mice that were injected with autologous nickel-reactive T cell lines led to massive accumulation of T cells within 3 d. Only scattered T cells accumulated in the skin when grafted mice received vaseline plus T cells, nickel sulfate alone, T cells alone, or nickel sulfate plus an allogeneic nickel-nonreactive T cell clone. When the T cell lines were labeled with the fluorochrome PKH-26 before cell injection, spots of fluorescent label in the size and shape of cells were found in the grafts challenged with nickel. Together, these results clearly demonstrate that human T cells can migrate to human skin in this chimeric human/mouse model.

Lung transplantation for COPD - evidence-based?

Lung transplantation has now been performed for more than 30 years in patients with end-stage chronic obstructive pulmonary disease (COPD). This disease is the major indication for lung transplantation, involving more than one third of the procedures worldwide. Although lung transplantation in COPD patients has clearly shown a positive impact on lung function, exercise capacity and quality of life, the survival benefit remains difficult to ascertain. Several methodological difficulties, particularly the absence of classical randomised studies, make the analysis especially challenging. There is however indirect but convincing evidence that lung transplantation can, when appropriate selection criteria are applied, provide not only an active post-transplant lifestyle but also a survival benefit for patients with COPD.

Cataractogenesis after total body irradiation.

PURPOSE: To evaluate the prognostic factors and the ophthalmologic follow-up on cataract formation following total body irradiation (TBI) prior to bone marrow transplantation (BMT). METHODS AND MATERIALS: Between 1980 and 1992, 494 patients were referred to our department for TBI prior to BMT. The mean age was 32 +/- 11 (median: 32, range: 2-63) years and the male to female ratio was 1.6 (304:190). The majority of patients were treated for acute leukemia (lymphoblastic, n = 177, 36%; or nonlymphoblastic , n = 139, 28%); 80 (16%) for chronic myeloid leukemia, 60 (12%) for non-Hodgkin's lymphoma, 23 (5%) for multiple myeloma, and 15 (3%) for other malignancies. Two hundred and fifty-four (51%) patients were grafted in the first complete remission (CR), 118 (24%) in second CR. Allogenic BMT was performed in 210 (43%) patients, and autologous BMT in 284 (57%). Methotrexate combined to steroids (n = 47, 22%) or to cyclosporine (n = 163, 78%) was administered for graft-versus-host disease (GvHD) prophylaxis. In 188 patients (38%), heparin was used in the prevention of veno-occlusive disease (VOD) of the liver. Furthermore, steroid administration was registered in 223 (45%). The conditioning chemotherapy consisted of cyclophosphamide (Cy) alone in 332 (67%) patients. Total-body irradiation was administered either in single dose (STBI; 10 Gy in 1 day, n = 291) or in six fractions (FTBI; 12 Gy over 3 consecutive days, n = 203) before BMT. The mean instantaneous dose rate was 0.0574 +/- 0.0289 Gy/min (0.024-0.1783). It was < 0.048 Gy/min in 157 patients (LOW group), > or = 0.048 Gy/min and <0.09 Gy/min in 301 patients (MEDIUM group), and > or = 0.09 Gy/min in 36 patients (HIGH group). RESULTS: When considering all patients, 42 (8.5%) patients developed cataracts after 13 to 72 months (median: 42 months) with a 5-year estimated cataract incidence (ECI) of 23%. Thirty-three (11.3%) out of 291 patients in the STBI group, and 9 (4.4%) out of 203 patients in the FTBI group developed cataracts with 5-year estimated incidences of 34 and 11%, respectively (p = 0.0004). Seven (19.4%) out of 36 patients in the HIGH group, 33 (10.9%) out of 301 in the MEDIUM group, and 2 (1.2%) out of 157 in the LOW group developed cataracts with respective 5-year cataract incidences of 54%, 30%, and 3.5% (HIGH vs. MEDIUM, p = 0.07; MEDIUM vs. LOW, p = 0.0001; HIGH vs. LOW, p < 0.0001). On the other hand, patients who received heparin as prophylactic treatment against VOD of the liver had less cataracts than those who did not receive (5-year ECI of 16% vs. 28%, respectively; p = 0.01). There was no statistically significant difference in terms of 5-year ECI according to age, sex, administration of steroids, GvHD prophylaxis, type of BMT, or previous cranial radiotherapy in children. Multivariate analysis revealed that the instantaneous dose rate (p = 0.001), and the administration of heparin against VOD (p = 0.05) were the two independent factors influencing the cataract incidence, while age, fractionation, and use of steroids were not. Among the 42 patients who developed cataracts, 38 had bilateral extracapsular cataract extraction and intraocular lens implantation, and only 4 (10%) developed secondary cataracts in a median follow-up period of 39 months. CONCLUSION: Among the abovementioned TBI parameters, high instantaneous dose rate seems to be the main risk factor of cataract formation, and the administration of heparin appears to have a protective role in cataractogenesis. On the other hand, ionizing radiation seems to have a protective effect on posterior capsule opacification following extracapsular cataract extraction and intraocular lens implantation.

Gas6 deficiency in recipient mice of allogeneic transplantation alleviates hepatic graft-versus-host disease.

Growth arrest-specific gene 6 (Gas6) is expressed in antigen-presenting cells and endothelial cells (ECs) but not in T cells. When wild-type (WT) or Gas6(-/-) mice received allogeneic non-T cell-depleted bone marrow cells, hepatic graft-versus-host disease (GVHD) was alleviated in Gas6(-/-) recipients regardless of donor genotype, but not in WT recipients. T-cell infiltration was more prominent and diffuse in WT than in Gas6(-/-) recipients' liver. When mice received 0.5 x 10(6) allogeneic T cells with T cell-depleted allogeneic bone marrow, clinical signs indicated that GVHD was less severe in Gas6(-/-) than in WT recipients, as shown by a significant improvement of the survival and reduced liver GVHD. These data demonstrate that donor cells were not involved in the protection mechanism. In addition, lack of Gas6 in antigen-presenting cells did not affect WT or Gas6(-/-) T-cell proliferation. We therefore assessed the response of WT or Gas6(-/-) ECs to tumor necrosis factor-alpha. Lymphocyte transmigration was less extensive through Gas6(-/-) than WT ECs and was not accompanied by increases in adhesion molecule levels. Thus, the lack of Gas6 in ECs impaired donor T-cell transmigration into the liver, providing a rationale for considering Gas6 pathway as a potential nonimmunosuppressive target to minimize GVHD in patients receiving allogeneic hematopoietic stem cell transplantation.

Facteurs influençant le retour au travail après transplantation chez 61 patients rénaux ou hépatiques

Le taux de retour au travail après greffe est généralement bas. Or, on sait que le retour au travail après greffe améliore la qualité de vie des transplantés. Le but de notre étude était donc de comprendre les raisons possibles à ce faible taux en montrant les facteurs professionnels, individuels ou médicaux pouvant l'influencer. Parmi les 61 greffés rénaux ou hépatiques suivis au centre de transplantation d'organe (CTO) du CHUV, 39% ont repris le travail après greffe. Trois facteurs étaient significatifs de retour au travail après greffe, à savoir «travail avant greffe», «diplôme» et «âge < 45 ans». Ainsi, il est utile pour la pratique médicale de connaître les facteurs potentiels influençant le retour au travail car cela permet d'évaluer, au stade prégreffe, les chances de retour au travail et si besoin de proposer des mesures spécifiques le favorisant.

Beta cell mass and growth after syngeneic islet cell transplantation in normal and streptozocin diabetic C57BL/6 mice

In islet transplantation, nonimmunological factors such as limited growth capacity or increased death rate could reduce the beta cell mass in the graft and lead to failure of the transplant. We studied the evolution of beta cell replication and mass after transplantation of insufficient, minimally sufficient, or excessive islet tissue. Streptozocin diabetic C57BL/6 mice received 150 or 300 syngeneic islets under the kidney capsule and normal mice received 300 islets. In streptozocin diabetic mice 300 islets restored normoglycemia; beta cell replication in transplanted islets was similar to replication in normal pancreas and beta cell mass in the graft remained constant. In contrast, 150 islets were insufficient to achieve normoglycemia; beta cell replication was increased initially but not by 18 or 30 d despite persistent hyperglycemia, and beta cell mass fell progressively. When islets were transplanted into normal recipients, beta cell replication remained normal but beta cells underwent atrophy and mass in the graft was substantially reduced. Therefore, with a successful islet transplant, in diabetic mice beta cell replication and mass remain constant. In contrast, when insufficient islet tissue is transplanted an initial increase in beta cell replication can not compensate for a decline in beta cell mass. When excessive islet tissue is transplanted, beta cell mass is reduced despite normal beta cell replication.

Reduced atrial emptying after orthotopic heart transplantation masquerading as restrictive transmitral Doppler flow pattern?

BACKGROUND: An elevated early (E) to late (A) diastolic filling velocities ratio, typically seen in advanced diastolic dysfunction, has also been observed after cardioversion of atrial fibrillation as a consequence of the depressed left atrial (LA) contractility. We hypothesized that the impaired LA contractile function demonstrated after orthotopic cardiac transplantation (OCT) could also lead to this "pseudorestrictive" pattern. METHOD: E/A ratio related to the tissue Doppler early mitral annular velocity (Ea) as preload-independent index of LV relaxation was evaluated in all consecutive OCT patients between 2005 and 2007. RESULTS: The study population comprised 48 patients 97 ± 77 months after OCT. Thirty-two patients (67%) had an E/A ratio > 2. LV systolic function and myocardial relaxation assessed by the Ea velocity were similar compared to patients with normal ratio (61 ± 6% vs. 60 ± 12%, P = 0.854 and 15 ± 4 cm/s vs. 14 ± 3 cm/s, r = 0.15, P = 0.323, respectively). On the other hand, the proportion of the recipient and donor LA cuffs as estimated by the recipient/global LA area ratio and the LA emptying fraction significantly correlated with the E/A ratio (r = 0.40, P = 0.005 and r =-0.33, P = 0.022, respectively). CONCLUSION: Our study shows that there is a high prevalence of elevated E/A ratio after standard OCT which seems mainly related to reduced LA contractility. Recognition of this "pseudorestrictive" pattern may avoid misdiagnosis of diastolic dysfunction.

Prospective monitoring of a CD4+ CD25high CD45RO+ CD127high T-cell population after first kidney transplantation following thymoglobulin or basiliximab induction

Background: Recent data have suggested that a population of CD4+ CD25high T cells, phenotypically characterized by the expression of CD45RO and CD127, is significantly expanded in stable liver and kidney transplant recipients and represents alloreactive T cells. Induction therapies may have an impact on this alloreactive T cell population. In this study, we prospectively analyzed CD4+ CD25high CD45RO+ CD127high T cells after induction with either thymoglobulin or basiliximab. Patients and methods: A total of twenty-seven kidney transplant recipients were prospectively enrolled; 14 received thymoglobulin induction followed by a 4-day course of steroids with tacrolimus and mycophenolate mofetil («thymo group»), and 13 received basiliximab induction followed by standard triple immunosuppression (tacrolimus, mycophenolate mofetil and prednisone) («BSX group»). Phenotypical analysis by flow cytometry of the expression of CD25, CD45RO and CD127 on peripheral CD4+ T cells was performed at 0, 3 and 6 months after transplantation. Twenty-four healthy subjects (HS) were studied as controls. Results: There were no differences in baseline characteristics between the groups; at 6 months, patient survival (100%), graft survival (100%), serum creatinine (thymo group versus BSX group: 129 versus 125 micromol/l) and acute rejection (2/14 versus 2/13) were not significantly different. Thymo induction produced a prolonged CD4 T cell depletion. As compared to pre-transplantation values, an expansion of the alloreactive T cell population was observed at 3 months in both thymo (mean: from 6.38% to 14.72%) and BSX (mean: from 8.01% to 18.42%) groups. At 6 months, the alloreactive T cell population remained significantly expanded in the thymo group (16.92 ± 2.87%) whereas it tended to decrease in the BSX group (10.22 ± 1.38%). Conclusion: Overall, our results indicate that the expansion of alloreactive T cells occurs rapidly after transplantation in patients receiving either thymo or BSX induction. Whether differences at later timepoints or whether different IS regimens may modify this alloreactive population remains to be studied.

International consensus guidelines on the management of cytomegalovirus in solid organ transplantation.

Cytomegalovirus (CMV) remains one of the most common infections after solid organ transplantation, resulting in significant morbidity, graft loss, and occasional mortality. Management of CMV varies considerably among transplant centers. A panel of experts on CMV and solid organ transplant was convened by The Infectious Diseases Section of The Transplantation Society to develop evidence and expert opinion-based consensus guidelines on CMV management including diagnostics, immunology, prevention, treatment, drug resistance, and pediatric issues.