[Fungal contamination detection in cornea preservation media]. / Détection de la contamination fongique des liquides de conservation de cornées.

PURPOSE: Fungi can cause major complications following corneal grafting. In this study we aimed to verify the efficiency of a fungal contamination detection protocol for human corneas in preservation before clinical use. MATERIALS AND METHODS: The 12 most frequently found species of fungi responsible for keratitis and endophthalmitis were inoculated to preservation medium used by most French eye banks. A protocol used by several centers, including a daily visual control, was followed in order to check that it showed the presence of all microorganisms, particularly slow-growing filamentous fungi. RESULTS: Every species was detected in a time from 2 to 4 days. CONCLUSION: This microbiological contamination detection protocol of detection for human corneas in organ culture at +31 degrees C, seems to effectively detect the main agents responsible for fungal contamination.

Transplantation with selected autologous peripheral blood CD34+Thy1+ hematopoietic stem cells (HSCs) in multiple myeloma: impact of HSC dose on engraftment, safety, and immune reconstitution.

OBJECTIVE: The aims of our study performed in myeloma were to evaluate the performance and the safety of Systemix's high-speed clinical cell sorter, to assess the safety and efficacy of deescalating cell dose cohorts of CD34+Thyl+ hematopoietic stem cells (HSCs) as autologous grafts by determining engraftment, and to assess the residual tumor cell contamination using polymerase chain reaction (PCR) amplification assays of patient-specific complementarity determining region III (CDR III) analysis for residual myeloma cells. MATERIALS AND METHODS: The clinical trial was performed in 31 multiple myeloma patients, using purified human CD34+Thyl+ HSCs mobilized from peripheral blood with cyclosphosphamide and granulocyte-macrophage colony-stimulating factor to support a single transplant after high-dose melphalan 140 mg/m2 alone (cohort 1) and with total body irradiation (TBI) (cohorts 2-5) after an HSC transplant cell dose de-escalation/escalation design. RESULTS: Twenty-three patients were transplanted. Engraftment data in the melphalan + TBI cohorts confirmed that HSC doses above the threshold dose of 0.8 x 10(6) CD34+Thy1+ HSCs/ kg provided prompt engraftment (absolute neutrophil count >0.5 x 10(9)/L day 10; platelet count >50 x 10(9)/L day 13). A higher rate of infections was observed in the early and late follow-up phases than usually reported after CD34+ selected or unselected autologous transplantation, which did not correlate with the CD34+Thy1+ HSC dose infused. Successful PCR for CDR III could only be performed in five patients on initial apheresis product and final CD34+Thy1+ HSC product and showed a median tumor log reduction >3.12. CONCLUSIONS: CD34+Thy1+ HSCs are markedly depleted or free of detectable tumor cells in multiple myeloma and are capable of producing fast and durable hematopoietic reconstitution at cell doses >0.8 x 10(6) CD34+Thy1+ HSCs/kg. The delayed immune reconstitution observed is not different from that described in unselected autologous bone marrow and peripheral blood mononucleated cells transplants in multiple myeloma and may be corrected by addition of T cells either to the graft or to the patient in the posttransplant phase.

[Preparation of cell therapy products: contribution of closed systems]. / Préparation de produits de thérapie cellulaire: apport des systèmes clos.

A phase I clinical trial is being currently performed in our institution, aiming at evaluating the feasibility and toxicity related to the administration of Herpes Simplex-thymidine kinase gene-expressing human primary T lymphocytes following allogeneic hematopoietic stem cell transplantation. The need for safe and standardized preparation conditions for gene-modified cells is crucial. We describe the closed culture system used in the current trial for ex vivo retroviral-mediated gene transfer and transduced cell selection. Cell handling is performed in closed systems using sampling and transfer pack bags, culture bags and a sterile connection device which avoids opening the culture system. This closed system allows safe and reproducible ex vivo preparation of gene-modified primary T-lymphocytes for clinical use.

Definition of optimal conditions for collection and cryopreservation of umbilical cord hematopoietic cells.

Prior studies have shown that human umbilical cord blood cells can restore hematopoiesis and be used as a source of stem cells for hematopoietic transplantation. We have performed a study of the best conditions of collection and cryopreservation of blood from eight umbilical cords. We compared the influence of cell separation and of delay between collection and cryopreservation on the numbers of nucleated cells and of hematopoietic progenitors recovered before and after cryopreservation. Ficoll separation resulted in the loss of more than 50% of nucleated cells, but also of a significant number of progenitors before freezing. Unseparated cells could be kept at 25 degrees C as long as 24 h before freezing with minimal loss of progenitors before and after freezing and thawing. In contrast, there was a significant decrease in the number of viable cells and progenitors when cells were maintained at 4 degrees C before freezing. Our data show that cord blood banking is feasible with simple collection and cryopreservation procedures.

IL-3 increases marrow and peripheral erythroid precursors in chronic pure red cell aplasia presenting in childhood.

In most patients with Diamond-Blackfan anaemia (DBA) the addition of IL-3 to in vitro cultures increases the number of erythroid progenitors. However, a small proportion of patients show an erythroid response to in vivo administration of IL-3. We treated two adult patients with corticosteroid-refractory DBA, who had shown a clear in vitro erythroid response to IL-3, with increasing doses of IL-3 (from 2.5 to 10 micrograms/kg/d) by subcutaneous injections for 7 and 9 weeks. Monitoring of marrow and circulating progenitors showed a sustained elevation of BFU-E and CFU-E as well as an increase of other progenitors and CD34+ cells during therapy. However, this effect did not translate into a clear clinical response, although transfusion requirements decreased transiently in one patient. This report shows that a sustained elevation of erythroid progenitors induced by in vivo IL-3 administration may not translate into an increase of mature red cells production in DBA patients.

Peripheral blood stem cells harvested after chemotherapy and GM-CSF for treatment intensification in patients with advanced lymphoproliferative diseases.

Peripheral blood stem cells (PBSC) from 15 patients with advanced non-Hodgkin's lymphoma (NHL), two patients with chronic lymphocytic leukemia, and two patients with myeloma were collected by continuous-flow leukapheresis after chemotherapy with MIV (mitoxantrone, ifosfamide, and etoposide, five patients) or high-dose cyclophosphamide (14 patients), followed by administration of GM-CSF. Sixteen patients (84%) had persistent marrow involvement at time of inclusion. Results were compared to those obtained in a control group of similar age and disease status in whom collection had been performed after MIV chemotherapy alone. The number of mononuclear cells, granulocyte-macrophage colony-forming units (CFU-GM), CD34+ cells were higher in GM-CSF treated patients with a lower mean number of leukapheresis (3.5 versus 6.4). Among the 19 patients harvested after chemotherapy plus GM-CSF, more progenitor cells were obtained in the cyclophosphamide group than in the MIV group. In all these patients except one, the number of mononuclear cells was sufficient to realize a transplantation. Seventeen patients received intensification with BEAM regimen (8 patients) or cyclophosphamide plus etoposide and total body irradiation (9 patients). Two patients failed to reconstitute correct hematopoiesis and three early toxic deaths occurred for a total of five procedure-related deaths. Nine of these 17 patients are in persistent complete remission with a median post-transplant follow-up of 18 months. Time to reach granulocyte and platelet recovery was not correlated with the number of mononuclear cells, CFU-GM, granulocyte-erythroid-macrophage-megakaryocyte colony-forming units (CFU-GEMM), CD34+ cells, and CD34+ CD33- cells but with the number of previous chemotherapy regimens. PBSC harvesting is achievable after chemotherapy plus GM-CSF in heavily pretreated patients with persistent marrow involvement. Moreover, these cells are able to reconstitute correct hematopoiesis after intensive treatment in these patients.

High expression of bcl-2 protein in acute myeloid leukemia cells is associated with poor response to chemotherapy.

The BCL-2 proto-oncogene encodes a mitochondrial protein that blocks programmed cell death. High amounts of bcl-2 protein are found not only in lymphoid malignancies, but also in normal tissues characterized by apoptotic cell death, including bone marrow. Using a monoclonal antibody to bcl-2 protein, we analyzed 82 samples of newly diagnosed acute myeloid leukemia. The number of bcl-2+ cells in each sample was heterogeneous (range, 0% to 95%), with a mean of 23%. The percentage of bcl-2+ cells was higher in M4 and M5 types, according to French-American-British classification, and in cases with high white blood cell counts. bcl-2 expression was also correlated with that of the stem cell marker CD34. In vitro survival of leukemic cells maintained in liquid culture in the absence of growth factors was significantly longer in cases with a high percentage of bcl-2+ cells. High expression of bcl-2 was associated with a low complete remission rate after intensive chemotherapy (29% in cases with 20% or more positive cells v 85% in cases with less than 20% positive cells, P < 10(-5)) and with a significantly shorter survival. In multivariate analysis, the percentage of bcl-2+ cells (or the blast survival in culture), age, and the percentage of CD34+ cells were independently associated with poor survival.