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P Ladaique

Publications and source records attributed to P Ladaique.

16 recordsLinked to original sources
PubMed2005

Early administration of recombinant erythropoietin improves hemoglobin recovery after reduced intensity conditioned allogeneic stem cell transplantation.

The use of recombinant human erythropoietin (rHuEPO) has been controversial after myeloablative allogeneic Stem cell transplantation (allo-SCT). Reduced intensity conditioning regimens (RIC) offer a novel approach that might translate into a different profile of erythropoietic recovery. We treated 20 consecutive patients with rHuEPO early after matched sibling RIC allo-SCT. Conditioning included fludarabine, busulfan and antithymocyte globulin. EPO treatment was analyzed in terms of toxicity, impact on the frequency of Red blood cell transfusions (RBCT) and kinetics of Hemoglobin recovery within the 60 days post-allo-SCT. Results were compared with 27 matched patients who did not receive rHuEPO. In the first 2 months after allo-SCT all patients receiving rHuEPO (100%) achieved an Hb level > 11 g/dl at a median of 30 (15-35) days post-allo-SCT, as compared to only 63% of the patients not receiving rHuEPO (P = 0.007) at a median of 35 (20-55) days (P = 0.03). A total of 70% (95% CI, 50-90) of rHuEPO patients maintained an Hb over 11 g/dl in the second month as compared to only 19% (95% CI, 4-34) in the other group (P = 0.0004). For patients receiving RBCT, the use of rHuEPO was associated with a trend towards reduced RBCT requirements. This pilot study suggests a potential benefit of early administration of rHuEPO after RIC allo-SCT on early erythropoietic recovery.

Adult↗
PubMed2005

The role of reduced intensity conditioning allogeneic stem cell transplantation in patients with acute myeloid leukemia: a donor vs no donor comparison.

Using a genetic randomization through a 'donor' vs 'no donor' comparison, the aim of this analysis was to assess the real benefit of reduced intensity conditioning allogeneic stem cell transplantation (RIC-allo-SCT) among 95 adult high-risk acute myeloid leukemia (AML) patients. In an 'intention-to-treat' analysis, leukemia-free survival (LFS) was significantly higher in the 'donor' group as compared to the 'no donor' group (P=0.01; 54 vs 30% at 4 years). The latter held true when restricting the analysis to the 25 patients who could actually receive the RIC-allo-SCT (P=0.001). Overall transplant-related mortality in the 'transplant' group was 12%, with overall survival (OS) being significantly higher in the 'transplant' group as compared to the 'no transplant' group (P=0.01). Also, in the 'intention-to-treat' analysis, OS was significantly higher in the 'donor' group as compared to the 'no donor' group (P=0.04). In the multivariate analysis, actual performance of RIC-allo-SCT (P=0.001; RR=4.0; 95% CI, 1.7-9.6) was the strongest factor significantly predictive of an improved LFS. We conclude that if a matched related donor is identified, RIC-allo-SCT should be proposed for AML patients not eligible for standard myeloablative allo-SCT.

Acute Disease↗
PubMed2004

Decreased RBCTs after reduced intensity conditioning allogeneic stem cell transplantation: predictive value of prior Hb level.

BACKGROUND: RBCT (RBCT) requirements of stem cell transplant (SCT) recipients are often substantial and may be related to transplant type. STUDY DESIGN AND METHODS: An analysis was done of RBCT requirements and Hb recovery kinetic in the first 60 days after HLA-identical sibling allogeneic SCT in a series of 110 consecutive patients treated for various malignant diagnoses. Patients were prepared with either an antithymocyte globulin (ATG) and reduced intensity chemotherapy-based conditioning (RIC) (n=64) or a myeloablative conditioning regimens (MAC; n=46). Patients received marrow (n=64) or PBPCs (n=46). RESULTS: Overall, intensity of conditioning regimen (RIC vs. MAC; p=0.0005) and graft source (PBPC vs. marrow; p<0.0001) independently predicted RBCT requirements. Hb recovery was accelerated after RIC when compared to MAC allo-SCT (p=0.02). In RIC patients, RBCTs were inversely correlated to Hb level before conditioning (p<0.0001) and the dose of ATG (p=0.009). Moreover, Hb level before allo-SCT significantly influenced Hb recovery kinetic after RIC but had no impact on RBCT requirements and Hb recovery after MAC. CONCLUSION: Thus, RIC conditioning creates a different pattern of erythropoiesis recovery as compared to a MAC regimen and suggest a need for studies aimed at further reducing RBCT and accelerating Hb recovery.

Adolescent↗
PubMed2003

Occult tumor cell contamination in patients with stage II/III breast cancer receiving sequential high-dose chemotherapy.

The purpose of this study was to evaluate the presence of micrometastatic cells in the apheresis products from patients with breast cancer, and also to determine if repeated infusion of contaminated products had any clinical impact. A total of 94 patients with high-risk breast cancer were enrolled in a prospective single center study to evaluate the use of dose-intensified chemotherapy (doxorubicine 75 mg/m(2) and cyclophosphamide 3000 or 6000 mg/m(2) for four cycles) with repeated (x 2) stem cell reinfusion. All women were monitored for the presence of metastatic cells in aphereses, collected after first course of intensive chemotherapy, and following additional mobilization with rhG-CSF. Epithelial cells were screened with monoclonal antibodies directed to cytokeratin. Eight of the 94 patients had detectable tumor cells in one or several aphereses collected after intensive chemotherapy; this was unrelated to other tumor characteristics, including size, histology, Scarff Bloom and Richardson (SBR) grading (presence or absence of hormone receptors). Hemato-poietic reconstitution was similar in the cells from these eight patients, and in the total patient population. Three of these eight patients relapsed. This study has confirmed that contamination of apheresis products remains a rare event, which does not seem to affect clinical evolution, even when reinfused into the patient.

Adult↗
PubMed2000

High rate of secondary viral and bacterial infections in patients undergoing allogeneic bone marrow mini-transplantation.

New approaches using nonmyeloablative-conditioning regimens have been developed to cause minimal procedure-related toxicity. Such novel therapeutic options are being explored with good preliminary results concerning feasibility and engraftment. However many aspects remain under-evaluated, and few data are available about viral and nonviral infections after these highly immunosuppressive regimens. We present our preliminary data on 21 patients receiving a highly immunosuppressive conditioning strategy, focusing on early infectious complications. Early viral infections before day 45, especially CMV, occurred at a high rate (65%). Furthermore, 33% of patients presented with late bacterial infections (predominately gram negative) although they were not neutropenic compared to conventional conditioning regimens. Although there is presently real interest in these new conditioning regimens which result in reduced immediate transplant-related mortality, it is important that investigators be aware of these pitfalls which may secondarily increase transplant toxicity. Further studies are needed to confirm these findings.

Adult↗
PubMed2000

CD34(+) immunoselected cells for poor graft function following allogeneic BMT.

BACKGROUND: Poor graft function without signs of graft rejection following allogeneic BMT (allo-BMT) occurs in around 9% of patients. A high incidence of hazardous complications may be encountered, leading to life-threatening situations. METHODS: We describe three patients who underwent allo-BMT for acute leukemia in first complete remission and untreated myelodysplastic syndrome. The three patients experienced prolonged and profound granulocytopenia, anemia and thrombocytopenia, despite growth factors and transfusions. This was not corrected by donor leukocytes infusion. They received a boost of CD34(+) positively-selected cells from their HLA-identical sibling donors. RESULTS: A rapid improvement of peripheral blood cell counts was observed in both patients who were in full donor chimerism status at time of boost infusion, whereas the patient with mixed chimerism did not show any signs of improvement. Neither patient suffered further exacerbation of GvHD. DISCUSSION: Allogeneic positively-immunoselected CD34(+) cells can represent an interesting alternative treatment for poor graft function following allo-BMT, in the absence of graft rejection signs.

Adult↗
PubMed1999

Positive selection of CD34+ peripheral blood progenitor cells in patients with low-grade lymphoid malignancies and bone marrow involvement.

PURPOSE: 16 patients with low-grade lymphoid malignancies and bone marrow involvement were transplanted with selected CD34 positive Peripheral Blood Progenitor Cell (PBSC) prepared from autologous aphereses. PATIENT AND METHODS: All but one patients were mobilized with a combination of chemotherapy (including high-dose cyclophosphamide and VP16 or adriamycin, aracytin with cysplatyl) and recombinant human Granulocyte Colony-Stimulating Factor (rhG-CSF). RESULTS: A median of 3 (range, 1 to 9) aphereses yielded 15.35 x 10(6) CD34+ cells/kg (range, 4.45 to 70.88). A median of 5.01 x 10(6) adsorbed CD34+ cells/kg (range 2.01 to 24.13) was obtained after selection (median purity: 86%; range, 59-99%). The CD34 PBSC were infused one day after either one of two conditioning regimens: 11 patients received the association of cyclophosphamide (120 mg/kg) and TBI (8Gy), and 5 patients received the BEAM regimen. No recombinant hematopoietic growth factor was used after cell reinfusion. Median days to 0.5 x 10(9)/l neutrophils and 50 x 10(9)/l platelets were 13 (range, 9 to 18) and 16 (range, 11 to 35), respectively. The median number of red blood cell (RBC) unit transfusions was 4 (range, 0 to 10). The median number of platelet transfusions was 3.5 (range, 0 to 8). No individual received backup PBSC, nor required platelet transfusion beyond 3 months post-transplant. CONCLUSION: This study confirms the feasability of using blood CD34 cells to support hematopoietic recovery after myelo-suppressive or myelo-ablative regimens, in patients with low-grade NHL.

Adult↗
PubMed1999

Optimization of peripheral blood stem cell collection by leukopheresis. Interaction between economic and clinical assessment of an innovation.

Using the example of substitution of peripheral blood stem cell (PBSC) collection to bone marrow harvest for autologous transplantation in cancer patients, our study attempts to illustrate how economic assessment, starting at an early stage of medical innovation, can influence the development and diffusion process of a new technological procedure whose optimal design has not yet been established. Two cost minimization studies comparing costs for obtaining a clinically reinfusable graft using bone marrow harvest or alternatively various protocols of PBSC collection contributed to a change in the French clinical standard for this procedure.

Bone Marrow Transplantation↗
PubMed1999

CD34+ cell enumeration in peripheral blood and apheresis samples, using two laboratory diagnostic kits or an institutional protocol.

In order to prepare the substitution of a commercially available diagnostic kit, ProCOUNT (Becton Dickinson) or Stem-Kit (Coulter Immunotech), for our institutional protocol, we compared the three techniques for the numeration of CD34+ progenitor cells in 50 peripheral blood and 51 apheresis samples, obtained from cancer patients or healthy donors. We show here that the three techniques yield results of the same order of magnitude. Although statistical analyses demonstrate significant differences between the three methods, these differences turned out to be clinically insignificant in most situations. Observed differences mostly affect samples with the highest content of CD34+ cells, while the three assays provide equivalent results for values that are close to clinically relevant thresholds (20 x 10(3) CD34+ cells/ml in peripheral blood to start apheresis, and accumulated number above 3 x 10(6) CD34+ cells/kg to stop apheresis). This study also supports the view that institutional protocols can provide a highly reliable determination of CD34+ cells counts and percentages. However, because institutional protocols often use research reagents and vary from institution to institution, the use of diagnostic kits may be prefered as one way to improve quality assurance in the practice of cell therapy.

Antigens, CD34↗
PubMed1999

Intensive sequential chemotherapy (ISC 95) with growth factors and blood stem cell support in high-intermediate and high-risk (IPI 2 and IPI 3) aggressive non-Hodgkin's lymphoma: an oligocentric report on 42 patients.

We previously reported feasibility and efficacy of a monocentric pilot study of intensive sequential chemotherapy (ISC) in poor-risk aggressive non-Hodgkin's lymphoma (NHL) in patients < 60 years. To validate these results on a large cohort of patients, we designed a new and oligocentric study. After a COP (cyclophosphamide (Cy), vincristine (Vcr), prednisone (Pred) debulking, patients received four courses of high-dose CHOP (Cy, doxorubicin (Doxo), Ver, Pred), with the addition of etoposide and cisplatin during the two last courses. G-CSF was delivered after each cycle, and peripheral blood stem cells (PBSC) were used to support the two last cycles. Total duration of chemotherapy was 13 weeks, with a planned dose-intensity (DI) of 1420 mg/m2/week and 23 mg/m2/week for Cy and Doxo, respectively. Radiotherapy (involved fields) was then delivered for patients with node size > or = 5 cm at diagnosis. Forty-two patients were enrolled in this study; 36 completed the treatment and received 75% or more of the planned DI for both Cy and Doxo. Median duration of grade 4 neutropenia was 14 days (range, 2 to 28) for the regimen as a whole, and median duration of rehospitalization for febrile neutropenia was 18 days (range, 4 to 41). Overall response rate was 83%, with 29 patients (69%) in complete response (CR). Six patients failed to respond and one died of toxicity. With a median follow-up of 22.5 months (range, 10 to 42), the 3-year event-free survival (EFS) is 55% (95% CI, 39-71), while disease-free survival (DFS) is 79% (95% CI, 63-95). Ambulatory ISC is accessible and feasible in an oligocentric study. PBSC allow repeated delivery of high-dose chemotherapy cycles, and result in encouraging CR, EFS, and DFS rates for poor-risk aggressive NHL's patients.

Adult↗
PubMed1997

CNS axonal regeneration with peripheral nerve grafts cryopreserved by vitrification: cytological and functional aspects.

To test cool-warm protocols for storing peripheral nerves, 4-cm-long-nerve segments were removed from the hindleg of adult rats and cryopreserved using a vitrification solution (or cryoprotective mixture) containing a mixture of polyalcohols (2,3-butanediol, 1,2-propanediol, polyethylene glycol, and Belzer U.W. medium). Schwann cell viability and morphology were studied with regard to the effect of (i) cryoprotective mixture concentration (100, 50, and 30% diluted in human serum albumin at 4%), (ii) duration of exposure (10, 15, or 30 min in a single step) of nerves to the cryoprotective mixture, (iii) cooling rate (F1/F2, F3, and F4: 3, 12, and 231 degrees C/min, respectively), and (iv) type of replacement of cryoprotectant (T1, one step; or T2, perfusion) after warming. Nerves exposed 10 min to cryoprotective mixture 50% (2,3-butanediol, 1.926 mol.liter-1; 1,2-propanediol, 3.063 mol.liter-1; polyethylene glycol, 0.084 mol.liter-1; and Belzer U.W., 22.4 mosm-1) and cooled-warmed with the F2/F3/F4-T2 protocols contained live and correctly cryopreserved Schwann cells. The capacity of these cryopreserved nerve segments (n = 6) to be subsequently repopulated by regenerating axons from central neurons was compared to that of fresh nerves when used as peripheral nerve autografts implanted within the spinal cord at the level of the descending respiratory pathways. All cryopreserved nerve grafts were successfully reinnervated by regenerated central axons. Unitary spontaneous action potentials propagated along these axons were assessed by recording the discharge of tested nervous filaments (T) from the grafts in artificially ventilated and paralyzed animals. Out of 535 T, 32 (6 +/- 1.2%) presented spontaneous unitary activity with respiratory (R, n = 2) and nonrespiratory (NR, n = 30) pattern of discharge. The T mean number, the occurrence rate referenced to the total number of T (R/T, NR/T, and R + NR/T) and the mean number of spontaneous units (R, NR, R + NR) were compared to those of fresh spinal peripheral nerve grafts. Except for T, cryopreserved peripheral nerve grafts contained statistically significantly (P < 0.05) less spontaneous R and NR unitary activity, which represented, respectively, 6.2 +/- 6.2 and 26.8 +/- 5.7% of that found in the control group. These data indicate that nerves cryopreserved with the protocols described above contain viable Schwann cells which constitute a suitable support to induce regeneration of central fibers. The effectiveness of nerve cryopreservation by vitrification is discussed with regard to Schwann cell viability following cool-warm protocols and to subsequent reinnervation of the cryopreserved peripheral nerve grafts.

Animals↗
PubMed1997

In vitro cytotoxicity of dental adhesive systems under simulated pulpal pressure.

OBJECTIVES: Most of the devices used to evaluate the cytotoxicity of resin-based composites in vitro use a dentin barrier test. However, it is difficult to obtain the number of freshly extracted teeth, all on the same day, that is necessary for powerful statistical analysis. Tooth cryopreservation provides a way to build up a supply of teeth. This in vitro study compared cryopreserved teeth and freshly extracted teeth in an evaluation of the cytotoxicity of resin-based composites. In addition, this study also evaluated the effects of pulsatile pressure and the importance of dentin permeability on the cytotoxic response to bonding resins. METHODS: Forty freshly extracted and forty cryopreserved third molars were used. A standardized Class I cavity was prepared within the dentin. The hydraulic conductance of each tooth was recorded. The cavities were filled either with Scotchbond Multi-Purpose Plus and Z 100 (3M Dental Products) or with Optibond and Herculite (Kerr). A plexiglas device was designed to permit 24 h long contact between culture medium and the roof of the pulp chamber while a pulsatile pulpal pressure was simulated. The viability of L 929 cells cultured with a control medium and evaluated by an MTT assay was compared to that of L 929 cells cultured with medium which remained for 24 h in contact with the pulp chamber of restored teeth. A three-way ANOVA was used to compare the cytotoxicity among the different groups. A simple least-squares linear regression was used to seek a relationship between the hydraulic conductance of dentin and the cytotoxicity of composite restorative materials. RESULTS: No significant differences in cytotoxicity were found between the freshly extracted teeth and the cryopreserved teeth (p = 0.53). The cytotoxicity of the resin adhesives was statistically higher when a pulsatile pulpal pressure was simulated (p = 0.04). A significant relationship was found between the hydraulic conductance of dentin and the cytotoxicity of resin-based composites (p = 0.02). SIGNIFICANCE: Cryopreserved teeth can be used for in vitro evaluation of the cytotoxicity of resin adhesives. Pulsatile pulpal pressure simulations increased the in vitro cytotoxicity of the tested materials.

Adult↗
PubMed1997

Early and fatal immune haemolysis after so-called 'minor' ABO-incompatible peripheral blood stem cell allotransplantation.

A 38-year-old man, blood group A+, was allotransplanted for multiple myeloma from his fully matched sister, blood group O+. Anti-A antibodies IgG and IgM titres of the donor were low. Allogeneic peripheral blood stem cells were harvested by leukapheresis after subcutaneous administration of G-CSF. Rapid engraftment occurred since 5.6 x 10(9)/l leukocytes were achieved on day +9 post-transplant. At this time a severe immune haemolytic syndrome occurred and direct antiglobulin test was positive (IgG and C3d). Elution showed an anti-A specificity. Evolution was rapidly unfavourable related to multiorgan failure. The patient died on day +20 post-transplant.

ABO Blood-Group System↗
PubMed1992

[Establishment of a bank of cryopreserved valve homografts and clinical use in ninety-two patients].

Good long-term results obtained with homologous valve grafts, specially for correction of congenital cardiac defects, prompted us to create a local cryopreserved homograft bank. A 5-year experience is described, including indications for harvesting, techniques of preparation, cryopreservation and thawing. During this period, 195 homografts entered the bank and 92 were used. Among these 92 clinical cases, 74 consisted of right ventricular outflow tract reconstruction (47 valved conduit and 27 monocusp bearing patch) and 17 were left ventricular outflow tract reconstructions (11 free hand aortic valve and 6 aortic root replacement). Only one case was a tricuspid replacement with a stented homograft. Short-term results, with these homografts, are satisfactory and are compared with long-term results reported in the literature. The authors insist on using very thorough techniques and constant quality control. New developments should include viability control and immunological studies.

Aortic Valve↗