Changing the outcome of toxoplasmosis in bone marrow transplant recipients.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
P Martiat
Publications and source records attributed to P Martiat.
Ex vivo expansion of neutrophil precursor cells from mobilized peripheral blood cells: similar results in cancer patients and normal donors.
BACKGROUND: Infusion of ex vivo differentiated myeloid progenitors may reduce or abrogate severe neutropenia following mobilized peripheral blood transplantation. We compared the ex vivo expansion of myeloid progenitor cells starting from cancer patients (CP) and from normal donors (ND) and evaluated the influence of the CD34(+) cell mobilization on the capacities of cells to be expanded. METHODS: The ex vivo-expanded cells were evaluated for their phenotype, the presence of primary and secondary granules and their functional capacities (oxidative burst activity and phagocytosis). RESULTS: We did not observe significant differences between ND and CP for the total leukocyte and CD34(+) cell expansions nor for the myeloid progenitor production. In CP as well as in ND, the expanded cells were functionally competent. DISCUSSION: This suggests that the capacities of CD34(+) cells to proliferate and differentiate ex vivo are not impaired by prior chemotherapy and/or disease status. On the other hand, we did not observe any significant correlation between the number of mobilized CD34(+) cells before apheresis and the cell expansion. In conclusion, the ex vivo expansion of CP and ND cells is comparable and achievable even with a low CD34(+) cell number in mobilized peripheral blood.
Antigens, CD34↗
Ex vivo expansion of megakaryocyte progenitor cells: cord blood versus mobilized peripheral blood.
Thrombocytopenia is a problematic and potentially fatal occurrence after transplantation of cord blood stem cells. This problem may be alleviated by infusion of megakaryocyte progenitor cells. Here, we compared the ability of hematopoietic progenitor cells obtained from cord blood and expanded in culture to that of mobilized peripheral blood cells. The CD34(+) cells were plated for 10 days in presence of thrombopoietin (TPO) alone and combined with stem cell factor (SCF), Flt3-ligand (FL), interleukin-3 (IL-3), IL-6, and IL-11. Cells were analyzed for the CD41 and CD42b expression and for their ploidy status. Ex vivo produced platelets were enumerated. We show that (1) TPO alone was able to induce differentiation of CD34(+) cells into CD41(+) cells, with limited total leucocyte expansion; (2) the addition of SCF to TPO decreased significantly CD41(+) cell percentage in CB, but not in MPB; and (3) in CB, the addition of FL, IL-6, and IL-11 to TPO increased the leukocyte expansion with differentiation and terminal maturation into MK lineage. In these conditions, high numbers of immature CD34(+)CD41(+) MK progenitor cells were produced. Our results thereby demonstrate a different sensitivity of CB and MPB cells to SCF, with limited CB MK differentiation. This different sensitivity to SCF (produced constitutively by BM stromal cells) could explain the longer delay of platelet recovery after CB transplant. Nevertheless, in CB, the combination of TPO with FL, IL-6, and IL-11 allows generation of a suitable number of immature MK progenitor cells expressing both CD34 and CD41 antigens, which are supposed to be responsible for the platelet recovery after transplantation.
Antigens, CD34↗
Donor lymphocyte infusions in adult haploidentical transplant: a dose finding study.
Haploidentical transplantation has become a clinical option for patients lacking a compatible donor. However, patients are still referred at advanced stages and are usually heavily pretreated. This results in a high risk of toxicity, relapses and infections. We therefore started a donor lymphocyte infusion (DLI) dose-finding protocol, to try to improve both relapse rate and immunity reconstitution. In all, 12 consecutive patients were investigated. All had a refractory, some progressive, disease. Conditioning consisted of TBI, melphalan, ATG, fludarabine and CSA pretransplant. In four rapidly progressive patients, Ara-C had to be given 1 week preconditioning. The graft was T- and B-cell depleted with a fixed reinfused CD3 dose of 5 x 10(4)/kg. All patients engrafted before day 20. G-CSF was given from day 5 post-transplant and replaced with GM-CSF in the last three patients. Nonrelapse related mortality was 0/12 at 1 year. DLI were started at day 28 (3 x 10(4) CD3/kg) in the two first patients. This resulted in acute graft-versus-host disease (aGVHD) and chronic graft-versus-host disease (cGVHD) in both, but they did not relapse. The next dose was 1 x 10(4)/kg monthly for 3 months. This was well tolerated with only one grade I GVHD. Given the high relapse rate, we escalated doses (1, 3 and 10 x 10(4)/kg). This produced GVHD in all. We next moved, to GM-CSF and 1 x 10(4) CD3/kg monthly. Overall, 6/12 patients relapsed and received therapeutic DLI, starting at 1 x 10(5) CD3/kg with escalation every 2 weeks. We conclude that prophylactic DLI are feasible in adult haploidentical transplantation, without GVHD at a monthly dose of 1 x 10(4) CD3/kg. They result in faster CD4 recovery and a low rate of infections. The impact of GM-CSF remains to be further investigated. This scheme seems ideal for patients transplanted early in the course of their disease. In very bad prognosis patients, it remains insufficient to rapidly induce a GVL effect. Escalated doses are feasible but the price is aGVHD. Therapeutic DLI can be given at higher doses, depending on the time post-transplant. Haploidentical transplantation with low-dose DLI is a safe procedure that should be considered in all patients needing a transplant, but lacking a matched donor, early in the course of the disease.
Adolescent↗
[Chronic myeloid leukemia in 2003].
The recent introduction of imatinib mesylate has deeply changed the treatment of chronic myeloid leukemia. This first physiopathology-based therapy, which targets the molecular anomaly that gives rise to the disease (the abnormal tyrosine kinase activity generated by the fusion protein P210 Bcr-Abl) has demonstrated an impressive activity. However, its long-term efficacy remains unknown. On the other hand, other treatment modalities, such as stem cell transplantation or experimental ones (immunotherapy) are also profoundly evolving. In this review, the authors have tried to synthesize the current knowledge of this disease and suggest a therapeutic strategy based on the currently available data.
Antineoplastic Agents↗
Freezing of dendritic cells, generated from cryopreserved leukaphereses, does not influence their ability to induce antigen-specific immune responses or functionally react to maturation stimuli.
It is of practical clinical importance to be able to reinfuse into patients dendritic cells which have been previously frozen in aliquots. However, there are few studies comparing the function of fresh and frozen dendritic cells. We therefore decided to perform a systematic immunophenotypic and functional comparison of fresh and frozen dendritic cells. We chose to assess functional properties using proliferation tests and evaluating the preservation of specific antigens presentation in the context of MHC class II. Dendritic cells, generated from leukaphereses of normal volunteers, were loaded with proteins by a 2-h incubation at a protein concentration of 50 microg/ml, and were thereafter used fresh or after freeze-thawing in an IFNgamma Elispot assay. The IFNgamma release from antigen specific T cells was not affected by liquid nitrogen storage of pulsed immature dendritic cells. In the same way, the storage did not alter their stimulatory properties for antigen specific autologous T cells or for allogeneic CD8+ T lymphocytes in a proliferation assay. We also showed that freezing non-pulsed immature dendritic cells did not alter their capacity to capture, process and generate antigen-specific reactions once thawed, nor did it impair their capacity to acquire fully mature characteristics using CD40L and IFNgamma, with respect to immunophenotype and bioactive IL-12 secretion.
Antigen Presentation↗
The value of interphase fluorescence in situ hybridization for the detection of translocation t(12;21) in childhood acute lymphoblastic leukemia.
Translocation t(12;21)(p13;q22) is the most frequent cytogenetic abnormality in childhood acute lymphoblastic leukemia (ALL) and is generally associated with favorable prognosis. In this report, we assessed the value of dual-color interphase fluorescence in situ hybridization (FISH) for the detection of t(12;21). Fifty-three patients were screened for ETV6/CBFA2 fusion by means of FISH, using two cosmid probes mapped on ETV6 and on CBFA2, respectively. The cut-off value (mean + three standard deviations) for positivity established on control patients was 9.3%. A comparison between FISH and molecular methods [reverse-transcriptase polymerase chain reaction/Southern blot (RT-PCR/SB)] was possible in 52 patients: 34 of 52 (65.4%) showed negative results with both approaches, and 13 of 52 (25%) were positive; 5 of 52 (9.6%) showed discrepancies: four patients who were positive using RT-PCR/SB were negative using FISH. Conversely, one patient negative when using RT-PCR/SB was positive with FISH. Further investigations on this patients, cytogenetically characterized by add(12p), showed an atypical breakpoint on ETV6, located 5' to the common breakpoint. Compared with RT-PCR and SB, dual-color interphase FISH with the cosmid probe set proved to be highly specific but showed limited sensitivity.
Blotting, Southern↗
A quantitative study of peripheral blood stem cell contamination in diffuse large-cell non-Hodgkin's lymphoma: one-half of patients significantly mobilize malignant cells.
Autologous transplantation using peripheral blood stem cells (PBSCs) collected after chemotherapy, followed by growth factor administration (ASCT), is increasingly used in the treatment of non-Hodgkin's lymphoma (NHL). However, quantitative data regarding contaminating malignant cells in the harvests are still scarce. We prospectively investigated 37 diffuse large-cell lymphomas (DLCLs) in complete remission (CR) that were treated according to multicentric protocols at our centre. DNA was extracted from the diagnostic lymph node. The complementarity-determining region (CDR) III was sequenced and a patient-specific oligomer synthesized. Contamination was evaluated semiquantitatively by polymerase chain reaction (PCR) and was confirmed by a limiting dilution analysis. PBSCs collected at regeneration after administration of granulocyte colony-stimulating factor (G-CSF), steady-state bone marrow (BM) and peripheral blood samples at CR were compared. DNA was available in 37 patients, from which 22 rearrangements could be sequenced. Patients (n = 15) who had both the required follow-up samples and a suitable clonal marker were investigated. In two cases, the patient-specific PCR assay set up at diagnosis later gave false-negative results in samples in which clonal DNA was still detectable by other sets of primers. PBSC contamination was highly variable: 7 out of 15 patients showed a PBSC/BM ratio of NHL cells greater than 1 log, whereas 8 out of 15 patients showed no difference and could vary from one apheresis to another. Eight ASCTs were performed, five of which used highly contaminated PBSCs: four patients relapsed early, three with disseminated lymphoma. Thus, 50% of DLCLs in CR seem to mobilize significantly malignant cells at regeneration under G-CSF. Considering the higher numbers of cells reinfused, this translates into a much higher number of lymphoma cells reinfused when compared with autologous bone marrow transplantation (ABMT). However, their clonogenic potential remains unknown and, despite concerning observations in certain cases, it is still unclear whether this has an impact upon the outcome of ASCT.
Bone Marrow Cells↗
Peripheral blood stem cell contamination in mantle cell non-Hodgkin lymphoma: the case for purging?
Intensification using peripheral blood stem cells collected after chemotherapy followed by growth factors is being increasingly investigated as an alternative to conventional chemotherapy for mantle cell non-Hodgkin lymphoma. We investigated 14 grades III-IV, t(11;14)-positive cases for contamination of PBSC collected after a polychemotherapy regimen followed by G-CSF. Patients were first treated with a polychemotherapy regimen. There were four CR, seven PR, two refractory and one early death. Seven patients have been transplanted, in whom PBSC were mobilized, using either cyclophosphamide/VP16 or Dexa-BEAM followed by G-CSF. For all patients, whether actually autografted or not, PB cells were tested at the time of regeneration on G-CSF after the first polychemotherapy or after the mobilizing regimen. PCR evaluation of contamination was performed first by a semi-quantitative approach, using serial dilutions of initial DNA, then confirmed using a limiting-dilution analysis. Two patients were not informative (one early death and one without an available molecular marker). PB cells collected at regeneration contained at least one log more lymphoma cells than steady-state blood or marrow, apart from in two cases. Moreover, where a mobilizing treatment diminished tumor burden in the patient, at the same time it increased PB contamination in most cases. We conclude that advanced mantle cell NHL appears to be largely resistant to significant in vivo purging by conventional chemotherapy. Where treatment brings benefits by reducing tumor load, it may at the same time negate it by mobilizing malignant cells into the collections used to intensify. Although the clonogenic potential of this massive infiltration is unknown (only gene marking studies could provide a definitive answer regarding the source of relapses), strategies aimed at reducing the level of contamination in the graft should be considered when designing future protocols.
Adult↗
Use of image analysis and immunostaining of bone marrow trephine biopsy specimens to quantify residual disease in patients with B-cell chronic lymphocytic leukemia.
Marrow residual disease (RD) in patients with B-cell chronic lymphocytic leukemia (B-CLL) who are in complete remission (CR) after treatment with purine analogues is reported to have a prognostic value, but sample dilution, factors interfering with marrow aspiration, or undetectable immunoglobulin rearrangement can affect the assessment of RD by molecular or immunologic methods. As demonstrated for hairy cell leukemia and follicular lymphoma, bone marrow trephine biopsy specimen immunostaining (BMT/IS) can successfully detect residual malignant cells. The aim of this study was to use BMT/IS and computerized image analysis (CIMA) of bcl-2-positive cells to quantify RD in B-CLL patients in CR, after achievement of CR and more than 1 year later. This methodology was compared with other conventional techniques, i.e., cytologic, flow cytometric, cytogenetic, and molecular analysis. BMT/IS readily detected RD in every trephine biopsy specimen examined, either after CR or at distant follow-up. CIMA allowed an objective quantification of residual B-CLL cells, as evidenced by the correlation with semiquantitative polymerase chain reaction results. Both analyses indicated a progression of RD. This finding was also supported (but inconsistently) by the other techniques. CIMA with an interstitial labeling index, therefore, seems to be a reproducible and sensitive method to detect persistence and progression of RD in patients with B-CLL. This method could apply to other hematologic malignancies infiltrating the bone marrow.
Adult↗
2-Chlorodeoxyadenosine with or without daunorubicin in relapsed or refractory acute myeloid leukemia.
2-Chlorodeoxyadenosine (2-CdA) is a purine analogue which has proved to be active in acute myeloid leukemia (AML), especially in children. In adults, results yielded by 2-CdA alone or with ara-C were less encouraging. Here we report on the efficacy of 2-CdA with or without daunorubicin (DNR) in 19 relapsing or refractory adult AML patients, with a median age of 57 years. 2-CdA was administered as a continuous infusion to all patients at a dose of 0.1 mg/kg per day for 7 days. For 14 patients, DNR was added at a dose of 50 mg/m2 per day on days 5, 6, and 7. Antileukemic activity was observed in all the patients, but no single complete remission was achieved. One patient had a long-lasting partial response (response rate=5%). The remaining patients died of progressive AML (n=7), uncontrollable infection with persistent disease (n=10), and cerebral hemorrhage (n=1). Median survival from start of 2-CdA therapy was 56 days. Long-lasting neutropenia and transfusion-dependent thrombopenia were encountered in all 16 evaluable patients. Grade 4 hepatic toxicity occurred in one patient. Other side effects included nausea in six, mucositis in three, and mental disturbances in three patients. Compared with 2-CdA alone, the addition of DNR to 2-CdA changed neither the response rate nor the toxicities. In conclusion, our data do not support the use of 2-CdA +/- DNR for relapsing or refractory adult AML patients, at least as used in the present regimen.
Adolescent↗
Antisense oligodeoxyribonucleotides suppress hematologic cell growth through stepwise release of deoxyribonucleotides.
Antisense oligodeoxyribonucleotides (ODNs) are now being extensively investigated in an attempt to achieve cell growth suppression through specific targeting of genes related to cell proliferation, despite increasing evidence of non-antisense cytotoxic effects. In the context of anti-BCR/ABL antisense strategies in chronic myeloid leukemia, we have reexamined the antiproliferative effect of phosphodiester and phosphorothioate ODNs on the leukemic cell line BV173 and on CD34+ bone marrow cells in liquid culture. The 3' sequences of the ODNs determine their effect. At concentrations of 10 micromol/L (for phosphorothioate ODNs) or 25 micromol/L (for phosphodiester ODNs), all the tested ODNs exert an antiproliferative activity, except those that contain a cytosine residue at either their two most terminal 3' positions. We show that this antiproliferative effect is due to the toxicity of the d-NMPs (5' monophosphate deoxyribonucleosides), the enzymatic hydrolysis products of the ODNs in culture medium. The toxicity of the d-NMPs on hematologic cells depends on their nature (d-CMP [2'deoxycytidine 5'-monophosphate] is not cytotoxic), on their concentration (d-GMP [2'-deoxyguanosine 5'-monophosphate], TMP [thymidine 5'-monophosphate], and d-AMP [2'-deoxyadenosine 5'-monophosphate] are cytotoxic at concentrations between 5 and 10 micromol/L), and on the coincident presence of other d-NMPs in the culture medium (d-CMP neutralizes the toxicity of d-AMP, d-GMP, or TMP). The antiproliferative activity of ODNs is thus restricted to conditions where the 3' hydrolysis process by exonucleases generates significant amounts of d-NMPs with a low proportion of d-CMP. Our results reveal a novel example of a nonantisense effect of ODNs, which should be taken into account when performing any experiment using assumed antisense ODNs.
Cell Division↗
Philadelphia-like translocation t(9;22)(q34;q11) found in a follicular lymphoma involving not BCR and ABL but IGL-mediated rearrangement of an unknown gene on 9q34.
In a case of follicular center cell lymphoma (FCCL) without evidence of histologic progression towards a high-grade lymphoma, t(9;22)(q34;q11) was found simultaneously with a t(14;18)(q32;q21) and a t(8;14)(q24;q32). Molecular studies of this case showed BCL2 and MYC rearrangements in addition to the rearrangements of immunoglobulin heavy (IGH) and lambda (IGL) loci. Investigation of the t(9;22) using Southern blot and RT-PCR analysis failed to detect M-bcr or m-bcr rearrangements of BCR. Two-color fluorescence in situ hybridization (FISH) with ABL and BCR probes revealed presence of a "fusion" signal, but its atypical localization [der(9)] and gene order [cen-ABL-BCR-tel] indicated that this translocation differed from the t(9;22) in chronic myeloid leukemia and did not involve either ABL or BCR. In addition, further FISH analysis using 9q34- and 22q11-specific probes localized the breakpoint on chromosome 9 distal to the NOTCH1 gene and the breakpoint on 22q11 in the IGL gene cluster. These results indicate an IGL-mediated rearrangement of an unknown gene at 9q34 that together with BCL2 and MYC might be involved in the lymphomagenesis of the present case of FCCL and perhaps in other cases of non-Hodgkin lymphoma in which t(9;22) is sporadically occurring.
Blotting, Southern↗
A prospective study of minimal residual disease in childhood B-lineage acute lymphoblastic leukaemia: MRD level at the end of induction is a strong predictive factor of relapse.
We prospectively investigated minimal residual disease (MRD) in 51 children with B-lineage acute lymphoblastic leukaemia (ALL) treated according to the Fralle 93 protocol. PCR follow-up was performed in children in morphological and cytogenetic complete remission, provided an immunoglobulin (IgH) gene rearrangement could be detected using FR 3/J(H) amplimers. MRD was studied according to our previously described methodology, with a few modifications including the use of a consensus J(H) probe to control for PCR efficiency variations. Out of the initial 51 patients, 34 were assessable for MRD at the end of induction at the time of analysis. MRD levels were as follows: > 1/10(3) in 26%, 1/10(3) to 1/10(4) in 50% and < 1/10(4) or not detectable in 24%. With a median follow-up of 20 months there were five relapses, all of which occurred in the group of patients with MRD > 1/10(3). To date, none of the patients with MRD < or = 1/10(3) (good molecular responder) has relapsed. Classification according to molecular response at the end of induction did not correlate with the conventional risks groups: there were no statistically significant differences between good and bad molecular responders. Of particular interest is the absence of correlation between WBC at diagnosis and MRD level at the end of induction. We conclude that classification of patients into good and bad molecular responders using PCR seems to be a better prognostic indicator than conventional risk factors in childhood B-lineage ALL. Patients with MRD level > 1/10(3) have a particularly poor outcome and should always be considered for alternative therapeutic strategies in the future, whereas in good molecular responders belonging to poor or intermediate risk categories, treatment de-escalation might be contemplated.
Antineoplastic Combined Chemotherapy Protocols↗
ider(9)(q10)t(9;22)(q34;q11) is a recurrent chromosomal abnormality in acute lymphoblastic leukemia and lymphatic blastic phase of chronic myelogenous leukemia.
We report on two cases, one with acute lymphoblastic leukemia and a second with lymphatic blastic phase of Philadelphia chromosome-positive chronic myelogenous leukemia, cytogenetically characterized by ider(9)(q10)t(9;22)(q34;q11). Our findings and the data of the 4 cases previously published indicate that ider(9)(q10)t(9;22)(q34;q11) represents a rare but recurrent chromosomal abnormality occurring in hematological malignancies with lymphoid differentiation, namely acute lymphoblastic leukemia and lymphatic blastic phase of chronic myelogenous leukemia, and most likely evolves from a preexistent der(9) involved in the standard t(9;22).
Adult↗
Infectious complications after 2-chlorodeoxyadenosine therapy.
Infection is a common adverse event after therapy with nucleoside analogs, including 2-chlorodeoxyadenosine (CdA). However, the incidence of CdA-related infections has been poorly documented. In this study we compare, in the same patient population, the incidence of infectious episodes during the 6-month period before CdA to their incidence during the 6 months after initiating therapy. Ninety-five patients with hematological malignancies were studied. The incidence of infectious episodes almost doubled after CdA (0.87 vs. 0.47 during the pre-CdA period). The following factors were associated with an increased risk of infection after therapy: a history of previous chemotherapy, infection during the pre-CdA period and a diagnosis of chronic lymphocytic leukemia or of non-Hodgkin's lymphoma. Age, neutrophil and lymphocyte count at onset of CdA and time interval between diagnosis and therapy with CdA did not correlate with the infectious risk. The pattern of infections was modified after therapy with an increase of herpes virus infections ( 1 vs. 8 episodes, p=0.04) and of fever of unknown origin (6 vs. 17 episodes, p=0.03). In conclusion, a population at high risk for developing infectious complications after CdA therapy can be identified. Specific measures aimed at reducing the incidence of infectious events should concentrate on this population.
Adult↗
Limited activity of mini-dose interferon alpha-2a in the treatment of myelodysplastic syndrome.
Impairment in marrow function often characterizes the evolution of myelodysplastic syndrome. As a differentiating agent, interferon alpha 2a (INF alpha) has been shown to be active in the correction of cytopenias related to myelodysplastic syndromes (MDS). We report the clinical course of 9 patients with MDS treated with low-dose subcutaneous INF alpha (1 x 10(6), 3 times per week). A significant effect on anemia was only demonstrated in one patient (11%). In the other, eight, therapy was totally ineffective and four of them could not receive the complete treatment due to worsening cytopenias or leukemic transformation. In conclusion, in our study, INF alpha had only limited activity in the treatment of myelodysplastic syndrome.
Drug Evaluation↗
BCR-ABL antisense oligodeoxyribonucleotides suppress the growth of leukemic and normal hematopoietic cells by a sequence-specific but nonantisense mechanism.
We have examined the effect of BCR/ABL junctional antisense phosphodiester oligodeoxyribonucleotides (ODNs) on BV173 and other chronic myeloid leukemia (CML) cell lines. Various control ODNs were used to understand the mechanism of the observed antiproliferative effect. Not only the antisense ODNs but also several control ODNs inhibit the proliferation of the leukemic cell lines. All the ODNs that inhibit the cell proliferation share a TAT consensus sequence at their 3' end. A 1-base mismatch within this consensus sequence abolishes the antiproliferative effect. Mismatches of several bases at any other position within the sequence of the active ODNs do not suppress the observed effect. Similar experiments on normal or CML CD34+ cell fraction led to the same observations. We conclude that the antiproliferative effect of the phosphodiester BCR/ABL antisense ODNs cannot be attributed to an antisense mechanism but rather to a nonelucidated effect of a 3' terminal TAT sequence. This effect is not CML specific.
Base Sequence↗