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Biomedical subjects

D Sainty

Publications and source records attributed to D Sainty.

At least 73 records · Page 4Linked to original sources
PubMed1996

Correction of aplastic anaemia complicating paroxysmal nocturnal haemoglobinuria: absence of eradication of the PNH clone and dependence of response on cyclosporin A administration.

Paroxysmal nocturnal haemoglobinuria (PNH) is defined as a somatic mutation of a clonal population of stem cells. Consequently, when aplastic anaemia (AA) occurs in patients with a history of PNH, allogeneic bone marrow transplantation is considered as the only effective treatment. The impact of immunosuppressive therapy has not been reported in this situation. We present observations of three PNH patients who developed AA and were effectively treated with cyclosporin A (CSA). Because of lack of improvement with other treatments, CSA alone was given at a dose of 5-10mg/kg/d. Complete response (CR) was obtained in two patients after 6 and 24 months respectively. A partial response (PR) was observed in the third patient after 12 months. Transient elevated LDH and haemosiderinuria persisted in all cases. DAF and MIRL deficiency were still documented in the two patients in CR. Two patients (one CR, one PR) ceased CSA therapy after 12 months and relapsed within 3-6 months. CSA was reinitiated and led to platelet recovery in one patient after 6 months. The persistence of the abnormal PNH clone is coherent with the hypothesis that CSA does not act directly on the PNH clone but probably acts through regulation of the inhibitory effects of immunocompetent cells on haemopoiesis. These observations suggest that patients suffering from severe AA complicated PNH should not be excluded from immunosuppressive therapy.

Adult↗
PubMed1996

Human FLT3/FLK2 receptor tyrosine kinase is expressed at the surface of normal and malignant hematopoietic cells.

FLT3/FLK2 is a receptor tyrosine kinase (RTK) which is thought to play an important role in early stages of hematopoiesis. Monoclonal antibodies (mAbs) against the extracellular domain of human FLT3 were generated to study the cell surface expression of this class III RTK on normal bone marrow cells and on leukemic blasts from patients with acute leukemias. Functional analysis of five mAbs (SF1 series) revealed that all of them can mimic to variable extents the activity of the FLT3 ligand (FL) upon receptor activation and modulation, while only one mAb weakly inhibited ligand binding. Using flow cytometry, we detected surface expression of FLT3 on cell lines of the myeloid (4/8) and B lymphoid (7/10) lineages. On normal human bone marrow cells, the expression of FLT3 is restricted, in agreement with a presumed function of this receptor at the level of the stem cells and early committed progenitors. Expression of FLT3 was found on a fraction of CD34-positive and CD34-negative cells. Three-color analysis further revealed that most of the CD34 FLT3+ cells coexpress CD117 (KIT) at a high level. Finally, FLT3 is expressed on leukemic blasts of 18/22 acute myeloid leukemias (AML) and 3/5 acute lymphoid leukemias (ALL) of the B lineage, providing a possible application in diagnosis and therapy of these diseases.

Antibodies, Monoclonal↗
PubMed1996

[Contamination of cytapheresis by tumor cells: apropos of 39 breast cancer cases].

The purpose of the present study was the detection of tumor cells in aphereses after mobilization of peripheral blood stem cells (PBSCs) with G-CSF from 39 breast cancer patients. Circulating tumor cells were searched using sensitive immunocytochemical technique (APAAP) with three anticytokeratin monoclonal antibodies. Counting of mononuclear cells and CD34 progenitor cells was also performed. Circulating tumor cells were detected in 35% of the patients. Cytokeratin-positive cells were detected in 45% of the patients of the metastatic group compared with 20% of the non metastatic one. Aphereses contamination was not correlated with lymph node involvement. Numbers of mononuclear cells and CD34 cells were not significantly different in positive and negative PBSCs collections. In our study, presence of tumor cells was associated with advanced clinical stage and could not be related to a higher CD34 cells mobilization by G-CSF.

Adult↗
PubMed1996

A pilot study of busulfan and melphalan as preparatory regimen prior to allogeneic bone marrow transplantation in refractory or relapsed hematological malignancies.

In this pilot study; we assessed the immunosuppressive and the antileukemic potential of a combination of busulfan and melphalan prior to allogeneic BMT in 25 adult patients with refractory or relapsed hematological malignancies. Twelve patients were transplanted for acute myeloid leukemia (relapse: five patients; primary refractory: four patients; second remission: two patients), two patients for primary refractory acute lymphoblastic leukemia, nine patients for chronic myelogenous leukemia (accelerated phase: six patients; blastic phase: three patients) and two patients for primary refractory lymphoma. All received an unmanipulated marrow from HLA-identical siblings. All patients but one engrafted (median time to ANC > or = 0.5 x 10(9)/l = 17 days, to platelets > or = 50 x 10(9)/l = 29 days). Full chimerism was documented in the seven evaluable patients. The probability for developing acute GVHD was 58%. Complete remission was obtained in 17/18 measurable patients. With a 42 month median follow-up, eight patients are alive in unmaintained remission. The 4-year probabilities for relapse, survival, and DFS are respectively: 42%, 35%, and 31%. These results show that the combination of busulfan and melphalan ensures an effective immunosuppression allowing long-term engraftment. This regimen can provide long-term disease-free survival in patients with high-risk disease and thus represents an interesting alternative to the CY and/or TBI-containing regimens.

Adult↗
PubMed1995

Acute promyelocytic leukemia cases with nonreciprocal PML/RARa or RARa/PML fusion genes.

Tumor-associated chromosome translocations usually lead to the formation of two reciprocal fusion genes: one thought to be involved in the transformation process, the other the mechanical consequence of the translocation event. In the case of acute promyelocytic leukemia (APL) blasts, the 15;17 chromosome translocation generates the putatively transforming PML/RARa fusion gene and its reciprocal RARa/PML. We report APL cases with submicroscopic 15;17 recombinations leading to the formation of nonreciprocal PML/RARa or RARa/PML fusion genes. Therefore, each of the two reciprocal translocation products may be independently formed and selected by the leukemic phenotype, implying that both are involved in tumorigenesis.

Base Sequence↗
PubMed1995

Unbalanced translocation t(5;17) in an typical acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL; M3 in the FAB classification) is specifically associated with the t(15;17)(q23;q12) and the consequent formation of a PML/RARA fusion gene. A few cases of APL with a t(11;17)(q23;q12) and a PLZF/RARA fusion gene have recently been reported. In addition, a new variant, t(5;17)(q32;q12), with a RARA rearrangement was described in a child with atypical APL. We report an unbalanced der(5)t(5;17) in an atypical APL case showing unusual dysgranulopoiesis and some M2 features. The breakpoints were difficult to localize precisely on chromosome 5, because the translocation may have occurred on a previous del(5q). The karyotype also showed del(8q) and multiple double-minutes (dmin). Molecular studies evidenced RARA rearrangement but showed neither PML rearrangement nor PML/RARA fusion. Fluorescence in situ hybridization revealed that the dmin were of chromosome 8 origin and that they accounted for the MYC amplification observed in Southern blots. The patient did very poorly despite chemotherapy and all-trans retinoic acid (ATRA) treatment. Thus, the t(5;17) could represent a second type of variant translocation in APL that, like the disease associated with t(11;17), does not seem to respond to ATRA therapy. Whereas RARA rearrangement appears sufficient for an APL-like phenotype, it seems that the presence of a classical PML/RARA is required for typical APL with response to ATRA.

Aged↗
PubMed1995

Translocation of BCR to chromosome 9 in a Philadelphia-negative chronic myeloid leukemia.

We report the case of a patient having Philadelphia-negative, bcr-abl-positive chronic myeloid leukemia. In situ hybridization showed the presence of the bcr-abl fusion on the chromosome 9 long arm in all mitoses observed. Stability of the disease was very difficult to obtain because of serious adverse effects to interferon and chemotherapy, mainly grade IV neutropenia, and a blast crisis occurred 12 months after diagnosis. Only three other patients with such presentation (Philadelphia negative, bcr-abl positive with bcr-abl fusion on the chromosome 9 long arm) have been reported, with a poor therapeutic response and outcome in two of them. Translocation of BCR to chromosome 9 may therefore have a worse prognosis than translocation of ABL to chromosome 22 in Philadelphia-negative chronic myeloid leukemia.

Adult↗
PubMed1995

Direct evidence for dissociated megakaryocytic chimaerism in a Wiskott-Aldrich patient successfully allografted.

We report a Wiskott-Aldrich patient who underwent allogeneic bone marrow transplantation from his HLA-identical sister at the age of 25. Conditioning regimen consisted of cyclophosphamide (180 mg/kg) and thoraco-abdominal irradiation (6 Grays). Cytogenetic follow-up revealed rapid and complete lymphoid chimaerism, but prolonged mixed bone marrow chimaerism. Correlative interphase cytogenetics performed on bone marrow smears using dual-colour fluorescence in situ hybridization with X and Y specific probes showed that the proportion of donor cells was significantly higher within megakaryocytes than in other lineages. This patient therefore presented with dissociated lineage engraftment, which is not exceptional in congenital diseases and aplastic anaemia, but has not previously been described in Wiskott-Aldrich syndrome. Bone marrow transplantation was successful despite this delayed engraftment which ensured adequate production in the involved cell lines.

Adult↗
PubMed1995

Philadelphia chromosome-negative chronic myeloid leukaemia: a report of 14 new cases.

The Philadelphia chromosome (Ph) is the cytogenetic hallmark of chronic myeloid leukaemia (CML) and is used to confirm the diagnosis of CML based on clinical and morphological criteria. We investigated 14 patients with features of CML but without detectable Ph chromosome. In seven patients, referred to as BCR+, M-bcr/abl rearrangement was detected by polymerase chain reaction (PCR). The seven remaining patients did not have M-bcr/abl rearrangement and are described as BCR-. BCR- patients were younger, had lower white blood cell counts (WBC) and lower basophilia. Four BCR- and four BCR+ patients underwent blastic transformation (BT). Response to therapy was fairly similar in both populations. According to French-American-British (FAB) Cooperative Leukaemia Group guidelines, all BCR- patients were classified as having classic form CML or 'chronic granulocytic leukaemia' (CGL) when based only on morphological data. This study further confirms the existence of true CML cases without Ph chromosome or M-bcr/abl rearrangement and shows that this entity differs only slightly from classic form Ph+ CML. The Ph-BCR- subgroup raises two problems. First, the differential diagnosis with atypical CML or CMML, based on morphological data, and secondly, the therapeutic follow-up in the absence of a specific marker. In contrast, the residual disease of Ph-BCR- patients can be monitored by PCR. More advanced molecular and biochemical techniques will be required to understand which molecular mechanisms underlie Ph-BCR- CML, resulting in phenotypes sometimes indistinguishable from Ph+ CML.

Base Sequence↗
PubMed1995

Minor breakpoint cluster region (m-BCR) positive chronic myeloid leukaemia with an acute lymphoblastic leukaemia onset: a case report.

m-BCR chronic myeloid leukaemia (CML) is a rare entity. We report a patient presenting with Philadelphia (Ph)-positive, m-BCR-positive acute lymphoblastic leukaemia (ALL) who achieved complete remission after induction chemotherapy, but showed a majority of Ph-positive mitoses during this remission. A diagnosis of m-BCR CML was established and the patient was given interferon alpha therapy. This is the first m-BCR CML presenting as ab initio ALL. This report emphasizes the importance of karyotyping Ph-positive ALL during remission so as not to misdiagnose CML patients who can benefit from Interferon therapy.

Adult↗
PubMed1995

Persistence of BCR/ABL mRNA-expressing bone-marrow cells in patients with chronic myelogenous leukemia in complete cytogenetic remission induced by interferon-alpha therapy.

Complete hematologic and cytogenetic responses can be obtained with interferon-alpha (IFN-alpha) in 15-25% of the patients with chronic myelogenous leukemia (CML). In these patients, reverse-transcription polymerase chain reaction (RT-PCR) can be used to evaluate minimal residual disease. We studied 12 patients who remained Philadelphia-negative for a median period of 21 months on IFN-alpha therapy. Using RT-PCR, the specific transcript was found in all bone marrow (BM) samples. Ten patients still exhibiting a persistent residual clone remained in cytogenetic remission for a median period of 14 months. As we observed a dissociation between bcr-abl expression in BM and peripheral blood (PB) cells, and given the known fluctuations of the bcr-abl PCR results, we suggest that PB negative results should be confirmed on BM specimens. Alternatively, it remains to be demonstrated whether longitudinal monitoring of residual disease would benefit from quantitative PCR or double fluorescence in situ hybridization.

Adult↗
PubMed1994

In vivo stimulation of neutrophil function by lenograstim (glycosylated rHuG-CSF) in oncohematologic patients: results of a phase I trial.

The aim of this work was to study the evolution of neutrophil functions in non-neutropenic cancer patients. Thirty non-neutropenic patients, median age 35 years (range 19-52), with solid tumors (n = 21) or lymphomas (n = 9) entered a phase I study of five days of s.c. (n = 24) or i.v. bolus (n = 6) lenograstim, recombinant human glycosylated granulocyte colony-stimulating factor (rHuG-CSF Chugai-Rhône-Poulenc), with dose escalation from 1 to 40 micrograms/kg/day. Neutrophil functions were studied before lenograstim (D1) and 24 h after the last dose (D6). Granulocyte count rose in a significant way, and enzyme release, phagocytosis and bacterial killing were stimulated. All patients had improvement of at least one neutrophil function. Directed migration was depressed, although it was still in the normal range. These findings confirm that lenograstim is a potent activator of neutrophil functions in non-neutropenic cancer patients and may be useful as an adjunct to conventional antimicrobial therapy.

Adult↗
PubMed1994

Bone marrow transplantation in 63 adult patients with acute lymphoblastic leukemia in first complete remission.

Over a 10 year period, we transplanted 63 patients with acute lymphoblastic leukaemia (ALL) who had achieved first complete remission (CR). All were > 15 years old and 45 (71%) had at least one poor prognostic factor. Twenty-nine patients with a suitable sibling underwent autologous bone marrow transplantation (BMT). Beginning in 1984, patients without a donor received an allogeneic BMT (34 patients). Preparation consisted of cyclophosphamide (CY)/TBI (78%) or melphalan (Mel)/TBI (22%); marrow was treated in vitro in 31 patients (allogeneic: 7; autologous: 24). Kaplan-Meier estimates of the probability at 6 years of relapse, survival and DFS were 41% (allogeneic: 10%, autologous: 65%, p < 0.05), 44% (allogeneic: 62%, autologous: 26%, p = NS) and 42% (allogeneic: 62%, autologous: 27%, p < 0.06), respectively. This report confirms that allogeneic BMT permits long-term remissions giving high levels of survival when performed shortly after entering first CR while autologous BMT, when performed in the same setting, is less successful at preventing relapse. This study also confirms the high sensitivity of ALL to the graft-versus-leukemia effect provided by allogeneic BMT. Chemoradiotherapy dose intensification delivered at autologous BMT is not sufficient to prevent relapses. Autologous BMT must therefore be augmented by other approaches of which immunotherapy may be one.

Adolescent↗
PubMed1994

Modifications of leukemic blast cells induced by in vivo high-dose recombinant interleukin-2.

High-dose recombinant human Interleukin-2 was given to 21 patients with acute myeloid (n = 11) or lymphoid (n = 10) leukemia in relapse. A rapid decrease in the peripheral leukemic blasts numbers was observed in six patients. We were unable to demonstrate at the bone marrow level a diminution in the percentage of leukemic blasts. However an increase in the expression of the adhesion molecule CD54/ICAM-1(LFA-1 ligand) affected the leukemic bone marrow blasts of these six patients. This increase in CD54 was found in eight of the 11 (73%) AML and four out of the ten (40%) ALL blasts and CD58/LFA-3 (CD2 ligand) to a lesser extent. This increased expression was not associated with modifications in the expression of MHC class II molecules. In vivo IL-2 also dramatically modified the bone marrow T-cell subsets via the increase of CD3+ cells expressing the CD45RO 'memory' marker (six out of the eight tested patients) or CD54 (seven out of the eight tested patients). Altogether these results demonstrate that leukemic blasts can be affected by in vivo IL-2 via mechanisms that could involve T cells.

Acute Disease↗
PubMed1993

In vitro inhibition of interleukin-2-induced defective polymorphonuclear chemotaxis by TNF inhibitor.

Patients undergoing immunotherapy with interleukin-2 experience multiple side effects and are highly susceptible to bacteremia. In a previous study, we confirmed that a profound deficiency of neutrophil chemotaxis is induced by interleukin-2 therapy. Migration in response to N-formyl-methionyl-leucyl-phenylalanine (FMLP), being normal before therapy, was markedly impaired after the first cycle and further decreased after the third cycle of treatment. A direct effect of interleukin-2 on neutrophil chemotaxis is controversial. However, peripheral blood cells exposed to interleukin-2 secrete secondary cytokines. In particular, the release of tumor necrosis factor after interleukin-2 injection has been proposed as an important regulatory mechanisms. When testing random migration and chemotaxis of neutrophils from normal subjects after incubation with the serum from treated patients, we found that this serum induced a defective chemotaxis similar to that of neutrophils from interleukin-2-treated patients. In order to assess the influence of tumor necrosis factor, we tested the effect of anti-tumor necrosis factor-alpha antibody on the chemotactic response of cells after incubation with the serum, and we observed a dose-dependent reduction of neutrophil chemotaxis deficiency. These data suggest that TNF is counteracting the neutrophil chemotactic deficiency observed during IL-2 treatment.

Adult↗
PubMed1993

Translocation t(1;19) in acute lymphoblastic leukemia patients with cytological presentation simulating L3-ALL (Burkitt-like).

The t(1;19) in B-lineage ALL is classically associated with a FAB L1/L2 phenotype and the expression of cIg. Recent reports have demonstrated immuno-phenotypic and molecular heterogeneity among cases demonstrating apparently identical karyotypic abnormalities. We report 5 cases of t(1;19) with cytological features resembling an L3 (Burkitt-like) phenotype, suggesting that accurate assessment of these cases requires detailed correlation of cytological, immunological and molecular characteristics.

Adult↗