Biomedical subjects

S Siena

Publications and source records attributed to S Siena.

119 records · Page 7Linked to original sources

PubMedDate not supplied

Flow cytometry to estimate circulating hematopoietic progenitors for autologous transplantation: comparative analysis of different CD34 monoclonal antibodies.

We report that the 2 fluorescein (FITC) conjugated CD34 monoclonal antibodies available to date, namely FITC-8G12 and FITC-QBEND10, exhibit different capabilities of detecting circulating hematopoietic progenitors (CHP) as cells expressing the CD34 antigen (CD34+) by direct immunofluorescence flow cytometry. Mean fluorescence intensity conferred by FITC-QBEND10 to CD34+ CHP is 2.8-4.3 times lower than that conferred by FITC-8G12. By indirect immunofluorescence, native unconjugated QBEND10 and 8G12 antibodies detect CD34+ CHP in a comparable manner, thus indicating that the decrease in QBEND10 affinity is due to FITC-conjugation. Utilization of FITC-QBEND10 instead of FICT-8G12 to estimate infrequent (usually less than or equal to 5%) CD34+ CHP for clinical decision-making in autologous transplantation of CHP exposes clinicians to the risk of either overestimating (false positive) or underestimating (false negative) these cells in peripheral blood. Recently published guidelines for large-scale collection of CHP for autologous transplantation in cancer patients were based on data obtained with FITC-8G12. The same guidelines cannot be considered valid if FITC-QBEND10 is employed. We recommend FITC-8G12 as the optimal reagent to date for standardizing results of autologous CHP transplantation in cancer therapy.

Antibodies, Monoclonal↗

PubMedDate not supplied

GM-CSF-exposed peripheral blood progenitors as sole source of stem cells for autologous transplantation in two patients with multiple myeloma.

Two patients (aged 52 and 44) received high-dose sequential chemotherapy followed by myeloablative therapy and autotransplantation as first line treatment of a stage III multiple myeloma with high plasmacell labelling index. Autograft was performed with peripheral blood cells collected after high-dose etoposide followed by rhGM-CSF continuous infusion. During this period very high numbers of circulating hemopoietic progenitors were detected in both patients. Prompt, complete and durable hematological recovery was observed after autograft with peripheral blood stem cells. Thus, we conclude that massively released progenitors after high-dose chemotherapy and rhGM-CSF include stem cells capable of marrow reconstitution.

Adult↗

PubMedDate not supplied

Role of recombinant human granulocyte-macrophage colony stimulating factor for large scale collection of peripheral blood stem cells for autologous transplantation.

Twenty-seven cancer patients underwent peripheral blood stem cell apheresis during hematopoietic regeneration following induction high-dose cyclophosphamide (7 g/sqm; HD-CTX). Among these patients, eleven were also treated with granulocyte-macrophage colony stimulating factor (rhGM-CSF) for 14 days after HD-CTX. We describe technique, peripheral blood cell yields and side effects of 76 leukaphereses performed using a continuous-flow blood cell separator COBE 2997. Leukaphereses, carried out through 2-5 consecutive days per patient, were started significantly earlier in rhGM-CSF treated patients. In comparison to patients receiving HD-CTX only, administration of rhGM-CSF resulted in a significantly higher yield per leukapheresis of mononuclear cells and granulocyte-macrophage colony forming units (CFU-GM) (two-fold and eight-fold, respectively). Procedures were completed and well tolerated in all cases. Minor side effects were unfrequent. Our results suggest that rhGM-CSF accelerates hematopoietic recovery after HD-CTX and facilitates large-scale collection of peripheral blood stem cells utilizable for autologous transplantation.

Bone Marrow Transplantation↗

PubMedDate not supplied

Heterogeneity of circulating hematopoietic progenitors in cancer patients treated with high-dose cyclophosphamide and recombinant human granulocyte macrophage colony stimulating factor (rhGM-CSF).

Antigen CD34+ cells represent 1-4% of adult bone marrow cells comprising virtually all hematopoietic colony-forming progenitors in-vitro and probably also stem cells capable of restoring hematopoiesis of lethally irradiated hosts. We report that sizable numbers of CD34+ cells transiently circulate in the peripheral blood (PB) of patients treated with high-dose (7 g/sqm) cyclophosphamide (HD-CTX) with or without recombinant human glycosylated granulocyte macrophage colony stimulating factor (rhGM-CSF). Evidence is presented demonstrating that CD34+ cells from PB possess qualitatively normal hematopoietic colony growth and high cloning efficiency similarly to marrow CD34+ cells. In addition, CD34+ cells from PB are shown to display heterogeneous flow cytometry characteristics and differentiation antigens analogous to those from bone marrow, i.e., CD34+/CD33-, CD34+/CD13-, CD34+/CD38-, CD34+/CD11b, CD34+/DRlow+ cells have light scatter properties of small lymphocytes while CD34+/CD33+, CD34+/CD13+, CD34+/CD38+, CD34+/CD11b+, CD34+/DRhigh+ cells have light scatter properties of blast-like cells. In HD-CTX treated patients, CD34+ cell circulation is 5-fold enhanced by rhGM-CSF 5.5 micrograms/kg/day by continuous iv infusion for 14 days. During the second-third week after HD-CTX, large-scale collection of PB leukocytes by 3-4 continuous-flow leukaphereses allows the yield of 2.19-2.73 x 10(9) or 0.45-0.56 x 10(9) CD34+ cells, depending on whether or not patients receive rhGM-CSF. The number of CD34+ cells retrieved from PB by leukaphereses exceeds the number that can be harvested by multiple bone marrow aspirations under general anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗

PubMedDate not supplied

High-dose cyclophosphamide in patients with operable breast cancer: recombinant human GM-CSF ameliorates drug-induced leukopenia and thrombocytopenia.

Seventeen patients with breast cancer (nine patients with 10 ipsilateral metastatic axillary nodes, eight patients with inflammatory breast carcinoma) previously untreated with cytotoxic chemotherapy received high-dose cyclophosphamide, 7 g/sqm (HD-CTX) as initial step of a high-dose sequential chemotherapy program. Eleven patients received also intravenous recombinant human granulocyte macrophage-colony stimulating factor (GM-CSF), 5.5 micrograms/kg per day for 7-14 days after HD-CTX. This growth factor significantly ameliorated leukopenia and thrombocytopenia induced by HD-CTX therapy thus allowing earlier delivery of subsequent courses of chemotherapy.

Adult↗

PubMedDate not supplied

Conditions influencing the expansion of the circulating hemopoietic progenitor cell compartment.

Eighteen patients (6 breast cancer, 10 non-Hodgkin's lymphoma, 2 Hodgkin's disease) were treated with high-dose cyclophosphamide (7 gr/mq), while 12 (2 breast cancer, 5 non-Hodgkin's lymphoma, 5 multiple myeloma) were additionally treated with rhGM-CSF for 14 days after cyclophosphamide. During recovery, increased peak values of circulating CFU-GM were observed in 23 out of 30 patients (13 patients after cyclophosphamide, median: 5,000 CFU-GM/ml; 10 patients after cyclophosphamide + rhGM-CSF, median: 20,150 CFU-GM/ml); five of these "high releaser patients" were in 1st relapse after MACOP-B. Seven patients showed low release of CFU-GM; they had either a history of multiple exposures to chemoradiotherapeutic treatments or bone marrow replacement by neoplastic cells or both. Four out of 23 patients with high CFU-GM release were subsequently studied after administration of high-dose etoposide (2 gr/mq): increased levels of circulating progenitors were seen again, although peak values were reduced when compared to post-cyclophosphamide period. Three patients with low release and bone marrow involvement had a clear increase of circulating CFU-GM after etoposide. The results show the influence of high-dose chemotherapy, rhGM-CSF, type of previous treatment and bone marrow involvement on the degree of circulating CFU-GM release.

Antineoplastic Agents↗

PubMedDate not supplied

Immunotoxin mediated killing of clonable T-lymphocytes infiltrating an irreversibly rejected human renal allograft.

We isolated and treated in vitro with a novel CD5-specific saporin immunotoxin, referred to as OKT1-SAP, the cells infiltrating an irreversibly rejected renal allograft from a patient who rejected while on cyclosporine plus steroids and then failed to respond to multiple courses of high-dose steroids, intravenous OKT3 antibody, and local irradiation to the graft. We report here that under experimental conditions achievable in vivo the immunotoxin OKT1-SAP was capable of eliminating in vitro more than 95% of clonable T-lymphocytes infiltrating the rejected allograft of this patient despite their resistance to previous aggressive immunosuppression. To our knowledge, this is the first report of an immunotoxin-mediated suppression of the clonogenic growth of rejected renal allograft infiltrating T-lymphocytes.

Adult↗

PubMedDate not supplied

Detection of occult leukemic cells in the autologous bone marrow graft of a patient with T-cell acute lymphoblastic leukemia by a highly specific and sensitive assay.

A patient with T-cell acute lymphoblastic leukemia (T-ALL) in second remission was treated with high doses of chemotherapy and radiotherapy, followed by transplantation of autologous bone marrow purged ex-vivo with an anti-CD5-saporin immunotoxin (OKT1-SAP). Prior to transplantation the bone marrow graft had been considered in complete remission, as assessed by morphology and immunophenotyping. Twenty-two days after transplantation, the disease relapsed in the bone marrow with the same phenotype as at the onset. Retrospective analysis of the transplanted marrow cells by a recently developed high sensitivity and specificity assay (HSS assay), involving immunologic fractionation and T-cell receptor rearrangement analysis, revealed a graft contamination of approximately 0.5% malignant T-cells. This finding, together with the early post-transplant leukemic relapse, strongly suggests that the bone marrow was the source of the leukemic cells. The data are discussed for their implications on residual leukemia detection by gene rearrangement studies.

Adolescent↗

PubMedDate not supplied

Detection of bone marrow minimal disease in non-Hodgkin's lymphoma patients by gene rearrangement analysis.

Bone marrow aspirates from 13 patients with non-Hodgkin's lymphoma of B- and T-lineage were drawn during staging procedures and examined by a combined technique involving immune selection and gene rearrangement analysis with DNA probes specific for the heavy-chain immunoglobulin gene (JH) or T cell receptor gene (T beta and T gamma). Morphologic examination of bone marrow biopsies revealed involvement by lymphoma in one case and suspicious accumulation of blasts in another. Southern blot analysis of the samples showed the presence of a rearranged clonal band in two samples, including the morphologically involved marrow. Clonal rearrangements were not detected in the suspected marrow. Bone marrow relapses were not observed in any of these patients after a median follow-up of 20 months. Antigen receptor rearrangements are tumor-specific markers which may increase the sensitivity and the specificity of morphologic examination, and may be useful in the proper staging and follow-up of lymphoma patients.

Bone Marrow↗

PubMedDate not supplied

[Long-term hematopoietic reconstitution after myeloablative antitumor therapy and circulating hematopoietic stem cell transplantation].

BACKGROUND: It remains unknown if hematopoiesis reconstituted by autografting with the sole peripheral blood hematopoietic progenitors (CPCs) after myeloablative high dose radiotherapy and/or chemotherapy is durable and capable of coping with increased demand due to boost radiotherapy, surgery, or infection. PATIENTS AND METHODS: Durability of hematopoiesis was evaluated in 34 consecutive cancer patients treated with myeloablative total body irradiation (n = 17, median follow-up 3 years, range 3-49 months) and/or alkylating agent chemotherapy (n = 17, median follow-up 8 months, range 6-41 months) and autografted with CPCs because bone marrow autografting was contraindicated. CPCs (> or = 8 x 10(8) CD34+ cells/kg) had been collected during mobilization into the circulation in response to previous anticancer therapy and hematopoietic growth factor(s). RESULTS: Following brief temporary pancytopenia, all patients achieved normal and durable hematopoiesis. The newly reconstituted hematopoietic system was capable of reacting favorably to stressful and noxious events such as surgery, radiotherapy, or varicella-zoster infection. No secondary irreversible failure of blood cell production occurred. CONCLUSIONS: The documentation of the durability of normal hematopoiesis following myeloablative cancer therapy and autografting with mobilized CPCs implies that the latter procedure, rather than solely an alternative to bone marrow autografting, represents an advantageous tool of choice permitting substantial amelioration of the therapeutic index of high-dose cancer therapy.

Cryopreservation↗

PubMedDate not supplied

Gene transfer into human dendritic antigen-presenting cells by vaccinia virus and adenovirus vectors.

In a search for means to deliver exogenous gene(s) into human dendritic cells (DCs) from the perspective of tumor-specific vaccination, we have evaluated two recombinant viruses, both of which carry a reporter gene which is namely a modified vaccinia virus Ankara (MVA) and an adenovirus, as possible expression vectors. The recombinant MVA-P11 LZ vector carries the Escherichia coli lacZ gene coding for the enzyme beta-galactosidase, and the recombinant Ad-MFG-AP vector carries a modified membrane-exposed alkaline phosphatase (AP) gene. DCs were generated ex vivo in the presence of tumor necrosis factor-alpha, granulocyte macrophage colony-stimulating factor, stem cell factor, and flk-2/flt-3 ligand taken from CD34+ hematopoietic progenitors that were mobilized into the peripheral blood of cancer patients treated with high-dose cyclophosphamide and filgrastim. The target cells used for gene delivery were either CD34+ cells that had been subsequently induced to differentiate into mature DCs or DCs transduced after ex vivo generation from CD34+ cells. The results showed that: (a) infection of CD34+ cell derived-DCs (mature DCs) with either viral vector resulted in the efficient synthesis of recombinant protein, and (b) CD34+ cells were permissive for the expression of the recombinant reporter gene after infection with Ad-MFG-AP but not after infection with MVA-P11 LZ. In conclusion, these results suggest that vaccinia and adenovirus vectors are candidate to act as vehicles in genetically engineering human DCs.

Adenoviridae↗