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Biomedical subjects

L De Felice

Publications and source records attributed to L De Felice.

At least 19 recordsLinked to original sources
PubMed2004

Pre-transplant prognostic factors for patients with high-risk leukemia undergoing an unrelated cord blood transplantation.

From July 1995 to December 2001, 42 patients with leukemia aged 1-42 years underwent cord blood transplant (CBT) from unrelated, < or = 2 antigen HLA mismatched donors. In all, 26 patients were in < or = 2nd complete remission and 16 in more advanced phase. Conditioning regimens, graft-versus-host disease (GVHD) prophylaxis and supportive policy were uniform for all patients. The cumulative incidence of engraftment was 90% (95% CI: 0.78-0.91). The cumulative incidence of III-IV grade acute- and chronic-GVHD was 9% (95% CI: 0.04-0.24) and 35% (95% CI: 0.21-0.60), respectively. The 4-year cumulative incidence of transplant-related mortality (TRM) and relapse was 28% (95% CI: 0.17-0.47) and 25% (95% CI: 0.14-0.45), respectively. The 4-year overall survival (OS), leukemia-free survival (LFS) and event-free survival (EFS) were 45% (95% CI: 0.27-0.63), 47% (95% CI: 0.30-0.64) and 46% (95% CI: 0.30-0.62), respectively. In multivariate analysis, the most important factor affecting outcomes was the CFU-GM dose, associated with CMV serology (P=0.003 and 0.04, respectively) in influencing OS and with patient sex (P=0.008 and 0.03, respectively) in influencing LFS. Finally, CFU-GM dose was the only factor that affected EFS significantly (P=0.02). In conclusion, the infused cell dose expressed as in vitro progenitor cell growth is highly predictive of outcomes after an unrelated CBT and should be considered the main parameter in selecting cord blood units for transplant.

Adolescent↗
PubMed2000

Idarubicin intensified BUCY2 regimen in allogeneic unmanipulated transplant for high-risk hematological malignancies.

Twenty-nine consecutive patients with high-risk hematological malignancy aged from 3 to 58 years underwent an unmanipulated graft from an HLA-identical sibling after an irradiation-free preparative regimen consisting of idarubicin (IDA), 21 mg/m2/day administered by continuous infusion on days -12 and -11, followed by busulphan (BU), 4 mg/kg/day orally from day -7 to -4, and cyclophosphamide (CY), 60 mg/kg/day intravenously on days -3 and -2 (IDA-BUCY2). Most clinically relevant extra-hematological regimen-related toxicities consisted of stomatitis observed in all subjects and hemorrhagic cystitis occurred in five cases (17%) within 100 days after transplant. Six patients (21%) developed a grade 2 acute graft-versus-host disease (GVHD) and three (10%) a grade 3 or 4; extensive chronic GVHD was assessed in nine of 22 (41%) evaluable patients. So far, 12 patients have died and 17 are alive, 16 of whom disease-free, 5-41 months after transplant (median, 15 months). The causes of death were related to GVHD in three patients, to sepsis in one and to disease recurrence in the remaining eight. At present, only one of nine relapsed patients is alive. For all patients the actuarial probability of survival (OS) at 1 and 2 years +/- standard error (s.e.) was 63 +/- 9% and 52 +/- 10%, respectively. The actuarial probabilities of disease-free survival (DFS), relapse and transplant-related mortality (TRM) at both 1 and 2 years +/- s.e. were 53 +/- 9%, 35 +/- 9% and 16 +/- 7%, respectively. These results are encouraging but not substantially different from those obtained in 28 patients with malignancy in advanced phase transplanted after the standard BUCY2 regimen, who had an actuarial probability of OS, DFS, relapse and TRM projected at 10 years +/- s.e. of 54 +/- 10%, 57 +/- 9%, 36 +/- 9% and 11 +/- 6%, respectively. Although the retrospective comparison between the two groups does not seem to show any advantage in the use of the IDA intensified regimen, only a prospective randomized trial could answer this question.

Adolescent↗
PubMed1999

Umbilical cord blood transplant from unrelated HLA-mismatched donors in children with high risk leukemia.

In the last 3 years, 14 children with high-risk leukemia (11 ALL, 2 AML and 1 CML) underwent cord blood transplantation from unrelated HLA-mismatched donors at a median of 99 days from the start of search. Eight patients were transplanted in second CR, one in accelerated phase, three at relapse and two patients in first CR. Conditioning regimen (fractionated TBI, etoposide, CY and anti-lymphocyte serum) and prophylaxis of GVHD (CsA and 6-methylprednisolone) were identical for all patients. Neutrophils >0.5x10(9)/l were reached at a median of 33 days from transplant, but in four cases we observed an autologous hematopoietic reconstitution (three spontaneous, one after autologous BM rescue). Acute and chronic GVHD were observed in 10/14 and 3/8 evaluable cases, respectively. Three patients died of transplant-related toxicity and three patients relapsed. The probabilities of event-free, disease-free and overall survival were 50, 53 and 64%, respectively. Cord blood transplant from HLA-mismatched unrelated donor is a valid option for the treatment of children with high-risk leukemia. With our eligibility criteria, conditioning regimen and prophylaxis of graft-versus-host disease, the main obstacles to successful transplant were represented by graft failure and fatal acute GVHD.

Adolescent↗
PubMed1999

A prospective molecular study of chimaerism in patients with haematological malignancies receiving unrelated cord blood or bone marrow transplants: detection of mixed chimaerism predicts graft failure with or without early autologous reconstitution in cord blood recipients.

We prospectively studied the chimaerism status in the bone marrow (BM) and peripheral blood (PB) of 23 patients receiving umbilical cord (UCB, 14 cases) or BM (nine cases) transplants from unrelated donors by PCR amplification of four individual-specific VNTR genetic loci. Haematological engraftment, with persistent full donor pattern. was observed in 10/14 (72%) patients receiving UCB and in 9/9 (100%) patients transplanted with marrow from an unrelated donor (MUD). In contrast, the remaining four patients converted to an autologous pattern. Three out of these four patients had an early autologous haematological reconstitution reaching a neutrophil level >0.5 x 10(9)/l at days 27, 33 and 37 after transplant, respectively. In all three of these patients, chimaerism analysis demonstrated an early appearance of donor cells (i.e. within 35 d after UCB transplant) showing a transient full donor (one case) or mixed chimaerism condition (two cases). Despite the early autologous haemopoietic reconstitution, one of the three patients died of GVHD at day 60, which was explained by the demonstration of low levels of donor lymphoid cells. In the MUD group all nine patients converted to a persistent full donor pattern with haematological reconstitution, accompanied in two of them by transient mixed chimaerism lasting to days 60 and 270 after transplant. Our data show that monitoring of chimaerism may predict graft failure with or without early autologous haemopoietic reconstitution in patients receiving unrelated UCB transplants. Furthermore, chimaerism analysis may identify, in patients with autologous reconstitution, those at risk of severe GVHD in whom immunosuppressive therapy should not be discontinued.

Adolescent↗
PubMed1999

Flt3LP3nduces the ex-vivo amplification of umbilical cord blood committed progenitors and early stem cells in short-term cultures.

Umbilical cord blood (UCB) has been successfully used for haemopoietic stem cell transplantation, although its use has been cautiously limited to paediatric patients because of the reduced volume produced. The clinical results have confirmed that either engraftment or survival significantly correlate with cell dose infused. We have standardized a culture method providing in a short time a significant amplification of both committed progenitors and primitive stem cells for clinical use. Eight-day culture of UCB cells with flt3L/SCF/PIXY 321 induced a 10-fold amplification of CD34+ cells and the expansion of multipotent (CFU-GEMM) and committed (CFU-GM, BFU-E) progenitors respectively of 5-, 7- and 9-fold over input cells. As to the early stem cell pool, the primitive CD34+Thy-1+ cell fraction increased 6-fold and the LTC-IC were amplified 17-fold. Furthermore, the in vitro proliferation was detected by the gradual loss of fluorescence of the CD34+ cells tracked at day 0 with the dye PKH26. After 8 d of amplification >6% of the CD34+ cells remained intensely fluorescent. This subpopulation represents a deeply quiescent cell fraction unresponsive to cytokines and very enriched of primitive stem cells. These cells are most likely to be responsible for long-term reconstitution after transplant.

Antigens, CD34↗
PubMed1999

Mechanisms of osteoclast dysfunction in human osteopetrosis: abnormal osteoclastogenesis and lack of osteoclast-specific adhesion structures.

Osteoclasts from a patient affected by osteopetrosis were examined in vivo and in vitro. Iliac crest biopsy revealed an osteosclerotic pattern, with prominent numbers of osteoclasts noted for hypernuclearity and incomplete adherence to the bone surface. A population comprising tartrate-resistant acid phosphatase (TRAP)-positive, multinucleated and mononuclear cells, and alkaline phosphatase-positive stromal fibroblasts was obtained in vitro from bone marrow. Mononuclear TRAP-positive precursors spontaneously fused in culture to form giant osteoclast-like cells. These cells expressed the osteoclast marker MMP-9 and calcitonin receptor, and lacked the macrophage marker, Fc receptor. Expression and distribution of c-src, c-fms, and CD68, and response to steroid hormones relevant to osteoclast differentiation and function were apparently normal, whereas cell retraction in response to calcitonin was impaired. TRAP-positive multinucleated cells did not form osteoclast-specific adhesion structures (clear zone, podosomes, or actin rings). Bone resorption rate was severely reduced in vitro. Focal adhesions and stress fibers were observed en lieu of podosomes and actin rings. Adhesion structures contained low levels of immunoreactive vitronectin receptor, most of this integrin being retained in cytoplasmic vesicles. These data provide the first characterization of abnormal differentiation and function of human osteopetrotic osteoclast-like cells.

Acid Phosphatase↗
PubMed1998

Intravenous immune globulin in lysinuric protein intolerance.

In addition to systemic manifestations with skeletal, pulmonary, renal, and haematological signs, lysinuric protein intolerance (LPI), a membrane transport defect of cationic amino acids, is often complicated by severe life-threatening immunological manifestations. A 10-year-old boy with LPI who exhibited a severe systemic immunohaematological disease is described here. This patient showed cutaneous lesions similar to the subacute form of systemic lupus erythematosus, severe anaemia and dysproteinaemia, and a marked reduction of circulating T lymphocytes, mainly the CD4+ cells. In vitro bone marrow cell culture studies showed that addition of patient's serum induced macrophage proliferation and inhibited erythroid progenitor cell growth. Treatment with high-dose intravenous immune globulin resolved most of the clinical and laboratory abnormalities.

Amino Acid Metabolism, Inborn Errors↗
PubMed1998

Umbilical cord blood transplant from HLA-mismatched unrelated donor in high-risk leukemia.

Twelve consecutive children with high-risk leukemia have been submitted to UCB transplant from unrelated 1 or 2 loci HLA-mismatched donor. All patients received an identical regimen for conditioning and GVHD prophylaxis. The median dose of viable nucleated cells infused was 2.8 x 10(7)/kg bw (range 1.4-7.9). Of 11 patients evaluable for engraftment, the hematopoiesis was of full donor origin in seven patients and autologous in four. The probability of disease-free survival at 1 and 2 years from UCB transplant is 60 and 42%, respectively.

Adolescent↗
PubMed1998

Flt3L enhances the early stem cell compartment after ex vivo amplification of umbilical cord blood CD34+ cells.

Umbilical cord blood (UCB) transplant represents a promising therapeutic approach, nevertheless this procedure has been so far almost exclusively used in pediatric patients because of the reduced volume of UCB units. The availability of larger numbers of early and late hematopoietic progenitors by ex vivo amplification procedure may allow the use of UCB in adults and improve the rate and time to engraftment. We describe a stroma-free liquid culture system that induces a 10-fold increase of CD34+ cells and hematopoietic progenitors after 8 days in vitro amplification. The presence of flt3L is essential to preserve and amplify the early stem cell compartment identified by the phenotype CD34+Thy-1+CD45RO+.

Adult↗
PubMed1998

Umbilical cord blood (UCB) transplant from unrelated mismatched donor in patients with high risk (HR) leukemia.

Ten consecutive children with high risk leukemia have been submitted to UCB transplant from unrelated HLA mismatched donors. All patients received an identical regimen for conditioning and GVHD prophylaxis. The median dose of viable nucleated cells infused was 2.6 x 10(6)/kg b.w. Among the nine patients evaluable for engraftment the hematopoiesis was of full donor origin in six patients and autologous in three. At a median follow-up of 9 months, six of nine (67%) patients are alive in CR.

Adolescent↗
PubMed1996

Stem cell factor and PIXY-321 in acute lymphoblastic leukemia: in vitro study on proliferative effects and apoptosis.

Management of acute lymphoblastic leukemia (ALL) patients may include growth factors (GFs) to reduce post-chemotherapy aplasia. A potential risk of GF administration is a stimulatory signal on the leukemic population. In the present study we investigated the proliferative and programmed cell death (PCD) effect of two cytokines that have recently entered clinical use, stem cell factor (SCF) and the granulocyte colony stimulating factor/IL-3 fusion molecule (PIXY-321), on 14 ALL samples. The activity of IL-7, a cytokine involved in the regulation of ALL cell proliferation, was also tested alone and in combination with these two cytokines. Using the acridine orange flow cytometric technique and the clonogenic assay, we showed that none of these cytokines was capable of significantly increasing the mean percentage of S-phase cells and CFU-L number. A mean decrease of G0 cells from 60.6% to 52.6% (p = 0.02), coupled by a significant increase of G1 cells from 28.2% to 37.9% (p = 0.003) was demonstrated in the presence of PIXY-321. IL-7 alone and in combination with either PIXY-321 or SCF induced similar changes in the percentage of cells in G0 and G1. SCF showed no activity on G0 depletion. When each individual samples was analyzed separately, some heterogeneity was observed. An increase of S phase was recorded in a proportion of cases after SCF and PIXY-321 exposure. However, none of the cytokines evaluated by a clonogenic assay following liquid culture was capable of maintaining or promoting self-renewal of leukemic precursors, as determined by plating fresh cells at time 0. Detection of cytokine effects of apoptosis showed that SCF and PIXY-321 did not significantly reduce the mean percentage of cells in PCD, whereas a significant protective effect was observed in the presence of IL-7 (p = 0.02). We conclude that PIXY-321 and, to a further extent, SCF fail to induce leukemic lymphoid cell proliferation, and do not protect cells from entering apoptosis. These in vitro findings may be useful for ALL clinical trial design.

Adolescent↗
PubMed1995

Multidrug resistance expression and proliferative studies in poor risk acute myeloid leukemia treated with the FLAG (G-CSF plus fludarabine and Ara-C) regimen.

Fourteen poor risk acute myeloid leukemia (AML) patients were treated with G-CSF prior (from day 0) and during chemotherapy with fludarabine and Ara-C from day 1 to day 5 (the FLAG regimen). Several biological parameters were monitored on the blast population: multidrug resistance (MDR) functional expression by rhodamine-123 efflux (Rhd-E), cell cycle changes, induction of apoptosis and leukemic clonogenic cell growth (CFU-L). The mean basal Rhd-E value was 14.4% (range 0-51.2), and 12/14 patients exhibited a dye efflux > 4%, efficiently blocked by the MDR-reversal agent cyclosporin A. After 24 h of G-CSF administration, cell cycle studies showed in bone marrow (BM) samples a significant mean increase in S phase (p = 0.04) and in RNA content of G1 cells (p = 0.01), coupled to a significant increase in apoptosis (p = 0.02). Clonogenic cell growth analysis showed a twofold increase in BM CFU-L in 6 of the 14 cases tested. When G-CSF activity was assessed without the addition of exogenous growth factors (autonomous proliferation), a significant increase (p = 0.02) in CFU-L was found only in patients who achieved a complete remission (CR); these patients were also characterized by lower S-phase values at diagnosis. Eight of the 14 patients treated achieved CR, but the median response duration was three months, and only two cases are still in CR. The FLAG regimen can thus induce remission in poor risk AML patients. The responses, however, are short, suggesting that resistant cells are not efficiently affected by either the use of agents not involved in the MDR-efflux mechanism or by the G-CSF priming strategy. Other post-induction therapies need to be considered in further approaches.

Acute Disease↗
PubMed1994

Myelodysplastic syndromes in childhood: description of seven cases.

Seven children with a primary myelodysplastic syndrome were seen at our center over a 9-year period. Two presented with refractory anemia, three with refractory anemia with excess of blasts, and two with refractory anemia with excess of blasts in transformation. All children received supportive therapy, including blood transfusions in five of them. Three patients developed acute myeloid leukemia and were treated with intensive chemotherapy, followed by allogeneic or autologous marrow transplantation in the two responders. All three died of either infection or progressive disease. The other four patients are still alive a median of 71 months (range 38-130) after diagnosis. These results confirm the difficulties in managing patients with myelodysplastic syndromes.

Anemia, Refractory↗
PubMed1993

Polyclonal hematopoietic reconstitution in leukemia patients at remission after suppression of specific gene rearrangements.

Clonality studies of hematopoietic reconstitution after remission were performed in 24 female patients (pts) with leukemias characterized by specific molecular markers. At diagnosis, 13 pts had promyelocytic leukemia (PML) retinoic acid receptor-alpha (RAR-alpha)-rearranged acute promyelocytic leukemia (APL), 8 Philadelphia positive (Ph'+) break-point cluster region (BCR+) chronic myeloid leukemia (CML), and 3 Ph'+ (BCR+) acute lymphoblastic leukemia (ALL). All pts were analyzed at presentation and after Southern blot suppression of specific rearrangements after various treatments, including conventional chemotherapy, autologous or allogeneic bone marrow transplant (BMT), all-trans retinoic acid, and alpha-2b interferon. DNA from BM samples collected at diagnosis and, during remission phases, were subjected to Southern blot analysis with the M27 beta probe to detect X chromosome methylation differences, and with BCR, in CML and ALL cases, or PML/RAR-a probes for gene rearrangements, in APL cases. Twenty-one of the 24 pts had polyclonal methylation patterns at remission, together with disappearance of the specific rearrangement, whereas 3 pts retained the same single unmethylated DXS255 allele detected at diagnosis despite no evidence of gene rearrangement. Concerning these 3 pts, such an apparently clonal pattern was also observed in one case in T lymphocytes and skin-derived DNA; in a second case in BM fibroblasts and T lymphocytes; and, in the third case, in blood mononuclear cells obtained from her healthy female BM donor. All these 3 pts are in unmaintained clinical and cytogenetic remission after more than 20 months off therapy. These data suggest that (1) polyclonal and presumably normal hematopoiesis occurs in APL, CML, and Ph'+ ALL pts once the major burden of leukemic cells carrying a specific rearrangement is suppressed by treatment; and (2) unbalanced X chromosome methylation patterns, or aberrant methylation of X chromosome regions may be observed in some cases, most likely reflecting constitutional features simulating a clonal picture.

Adolescent↗
PubMed1993

Effects of mast cell growth factor on Ara-C mediated acute myeloid leukemia cell killing.

Cell kinetic studies of acute myeloid leukemia (AML) have provided evidence for the presence of nonproliferating cells. Hemopoietic growth factors (GF) can regulate proliferation of leukemic cells, furnishing new possibilities for recruiting quiescent cells into the cycle and overcoming cytokinetic resistance in AML. To assess the role of the novel identified cytokine, mast cell growth factor (MGF), in enhancing cytosine arabinoside (Ara-C) cytotoxicity, we have primed AML blasts with MGF and then exposed these cells to the S phase specific agent Ara-C. Other growth factors such as PIXY, interleukin 3 (IL-3), granulocyte-macrophage colony stimulating factor (GM-CSF) and granulocyte CSF (G-CSF) and the combination of MGF plus PIXY were also tested. Cytokinetic changes and clonogenic growth of leukemic colony forming unit (CFU-L) cells in methylcellulose were used to detect proliferative and cytotoxic effects on AML blasts. Expression of MGF receptor, the c-kit protein, was also measured by flow cytometry. We report in this preliminary study that MGF is able to increase proliferation in 75% of the samples studied and enhance Ara-C cytotoxicity in some of these cases. When MGF proliferative activity was compared with other GFs, individual cases showed heterogeneity in response, although the combination of MGF plus PIXY was always the most effective.

Cell Cycle↗