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Franco Mandelli

Publications and source records attributed to Franco Mandelli.

At least 55 records · Page 3Linked to original sources
PubMed2004

A long-term study of young patients with essential thrombocythemia treated with anagrelide.

BACKGROUND AND OBJECTIVES: Essential thrombocythemia (ET) can be complicated by life-threatening thrombosis and has a risk of converting into acute leukemia. Cytoreductive therapy may reduce the risk of thromboembolic complications. Herein, we report the results of a long-term study of patients with ET treated with anagrelide to control thrombocytosis. DESIGN AND METHODS: Thirty-nine (34 evaluable) patients (median age, 33 years; 24 previously untreated) were enrolled between 1989-1996; the mean platelet count prior to therapy was 1197x10(9)/L. Only 9 out of 34 evaluable patients were at high risk of thrombosis (platelet count more than 1500x10(9)/L). The initial dose of anagrelide (0.5 mg/bid for 7 days) was increased by 0.5 mg/day (maximum dose: 3 mg/day) until a response was seen. RESULTS: A complete response (platelets < 450x10(9)/L for >1 month) was seen in 15 /34 (44%) patients and a partial response (platelets 450-600x10(9)/L for >1 month) was seen in 17/34 ( 50%), so that the some kind of response was seen in 32/34 (94%) of the patients at a median time of 4.2 months after starting treatment. Seventeen patients (50%) are still being treated and have achieved platelet control for a maximum follow-up of 12.5 years. Late onset anemia occurred in 4/39 patients. Three out of 39 patients (8%) had cardiac disorders. INTERPRETATION AND CONCLUSIONS: Anagrelide appears suitable for controlling thrombocytosis in ET patients over the long-term. This drug may be used in patients younger than 60 years, with the exclusion of women of child-bearing potential and subjects aged 40-60 years with a history of major thrombotic events. Anagrelide should not be administered to patients with cardiac disorders, and a careful approach to patients should include monitoring of heart function before and during treatment.

Adult↗
PubMed2003

Gene expression profile of adult T-cell acute lymphocytic leukemia identifies distinct subsets of patients with different response to therapy and survival.

Gene expression profiles were examined in 33 adult patients with T-cell acute lymphocytic leukemia (T-ALL). Nonspecific filtering criteria identified 313 genes differentially expressed in the leukemic cells. Hierarchical clustering of samples identified 2 groups that reflected the degree of T-cell differentiation but was not associated with clinical outcome. Comparison between refractory patients and those who responded to induction chemotherapy identified a single gene, interleukin 8 (IL-8), that was highly expressed in refractory T-ALL cells and a set of 30 genes that was highly expressed in leukemic cells from patients who achieved complete remission. We next identified 19 genes that were differentially expressed in T-ALL cells from patients who either had a relapse or remained in continuous complete remission. A model based on the expression of 3 of these genes was predictive of duration of remission. The 3-gene model was validated on a further set of T-ALL samples from 18 additional patients treated on the same clinical protocol. This study demonstrates that gene expression profiling can identify a limited number of genes that are predictive of response to induction therapy and remission duration in adult patients with T-ALL.

Adult↗
PubMed2003

Clinico-biologic features and treatment outcome of adult pro-B-ALL patients enrolled in the GIMEMA 0496 study: absence of the ALL1/AF4 and of the BCR/ABL fusion genes correlates with a significantly better clinical outcome.

To elucidate the biologic and clinical heterogeneity of adult pro-B acute lymphoblastic leukemia (ALL) (ie, terminal deoxynucletidyl-transferase-positive[TdT+], CD19+, CD10-, surface immunoglobulin-negative [SIg-]), we evaluated 66 patients enrolled in the Italian multicentric Gruppo Italiano Malattie Ematologiche dell'Adulto (GIMEMA) 0496 study between October 1996 and December 1999. The ALL1/AF4 fusion transcript, originating from the t(4;11) translocation, was detected in 24 patients (36.4%), and the BCR/ABL chimeric product was found in 6 patients (9%), while the remaining 36 cases (54.6%) were ALL1/AF4-BCR/ABL-negative. A white blood cell (WBC) count higher than 50 x 109/L was found in 13 of 24, 2 of 6, and 6 of 36 of the ALL1/AF4-positive, BCR/ABL-positive, and ALL1/AF4-BCR/AB-negative patients, respectively (P =.007). None of the 24 ALL1/AF4-positive patients coexpressed the CD13 and/or CD33 myeloid antigens. By contrast, CD13 and CD33 molecules were detected, respectively, in 3 of 6 and in 14 of 33 cases of the BCR/ABL-positive patient group, and in 2 of 6 and 9 of 35 cases of the ALL1/AF4-BCR/ABL-negative patient group. These differences still remained statistically significant even if the BCR/ABL-positive patients were excluded from the analysis. A complete remission (CR) was achieved in 52 (83.4%) of the 62 patients with ALL evaluable for response to treatment. CR rates were similar in the 3 genotypic groups. By contrast, comparing patients with or without the ALL1/AF4 gene the probability of remaining in continuous complete remission (CCR) at 3.5 years was 16% and 49.8%, respectively (P =.005). Our data demonstrate that in adult pro-B-ALL a distinction should be made between pro-B-ALL cases with and without the ALL1/AF4 or the BCR/ABL chimeric genes, since the absence of both of these fusion genes correlates with a significantly better clinical outcome after intensive polychemotherapy treatment without hematopoietic stem cell transplantation.

Adolescent↗
PubMed2003

Hepatitis C virus and B-cell non-Hodgkin lymphomas: an Italian multicenter case-control study.

The existence of an association between infection with hepatitis C virus (HCV) and B-cell non-Hodgkin lymphoma (B-NHL) remains controversial, largely because previous studies were based on prevalent case series or comparisons with less than optimal control groups. This hospital-based case-control study was conducted from January 1998 through February 2001 to evaluate the association between HCV infection and B-NHL of different types. Cases were consecutive patients with a new diagnosis of B-NHL; controls were patients from other departments of the same hospitals. Both groups were interviewed using a standardized questionnaire. The prevalence of HCV infection was calculated by histologic type of B-NHL and clinical behavior (indolent or aggressive). Adjusted odds ratio (OR) and HCV-attributable risk (AR) were estimated. HCV prevalence was 17.5% among the 400 lymphoma patients and 5.6% among the 396 controls. The OR of B-NHL (patients vs controls), adjusted by age, sex, level of education, and place of birth, was 3.1 (95% confidence interval [CI], 1.8-5.2); an OR indicative of positive association was found for indolent and aggressive B-NHL. The estimated AR was 4.6%. This study confirms an association between HCV and B-NHL. In Italy, 1 of 20 instances of B-NHL may be attributable to HCV infection and may, thus, benefit from antiviral treatment.

Adolescent↗
PubMed2003

Allogeneic compared with autologous stem cell transplantation in the treatment of patients younger than 46 years with acute myeloid leukemia (AML) in first complete remission (CR1): an intention-to-treat analysis of the EORTC/GIMEMAAML-10 trial.

In the European Organization for Research and Treatment of Cancer Leukemia Group and Gruppo Italiano Malattie Ematologiche dell' Adulto (EORTC-LG/GIMEMA) acute myeloid leukemia (AML)-10 trial, patients in first complete remission (CR1) received a single intensive consolidation (IC) course. Subsequently, those patients younger than 46 years with an HLA-identical sibling donor were assigned to undergo allogeneic (allo) stem cell transplantation (SCT), and patients without such a donor were planned for autologous (auto) SCT. Between November 1993 and December 1999, of 1198 patients aged younger than 46 years, 822 achieved CR. The study group constituted 734 patients who received IC: 293 had a sibling donor and 441 did not. Allo-SCT and auto-SCT were performed in 68.9% and 55.8%, respectively. Cytogenetic determination was successfully performed in 446 patients. Risk groups were good (t(8;21), inv16), intermediate (NN or -Y only), and bad/very bad (all others). Median follow-up was 4 years; 289 patients relapsed, 66 died in CR1, and 293 died. Intention-to-treat analysis revealed that the 4-year disease-free survival (DFS) rate of patients with a donor versus those without a donor was 52.2% versus 42.2%, P =.044; hazard ratio = 0.80, 95% confidence interval (0.64, 0.995), the relapse incidence was 30.4% versus 52.5%, death in CR1 was 17.4% versus 5.3%, and the survival rate was 58.3% versus 50.8% (P =.18). The DFS rates in patients with and without a sibling donor were similar in patients with good/intermediate risk but were 43.4% and 18.4%, respectively, in patients with bad/very bad risk cytogenetics. In younger patients (15-35 years), the difference was more pronounced. The strategy to perform early allo-SCT led to better overall results than auto-SCT, especially for younger patients or those with bad/very bad risk cytogenetics.

Adolescent↗
PubMed2003

Early autologous stem-cell transplantation versus conventional chemotherapy as front-line therapy in high-risk, aggressive non-Hodgkin's lymphoma: an Italian multicenter randomized trial.

PURPOSE: To evaluate the role of early intensification with high-dose therapy (HDT) and autologous stem-cell transplantation (ASCT) as front-line chemotherapy for patients with high-risk, histologically aggressive non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: We planned a multicenter, randomized trial to compare a conventional chemotherapy regimen of methotrexate with leucovorin rescue, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin (MACOP-B; arm A) with an abbreviated regimen of MACOP-B (8 weeks) followed by HDT and ASCT (arm B) for intermediate-high-risk/high-risk patients (according to the age-adjusted International Prognostic Index). From September 1994 to April 1998, 150 patients with aggressive lymphoma were enrolled onto the trial. Seventy-five patients were randomly assigned to arm A and 75 patients were randomly assigned to arm B. In both arms, involved-field radiation therapy (36 Gy) was delivered to the site of bulky disease. RESULTS: The rate of complete response was 68% in arm A and 76% in arm B (P = not significant [NS]). Three toxic deaths (4%) occurred in arm B and one (1%) occurred in arm A (P = NS). In arm B, 30 patients (40%) did not undergo HDT and ASCT. According to the intention-to-treat analysis at a median follow-up of 24 months, 5-year overall survival probability in arms A and B was 65% and 64% (P =.95), 5-year progression-free survival was 49% and 61% (P =.21), and 5-year relapse-free survival was 65% and 77% (P =.22), respectively. CONCLUSION: Abbreviated chemotherapy followed by intensification with HDT-ASCT is not superior to conventional chemotherapy in patients with high-risk, aggressive NHL. Additional randomized trials will clarify whether HDT-ASCT as front-line therapy after a complete course of conventional chemotherapy improves survival in this group of patients.

Adolescent↗
PubMed2003

Outcome prediction by immunophenotypic minimal residual disease detection in adult T-cell acute lymphoblastic leukaemia.

Flow-cytometric detection of minimal residual disease (MRD) identifies patients with high relapse risk in childhood acute lymphoblastic leukaemia (ALL). We studied the efficacy of this method in adult T-ALL treated with the Italian co-operative GIMEMA (Gruppo Italiano Malattie Ematologiche dell'Adulto) LAL0496 protocol. Bone marrow samples from 53 patients were taken at fixed treatment time points and MRD was analysed using a leukaemia-specific immunophenotype (cytoplasmic-CD3/nuclear-terminal desoxynucleotidyl transferase). The median follow-up was 17 months (range 3-61) and a median of 4.5 analyses/patient was performed (range 3-12). Six out of 53 (11.3%) patients were refractory to treatment, 30/53 (56.6%) relapsed and 17/53 (32.1%) remain in continuous complete remission. The probability of relapse at 2 years for MRD-positive patients at preconsolidation was 81.5%vs 38.9% for MRD-negative patients (P = 0.00078). This risk was still 54.5% for MRD-positive vs 15.8% for MRD-negative patients pre-third reinduction (P = 0.0098) and 50.0% for MRD-positive vs 16.4% for MRD-negative patients pre-sixth reinduction (P = 0.032). The relapse-predicting value of MRD did not depend on features at diagnosis such as age, sex and leucocyte count. Our data suggest that immunophenotypic MRD monitoring in the first year of treatment is a useful outcome predictor for adult T-ALL patients.

Flow Cytometry↗
PubMed2003

Early detection of meningeal localization in acute promyelocytic leukaemia patients with high presenting leucocyte count.

Extramedullary relapse occurs infrequently in acute promyelocytic leukaemia (APL) but has been increasingly reported after the advent of all-trans retinoic acid (ATRA) treatment, probably as a consequence of improved patient survival. We describe our single centre experience of six APL patients who had disease localization in the central nervous system (CNS). In three patients, clinical symptoms (headache and/or nausea) that presented during follow-up led to the performance of a lumbar puncture and detection of overt CNS infiltration. Two of these patients had simultaneous haematological relapse and one was in molecular remission when CNS leukaemia was documented. One patient with no local symptoms showed CNS infiltration at the time of molecular relapse. Following the introduction of routine lumbar puncture, carried out after front-line induction in all newly diagnosed patients with white blood cell count (WBC) greater than 10 x 109/l, two additional patients in molecular remission with no local symptoms were found to have initial APL localization in the CNS. Presenting features included in 6/6 patients an elevated WBC count (> 10 x 109/l) and a predominance of the PML/RAR bcr3 type (5/6 patients) and of microgranular morphology (5/6 patients). Our findings highlight the importance of carrying out lumbar puncture in APL patients presenting with high-risk features.

Adult↗
PubMed2003

E2A-PBX1 fusion in adult acute lymphoblastic leukaemia: biological and clinical features.

Molecular and cytogenetic studies performed in 305 adult acute lymphoblastic leukaemia (ALL) patients enrolled in the gimema (Gruppo Italiano Malattie EMatologiche dell'Adulto) multicentric protocols identified an E2A-PBX1 fusion and/or t(1;19) in 10 patients (3.3%). All had common ALL, were mostly CyIg+ and were CD34/CD13/CD33-. Nine patients achieved a complete remission (CR); five patients showed a haematological relapse after 7 months (median). Four patients are alive in first CR with a median follow-up of 29 months; three patients are molecularly negative. This abnormality is frequently associated with early treatment failure. E2A-PBX1+ adult ALL should be considered for intensified treatment strategies and monitoring of minimal residual disease.

Adolescent↗
PubMed2003

Long-term evaluation of 164 patients with essential thrombocythaemia treated with pipobroman: occurrence of leukaemic evolution.

Essential thrombocythaemia (ET) is usually considered an indolent disease, but it may progress during its natural course into acute leukaemia (AL); however, an influence of myelosuppressive agents in the blastic transformation of ET cannot be excluded. We performed a retrospective study to assess the incidence of AL in ET patients treated with pipobroman (PB) as first-line therapy. One hundred and sixty-four patients with ET were managed with PB at a dose of 1 mg/kg/d until a stable platelet count below 400 x 10(9)/l was achieved. Maintenance therapy was given at a planned dose ranging between 0.2 and 1 mg/kg/d according to platelet count, in all cases, with a median daily dose of 25 mg (range 7-75 mg/d). The median treatment time was 100 months (range 25-243 months). The patients were evaluated for the occurrence of AL and/or secondary malignancies and survival end-points. AL was observed in nine patients (5.5%) after a median treatment time of 153 months (range 79-227 months). The overall survival (OS) and the event-free survival (EFS) at 120 months were 95% and 97%, whereas at 180 months, they were 84% and 76% respectively. In conclusion, this retrospective analysis shows a low incidence of AL in a large group of patients consecutively treated with PB as first-line chemotherapy. Therefore, an investigation of the role of myelosuppressive agents in the blastic transformation of ET would be of interest.

Adult↗
PubMed2003

Extramedullary liver plasmacytoma a rare presentation.

Liver plasmacytoma is a very rare form of solitary plasmacytoma, in fact the presence of plasma cells in the liver is generally associated with a more aggressive form of multiple myeloma. We report an unusual case of liver plasmacytoma without systemic disease, diagnosed by percutaneous needle biopsy of the hepatic lesion, treated with six courses of melphalan and prednisone who achieved a good clinical remission after five years of follow-up.

Aged↗
PubMed2003

Intermediate-dose cyclophosphamide and granulocyte colony-stimulating factor is a valid alternative to high-dose cyclophosphamide for mobilizing peripheral blood CD34+ cells in patients with multiple myeloma.

Peripheral blood stem cells (PBSC) are widely used in the setting of dose-intensive chemotherapies in patients with multiple myeloma (MM). Although the granulocyte colony-stimulating factor (G-CSF), following chemotherapy or not, is considered the standard growth factor for mobilizing PBSC, the optimal chemotherapeutic regimen still remains to be defined. Cyclophosphamide (CTX) is an effective drug in the treatment of MM which is capable of mobilizing PBSC if followed by growth factors, even though administration of high-dose CTX (7 g/m(2)) results in severe toxicity requiring hospitalization and increasing costs. We have retrospectively analyzed the results obtained in 38 newly diagnosed MM patients treated with 1.2 g/m(2) CTX on days 1 and 3 combined with 40 mg dexamethasone daily for 4 days. The results were compared with those obtained in 25 newly diagnosed MM patients treated with 7 g/m(2) CTX. A higher number of CD34+ cells/kg was collected during the first leukapheresis and a statistically significant lower consumption of G-CSF was observed following two doses of 1.2 g/m(2) CTX compared to the 7 g/m(2) CTX dose. The possibility of treating patients with day-hospital regimens, with a satisfactory yield of hematopoietic cells harvested, may have relevant economic implications for treatment strategies in MM patients.

Adult↗
PubMed2003

Fludarabine + prednisone +/- alpha-interferon followed or not by alpha-interferon maintenance therapy for previously untreated patients with chronic lymphocytic leukemia: long term results of a randomized study.

BACKGROUND AND OBJECTIVES: Fludarabine is an effective therapy for patients with chronic lymphocytic leukemia (CLL) and interferon-alpha (IFN-alpha) has been reported to have anti-leukemic activity in CLL patients. A randomized study was designed to evaluate whether the addition of IFN-alpha to a first-line treatment with fludarabine and prednisone could increase the response rate in patients with advanced CLL and whether IFN-alpha given as maintenance therapy could improve the duration of response. DESIGN AND METHODS: One hundred and thirty-three patients were randomized to receive fludarabine (25 mg/m2/i.v., days 9-13) and prednisone (20 mg/m2, days 1, 3, 5, 7 and 14 and 40 mg/m2, days 9-13) (arm A: 66 patients) or in addition to the same schedule, IFN-alpha (2 MUI/sc, days 1, 3, 5, 7, 9, 11, 13 and 15) (arm B: 67 patients). Seventy-eight patients responsive to therapy entered the post-remission phase of the study in which 41 patients were randomized to receive IFN-alpha (3 MUI three times a week) and 37 to clinical observation. RESULTS: A similar response rate (complete responses + partial responses) was observed in the 2 arms: 86% for arm A and 84% for arm B (p = 0.4). A longer response duration was observed in patients who achieved a complete response (p = 0.001) and in patients who received maintenance therapy with IFN-alpha (p < 0.05). However, the quality of response was the only significant and independent factor influencing response duration (p < 0.01). No benefits in terms of infection-related mortality and morbidity could be ascribed to IFN-alpha administration. INTERPRETATION AND CONCLUSIONS: In previously untreated CLL patients with advanced disease a high response rate is obtained from first-line fludarabine and prednisone and no benefit is derived from the addition of IFN-alpha to this regimen. The achievement of a good quality response to therapy was the only independent predictor of a prolonged response.

Adult↗
PubMed2002

Induction therapy with idarubicin alone significantly influences event-free survival duration in patients with newly diagnosed hypergranular acute promyelocytic leukemia: final results of the GIMEMA randomized study LAP 0389 with 7 years of minimal follow-up.

Shortly before the all-trans retinoic acid (ATRA) era, the GIMEMA cooperative group initiated a randomized study comparing idarubicin (IDA) alone with IDA plus arabinosylcytosine (Ara-C) as induction treatment in patients with newly diagnosed hypergranular acute promyelocytic leukemia (APL). Of the 257 patients evaluable for induction treatment, 131 were randomized to receive IDA alone (arm A) and 126 to receive IDA + Ara-C (arm B). Treatment in arm A consisted of 10 mg/m(2) IDA daily for 6 consecutive days, whereas in arm B it consisted of 12 mg/m(2) IDA daily for 4 days combined with 200 mg/m(2) Ara-C daily in continuous infusion for 7 days. Once in complete remission (CR), patients received 3 consolidation courses of standard chemotherapy, and those still in CR at the end of the consolidation were randomized to receive or not receive 1 mg/kg 6-mercaptopurine daily and intramuscular injections of 0.25 mg/kg methotrexate weekly for 2 years. Overall, 100 (76.3%) patients in arm A and 84 (66.6%) patients in arm B achieved CR (P = NS). Event-free survival (EFS) rates were 35% and 23% for patients in arm A and arm B, respectively (P =.0352). Multivariate analysis revealed that EFS was favorably influenced by induction treatment with IDA alone (P =.0352) and unfavorably influenced by white blood cell (WBC) counts greater than 3000/microL (P =.0001) and increasing age (P =.0251). These results indicate that anthracycline monochemotherapy with IDA favorably influences the EFS of patients with newly diagnosed hypergranular APL.

Adolescent↗
PubMed2002

Clinicobiological features and outcome of acute promyelocytic leukemia occurring as a second tumor: the GIMEMA experience.

We analyzed the clinicobiological features and treatment outcome of a series of acute promyelocytic leukemias (APLs) occurring as a second tumor (APL-st's, n = 51) and compared these with a large group of de novo APL cases (n = 641), both observed by the Italian cooperative group GIMEMA. In the APL-st group, 37 patients had received radiotherapy and/or chemotherapy for their primary malignancy (PM), while 14 had been treated by surgery alone. Compared with de novo APL patients, APL-st patients were characterized by a predominance of females (P <.003), higher median age (P <.05), and worse performance status (P <.005). The median time elapsed between PM and APL-st was 36 months, with a longer latency for patients treated with surgery alone. No significant differences were found with regard to karyotypic lesions or type of promyelocytic leukemia/retinoic acid receptor alpha (PML/RARalpha) fusion in the 2 cohorts. A high prevalence of PMs of the reproductive system was observed among the female APL-st population (24 [71%] of 34 patients in this group had suffered from breast, uterine, or ovarian cancer). Thirty-one APL-st and 641 de novo APL patients received homogeneous APL therapy according to the all-trans retinoic acid (ATRA) and idarubicin regimen (the AIDA regimen). The complete remission (CR), 4-year event-free survival (EFS), and 4-year overall survival (OS) rates were 97% and 93%, 65% and 68%, and 85% and 78% in the APL-st and de novo APL groups, respectively. In spite of important clinical differences (older age and poorer performance status), the APL-st group responded as well as the de novo APL group to upfront ATRA plus chemotherapy, probably reflecting genetic similarity.

Adolescent↗
PubMed2002

MDR1 protein expression is an independent predictor of complete remission in newly diagnosed adult acute lymphoblastic leukemia.

Little is known about the prognostic role of multidrug resistance (MDR) in adults with newly diagnosed acute lymphoblastic leukemia (ALL). In the context of the GIMEMA ALL0496 protocol, we evaluated the impact of MDR1 (protein expression and function) on the achievement of complete remission (CR) and clinical outcome. Flow cytometric analysis of MDR1 expression (D) and function (rhodamine-123 efflux) was obtained in 203 and 158 patients, respectively. MDR1 expression was detected in 44 (21.7%) of 203 patients, and function was found in 23 (14.6%) of 158 (14.6%) patients. Expression of the multidrug resistance-associated protein 1 (MRP1) and lung-resistance protein (LRP) evaluated in 43 samples was found in 13 and 26 patients, respectively. Among the 200 patients evaluable for the clinical correlation study, 125 (79.6%) of 157 without MDR1 expression achieved CR compared with 23 (53.5%) of 43 with MDR1 expression (P =.001). At univariate analysis, MDR1 expression was significantly associated with CR when considered as a dichotomized (P =.001) or continuous (P =.01) variable. At multivariate analysis, dichotomized evaluation of MDR1 expression independently predicted CR (P =.004) with age (P =.03) and CD34 (P =.03); as a continuous variable, MDR1 expression (P =.03) was the only significant factor other than CD34 (P =.01). MDR1 function failed to predict achievement of CR or of MRP1 and LRP expression. MDR1 expression did not correlate with CR duration, nor did it predict for survival duration. These results demonstrate that MDR1 expression in de novo adult ALL is an independent predictor of CR achievement.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

Human acute stem cell leukemia with multilineage differentiation potential via cascade activation of growth factor receptors.

The morphologic, immunophenotypic, genotypic, genomic, and functional features of an undifferentiated acute leukemia with stem cell features are reported. At light and electron microscopy, the leukemic population was represented by primitive progenitor cells with no evidence of differentiation. The blasts were CD34(+), AC133(+), CD71(-), HLA-DR(-), CD38(-/dim+), CD90(+), CD117(dim+), flt3(+); did not express B, T, or myeloid-associated antigens; and showed a germline configuration of the immunoglobulin and T-cell receptor. Genomic profiling documented the expression of early stem cell and myeloid-associated genes. Receptors for early-acting hemopoietic growth factors (HGFs) were detected, while receptors for unilineage HGF were not expressed. Incubation with the flt3 or Kit ligand induced the expression of unilineage HGF receptors, allowing these cells to respond to their respective ligands. Growth without differentiation was sustained only in the presence of early-acting HGF, namely flt3 ligand, while early and unilineage HGF gave rise to all types of hemopoietic colonies.

Acute Disease↗