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T Barbui

Publications and source records attributed to T Barbui.

At least 37 records · Page 2Linked to original sources
PubMed2001

Anti-CD20 antibody (rituximab) administration in patients with late occurring lymphomas after solid organ transplant.

BACKGROUND AND OBJECTIVES: Aggressive diffuse large cell non-Hodgkin's lymphoma (DLCL) occurring late after a solid organ transplant fails to regress after discontinuation of immunosuppression. Moreover, chemotherapy treatment is associated with a high mortality rate due to severe toxicity. Since the majority of post-transplant lymphoproliferative disorders derive from B-lineage lymphocytes, the administration of anti-B monoclonal antibodies represents a rational therapeutic option. DESIGN AND METHODS: Five patients who developed CD20-positive DLCL more than two years after heart or liver transplantation were treated with a weekly chemotherapy program (2 patients), radiotherapy (2 patients) and surgery (1 patient) followed by a minimum of 4 intravenous doses of rituximab (375 mg/m(2)). RESULTS: A favorable clinical outcome was observed in three patients in whom surgery or radiotherapy had produced significant tumor debulking. Only a partial clinical effect was documented in the two patients with advanced clinical stage disease. INTERPRETATION AND CONCLUSIONS: Rituximab can be safely administered to patients with aggressive CD20-positive DLCL occurring late after a solid organ transplant. However, a positive clinical outcome may be expected only in patients in whom surgery or radiotherapy has achieved significant regression of tumor burden.

Adult↗
PubMed2000

Polymorphonuclear leukocyte activation and hemostasis in patients with essential thrombocythemia and polycythemia vera.

Thrombohemorrhagic complications are a major cause of morbidity and mortality in patients with essential thrombocythemia (ET) and polycythemia vera (PV). The pathogenesis of these complications is not completely clarified. Several studies have described abnormalities of red blood cells and platelets in these patients. However, no studies are available on changes in the polymorphonuclear leukocytes (PMNs), which can play an important role in the activation of the hemostatic system. In patients with ET (n = 37) and PV (n = 34), a series of PMN activation parameters (PMN membrane CD11b and leukocyte alkaline phosphatase [LAP] antigen expression, cellular elastase content, plasma elastase, and myeloperoxidase levels) was evaluated simultaneously with the levels of plasma markers of endothelial damage (thrombomodulin and von Willebrand factor antigen) and hypercoagulation (thrombin-antithrombin complex, prothrombin fragment 1 + 2, and D-dimer). The results show the occurrence of PMN activation in both groups of patients compared with a control group of healthy subjects. An increase in CD11b and LAP expression by PMN membrane was observed, together with a significant increase in cellular elastase content, plasma elastase, and myeloperoxidase levels. In addition, patients had high plasma levels of endothelial and hypercoagulation markers compared with controls. For the first time, these data show that in ET and PV, 2 hematologic conditions that place patients at increased risk for thrombosis, an in vivo leukocyte activation occurs and is associated with laboratory signs of endothelium and coagulation system activation. (Blood. 2000;96:4261-4266)

Adult↗
PubMed2000

Definition of relapse risk and role of nonanthracycline drugs for consolidation in patients with acute promyelocytic leukemia: a joint study of the PETHEMA and GIMEMA cooperative groups.

Preliminary independent reports of the Italian GIMEMA and the Spanish PETHEMA trials for newly diagnosed acute promyelocytic leukemia (APL) indicated a similarly high antileukemic efficacy in terms of complete remission and disease-free survival rates. To better investigate these studies and the prognostic factors influencing relapse risk, this study analyzed the updated results of 217 patients with PML/RAR alpha-positive APL enrolled in GIMEMA (n = 108) and PETHEMA (n = 109). All patients received identical induction (AIDA schedule) and maintenance. For consolidation, GIMEMA patients received 3 courses including idarubicin/cytarabine, mitoxantrone/etoposide, and idarubicin/cytarabine/thioguanine, whereas PETHEMA patients received the same drugs and dose schedule of idarubicin and mitoxantrone with the omission of nonintercalating agents. Depending on whether molecular relapses were classified as censored or uncensored events, the 3-year Kaplan-Meier estimates of relapse-free survival (RFS) for the combined series were 90 +/- 2% and 86 +/- 2%, respectively. Minor differences observed between the 2 patient cohorts were negligible. Multivariate regression analysis of RFS showed that initial leukocyte (WBC) and platelet counts were the only variables with independent prognostic value. The resulting predictive model for RFS demonstrated its capability of segregating patients into low-risk (WBC count </= 10 x 10(9)/L, platelet count > 40 x 10(9)/L), intermediate-risk (WBC count </= 10 x 10(9)/L, platelets </= 40 x 10(9)/L), and high-risk (WBC count > 10 x 10(9)/L) groups, with distinctive RFS curves (P <.0001). The conclusions are that omission of nonanthracycline drugs from the AIDA regimen is not associated with reduced antileukemic efficacy and a simple predictive model may be used for risk-adapted therapy in this disease. (Blood. 2000;96:1247-1253)

Adolescent↗
PubMed2000

Epstein-Barr virus-negative lymphoproliferate disorders in long-term survivors after heart, kidney, and liver transplant.

BACKGROUND: Solid organ transplant patients undergoing long-term immunosuppression have high risk of developing lymphomas. The pathogenesis of the late-occurring posttransplantation lymphoproliferative disorders (PTLD) have not yet been extensively investigated. METHODS: We studied 15 patients who developed PTLD after a median of 79 months (range 22-156 months) after organ transplant. Clonality, presence of Epstein-Barr virus (EBV) genome, and genetic lesions were evaluated by Southern blot analysis or polymerase chain reaction. RESULTS: All monomorphic PTLD and two of three polymorphic PTLD showed a monoclonal pattern. Overall, 44% of samples demonstrated the presence of the EBV genome. Within monomorphic PTLD, the EBV-positive lymphomas were even lower (31%). A c-myc gene rearrangement was found in two cases (13%), whereas none of the 15 samples so far investigated showed bcl-1, bcl-2, or bcl-6 rearrangement. The modulation of immunosuppression was ineffective in all patients with monomorphic PTLD independent of the presence of the EBV genome. The clinical outcome after chemotherapy was poor because of infectious complications and resistant disease. With a median follow-up of 4 months, the median survival time of these patients was 7 months. CONCLUSIONS: Late occurring lymphomas could be considered an entity distinct from PTLD, occurring within 1 year of transplant, because they show a histological and clinical presentation similar to lymphomas of immunocompetent subjects, are frequently negative for the EBV genome, are invariably clonal, and may rearrange the c-myc oncogene. New therapeutic strategies are required to reduce the mortality rate, and new modalities of long-lasting immunosuppression are called for.

Adolescent↗
PubMed2000

Antilymphocyte globulin, cyclosporine, prednisolone, and granulocyte colony-stimulating factor for severe aplastic anemia: an update of the GITMO/EBMT study on 100 patients. European Group for Blood and Marrow Transplantation (EBMT) Working Party on Severe Aplastic Anemia and the Gruppo Italiano Trapianti di Midolio Osseo (GITMO).

One hundred consecutive patients with severe aplastic anemia (SAA) received horse antilymphocyte globulin (ALG), cyclosporin A (CyA), 6-methylprednisolone (6Mpred), and granulocyte colony-stimulating factor (G-CSF) as first-line therapy. The median age was 16 years (range, 1-72 years) and median neutrophil count was 0.2 x 10(9)/L (range, 0-0.5 x 10(9)/L). Trilineage hematologic recovery (at a median interval of 96 days from treatment) was seen in 77 patients (48 complete, 29 partial) after 1 (n = 50) or more courses of ALG (n = 27). Of the 23 nonresponders, 11 patients died at a median interval of 83 days (range, 16-1132 days), 6 were considered treatment failures and underwent transplantation, and 6 were pancytopenic. Cytogenetic abnormalities were seen in 11% of patients, clonal hematologic disease in 8%, and relapse of marrow aplasia in 9%. The actuarial survival at 5 years was 87% (median follow-up 1424 days): 76% versus 98% for patients with neutrophil counts less than versus greater than 0.2 x 10(9)/L (P =.001) and 88% versus 87% for patients aged less than versus more than 16 years (P =.8). The actuarial probability of discontinuing CyA was 38%. Patients who did not achieve a white blood cell (WBC) count of 5 x 10(9)/L during G-CSF treatment have a low probability of responding (37%) and a high mortality rate (42%). This update confirms a high probability for SAA patients of becoming transfusion independent and of surviving after treatment with ALG, CyA, 6Mpred, and G-CSF, with a significant effect of neutrophil counts on outcome. Problems still remain, such as absent or incomplete responses, clonal evolution, relapse of the original disease, and cyclosporine dependence. Early transplantation, also from alternative donors, may be warranted in patients with poor WBC response to G-CSF. (Blood. 2000;95:1931-1934)

Adolescent↗
PubMed2000

Genetic modification of human T cells with CD20: a strategy to purify and lyse transduced cells with anti-CD20 antibodies.

A retroviral vector has been constructed that contains the human CD20 cDNA under the control of the Moloney murine leukemia virus (Mo-MuLV) LTR. Freshly isolated mononuclear cells are infected for three consecutive days in the presence of PHA and hrlL-2, and a mean 15.9% of the cells (range, 6.5 to 31.7%) acquire a CD3+CD20+ phenotype. Transduced T lymphocytes grow and expand in vitro for up to 3 weeks like mock-infected cells and, as observed for the T lymphoblastoid CEM cell line, CD20 expression is maintained for several months with no change in the growth curve of the cells. CD20-expressing CEM and fresh T lymphocytes can be positively immunoselected on columns using different anti-CD20 antibodies. Exposure to monoclonal chimeric anti-CD20 IgG1(kappa) Rituximab antibody (Roche), in the presence of complement, results in effective and rapid killing of the transduced CD3+CD20+ human T cells in vitro. This approach represents a new and alternative method to gene manipulation with "suicide" genes for the production of drug-responsive T cell populations, a crucial step for the future management of graft-versus-host disease in bone marrow transplant patients.

Antibodies, Monoclonal↗
PubMed2000

High-dose treatment with autologous bone marrow support as consolidation of first remission in younger patients with acute myelogenous leukaemia.

BACKGROUND: Debate and controversy remain as to the optimal post-remission therapy for younger patients with acute myelogenous leukaemia (AML). The aim of this study was to evaluate high-dose treatment (HDT) with autologous bone marrow support (ABMS) as consolidation of first complete remission (CR). PATIENTS AND METHODS: One hundred forty-four patients (AML-M3 excluded, median age 38 years, range 15-49 years) received remission induction therapy comprising: adriamycin 25 mg/m2, days 1-3, cytosine arabinoside (ara-C) and 6-thioguanine, both at 100 mg/m2 bid, days 1-7. Patients in whom CR was achieved received two further cycles of the same treatment prior to bone marrow being harvested and cryopreserved. HDT comprised ara-C: 1 g/m2 b.i.d. x six days and total body irradiation (TBI): 200 cGy b.i.d. for three days. Thawed autologous marrow was then re-infused. RESULTS: Complete remission was achieved in 106 of 144 patients (73%) who were thus eligible to receive ara-C + TBI + ABMS; 61 actually received it. Following HDT, the median time to neutrophil recovery (> 0.5 x 10(9)/l) was 25 days (range 11-72 days) and to platelet recovery (> 20 x 10(9)/l), 42 days (range 15-159 days). There were eight treatment-related deaths. Analysis by 'intention to treat' shows both remission duration (log-rank, P = 0.001) and survival (log-rank, P = 0.004) to be significantly longer for the 106 patients eligible to receive HDT than for a historical control group (n = 133) who received identical remission induction and consolidation therapy but without ara-C + TBI + ABMS. With a median follow-up of 5.5 years, 39 of 106 patients remain in CR (37%) and 54 (51% of those in whom CR was achieved) remain alive, with a predicted actuarial survival of 52% at 5 years. CONCLUSIONS: The addition of ara-C + TBI + ABMS to conventional consolidation therapy significantly improved remission duration and survival over those of a historical control group of patients with AML (aged < 50, AML-M3 excluded). HDT was, however, associated with significant treatment-related mortality and slow blood count recovery. The use of ara-C + TBI supported by peripheral blood progenitor cells should make the treatment safer and more widely applicable in AML.

Adolescent↗
PubMed2000

Recurrence after first cerebral infarction in young adults.

OBJECTIVE: We have investigated recurrence of stroke in a consecutive series of young adults, aged 16 to 45 years, after a first cerebral infarction. METHODS: From January 1, 1988 to December 31, 1996 we submitted those patients to a diagnostic protocol including angiographic, cardiological, and haematological investigations. The patients were followed at 6 month intervals up to December 31, 1998. RESULTS: We have evaluated and followed-up 135 patients, 71 men and 64 women, who were 3.99% of all the admitted stroke patients. At 12 months after stroke, 83 patients had returned to work, 40 patients were mildly to moderately handicapped, 4 were using a wheel-chair, and 8 had died. Follow-up was 26 to 123 months (mean 68.8). Recurrence of stroke, always of ischaemic nature, was seen in 15 patients (11.1%), 3 to 76 months after the first stroke (mean 27.4), for an annual incidence of 2.26%. Recurrence was significantly associated with Partial Anterior Circulation Syndrome and Haematological subtype of first stroke (respectively, P = 0.0209 and P = 0.0135, chi2 test), but not with age (< or = or > 35 years) or risk factors. Repetition of stroke was never fatal, but it caused heavy disability in 13 patients, 8 of whom had completely or nearly completely recovered after the first event. CONCLUSIONS: Our data suggest that recurrence of stroke is a major clinical problem also for the patients aged less than 45 years and that it might be more frequent with specific clinical syndromes and etiologic subtypes of first stroke.

Adolescent↗
PubMed2000

Trends in mortality from leukemia in subsequent age groups.

Trends in age-standardized death certification rates from leukemias in subsequent age groups were analyzed on the basis of the World Health Organization database over the period 1960-1997 in the European Union (EU) and other developed areas of the world. In the EU, the peak rate at age 0-14 was observed in 1960-1964, and the fall in mortality was over 70%, to reach 1.2/100,000 males and 0.9/100,000 females in 1995-1997. In the age group 15-44, the fall was about 40% for males and 45% for females. In the age group 45-59, the fall was around 25%. At age 60-69, the peak rate was observed in the late 1970s, and the subsequent fall was only 6% for females. At age > or =70, leukemia mortality rose up to the late 1980s, and levelled off there-after. Overall, the falls in leukemia mortality over the 35-year calendar period corresponded to the avoidance of about 7,000 deaths per year. In eastern Europe, the falls in children and young adults started later --in the late 1970s--and were less than 40% for children and 30% for young adults (15-44 years). Overall age-standardized mortality from leukemia did not appreciably change over the 35-year period considered. Leukemia mortality rates in the USA and Japan started from different values, but were similar to those of the EU in the late 1990s, indicating that the impact of therapeutic advancements has been comparable in developed areas of the world. In eastern Europe, however, the declines in leukemia mortality were later and appreciably smaller.

Adolescent↗
PubMed2000

Role of early anthracycline dose-intensity according to expression of Philadelphia chromosome/BCR-ABL rearrangements in B-precursor adult acute lymphoblastic leukemia.

INTRODUCTION: The use of anthracycline antibiotics in adult acute lymphoblastic leukemia (ALL) has resulted in an improved outcome to remission induction therapy. However,the exact role of these drugs in consolidation therapy is less clear, especially in specific ALL subsets. MATERIALS AND METHODS: A retrospective analysis was conducted on the outcome of 308 patients (median age 35 years, range 13-75) with the most frequent subtype, early-B ALL, treated between 1974 and 1998 on eight consecutive protocols. Anthracycline-related effects were assessed by evaluating the impact of planned anthracycline dose-intensity (A-DI) on long-term outcome. A-DI (in mg/m(2)/week) during the first twelve weeks of consolidation therapy was classified as either "high" (doxorubicin>20, idarubicin>7) or "low". RESULTS: Complete remission was achieved in 78% of cases. With a median follow-up of 6.5 years, on multivariate analysis, disease-free survival (DFS) correlated only with expression of the Philadelphia (Ph) chromosome and/or associated BCR-ABL rearrangements (Ph/BCR(+)) (P=0.0001) and planned A-DI (P<0.0001). On this basis, four major prognostic groups with significantly different DFS could be identified: (1) Ph/BCR(-), "high" A-DI (n=102), median 3.5 years and 41% at five years, respectively; (2) Ph/BCR(-), "low" A-DI (n=64), 1.3 years and 16%; (3) Ph/BCR(+), "high" A-DI (n=35), 1.7 years and 20%; (4) Ph/BCR(+), "low" A-DI (n=39), 0.75 years and 0%. When analyzed separately for Ph/BCR(-) (n=166) and Ph/BCR(+) (n=74) patients, the A-DI effect on DFS was preserved in the former (P=0.018) whereas, in Ph/BCR(+) patients, only age <50 years (P=0.004) and blast count <25 x 10(9)/l (P=0.02) correlated with better DFS. However, Ph/BCR(+) patients with the best prognostic profile (age <50 years and blast count <25 x 10(9)/l; n=21) who were treated on "high" A-DI regimens experienced a median DFS of 2.2 years with DFS 21% at five years, compared to 0.67-1 years and 0-10% in other cases (n=53, P<0.01). CONCLUSION: A "high" A-DI may act as a positive treatment-related prognostic factor in early B-lineage ALL. Although mainly restricted to patients with Ph/BCR(-) ALL, A-DI could also influence the outcome in Ph/BCR(+) patients with other favorable prognostic factors.

Adolescent↗
PubMed2000

Second malignancies in patients with essential thrombocythaemia treated with busulphan and hydroxyurea: long-term follow-up of a randomized clinical trial.

We have previously demonstrated that hydroxyurea (HU) reduces the rate of vascular complications in patients with essential thrombocythaemia (ET) at high risk of thrombosis. However, the relatively short follow-up (median 27 months) did not enable the evaluation of the risk of developing secondary malignancies. In this study, we report the long-term outcome of the 114 patients included in the trial: 56 patients randomized to receive HU and 58 patients to receive no cytoreductive therapy. Before randomization, 15 patients had been treated with busulphan. During the observation period, 29 patients (50%) shifted from the control to the HU group mainly because of thrombosis. Median follow-up was 73 months (range 3-94). Analysis was by intention to treat and, when indicated, by treatment. When analysed by intention to treat, 46 out of 54 patients (85%) originally randomized in the HU group are alive, compared with 49 of 58 patients (84%) in the control group [not significant (n.s.)]. Five patients (9%) in the HU group and 26 patients (45%) in the control group had thrombosis (P < 0.0001). Seven patients (13%) in the HU group developed secondary acute leukaemia, myelodysplastic syndromes or solid tumours, compared with only one of the control group patients (1.7%) (P = 0.032). The occurrence of secondary malignancies was also analysed by treatment: none of the 20 patients who had never been treated with chemotherapy developed neoplasia vs. three of the 77 patients given HU only (3.9% n.s.) and five of the 15 patients given busulphan plus HU (33% P < 0. 0001). This study showed that: (a) HU reduced the risk of thrombosis in ET patients; (b) the sequential use of busulphan and HU significantly increased the risk of second malignancies; and (c) overall survival was not affected by HU therapy.

Acute Disease↗
PubMed2000

Defibrotide for the treatment of hepatic veno-occlusive disease: results of the European compassionate-use study.

Severe hepatic veno-occlusive disease (VOD) is a recognized complication of autologous and allogeneic stem cell transplantation (SCT) that is often fatal. Defibrotide (DF) is a polydeoxyribonucleotide that has been found to have anti-thrombotic, anti-ischaemic and thrombolytic properties without causing significant anticoagulation. Preliminary studies have demonstrated activity for DF in the treatment of VOD, with minimal associated toxicity. In the present study, 40 patients who fulfilled established criteria for VOD were treated with DF on compassionate grounds in 19 European centres; 28 patients met risk criteria predicting progression of VOD and fatality or had evidence of multiorgan failure (MOF), and were defined as 'poor-risk'. DF was commenced intravenously at a median of 14 d (range, -2 d to 53 d) post SCT at doses ranging from 10 to 40 mg/kg. The median duration of therapy was 18 d (range, 2--71 d). Twenty-two patients showed a complete response (CR) (bilirubin < 34.2 micromol/l and resolution of signs/symptoms of VOD and end-organ dysfunction) [CR = 55%, confidence interval (CI) 40--70%] and 17 patients (43%) are alive beyond d +100. Ten poor-risk patients showed a complete response (CR = 36%, CI 21--51%). These results demonstrate that DF is an active treatment for VOD following SCT and a randomized trial is now underway in order to further evaluate its role.

Acute Disease↗
PubMed2000

Diagnosis and treatment of polycythemia vera and possible future study designs of the PVSG.

The present study describes clinicopathological criteria to distinguish the 5 sequential stages proposed by Wasserman et al in the natural history of newly diagnosed PV patients. The European Working Group on MPD (EWG.MPD) extended and modified the PVSG diagnostic criteria of PV by including bone marrow histopathology. From the results of prospective randomized studies in PV it became evident that new clinical trials in previously untreated PV patients should focus on comparing interferon-alpha, a non-leukemogenic approach, versus a potential leukemogenic myelosuppressive treatment modality. Hydroxyurea appears to be the least leukemogenic myelosuppressive agent in long-term prospective clinical PV-studies extending observation periods of more than 10 years. The rational for using IFN-alpha as a first-line treatment option in newly diagnosed PV-patient include its effectiveness to abate constitutional symptoms and to induce a complete remission thereby avoiding phlebotomy, iron deficiency, and macrocytosis associated with hydroxyurea. Moreover IFN-alpha may prevent or delay the development of postpolycythemic myelofibrosis if used early in the course of the disease. Clinicians will be reluctant to postpone the use of hydroxyurea in early stage PV as long as a conservative approach using phlebotomy aiming at a hematocrit below 0.45, plus low-dose aspirin for the control platelet function or anagrelide for the control platelet number is used to keep the patient healthy. Low-dose aspirin will prevent the microvascular thrombotic complications of thrombocythemia associated with PV in remission after phlebotomy, but lacks myelosuppressive activity. Control of megakaryocyte maturation and reduction of platelet production to normal (<400 x 10(9)/l) by relatively low doses of anagrelide will predict a significant reduction of vascular complications in the early stages of PV, may prevent progression to myelofibrosis during follow-up of PV and very probable will postpone the use of hydroxyurea treatment for controlling the platelet count in PV. Large scale randomized clinical trials in PV are proposed, which should aim not only for clinical and hematological response, safety, efficacy, but should also assess toxicity, the need for phlebotomy and whether the development of progressive disease such as splenomegaly, pruritus, myelofibrotic myeloid metaplasia, spent phase, myelodysplasia and acute leukemia can be delayed or prevented by IFN-alpha as compared to a conservative approach of phlebotomy plus low-dose aspirin or anagrelide followed by hydroxyurea when signs of myeloproliferative activity became evident.

Blood Platelets↗
PubMed2000

Need for an accurate molecular diagnosis to assess the donor origin of leukemia relapse after allogeneic stem cell transplantation.

BACKGROUND AND OBJECTIVES: Leukemia relapse occurring in donor cells after allogeneic hematopoietic stem cell transplantation has been reported in rare cases. Cytogenetic analysis and molecular probing of variable number of tandem repeats (VNTRs) have been used to confirm this unusual event in the few cases so far reported in the literature. The aim of this study was to demonstrate that extensive molecular characterization of leukemic cells at diagnosis and relapse may be necessary to avoid many technical pitfalls possibly leading to an erroneous diagnosis of leukemia relapse in donor cells after allogeneic transplantation. DESIGN AND METHODS: We report the case of a 49- year old man who received an allogeneic transplantation from his HLA-identical sister because of BCR-ABL+ acute lymphoblastic leukemia (ALL). After having achieved complete hematologic and molecular remission, two years later an overt leukemia relapse occurred with cytogenetic findings suggesting a leukemia relapse in donor cells. The donor or patient origin of leukemic cells at relapse was further investigated by fluorescence in situ hybridization (FISH) karyotyping, reverse transcription (RT) polymerase chain reaction (PCR) analysis of BCR-ABL chimeric transcripts, PCR amplification of several VNTRs and the Y chromosome-specific DYS14 sequence and finally by amplification, cloning and sequencing of the CDRIII region of the immunoglobulin heavy chain (IgH) gene. RESULTS: At the time of relapse, conventional and FISH karyotyping revealed the presence of a Phl+ chromosome and a female karyotype in all the 25 metaphases analyzed and PCR amplification of the Y chromosome-specific DYS14 sequence was negative. Moreover, the molecular evaluation of hematopoietic chimerism performed by the NZ-22 VNTR allowed us to demonstrate that at the time of relapse, a consistent proportion of hematopoietic cells was of donor origin. However, the molecular cloning and sequencing of the CDRIII region of the immunoglobuin heavy chain (IgH) gene rearrangement in leukemic blasts at diagnosis and relapse demonstrated their identity thus formally proving the patient origin of both leukemic clones. INTERPRETATION AND CONCLUSIONS: While the simplest interpretation of the apparent female karyotype at relapse is the consequence of a loss of the Y chromosome which in leukemic blasts took place along with duplication of an X-chromosome, this case strongly emphasizes the need for accurate and extensive molecular characterization to prove the donor origin of a leukemia relapse after allogeneic transplantation.

Base Sequence↗
PubMed2000

Lupus anticoagulants and thrombosis: clinical association of different coagulation and immunologic tests.

The dilute Russell's viper venom time (dRVVT) and the kaolin clotting time (KCT) are two among the most commonly used coagulation tests for the detection of lupus anticoagulants. The dRVVT seems superior to the KCT in identifying LA-positive patients at risk of thrombosis. However, this relationship is greatly influenced by both the source of reagents and the instrumentation employed to carry out the assays. Therefore, 4 dRVVTs ("home-made" dRVVT, DVV test, Bioclot LA, LA Screen), and one KCT (Kaoclot) were performed in two centers and compared for their retrospective correlation with the thrombotic complications of 72 patients with a previously established diagnosis of lupus anticoagulants. Two other assays ("home-made" KCT, and Colloidal Silica Clotting Time, CSCT) were performed in one of the two centers, and compared with Kaoclot for their clinical correlations in the same population of patients, 44 of whom (61%) had suffered from arterial and/or venous thrombosis. A rather good degree of inter-laboratory and inter-assay correlations of the different tests was found. However, a statistically significant association with thrombosis was found only with the coagulation profile generated using the "home-made" dRVVT. When the commercially available dRVVTs were used, none of the coagulation profiles remained associated with thrombosis. When the assays were analyzed separately, the association with thrombosis was statistically significant for LA screen (p = 0.0019), DVV test (p = 0.0043), and Bioclot (p = 0.0255), and of borderline significance for the "home-made" dRVVT (p = 0.0503) in one center. This last assay was also significantly associated with thrombosis in the other center (p = 0.0139). When venous and arterial thrombosis were considered separately, DVV test was statistically associated with venous thrombosis in both centers (p = 0.0076 and p = 0.0187, respectively), and LA screen in one center (p = 0.0303). No dRVVT was found to correlate with arterial thrombosis. Kaoclot, Colloidal Silica Clotting Time, and the "home-made" KCT did not correlate with thrombosis. The prevalence of IgG and/or IgM antibodies to cardiolipin, beta2-glycoprotein I and prothrombin were 74%, 86% and 85%, respectively. Increased titers of IgG anticardiolipin antibodies were associated with arterial thrombosis (p = 0.0375), whereas IgM anti-beta2-glycoprotein I antibodies were associated with venous thrombosis (p = 0.0433). In conclusion, these retrospective data support the notion that the dRVVT, rather than other coagulation or ELISA tests, are able to identify lupus anticoagulant-positive patients at risk of thrombosis. This property appears common to several commercially available dRVVT kits, making this type of assay the ideal target of future efforts of laboratory standardization.

Adult↗
PubMed1999

Neutrophil activation and hemostatic changes in healthy donors receiving granulocyte colony-stimulating factor.

Granulocyte colony-stimulating factor (G-CSF) enhances neutrophil functions in vitro and in vivo. It is known that neutrophil-derived products can alter the hemostatic balance. To understand whether polymorphonuclear leukocyte (PMN) activation, measured as PMN degranulation and phenotypical change, may be associated to hemostatic alterations in vivo, we have studied the effect of recombinant human G-CSF (rHuG-CSF) administration on leukocyte parameters and hemostatic variables in healthy donors of hematopoietic progenitor cells (HPCs). Twenty-six consecutive healthy donors receiving 10 micrograms/kg/d rHuG-CSF subcutaneously for 5 to 7 days to mobilize HPCs for allogeneic transplants were included in the study. All of them responded to rHuG-CSF with a significant white blood cell count increase. Blood samples were drawn before therapy on days 2 and 5 and 1 week after stopping rHuG-CSF treatment. The following parameters were evaluated: (1) PMN activation parameters, ie, surface CD11b/CD18 antigen expression, plasma elastase antigen levels and cellular elastase activity; (2) plasma markers of endothelium activation, ie, thrombomodulin (TM) and von Willebrand factor (vWF) antigens; (3) plasma markers of blood coagulation activation, ie, F1+2, TAT complex, D-dimer; and (4) mononuclear cell (MNC) procoagulant activity (PCA) expression. The results show that, after starting rHuG-CSF, an in vivo PMN activation occurred, as demonstrated by the significant increment of surface CD11b/CD18 and plasma elastase antigen levels. Moreover, PMN cellular elastase activity, which was significantly increased at 1 day of treatment, returned to baseline at day 5 to 6, in correspondence with the elastase antigen peak in the circulation. This change was accompanied by a parallel significant increase in plasma levels of the two endothelial and the three coagulation markers. The PCA generated in vitro by unstimulated MNC isolated from rHuG-CSF-treated subjects was not different from that of control cells from untreated subjects. However, endotoxin-stimulated MNC isolated from on-treatment individuals produced significantly more PCA compared with both baseline and control samples. All of the parameters were decreased or normal 1 week after stopping treatment. These data show that rHuG-CSF induces PMN activation and transiently affects some hemostatic variables in healthy HPC donor subjects. The clinical significance of these findings remains to be established.

Adolescent↗
PubMed1999

Apoptosis by anthracyclines at therapeutic concentrations in MDR1+ human leukemic cells.

Induction of apoptosis by daunorubicin (DNR) and idarubicin (IDA) was evaluated cytofluorometrically in CEM and CEM-MDR1+ leukemic cells exposed to drug concentrations similar to peak plasma levels obtainable in vivo (DNR 200-400 ng/ml, IDA 50-100 ng/ml, 30' incubation), and differentiating apoptosis from necrosis (FITC-annexin V+/propidium iodide- and + cells, respectively). Firstly, to set experimental conditions, apoptosis was evaluated in CEM cells at 3, 6, 12, 18, 24, 48, 72, and 96 hours from end of drug incubation, the maximal increase being noted at 24-48 hours. Net apoptosis rates were determined after subtraction of the spontaneous activity observed in untreated cells. The apoptotic effect from varying drug type and concentration was compared at 24 hours in CEM-MDR1+ cells, with and without co-incubation with MDR1 functional downregulator cyclosporin A (CSA) used at therapeutic concentration (1500 ng/ml). The results indicated that, at drug concentrations likely to be approached in vivo as a short-lasting peak level (IDA 100-200 ng/ml) with increased-dose IDA (> 12-15 mg/m2), pro-apoptotic effects by IDA+CSA in CEM-MDR1+ cells were significantly greater than by DNR+CSA, and corresponded to the levels observed with IDA 50 ng/ml without CSA in control CEM cells. This in vitro study demonstrates that it is possible to determine in the same sample cell fluorescence related to anthracyclines, apoptotic cells (FITC-annexin V positive), and necrotic cells (propidium iodide positive), and confirms that cytofluorimetric evaluation of apoptosis can reliably predict the effects of anthracycines in function of drug type, concentration and, in MDR1+ cells, concurrent MDR1 inhibition. Extension of this assay to the clinical ground may be warranted.

ATP Binding Cassette Transporter, Subfamily B, Mem↗