PubMed Health⌕ Search

Biomedical subjects

X Thomas

Publications and source records attributed to X Thomas.

At least 55 records · Page 3Linked to original sources

T-cell lineage acute lymphoblastic leukemia with chromosome 5 abnormality in a patient with Crohn's disease and lipoid nephrosis.

We describe a 17-year-old patient with a documented history of Crohn's disease (CD) and of minimal-change nephrotic syndrome (MCNS) in whom a diagnosis of T-cell acute lymphoblastic leukemia (ALL) was made. The diagnosis of ALL was established by morphological examination of bone-marrow aspirates and confirmed by means of immunophenotypic analysis showing the involvement of T-cell lineage leukemic cells. The lymphoid clone showed a karyotypic abnormality involving the long arm of chromosome 5 in a translocation (5;6). Few cases of CD complicated by ALL have been previously reported. The present one is the first case combining CD and ALL in a patient with a past history of MCNS. This raises the possibility of a relationship among those diseases. The possible mechanisms for such a relationship are discussed here.

Adolescent↗

Dose-escalation study of single dose mitoxantrone in combination with timed sequential chemotherapy in patients with refractory or relapsing acute myelogenous leukemia.

A dose-escalation study was realized in order to assess the maximally tolerated dose (MTD) of high-dose mitoxantrone in a single injection combined with cytarabine and etoposide (EMA regimen) in refractory or relapsed acute myelogenous leukemia (AML). Between July 1997 and June 1998, 24 patients with relapsed or refractory AML entered the study. All but one patient had normal left ventricular ejection fraction (LVEF) at baseline. Performance status according to World Health Organization (WHO) criteria was less than two in all cases. All patients have been previously treated by mitoxantrone or anthracyclines. Four cohort of ten patients were scheduled with the following doses: (1) mitoxantrone 36 mg/m2 on day 1; (2) mitoxantrone 45 mg/m2 on day 1; (3) mitoxantrone 60 mg/m2 on day 1; (4) mitoxantrone 75 mg/m2 on day 1 in combination with cytarabine 500 mg/m2 per day (days 1-3, and days 8-10), and etoposide 200 mg/m2 per day (days 8-10). All patients received the full doses of the three drugs. The limiting toxicity was defined as WHO grade 4 nonhematologic toxicity and for impairment of cardiac function by Alexander's criteria (moderate or severe toxicity). The occurrence of limiting toxicity in at least three patients from the same dose level determined the MDT. No limiting toxicity was observed in mitoxantrone dose level 1. Two limiting toxicities were observed in mitoxantrone dose level 2 (one mucositis, one moderate cardiac toxicity), and three limiting toxicities in mitoxantrone dose level 3 (1 high transaminase levels, two moderate cardiac toxicities) ending the assay. Overall, 16 patients (67%) achieved complete remission (CR). One drug-addict patient died from cerebral hemorrhage due to severe aspergillosis and was not considered as a limiting toxicity. After EMA chemotherapy, 13 patients received subsequent chemotherapy courses involving anthracyclines or their derivatives. Six patients underwent allogeneic bone marrow transplantation. No late toxicity occurred. The median survival of the entire cohort was 41.4 weeks. We conclude that (i) EMA chemotherapy using a single injection of mitoxantrone is effective in the treatment of refractory or relapsing AML; (ii) the recommended phase II dose of mitoxantrone is 45 mg/m2 administered over 30 min as a single dose in combination with cytarabine and etoposide.

Adolescent↗

Adult acute lymphocytic leukemia study testing chemotherapy and autologous and allogeneic transplantation. A follow-up report of the French protocol LALA 87.

The French protocol LALA 87 was designed to compare three different postinduction strategies in adult acute lymphocytic leukemia (ALL): chemotherapy, autologous transplantation, and allogeneic transplantation. This trial demonstrated a significant superiority of allogeneic bone marrow transplantation (BMT) in high-risk ALL patients. Similarly, there was a trend in favor of autologous BMT over chemotherapy in those same patients. Allogeneic BMT was not superior to autologous BMT or chemotherapy in less aggressive leukemia (standard-risk ALL). Further improvements are warranted in the treatment of adult ALL. The authors' current ongoing study is stratifying patients to allocate them to regimens with risk-adapted treatment intensity.

Adolescent↗

Long-term outcome after allogeneic hematopoietic stem cell transplantation for advanced stage acute myeloblastic leukemia: a retrospective study of 379 patients reported to the Société Française de Greffe de Moelle (SFGM).

To assess the place of allogeneic hematopoietic stem cell transplantation (HSCT) in the advanced stage of acute myeloid leukemia (AML), we retrospectively analyzed 379 consecutive patients who underwent allogeneic HSCT for advanced AML. The median follow-up of the entire cohort was 7.5 years. Sixty-nine patients (18%) were transplanted with primary resistant disease. Three hundred and ten (82%) were relapsed patients, 94 (30%) of whom were in untreated relapse, 67 (22%) in refractory relapse and 149 (48%) in 2nd or 3rd complete remission at time of transplantation. The 5-year probabilities of overall survival (OS), disease-free survival (DFS), and transplant-related mortality (TRM) were 22 +/- 4%, 20 +/- 4%, 45 +/- 6%, respectively. In multivariate analysis, we demonstrated the favorable impact on OS, DFS and TRM of two factors over which we have no control (age <15 years, complete remission achievement) and three factors over which we have some control (female donor, acute and chronic graft-versus-host disease). The results of this study suggest that the graft-versus-leukemia effect is important in advanced AML and that new HSCT modalities are needed for some patients with this indication.

Acute Disease↗

Treatment of relapsing acute promyelocytic leukemia by all-trans retinoic acid therapy followed by timed sequential chemotherapy and stem cell transplantation. APL Study Group. Acute promyelocytic leukemia.

The purpose of this study was to assess the safety and efficacy of stem cell transplantation (SCT) mainly autologous SCT as consolidation therapy in APL patients who relapsed and achieved a second complete remission (CR2). Fifty adult patients with a first relapsed APL, of whom 39 had been previously treated with ATRA, entered a multicenter trial of oral ATRA until complete remission (CR) achievement followed by timed sequential chemotherapy (EMA combining etoposide 200 mg/m2/day for 3 days, mitoxantrone 12 mg/m2/day for 3 days, and cytarabine 500 mg/m2/day for two sequences of 3 days). EMA was started either after CR achievement, or on day 1 of ATRA because of initial white blood cell (WBC) counts >5 x 10(9)/l, or rapidly added to ATRA in order to prevent ATRA syndrome because WBC count increased under ATRA. Forty-five patients (90%, 95% CI 78%-97%) were in CR after induction therapy. Five patients died from infection during aplasia following EMA chemotherapy. Eleven patients who achieved CR had a familial HLA-identical donor and were allografted. The median disease-free survival (DFS) of allografted patients was 8.2 months. The 34 other CR patients were scheduled for autologous peripheral blood (PB) SCT (intent-to-treat group). Actually, autologous transplantation was only carried out in 22 patients (65%) (17 PBSCT and five autologous bone marrow transplantation (BMT)). Reasons for not autografting were early relapse (three patients), severe toxicity of EMA chemotherapy (six patients), and refusal or failure of stem cell harvest (three patients). The 3-year DFS rate of patients actually autografted was 77%. Among the 17 autografted patients still in CR2, nine patients have already reached a longer CR2 than first CR (CR1). Results of detection of PML/RARalpha by RT-PCR after autologous transplantation show negative findings in eight of the nine patients tested. We conclude that (1) ATRA combined to EMA chemotherapy is effective in the treatment of relapsed APL; (2) allogeneic BMT may be too toxic after salvage treatment including EMA intensive chemotherapy; (3) clinical outcome of autografted patients and preliminary molecular results regarding detection of PML/RARalpha after autologous PBSCT are encouraging.

Adult↗

Long-term follow-up confirms the benefit of all-trans retinoic acid in acute promyelocytic leukemia. European APL group.

First results of a randomized trial (APL91 trial) and other randomized or non-randomized studies have shown that ATRA followed by chemotherapy significantly increased event-free survival (EFS) and survival, and decreased the incidence of relapse by comparison to chemotherapy alone in newly diagnosed APL. We present here long-term follow-up of the APL91 trial. In this trial, 101 patients had been randomized between ATRA followed by three courses of daunorubicin-AraC chemotherapy (ATRA group) and the same chemotherapy alone (chemotherapy group). Results were reanalyzed 73 months after closing of patient entry. Updated results of APL 91 trial found a Kaplan-Meier estimate of EFS and relapse rate at 4 years of 63% and 31% in the ATRA group, as compared to 17% and 78% in the chemotherapy group (P= 10(-4) and relative risk 2.95, P= 10(-4) and relative risk 3.68, respectively). Kaplan-Meier survival at 4 years was 76% in the ATRA group and 49% in the chemotherapy group (P= 0.026, relative risk 2.7). In the chemotherapy group, seven of the 27 relapses occurred after 18 months, but no relapse was seen after 43 months. In the ATRA group, four of the 17 relapses occurred after 18 months, including two late relapses (at 58 and 74 months). In the chemotherapy group, 23 of the 25 patients who relapsed achieved a second CR with ATRA, and the Kaplan-Meier estimate of second relapse was 40% at 30 months. In the ATRA group, the 10 patients who relapsed and were retreated with ATRA achieved a second CR. In conclusion, long-term results of APL91 trial confirm the superiority of the combination of ATRA and chemotherapy over chemotherapy alone in newly diagnosed APL, and that ATRA should be incorporated in the front-line treatment of APL.

Antineoplastic Agents↗

Late autologous transplantation in chronic myelogenous leukemia with peripheral blood progenitor cells mobilized by G-CSF and interferon-alpha.

In chronic myelogenous leukemia (CML), autologous stem cell transplantation could be a promising new approach for patients with no cytogenetic response after interferon alpha (IFN-alpha) therapy. We report data on 28 CML patients autotransplanted in chronic phase with peripheral blood progenitor cells mobilized with G-CSF (5 microg/kg/day x 5 days) given subcutaneously while continuing IFN-alpha therapy. At mobilization, 23 patients (82%) were in complete hematological remission (CHR), 16 (57%) achieved a minor cytogenetic response (mcr). We obtained, after stimulation, a median of 37.4 x 10(9)/l (6.9-108) white blood cells, 7.2 x 10(8)/kg (2.2-16.6) mononuclear cells, 39 x 10(4)/kg (4.8-403.5) CFU-GM and 4.2 x 10(6)/kg (0-58.6) CD34+ cells. Six patients received GM-CSF after transplantation. All patients engrafted, with no significant influence stemming from the Sokal index score and pretransplantation IFN-alpha therapy duration. The first cytogenetic evaluation after transplantation showed 11 (39%) major cytogenetic response (Mcr), and nine (32%) mcr with no significant correlation between these responses, the Sokal index score, and pretransplantation IFN-alpha therapy duration, although there was a significant impact from GM-CSF administration (P=0.01). After transplantation, 26 patients received IFN-alpha alone or associated with hydroxyurea. The median follow-up was 12 months after transplantation and 57 months after diagnosis. At the time of follow-up, nine patients were in CHR, six remained stable in chronic phase, three presented an mcr and one remained in Mcr. At the last follow-up, 22 patients were alive. We conclude that the results of this strategy are encouraging in poor IFN-alpha responders but that other prospective studies that try to maintain the cytogenetic responses obtained immediately after transplantation are needed.

Adult↗

Additional chromosomal abnormalities in patients with acute promyelocytic leukaemia (APL) do not confer poor prognosis: results of APL 93 trial.

In spite of the recent improvement in the outcome of acute promyelocytic leukaemia (APL) with treatment combining all trans retinoic acid (ATRA) and chemotherapy (CT), some patients with this disease still have a poor outcome. The prognostic significance of chromosomal abnormalities in addition to t(15;17) in APL is uncertain. We examined the prognostic significance of secondary chromosomal changes in 292 patients included in a European trial who were treated with ATRA and CT. The incidence of chromosomal abnormalities in addition to t(15;17) was 26% and trisomy 8 was the most frequent secondary change (46% of the cases with secondary changes). No significant differences were seen with regard to age, sex, initial white blood cell count, % of circulating blasts, platelet count, fibrinogen level and incidence of microgranular variants between patients with or without additional rearrangements. Outcome was also similar between patients with t(15;17) alone and patients with t(15;17) and other clonal abnormalities for complete remission (92% vs. 93% respectively), event-free survival at 2 years (76.1% vs. 78.1% respectively), relapse at 2 years (16.7% vs. 11.6% respectively) and overall survival at 2 years (79.9% vs. 79.5% respectively). Analysis according to the type of induction treatment (ATRA followed by CT or ATRA plus CT) or the type of maintenance treatment (with ATRA, low-dose CT or both) also failed to show any difference between the two groups. Thus, in a large cohort of APL patients treated with ATRA and CT, additional chromosomal abnormalities had no impact on prognosis.

Adult↗

Hypermethylation of calcitonin gene in adult acute leukemia at diagnosis and during complete remission.

Hypermethylation of the calcitonin gene has been described in various hematologic malignancies. In order to assess its frequency and potential usefulness as a marker for leukemic cells and to detect potential clinical correlations, 180 adult patients (aged > 15 years) with newly diagnosed acute leukemia including 133 cases of acute myeloid leukemia (AML) and 47 cases of acute lymphoblastic leukemia (ALL) were tested for its presence in leukemic blasts at diagnosis by Southern blot technique and polymerase chain reaction (PCR) using 3 sets of primers (P550, P566, P1400), amplifying the most frequent sites of hypermethylation upstream or within the gene. In AML, 92 patients (69%) had hypermethylation detected by Southern blot at diagnosis. This hypermethylation could be confirmed by PCR in 18 of 36 tested cases (50%). Hypermethylation was not significantly associated to any clinical or hematological characteristic of the disease. In ALL, 44 patients (94%) had hypermethylation detected by Southern blot at diagnosis. This hypermethylation could be confirmed by PCR in 33 of the 43 tested cases (77%). Sensitivity of PCR assessed by dilution was 1 to 0.1%. Hypermethylation was not either significantly related to any clinical or hematologic characteristics of the disease. Seven ALL cases which were positive by PCR at diagnosis and achieved cytological CR could be tested during CR. Five cases were negative and did not relapse after 3 to 27 months in CR. One case was positive at the beginning of CR and became negative after autologous transplant. However, he relapsed after 9 months in CR, 3 months after the last negative test. PCR for Bcr/Abl was also negative at this time. We conclude that hypermethylation of the calcitonine gene is frequent at diagnosis in adult acute leukemia, particularly in ALL.

Acute Disease↗

Multicenter randomized phase II trial of idarubicin vs mitoxantrone, combined with VP-16 and cytarabine for induction/consolidation therapy, followed by a feasibility study of autologous peripheral blood stem cell transplantation in elderly patients with acute myeloid leukemia.

To compare the antileukemic efficacy of idarubicin and mitoxantrone in elderly patients with acute myeloid leukemia (AML) and to evaluate the feasibility of autologous transplantation using PBSC after consolidation in those with a good performance status, 160 patients (median age 69 years), with AML at diagnosis, 118 of them with de novo AML and 42 with AML secondary to myelodysplastic syndrome or toxic exposure (sAML), received induction treatment with idarubicin, 8 mg/m2/day or mitoxantrone, 7 mg/m2/day, on days 1, 3, and 5, both combined with VP-16, 100 mg/m2/day on days 1 to 3 and cytarabine (araC), 100 mg/m2/day, on days 1 to 7. G-CSF, 5 microg/kg/day, was administered after chemotherapy in patients aged more than 70 years. Patients in complete remission (CR) received one course of consolidation using the same schedule as for induction except the araC administration was shortened to 5 days. Some patients younger than 70 years were then scheduled for autologous stem cell harvest on days 5 to 7 of G-CSF, 5 microg/kg/day, initiated after hematopoietic recovery from consolidation. Autologous transplantation was performed following an additional chemotherapy conditioning. Ninety-five patients (59%) achieved CR, without significant difference between the idarubicin (56% CR) and mitoxantrone (63% CR) group. There was also no significant difference in CR rate between de novo AML (63%) and secondary AML (55%) (P = 0.12). Patients aged < 70 years had 67% CR, while patients aged > or = 70 years had 49% (P = 0.02). There was no significant difference in the duration of aplasia between the two arms. Median time to neutrophil recovery was 22 days in patients who received G-CSF following induction and 27 days in patients who did not (P = 0.006). Severe extrahematologic toxicities of induction did not differ between the two arms and included sepsis (39%), diarrhea (13%), hyperbilirubinemia (8%), hemorrhage (6%) and vomiting (6%). Overall, 14 patients (9%), died from toxicity of induction. First consolidation was administered in 74 patients of whom seven (9%) died from toxicity. Nineteen patients have received transplantation. Median time to recovery of neutrophils > 0.5 x 10(9)/l was 13 days and of platelets > 50 x 10(9)/l 43 days following consolidation. There were two toxic deaths. Median disease-free survival and survival from time of achieving CR of non transplanted patients are 6 and 7 months respectively without difference between the two arms. Fourteen transplanted patients relapsed at a median of 5 months post-transplant. We conclude that this regimen is well tolerated and has a good efficacy to induce CR, without a significant difference in efficacy and toxicity between idarubicin and mitoxantrone. Intensive postinduction, including transplantation, is feasible; however, this procedure did not seem to prevent early relapse in the majority of patients. Neither the high rate of CR nor consolidation nor transplant procedure in a selected group of patients did translate into improved DFS and/or survival.

Acute Disease↗

Granulocyte-macrophage colony-stimulating factor (GM-CSF) to increase efficacy of intensive sequential chemotherapy with etoposide, mitoxantrone and cytarabine (EMA) in previously treated acute myeloid leukemia: a multicenter randomized placebo-controlled trial (EMA91 Trial).

The EMA86 study showed efficacy of intensive sequential chemotherapy with mitoxantrone, 12 mg/m2 day on days 1-3, etoposide, 200 mg/m2/day as a continuous infusion on days 8-10 and cytarabine (araC), 500 mg/m2/day as continuous infusion on days 1-3 and 8-10 (EMA regimen) in previously treated patients with AML. The goal of the EMA91 study was to determine whether administration of GM-CSF between the two sequences of EMA chemotherapy and during the second sequence could increase therapeutic efficacy by potentially increasing leukemic cell recruitment into the S phase of cell cycle before the second sequence. One hundred and ninety-two patients aged less than 65 years with previously treated AML received GM-CSF, 5 microg/kg/day or placebo from day 4 to day 8 of EMA chemotherapy. One hundred and twenty were refractory and 72 were in first relapse after a complete remission (CR) of more than 6 months duration. CR rates after one course of chemotherapy were 65% in the GM-CSF group (refractory: 51%; first relapse: 89%), not significantly different from the 59% CR rate (refractory: 46%; first relapse: 81%) in the placebo group. Median time to recovery of neutrophils was 38 and 37 days and median time to last platelet transfusion 32 and 32 days respectively in the GM-CSF and placebo groups. WHO grade > or = 3 non-hematologic toxicities were mainly sepsis (45% and 51%, respectively) and mucositis (34% and 31%) and did not differ between the two groups. Toxic death rate was 5% and 8%, respectively, in the GM-CSF and placebo groups. Patients achieving CR were scheduled to receive six courses of maintenance with reduced-dose EMA. Time to progression tended to be longer in the GM-CSF group (median 154 vs 115 days, progression-free rate at 18 months 33% vs 19%, P = 0.08), particularly in refractory patients (P = 0.06). However, at the current follow-up, this did not translate into a significantly longer disease-free survival and survival. Cell cycle studies showed increased recruitment of cells in the S phase between day 4 and day 8 in the GM-CSF group compared to placebo (P = 0.006). However, this did not significantly relate to prognosis in this cohort of patients. GM-CSF might marginally increase efficacy of sequential chemotherapy without increasing its toxicity in the absence of any detected relationship between this effect and observed leukemic cell recruitment into the cell cycle.

Acute Disease↗

Continuous-infusion carboplatin in combination with idarubicin or mitoxantrone for high-risk acute myeloid leukemia: a randomised phase II study.

Fifty-three patients of median age 66 years (39 patients > 60 yrs), including 5 with FAB unclassified or secondary acute myeloid leukemia (AML) at diagnosis, 14 with resistant AML, 19 in first and 15 in subsequent relapse, were treated with carboplatin (CBP), 200 mg/m2/day, as a continuous infusion, (days 3 to 7) with mitoxantrone (MIT) or idarubicin (IDA), (12 mg/m2/day) as an i.v. bolus, on days 1 to 3. Results were evaluated after one induction course. Overall, 15 patients (28% [95% confidence interval (CI), 17-42%], 8/28 with IDA and 7/25 with MIT) achieved complete remission (CR). There was no statistical difference between IDA and MIT arms. Fourty-nine percent (95% CI, 35-63%) had resistant disease (53% IDA versus 44% MIT respectively) and 23% (95% CI, 12-36%) died from toxicity (18% IDA versus 28% MIT). Median durations of neutrophils less than 0.5 x 10(9)/l and platelet counts less than 20 x 10(9)/l were 32 and 32 days respectively in the IDA arm and 31 and 26 days respectively in the MIT arm. Severe toxicity included infections (45%), diarrhea (21%), bleeding (9%), vomiting (7%), hyperbilirubinemia (6%), mucositis (4%) (no statistical difference was seen between both arms). Nephrotoxicity was observed in only one case in the IDA arm. Cardiac toxicity included reversible pulmonary oedema in one patient in the IDA arm. No severe ototoxicity was noted. CR patients received maintenance courses with 3 days of CBP and one day of IDA or MIT. Median survival was 2 months (range, 1-30+ months) and 2.5 months (range, 0.5-19.5 months), and median disease-free survival (DFS) 2 months (range, 1-30+ months) and 2.5 months (range, 1-14 months) in the IDA and MIT arms respectively. We conclude that CBP at a cumulative dosage of 1 g/m2 together with intercalating agents (IDA/MIT) has antileukemic efficacy in elderly patients.

Adult↗

[Cell adhesion molecules: expression and function in acute myeloid leukemia].

Adhesion molecules play a major role in the regulation of normal hematopoiesis. Precursor/cell matrix/endothelial interactions determine retainment or release of hematopoietic cells from the bone marrow microenvironment. Consequently, changes in the affinity or quantitative expression of adhesion molecules on either the bone marrow stroma or the cell precursor component during a malignant process will affect cell attachment. Adhesion molecules, therefore, are modulator molecules which alter the biological behavior of leukemic cells in terms of migration and localization properties. Several membrane-bound adhesion molecules and, in some instances, their soluble counterparts which may be biologically active, have been described in acute myeloid leukemia. The panel of receptors expressed demonstrates heterogeneity between various cases of acute myeloid leukemia. There is generally no correlation between the adhesion receptor phenotype and the morphologic or clinical features of acute leukemia. These receptors function in interactions of leukemic blasts with the cellular and matrix components of the marrow microenvironment. Adhesive interactions may influence the proliferation and survival of leukemic cells. However, the precise role that these molecules play in the generation and sustenance of the leukemic state remains undetermined.

Acute Disease↗

Expression of beta1-integrins and pseudo-immunoglobulins on acute promyelocytic leukemia cells and its modifications during in vitro differentiation.

Adhesion molecules are involved in cell-cell interactions and therefore probably play a role in the differentiation and egress of cells from the bone marrow, which might be potentially important in the biology of acute promyelocytic leukemia (APL). All-trans retinoic acid (ATRA) is known to induce in vitro and in vivo differentiation of APL cells and to favor their release from the bone marrow into the blood at initiation of therapy. In order to determine whether these effects might be mediated in part by modifications of beta1-integrin and pseudoimmunoglobulin expression on APL cells, the expression of these adhesion molecules on bone marrow (BM) blast cells from 24 APL patients was assayed at diagnosis by an indirect immunofluorescence method. CD49b, CD49d, CD49e, CD49f, CD54, CD58, and CD56 were expressed respectively on 18%+/-20% (0-66%), 40%+/-31% (0-96%), 48%+/-32% (0-97%), 29%+29% (1-94%), 51%+/-30% (5-98%), 37%+/-24% (1-85%) and 32%+/-31% (0-97%) of APL cells, with respectively 39%, 71%, 79%, 50%, 70%, 70%, and 53% positive cases (> or = 20% positive cells). Despite a wide variability between individual samples, the expression of beta1-integrins and that of pseudo-immunoglobulins tended to be higher in APL in comparison with that of a cohort of 63 patients with other AML subtypes with significant differences for CD54 expression (51%+/-30% vs 28%+/-27%, P=0.006) and CD56 expression (37%+/-24% vs 17%+/-19%, P=0.0003). An in vitro differentiation assay was performed in nine cases. Cells were harvested after 4-7 days of culture and studied for the expression of adhesion molecules. Granulocytic differentiation was marked by persistence of CD15 expression. Antigen expression was decreased after culture with ATRA for all beta1-integrins (except CD49b and CD49f) and pseudoimmunoglobulins (except CD54) tested. However, changes were statistically significant only for CD56 (P=0.04), CD49d (P=0.02) and CD49e (P=0.01). The modifications in the expression of the beta1-integrins and pseudo immunoglobulins were not specific to ATRA-induced differentiation, but commonly observed with differentiation. Furthermore, the modifications in the adhesive properties of APL cells to extracellular matrix proteins, observed on adhesion assays, were not statistically significant after ATRA-induced differentiation. Overall, the level of expression of beta1-integrins and pseudo-immunoglobulins was higher in APL than in other AML subtypes, and appeared modified with induced differentiation. This was not specific of ATRA, but might be involved in the general differentiation phenomenon. The modulation of adhesion molecules does not seem a sufficient requisite for the development of the retinoic acid syndrome, but could nevertheless be part of the increase in leukocyte counts observed during the first days of ATRA therapy.

Adolescent↗

Differential adhesiveness between blood and marrow leukemic cells having similar pattern of VLA adhesion molecule expression.

Functional adhesion of blood and marrow leukemic cells from 14 acute myeloid leukemia patients presenting with hyperleukocytosis was evaluated by performing cytoadhesion assays on purified (extracellular matrix proteins) and non-purified supports (MRC5 fibroblastic cell line). Results, in 30-min chromium release assay, show a mean +/- S.D. adhesion to fibronectin, collagen, and laminin respectively of 30 +/- 17%, 20 +/- 13%, 25 +/- 17% for blood leukemic cells and 18 +/- 11%, 11 +/- 10%, 11 +/- 8% for marrow leukemic cells. These differences between blood and marrow cells were statistically significant (respectively P = 0.005, P = 0.01 and P = 0.002), while no difference was noted regarding adhesion to non-purified supports. The higher adhesion of blood blast cells to purified supports was observed regardless of CD34 expression. No significant difference was observed in the expression of cell surface VLA-molecules (CD29, CD49b, CD49d, CD49e, CD49f) between blood and marrow blast cells. The addition of GM-CSF or G-CSF induced increased adhesion of marrow blasts and decreased adhesion of blood blasts leading to a loss of the difference between blood and marrow cells. In a 60-min chromium release assay, marrow blasts adhered even more than blood leukemic cells to fibronectin. In contrast, marrow blasts from 'aleukemic' acute myeloid leukemia patients did not show any modification regarding their adhesion to extracellular matrix proteins when co-cultured with growth factors.

Antigens, CD↗

Thrombopoietic factors potentially useful in the treatment of acute leukemia.

Thrombocytopenia is a major cause of morbidity following intensive chemotherapy for acute leukemia. Over recent years, there has been an increasing use of platelet transfusions which, although generally efficacious to prevent severe hemorrhage, have associated risks of transmitting blood-borne disease and of alloimmunization. Therefore, there is a clinical requirement for a drug that will reliably alleviate the thrombocytopenia associated with leukemia therapy. The c-mpl ligand thrombopoietin is the most interesting factor for the treatment of thrombocytopenia because of its lineage specificity. Phase I and II studies confirm its biological efficacy to induce rise in platelet count in patients with solid tumors and acute leukemia. Several other pleiotropic hematopoietic growth factors are also currently in clinical trials. These include interleukin-6, interleukin-3, interleukin-11, PIXY321 and stem cell factor. The effects of these cytokines appear to be modest at most and, with the exception of interleukin-11, their side effects are likely to limit their clinical application. Combinations of factors may prove more efficacious approaches to enhance platelet recovery.

Acute Disease↗

Clinical and biological characteristics of adult de novo and secondary acute myeloid leukemia with balanced 11q23 chromosomal anomaly or MLL gene rearrangement compared to cases with unbalanced 11q23 anomaly: confirmation of the existence of different entities with 11q23 breakpoint.

Although the presence of a chromosome 11q23 breakpoint is of recognized poor prognosis in acute lymphoblastic leukemia, its prognostic significance in acute myeloid leukemia (AML) has been the object of conflicting reports, perhaps reflecting the possibility of different entities. It has been found that only typical and generally balanced 11q23 chromosomal anomalies involve the MLL gene while atypical and generally unbalanced do not. To determine whether these two categories of AML patients had different initial characteristics and evolution, supporting different pathogenetic mechanisms, we analyzed clinical and biologic characteristics of newly diagnosed AML patients with balanced 11q23 breakpoint and/or MLL rearrangement seen over a 10-year period in our institution and compared them to cases with unbalanced 11q23 anomaly seen over the same period. These two categories of patients were compared with newly diagnosed patients with normal karyotype and no MLL rearrangement when tested, seen over the same period of time and treated similarly. Over this period, 442 newly diagnosed adult (> 15 years) AML seen in our institution had a successful karyotype performed before any therapy. Thirty-six cases (8%) had a chromosome 11q23 breakpoint including 19 cases with a balanced translocation or inversion and 17 cases with an unbalanced anomaly. Eighty-seven recently diagnosed cases of AML, for whom frozen cellular material was available, were analyzed by Southern blot for the presence of MLL gene rearrangement. Fourteen cases (16% of the tested cases) had a rearrangement of the MLL gene, including seven cases with an apparently successful karyotype not showing any 11q23 breakpoint and two cases with no available karyotype. The only case with unbalanced 11q23 chromosomal anomaly which was tested had no MLL rearrangement. There was a clear-cut clinical difference between the 28 patients having a balanced 11q23 anomaly/MLL rearrangement and the 17 patients having an unbalanced chromosomal anomaly: AML with unbalanced 11q23 anomalies occurred in older patients (P = 0.07) tended to be less frequently associated with previous exposure to topoisomerase II-active drugs and with M4/M5 FAB cytological subtypes, were always associated with other chromosomal anomalies (P < 0.0001), expressed more frequently the CD34 antigen (P = 0.05) and were of considerably poorer prognosis for achievement of CR (P = 0.005) and survival (P = 0.0005). When compared to the control population, patients with balanced anomalies had more frequent history of toxic exposure (P = 0.0003) particularly to topoisomerase II-active drugs, tended to be more frequently of M4/M5 FAB subtypes (P = 0.07), expressed more frequently HLA-DR antigen (P = 0.02) and had shorter DFS (P = 0.02). Patients with unbalanced anomalies had more frequent splenomegaly (P = 0.009), lower WBC count (P = 0.04), and much poorer prognosis for CR achievement (P = 0.0001), survival (P < 0.0001) and DFS (P = 0.01). This study confirms the high frequency of 11q23 chromosomal breakpoint/MLL rearrangement in adult AML and the probable existence of two different entities with different clinical features according to the presence of a balanced or unbalanced cytogenetic abnormality, the latter being not associated with MLL rearrangement.

Acute Disease↗