Liposome-encapsulated daunorubicin for PGP-related multidrug resistance.

The possibility that Daunoxome (DNX), a combination of daunorubicin (DNR) with a liposomal targeting system, escapes PGP was tested. Two pairs of leukaemic cell lines, each consisting of the parental non-multidrug resistance (MDR) line and of a MDR variant, were studied for cytotoxicity (MTT test) and for cellular DNR kinetic and accumulation (flow cytometry). DNX and free DNR were equally toxic against non-MDR cells, whereas the liposomal anthracycline was more toxic than the free drug against the MDR variant. Non-MDR cells accumulated DNR more rapidly when they were exposed to free DNR than to DNX, but MDR cells accumulated more DNR when they were exposed to DNX. The kinetics of DNX and free DNR were also studied in the blast cells of 41 cases of acute leukaemia and they were found to be related to blast cell PGP expression. In 15 cases with a low PGP expression intracellular DNR accumulation was faster and higher with free DNR than with DNX. In 26 cases with a high PGP expression the area under the curve was similar with DNX and free DNR, but the kinetics of intracellular DNR accumulation showed an early low plateau with free DNR and a slow and continuous increase with DNX. In MDR cell lines the ratio was more favourable to DNX than to free DNR. We conclude that liposome encapsulated DNR is partially protected from PGP and that it is worth testing for the treatment of PGP-positive acute leukaemia.     

Liposomal daunorubicin (DaunoXome) for treatment of poor-risk acute leukemia

Toxicity limits the use of anthracyclines in elderly sick patients and in heavily pretreated patients. Since the liposomal preparation of daunorubicin (DNR) (DaunoXome, or DNX) is expected to be less toxic than conventional DNR, we tested DNX combined with high-dose arabinosyl cytosine (HDAC) in 42 adult poor-risk acute leukemia patients. Thirty-one patients had acute non-lymphocytic leukemia (ANLL). Of these, 12 patients were newly diagnosed but were not eligible for standard induction treatment, 13 were in first relapse, and 6 were in second or subsequent relapse. Eleven patients had acute lymphocytic leukemia (ALL), in first (eight cases) or second (three cases) relapse. DNX was given i.v. in three doses of 80 or 100 mg/m(2) each (days 1-3) by a 60-min infusion in glucose 5%, followed by a 4-h infusion of HDAC 2 g/m(2) (days 1-5). Among 31 ANLL patients there were 16 (51%) complete remissions (CR), 5 deaths during induction, and 10 failures. Among 11 ALL patients there were 10 CRs and 1 failure. The response rate was not affected by the overexpression of MDR-related proteins (PgP, MRP-1, and LRP). Non-hemopoietic toxicity was negligible, with no intestinal toxicity and only one case of gram-negative bacteremia. We conclude that DNX, in combination with HDAC, is an effective treatment for poor-risk adult AL. Because of the low non-hematologic toxicity, it can be used to reinduce remission in poor-risk patients who are candidates for allogeneic bone marrow transplantation. The high CR rate observed in ALL requires confirmation.     

P-glycoprotein, lung resistance-related protein and multidrug resistance associated protein in de novo acute non-lymphocytic leukaemias: biological and clinical implications

P-glycoprotein (PGP), lung resistance-related protein (LRP) and multidrug resistance associated protein (MRP) expression and the blast cells' intracellular daunorubicin accumulation (IDA) were evaluated in 96 previously untreated cases of de novo acute non-lymphocytic leukaemia (ANLL). 47/96 patients (49%) were classified as PGP+ 44/ 96 (46%) as LRP+, and 8/96 (8%) as MRP+. The more frequent MDR clusters were PGP-/LRP-/MRP- (32/96 cases, 33%) and the PGP+/LRP+/MRP- (27/96 cases, 28%) followed by PGP+/LRP-/MRP- (15/96 cases, 16%) and PGP-/LRP+/MRP- (14/96 cases, 14%). A favourable karyotype was observed more frequently in PGP- and LRP-cases. A highly significant correlation was found between either PGP or LRP overexpression and leukaemic blast cell IDA. All the patients received standard induction and consolidation treatments containing MDR-related (idarubicin, mitoxantrone, etoposide) and other (arabinosyl cytosine) drugs. Multivariate analysis showed that PGP overexpression was significantly associated with a poor response to treatment, both in terms of primary resistance or shorter survival. Other independent prognostic factors were age and cytogenetics. LRP overexpression did not reach statistical significance, although for LRP+ cases the trend was unfavourable. Due to small numbers, no conclusion could be made regarding MRP overexpression, but 5/8 cases showed unfavourable karyotypic abnormalities, 8/8 had a defective IDA and 6/8 failed to achieve remission. This study showed that both PGP and LRP overexpression are common features in de novo ANLL at onset whereas MRP overexpression is more rare. It suggested that overexpression of one of the MDR related proteins was associated with a defective IDA, and confirmed that, in addition to age and cytogenetics, PGP retains an independent prognostic value. It also suggested that LRP did not affect clinical outcome when patients were treated with idarubicin or mitoxantrone and arabinosyl cytosine.     

Expression of P-glycoprotein,Cyclin D1 and Ki-67 in Acute Lymphoblastic Leukemia: Relation with Induction Chemotherapy and Overall Survival

Previous studies showed that non-cycling cells have a higher multidrug resistance (MDR) expression, which may be down-regulated by proliferation induction. Triggering these cells into proliferation down-regulates high MDR expression. The aim of this study was to determine the expression of P-glycoprotein (PGP) and cell cycle parameters (cyclin D1 and Ki-67) in acute lymphoblastic leukemia (ALL) at diagnosis, and to evaluate the correlation between the expressions of each marker, and the clinical significance of such expression with response to induction chemotherapy and overall survival. A total of 78 newly diagnosed ALL patients were enrolled in our study. PGP, cyclin D1 and Ki-67 were determined by flow cytometry. PGP expression was encountered in 10/78 (12.8%) of ALL cases. Cyclin D1 and Ki-67 were expressed in 16/77 (20.6%) and 27/76 (34.6%) of ALL cases, respectively. None of the parameters were associated with response to induction chemotherapy and overall survival. Based on the current analysis, we conclude that a joint immunophenotypic evaluation of PGP and cell cycle parameters like that adopted in this study is unlikely to reveal mechanisms of multidrug resistance associated with the clinical outcome.     

Reduced-intensity stem cell transplantation using allogeneic peripheral blood stem cells from the same donor for relapsed leukemia after bone marrow transplantation

We report the clinical courses of two cases with relapsed acute lymphoblastic leukemia (ALL) after allogeneic bone marrow transplantation (BMT). After reinduction chemotherapy, the patients received reduced-intensity stem cell transplantation using allogeneic peripheral blood stem cells harvested from their previous BMT donors. The conditioning regimen used consisted of fludarabine and melphalan. Graft-versus-host disease (GVHD) prophylaxis was performed with low dose cyclosporin A (CsA, 1 mg/kg/day d.i.v.) on its own. The regimen related toxicity was minimal, and stable engraftment was achieved. Since acute GVHD had not developed by day 30, CsA was stopped abruptly in both cases. After CsA withdrawal, acute GVHD developed, and subsequent chronic GVHD. One of two cases is alive without any relapse of the leukemia 40 months after the peripheral blood stem cell transplantation (PBSCT). In the other case, ALL relapsed 15 months after the PBSCT, however, complete remission was again induced concomitantly with reactivated GVHD. In both these cases, the results suggest that using PBSC as a stem cell source and abrupt cessation of GVHD prophylaxis provided a potent graft-versus-leukemia effect.     

Inversion of chromosome 16 observed in acute myeloblastic leukemia (M2) with biphenotypic surface markers lacking monocytosis and eosinophilia]

Inversion of chromosome 16 was found in a 73-year-old female with acute myeloblastic leukemia (FAB:M2). Complete remission was achieved by combined chemotherapy (DNR, Ara-C, 6-MP, Prednisolone), but she relapsed 6 months later without CNS involvement and died of respiratory failure presumably due to cerebrovascular accident during remission reinduction chemotherapy. Biphenotypic surface markers (CD2+ and CD13+) were observed on relapse. Eosinophilia was not observed throughout. Our patient and the other reported case suggest that biphenotypism and the lack of eosinophilia and monocytosis in inv (16) leukemia may be correlated with a poor prognosis.     

Liposomal daunorubicin versus standard daunorubicin: long term follow-up of the GIMEMA GSI 103 AMLE randomized trial in patients older than 60 years with acute myelogenous leukaemia

This randomized phase III clinical trial explored the efficacy of DaunoXome (DNX) versus Daunorubicin (DNR) in acute myeloid leukaemia (AML) patients aged >60 years. Three hundred and one AML patients were randomized to receive DNR (45 mg/m(2) days 1-3) or DNX (80 mg/m(2) days 1-3) plus cytarabine (AraC; 100 mg/m(2) days 1-7). Patients in complete remission (CR) received a course of the same drugs as consolidation and then were randomized for maintenance with AraC+ all trans retinoic acid or no further treatment. Among 153 patients in the DNR arm, 78 (51.0%) achieved CR, 55 (35.9%) were resistant and 20 (13.1%) died during induction. Among 148 patients in the DNX arm, 73 (49.3%) achieved CR, 47 (31.8%) were resistant and 28 (18.9%) died during induction. Univariate analysis showed no difference as to induction results. After CR, DNX showed a higher incidence of early deaths (12.5% vs. 2.6% at 6 months, P = 0.053) but a lower incidence of relapse beyond 6 months (59% vs. 78% at 24 months, P = 0.064), with a cross in overall survival (OS) and disease-free survival (DFS) curves and a later advantage for DNX arm after 12 months from diagnosis. DNX seems to improve OS and DFS in the long-term follow-up, because of a reduction in late relapses.     

Allogeneic SCT in refractory or relapsed adult ALL is effective without prior reinduction chemotherapy

We present 60 patients with refractory (n=8) or relapsed (n=52) adult ALL who received allogeneic hematopoietic SCT (HSCT) with (n=41) or without (n=19) prior reinduction chemotherapy. In our center, omission of reinduction is recommended if a suitable donor is promptly available, tumor burden is moderate and disease features suggest a highly aggressive course. Overall survival (OS) of the whole cohort at 1, 2 and 5 years was 42, 33 and 28%, respectively. Leukemia-free survival at 1, 2 and 5 years was 37, 33 and 24%. Deaths were due to relapse (n=25), acute or chronic GVHD (n=7), infections (n=8) or toxicity (n=4). Interestingly, patients who did not receive reinduction before HSCT had better outcomes than patients who received reinduction with OS at 1, 2 and 5 years being 58 vs 34%, 47 vs 25% and 47 vs 18%, respectively (P=0.039). Importantly, even achievement of a second CR after reinduction was not associated with improved survival compared to patients directly proceeding to HSCT. We conclude that patients who undergo HSCT for refractory or relapsed ALL can achieve long-term survival. In selected patients, reinduction chemotherapy can be omitted if immediate HSCT is feasible.     

Correlation of drug sensitivity in vitro with clinical responses in childhood acute myeloid leukemia

Clonogenic cells from 41 children with newly diagnosed acute myeloid leukemia (AML) were tested in vitro for their sensitivity to cytarabine (Ara-C) and daunorubicin (DNR). The findings were then compared with the patients' responses to induction chemotherapy that uniformly included Ara-C and DNR. Light-density marrow cells were incubated with either or both drugs for one hour and cultured over leukocyte feeder layers; clusters and colonies were scored on days 7, 10, and 14. Only the percentage of cell kill in the presence of 1.8 mumol/L DNR was significantly associated with responses to induction therapy: median of 45% (range, 0% to 98%) for patients achieving complete remission v 16% (range, 4% to 23%) for nonresponders (P = .007). The relationship between clonogenic cell kill less than or equal to 23% and clinical responses was striking. Of the 11 evaluable patients with in vitro findings in this category, ten either failed induction therapy or relapsed within 1 year after attaining remission. Kaplan-Meier analysis of relapse-free survival times indicated longer durations of remission for patients whose blast cells showed increased sensitivity in vitro to Ara-C alone, DNR alone, or a combination of the two agents. Seven of 11 patients with cell kills of greater than or equal to 49% in the presence of 1.25 mumol/L Ara-C remain free of leukemia, compared with only one of 12 whose cells were less sensitive to the drug (P = .006). We conclude that the in vitro sensitivity of clonogenic leukemic progenitors to DNR and Ara-C correlates with treatment outcome in children with newly diagnosed AML.     

Autologous bone marrow transplantation in patients with AML in first complete remission. Results of two different conditioning regimens after the same induction and consolidation therapy

Thirty-nine patients with acute myeloblastic leukemia (AML) in first complete remission (CR) were treated by autologous bone marrow transplantation. All patients received the same induction and consolidation chemotherapy consisting of a combination of daunorubicin (DNR) and cytarabine (Ara-C) followed by four courses of DNR, Ara-C and 6-thioguanine (6-TG). Two different conditioning regimens were used; 25 patients were submitted to the BAVC regimen (BCNU, amsacrine, VP-16 (etoposide) and Ara-C) and 14 to a cyclophosphamide/total body irradiation (CY + TBI) regimen. Six patients (one treated with BAVC and five treated with CY + TBI) died in aplasia. Twelve of the 25 BAVC treated patients and one of the nine CY + TBI treated patients relapsed; 12 (48%) of the BAVC treated patients are in CR with a median follow-up of 45 months and eight (57%) of the CY + TBI treated patients are in CR with a median follow-up of 50 months. All patients in CR have survived for more than 2 years since transplant.     

Chemotherapy for acute myeloid leukemias with cytosine arabinoside, daunorubicin, etoposide, and mitoxantrone may cause permanent oligoasthenozoospermia or amenorrhea in middle-aged patients

The aim was to follow-up gonadal functions in long-term survivors of acute myeloid leukemias (AML) after intensive chemotherapy based on high-doses of cytosine arabinoside (Ara-C) and anthracyclines in the study UHKT-911. Adult patients were treated with at least 3 cycles of chemotherapy including 1-3 courses of Ara-C 10 x 2000 mg/m2/12 h and daunorubicin (DNR) 2 x 45 mg/m2/d. Spermiologic examinations were performed in 7 men by the classic microscopic method and results were evaluated according to the WHOcriteria. Two patients (42- and 47-year-old) after DNR and Ara-C chemotherapy had nearly normal spermiologic findings. The semen of a 49-year-old patient contained normal numbers of spermatozoa with decreased velocity when examined 1 year after chemotherapy but 4 years later exhibited oligoasthenozoospermia. The patient received 4 cycles of Ara-C and DNR plus one cycle with etoposide 350 mg/m2 and mitoxantrone 30 mg/m2. Semen examination of two patients 55- and 59-year-old showed permanent oligoasthenozoospermia with only sporadic progressively motile spermatozoa which might not be compatible with fertilization by sexual intercourse. They received the same chemotherapy including cumulative doses of etoposide 500 mg/m2 and mitoxantrone 36 mg/m2. Semen of two patients after allogeneic bone marrow transplantation exhibited severe oligoasthenozoospermia with no motile spermatozoa. Permanent amenorrhea developed in two women (42- and 46-year-old) during chemotherapy with DNR, Ara-C, etoposide, and mitoxantrone which was not the case in three women (29-40 years old) treated without etoposide and mitoxantrone. Intensive chemotherapy with high-doses of Ara-C and DNR plus one cycle of etoposide and mitoxantrone may cause permanent gonadal dysfunction in middle-aged patients with AML.     

P-glycoprotein, lung resistance-related protein and multidrug resistance-associated protein in de novo adult acute lymphoblastic leukaemia

P-glycoprotein (P-gp), lung resistance-related protein (LRP) and multidrug resistance-associated protein (MRP) expression, and blast cell intracellular daunorubicin accumulation (IDA) were evaluated in 95 previously untreated cases of adult acute lymphoblastic leukaemia (ALL) using flow cytometry. Forty-five out of 95 (47%) patients were P-gp positive (+), 12/66 (18%) were LRP+ and 11/66 (17%) were MRP+. Eighteen out of 66 (28%) patients showed a simultaneous multidrug resistance (MDR)-related protein expression higher than controls for more than one protein, while 24/66 (36%) cases did not overexpress any protein. Twenty-one out of 24 (87%) cases overexpressing at least one MDR-related protein had a defect in accumulating daunorubicin into their blast cells, while only 4/24 (16%) cases who did not overexpress any protein had similar features. The complete remission rates were similar in MDR-positive and -negative (-) patients but relapses within 6 months were more frequent in P-gp+ cases, and therefore the disease-free survival duration was shorter in P-gp+ than in P-gp- patients (P = 0.01). The number of MRP+ and/or LRP+ cases was too small to be able to draw any conclusion on their role in affecting or predicting therapy outcome. In conclusion, P-gp overexpression associated with a defect in daunorubicin accumulation is a frequent feature in adult ALL at onset and seems to be related to poorer therapy outcome and, consequently, a shorter disease-free survival. LRP and MRP overexpression seems to be a rare event and no conclusion can be drawn on its prognostic role.     

Liposomal encapsulation diminishes daunorubicin-induced generation of reactive oxygen species, depletion of ATP and necrotic cell death in human leukaemic cells

In this study, we tested the mechanisms of daunorubicin (DNR)- and the liposomal encapsulated daunorubicin (DaunoXome or DNX)-induced killing in three human leukaemic cell lines, K562, K/Bax and CEM. DNX showed less cytotoxicity in leukaemic cells than conventional DNR. The intracellular accumulation of DNX was 10 times less than conventional DNR during exposure to drugs for up to 5 h. Cell cycle analysis indicated that DNR induced concentration-dependent G2/M arrest, apoptosis and necrosis. However, DNX induced G2/M arrest and apoptosis but not necrotic cell death, even at a higher concentration. DNR- or DNX-induced activation of caspase-9 and -3 was detected at concentrations that induced apoptosis and necrosis. The sensitivity of leukaemic cells to DNR- and DNX-induced apoptosis correlated with the activation of caspases and the reduction of mitochondrial membrane potential (DeltaPsim), but not the depletion of ATP and the generation of reactive oxidative species (ROS). DNX did not provoke ROS generation and ATP depletion in leukaemic cells. We conclude that the liposomal encapsulation of DNR restricts the intracellular accumulation speed and therefore diminishes ROS generation, ATP depletion and necrotic cell death. This may have implications for the cause of cardiotoxicity seen with DNR, its main dose-limiting step.     

Intensive therapy followed by bone marrow transplantation for patients with acute lymphocytic leukemia in second or subsequent remission: determination of prognostic factors (a report from the University of Minnesota Bone Marrow Transplantation Team)

Fifteen patients with acute lymphocytic leukemia (ALL) in second or subsequent remission received intensive therapy with cyclophosphamide and single dose, rapid rate (26 cGy/min) total body irradiation (TBI) followed by bone marrow transplantation (BMT) from a histocompatible sibling match. Outcome was compared to that of 23 conventionally treated control patients in second ALL remission who presented to the same institution during the same time period but had no available transplant donor. The 15 BMT patients and 23 control patients had similar characteristics, with the exception that the BMT patients were significantly older at the time of ALL diagnosis (12.6 yr versus 5.7 yr, p = 0.01). BMT patients had a significantly increased chance of remaining disease-free for 36 mo from time on study (43% actuarial versus 5%, p = 0.004) and a greater overall survival rate at 48 mo (47% actuarial versus 9%, p = 0.27) than the conventionally treated patients. In all, 5 of the bone marrow transplant patients (33%) remain alive and free of disease 24-48 + mo from transplantation. Several pre- and posttransplant characteristics were analyzed to determine predictive factors for a successful BMT outcome for patients with ALL in second or subsequent remission. Significant risk factors for predicting leukemic relapse included initial white blood count (WBC) greater than 50,000/microliters at ALL diagnosis (100% relapse rate versus 37% for patients with lower WBCs, p = 0.001) and presence of any extramedullary disease pre-BMT (100% relapse rate versus 37% for patients without extramedullary disease, p = 0.03). All 5 disease-free BMT survivors had initial WBCs less than 50,000/microliters and no evidence of extramedullary disease pretransplantation. Maintenance chemotherapy with 6-mercaptopurine (6MP) and methotrexate was given to four patients starting 100 days after bone marrow transplantation. Use of maintenance chemotherapy was associated with a significantly increased chance of remaining disease free (100% of patients surviving leukemia-free versus 17% for patients not receiving maintenance chemotherapy, p = 0.02). Presence of graft-versus-host disease (GVHD) did not influence leukemia-free survival. These results confirm that intensive therapy followed by bone marrow transplantation is the treatment of choice for patients with ALL in second or subsequent remission who have a histocompatible sibling match. Furthermore, the data suggest that a controlled trial to evaluate the efficacy of maintenance chemotherapy post-BMT for ALL patients is warranted.     

Contrasting in vitro effects for the combination of fludarabine, cytosine arabinoside (Ara-C) and granulocyte colony-stimulating factor (FLAG) compared with daunorubicin and Ara-C in P-glycoprotein-positive and P-glycoprotein-negative acute myeloblastic leukaemia

It has been suggested that the FLAG remission induction regimen comprising fludarabine (F-ara), cytosine arabinoside (Ara-C) and granulocyte colony-stimulating factor (G-CSF) may be capable of overcoming P-glycoprotein (P-gp)-related multidrug resistance (MDR) in patients with acute myeloblastic leukaemia (AML). We have investigated the in vitro response of P-gp-positive and -negative AML clones to FLAG and compared this with their response to treatment with Ara-C and daunorubicin (DNR). Twenty-four cryopreserved samples from patients with AML were studied using a flow cytometric technique for the enumeration of viable (7-amino actinomycin D negative) cells. Samples consisted of 12 P-gp-positive and 12 P-gp-negative cases, as measured by the MRK16 antibody. The results were analysed by calculating the comparative drug resistance (CDR), i.e. the percentage cell death caused by Ara-C + DNR subtracted from the percentage cell death, caused by FLAG after 48 h incubation in suspension culture. P-gp-positive clones were shown to have a significantly higher CDR than P-gp-negative clones (P = 0. 001). Furthermore, a significant positive correlation (r2 = 0.40, P < 0.01) was found between P-gp protein expression and CDR. However, P-gp function, measured using cyclosporin modulation of rhodamine 123 (R123) uptake, was not associated with the CDR, demonstrating that there are other properties of P-gp, besides its role in drug efflux, that modulate the responsiveness of AML blasts to chemotherapy. These results are consistent with a potential benefit for FLAG in P-gp-positive AML, but not P-gp-negative AML, compared with standard anthracycline and Ara-C therapy.     

Polyclonal hematopoietic reconstitution in leukemia patients at remission after suppression of specific gene rearrangements [see comments]

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

急性淋巴细胞白血病患儿肺耐药蛋白表达及临床意义

应用免疫组化法 ,对 2 7例初治和 2 1例复发及难治的急性淋巴细胞白血病 (AL L )患儿检测外周血或骨髓中白血病细胞的肺耐药蛋白 (L RP)表达情况 ,同时体外应用 MTT方法观察了所有患儿的白血病细胞对柔红霉素 (DNR)化疗的敏感性。结果 :2 7例初治患儿的 L RP表达率为 18.5 % ,2 1例复发及难治患儿的 L RP表达率为 6 6 .7% ,两者比较 P<0 .0 1。在 2 7例初治患儿组中 ,L RP表达阴性者对 DNR的敏感率为 86 .4 % ,L RP表达阳性者为 2 0 % ,两者比较 P<0 .0 1;在 2 1例复发及难治患儿中 ,L RP表达阴性者对 DNR敏感率为 2 8.6 % ,L RP表达阳性者为 2 1.4 % ,两者比较 P>0 .0 5。在 2 7例初治组患儿中 ,L RP表达阴性者的 CR率为 90 .9% ,L RP表达阳性者为 6 0 % ,两者比较 P<0 .0 1;在 2 1例复发及难治患儿中 ,L RP表达阴性者的 CR率为 4 2 .9% ,L RP表达阳性者为 5 0 % ,两者比较 P>0 .0 5。认为 L RP可能是产生多药耐药 (MDR)的另外一个重要因素     

Weekly polyethylene glycol conjugated L-asparaginase compared with biweekly dosing produces superior induction remission rates in childhood relapsed acute lymphoblastic leukemia: a Pediatric Oncology Group Study

The relapse rate in childhood acute lymphoblastic leukemia (ALL) is approximately 30% but few reinduction regimens have investigated the intensive use of polyethylene glycol Escherichia coli asparaginase (PEG-Asp). Therefore, we assessed the pharmocokinetics and efficacy of PEG-Asp in this setting. Children with B-precursor ALL, in first marrow and/or extramedullary relapse were eligible. Reinduction included doxorubicin on day 1, prednisone for 28 days, vincristine weekly for 4 weeks, and PEG-Asp either weekly or biweekly by randomization. Asparaginase levels and antibody to both E coli asparaginase and PEG-asp were measured weekly just before each PEG-asp dose. Overall, 129 of 144 patients (pts) (90%) achieved a complete remission (CR). There was a highly significant difference in CR rates between weekly (69 of 71; 97%) and biweekly (60 of 73; 82%) PEG-Asp dosing (P =.003). Grade 3 or 4 infectious toxicity was common (50%), but only 4 pts died of sepsis during induction. Other toxicities were infrequent and hypersensitivity was rare (6 of 144; 4%). Low asparaginase levels were associated with high antibody titers to either native (P =.024) or PEG asp (P =.0013). The CR rate was significantly associated with higher levels of asparaginase (P =. 012). Patients with ALL in first relapse receiving weekly PEG-Asp had a higher rate of second remission compared with biweekly dosing. Low levels of asparaginase were associated with high antibody titers. Increased asparaginase levels may correlate with an improved CR rate. The use of intensive PEG-Asp should be explored further in the treatment of ALL. (Blood. 2000;96:1709-1715)     

急性白血病化疗药物体外细胞毒性与临床指标的关系

对39例急性白血病用MTT法检测4种化疗药物的细胞毒性(CT)。结果显示柔红霉素的CT强于阿霉素(P<0.05),阿糖胞苷与环胞苷的CT差别无显著性(P>0.05)。同类药物的CT呈直线正相关,不同类药物的CT无相关。ALL与ANLL以及不同性别患者的白血病细胞对化疗药物的敏感性差别无显著性(P>0.05)。年龄、化疗前外周血Hb,WBC,BPC和骨髓原+早(幼)细胞波(%)与药物的细胞毒性无相关性。     

Allogeneic or autologous bone marrow transplantation for acute lymphoblastic leukemia in first complete remission

Forty-seven patients with high risk acute lymphoblastic leukemia (ALL) received an allogeneic (allo) or autologous (auto) bone marrow transplant (BMT). Patients in both groups were comparable in terms of age, initial presentation of ALL and induction chemotherapy. Allo patients were transplanted earlier (median 3 months after CR) than auto patients (median 6.5 months after CR). Auto patients received more consolidation chemotherapy before BMT. All patients received total body irradiation 2.2 Gy/day x 5 days after cyclophosphamide 60 mg/kg x 2 (18 allo and five auto) or melphalan 140 mg/m2 (seven allo and 17 auto). Prevention of graft-versus-host disease (GVHD) was by conventional immunosuppression in 17 patients and T cell depletion in eight. Seven patients (28%) developed moderate to severe acute GVHD. Auto marrow was treated in vitro in each case. Seven patients died in CR from BMT complications (five allo and two auto). The probability of relapse was 9% for patients receiving allo BMT and 52% for patients receiving auto BMT (p less than 0.01). The disease-free survival was 71% for allo BMT and 40% for auto BMT (p = NS). Early BMT is an effective form of consolidation for high risk patients with ALL in first CR. An allogeneic anti-leukemia effect was demonstrated in this study.