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D Haase

Publications and source records attributed to D Haase.

At least 19 recordsLinked to original sources

Predictors of pulmonary exacerbations in patients with cystic fibrosis infected with multi-resistant bacteria.

BACKGROUND: This study examined characteristics of adult and adolescent patients with cystic fibrosis (CF) to determine factors associated with an increased risk of pulmonary exacerbations. METHODS: 249 patients with CF infected with multidrug resistant bacteria were recruited and prospectively followed for up to 4.5 years until they experienced a pulmonary exacerbation severe enough to require intravenous antibiotics. Multivariable regression analyses were used to compare the characteristics of patients who experienced an exacerbation with those who did not. RESULTS: 124 of the 249 patients (50%) developed a pulmonary exacerbation during the first year and 154 (62%) experienced an exacerbation during the 4.5 year study period. Factors predictive of exacerbations in a multivariable survival model were younger age (OR 0.98, 95% CI 0.96 to 0.99), female sex (OR 1.45, 95% CI 1.07 to 1.95), lower forced expiratory volume in 1 second (FEV(1)) (OR 0.98, 95% CI 0.97 to 0.99), and a previous history of multiple pulmonary exacerbations (OR 3.16, 95% CI 1.93 to 5.17). Chronic use of inhaled corticosteroids was associated with an increased risk of exacerbation (OR 1.92, 95% CI 1.00 to 3.71) during the first study year. CONCLUSIONS: Patients who experience pulmonary exacerbations are more likely to be younger, female, using inhaled steroids, have a lower FEV(1), and a history of multiple previous exacerbations. It is hoped that knowledge of these risk factors will allow better identification and closer monitoring of patients who are at high risk of exacerbations.

Adolescent↗

Combined analysis of ZAP-70 and CD38 expression as a predictor of disease progression in B-cell chronic lymphocytic leukemia.

Prognostic predictions in B-cell chronic lymphocytic leukemia (B-CLL) at early clinical stage are based on biological disease parameters, such as ZAP-70 and CD38 protein levels, genomic aberrations as well as immunoglobulin variable heavy chain gene (IgV(H)) mutation status. In the current study, ZAP-70 and CD38 expressions were examined by flow cytometry in 252 patients with B-CLL. Cytoplasmic ZAP-70 expression in more than 20% (ZAP-70(+)) and surface CD38 expression on more than 30% (CD38(+)) of B-CLL cells were associated with an unfavorable clinical course. The levels of ZAP-70 and CD38 did not change over time in the majority of patients where sequential samples were available for analysis. Combined analysis of ZAP-70 and CD38 yielded discordant results in 73 patients (29.0%), whereas 120 patients (47.6%) were concordantly negative and 59 patients (23.4%) were concordantly positive for ZAP-70 and CD38 expression. Median treatment-free survival times in patients whose leukemic cells were ZAP-70(+)CD38(+) was 30 months as compared to 130 months in patients with a ZAP-70(-)CD38(-) status. In patients with discordant ZAP-70/CD38 results, the median treatment-free survival time was 43 months. Thus, ZAP-70 and CD38 expression analyses provided complementary prognostic information identifying three patient subgroups with good, intermediate and poor prognosis. Over-representation of high-risk genomic aberrations such as 17p deletion or 11q deletion and distribution of the IgV(H) mutation status in B-CLL discordant for ZAP-70/CD38 pointed toward a distinct biologic background of the observed disease subgroups. This finding was also supported by microarray-based gene expression profiling in a subset of 35 patients. The expression of 37 genes differed significantly between the three groups defined by their expression of ZAP-70 and CD38, including genes that are involved in regulation of cell survival and chemotherapy resistance.

ADP-ribosyl Cyclase↗

Refinement of the international prognostic scoring system (IPSS) by including LDH as an additional prognostic variable to improve risk assessment in patients with primary myelodysplastic syndromes (MDS).

The international prognostic scoring system (IPSS) is considered the gold standard for risk assessment in primary myelodysplastic syndromes (MDS). This score includes several prognostic factors except serum lactate dehydrogenase (LDH). We evaluated the prognostic power of LDH as an additional variable in IPSS-based risk assessment. For this purpose, a total of 892 patients with primary MDS registered by the Austrian-German cooperative MDS study group was analyzed retrospectively. Multivariate analysis confirmed the value of established parameters such as medullary blasts, karyotype and peripheral cell counts and showed that elevated LDH was associated with decreased overall survival (P<0.00005) and increased risk of AML development (P<0.00005), independent of the system used to classify MDS (FAB or WHO). Moreover, elevated LDH was found to be a significant predictor of poor survival within each IPSS risk group and within each FAB group except RAEB-T. To exploit these results for refined prognostication, each IPSS risk group was split into two separate categories (A=normal LDH vs B=elevated LDH). Using this LDH-assisted approach, it was possible to identify MDS patients with unfavorable prognosis within the low and intermediate IPSS risk groups. We propose that the IPSS+LDH score should improve clinical decision-making and facilitate proper risk stratification in clinical trials.

Adolescent↗

Complete defluorination of 1,2,3,4-tetramethyl-5-(trifluoromethyl)cyclopentadiene by titanium tetrakis(dimethylamide)--selective formation of a cyclic hexanuclear titanium fluoroamide and 6,6-dimethylaminotetramethylfulvene.

1,2,3,4-Tetramethyl-5-(trifluoromethyl)cyclopentadiene (Cp*CF3-H, 1) reacts with [Ti(NMe2)4] (2) under mild conditions to give [Ti(mu-NMe2)(NMe2)(mu-F)(F)]6 (3) in nearly quantitative yield. The molecular structure of 3 consists of a ring of six [TiF2(NMe2)2] edge-bridged octahedra. Titanium complexes containing the Cp*CF3 ligand, which was the primary intention of these investigations, were not observed. C5Me4=C(NMe2)2 (4) was isolated as a by-product. The complete defluorination of an aliphatic CF3 group occurs during the reaction. The reaction mechanism involves the primary formation of a difluorofulvene intermediate C5Me4=CF2 (5), which was monitored by NMR studies. Density functional theory calculations predict a highly charged C6 atom (+0.87) in 5, which is discussed as the driving force of the reaction.

Journal Article↗

Effects of amifostine in a patient with an advanced-stage myelodysplastic syndrome.

We report on a 63-year-old man with myelodysplastic syndrome at the stage of a refractory anemia with an excess of blasts in transformation (MDS-RAEB-T), first diagnosed in December 1996. After a period of stability, with no need for transfusions, the MDS progressed into acute myeloid leukemia (AML) in August 1998 with the emergence of a cytogenetic abnormality (11q-). Two courses of chemotherapy were given, resulting in prolonged pancytopenia; however, no clearance of bone marrow (BM) blasts was achieved. At that time, severe infections and daily epistaxis occurred. Frequent transfusions of packed red blood cells (RBC) and platelets (2-3/week) were necessary. After 2 months of persisting severe pancytopenia, we started a therapy with amifostine: 4 x 250 mg intravenously (i.v.) weekly for 1 month, followed by a maintenance therapy with 500 mg once weekly. After 2 weeks of amifostine therapy, hematopoiesis began to improve. In the subsequent 2 months, the patient became completely independent of the platelet transfusions; the transfusion frequency of RBC was permanently reduced (2 RBC transfusions/month) and a significant decrease of BM blasts was achieved. After 30 weeks of amifostine therapy, the morphology of the MDS switched to a chronic myelomonocytic leukemia (CMML)-like appearance, with continuously increasing leukocytes, so that we discontinued amifostine therapy for 1 month to exclude a possible side effect of amifostine. At that time, leukocytes further increased to 74,000/microl; thus, we decided to perform a cytoreductive chemotherapy (hydroxycarbamide) and continued weekly amifostine infusions. During 1 year of amifostine therapy, the patient had a good quality of life, with no need for hospitalization and a complete cytogenetic remission. We conclude that, in this case, amifostine had two effects: a significant improvement of impaired hematopoiesis and a slowing down of disease progression. Thus, amifostine might be a therapeutic option in older patients with advanced MDS.

Amifostine↗

Remission induction therapy: the more intensive the better?

Intensive induction therapy in acute myeloid leukemia (AML) as in some other systemic malignancies is a strategy fundamentally different from post-remission strategies. Approaches such as consolidation treatment, prolonged maintenance, and autologous or allogeneic transplantation in first remission are directed against the minimal residual disease in which a malignant cell population has survived induction treatment and shows resistance due to special genetic or kinetic features. In contrast, induction therapy deals with naive tumor cells possibly different from their counterparts in remission in terms of their kinetic status and sensitivity. Therefore, in AML the introduction of intensification strategies into the induction phase of treatment has been suggested as a new step in addition to intensification in the postremission phase. As expected from the dose effects observed in post-remission treatment with high-dose cytarabine (AraC) or longer treatment, similar dose effects have been found in induction treatment both from the incorporation of high-dose AraC and from the double-induction strategy used in patients up to 60 years of age. As a particular effect, patients with poor-risk AML according to an unfavorable karyotype, high LDH in serum, or a delayed response show longer survival following double induction containing high-dose AraC as compared to standard-dose AraC. A corresponding dose effect in the induction treatment of patients aged 60 years and older has been found with daunorubicin 60 vs 30 mg/m2 as part of the thioguanine/ AraC/daunorubicin (TAD) regimen with the higher dosage significantly increasing the response rate and survival in these older patients who represent a poor-risk group as a whole. Thus we have been able to demonstrate both in younger and older patients that a poor prognosis can be improved by a more intensive induction therapy. High-dose AraC in induction, however, exhibits cumulative toxicity in that repeated courses containing high-dose AraC in the post-remission period lead to long-lasting aplasias of about 6 weeks. Thus after intensive induction treatment, high-dose chemotherapy in remission may be practicable using stem-cell rescue and may contribute to a further improvement in the outcome in poor-risk as well as average-risk patients with AML. These approaches are currently under investigation by the German AML Cooperative Group (AMLCG). "The more intensive the better" is certainly not the way to go in the management of AML and other systemic malignancies but some increase in intensity may be possible and better.

Acute Disease↗

Increased peripheral stem cell pool in MDS: an indication of disease progression?

The colony-forming capacity of the peripheral blood stem/progenitor cells (PBSC) in different forms of myelodysplastic syndrome (MDS) was investigated. In most cases of refractory anemia (RA) the colony growth of PBSC was definitely reduced as compared to the controls. However, in RA with unfavorable chromosomal aberrations, in refractory anemia with ringed sideroblasts (RARS) and in advanced stages of MDS such as refractory anemia with excess blasts (RAEB) and refractory anemia in transformation (RAEB-t), the number of myeloid progenitor cells increased up to 100-fold. In chronic myelomonocytic leukemia (CMML), the increase was even more marked, up to 350-fold. Although the number of PBSC was strongly elevated, these cells were not able to restore hematopoiesis in vivo. In conclusion, the increase of circulating colony-forming cells (CFC) seems to be associated with disease progression, and thus, the evaluation of PBSC could be an important parameter in the diagnosis of MDS.

Anemia, Refractory↗

Effects of hexadecylphosphocholine on thrombocytopoiesis.

Hexadecylphosphocholine (HePC) is the first representative of the alkylphosphocholines, a novel group derived from the cytotoxic etherlysophospholipids. HePC shows a broad spectrum of antiproliferative effects in neoplastic cells in vitro and in vivo. HePC has been tested successfully in several clinical studies. One of the remarkable features of this compound has been the induction of a leucocytosis and a thrombocytosis in most of the patients receiving HePC systemically. In this paper, we have investigated the biological and molecular mechanisms by which HePC exerts this interesting effect. We found that HePC acts as an unspecific costimulator on human megakaryocytic proliferation in a soft agar assay system predominantly together with thrombopoietin (TPO). Furthermore, HePC leads to the synthesis and secretion of several haematopoietic growth factors in monocytes and bone marrow fibroblasts, determined by the direct measurement of growth factors in cellular supernatants and by the measurement of growth factor mRNA in cell extracts. Thus, HePC seems to produce the increase of blood platelets in tumour patients by two different mechanisms.

Antineoplastic Agents↗

Cytogenetic subgroups in acute myeloid leukemia differ in proliferative activity and response to GM-CSF.

The current study was undertaken to search for differences in the biology of cytogenetic subgroups in patients with de novo acute myeloid leukemia (AML). In addition, factors influencing the metabolism of cytosine arabinoside (araC) as the key agent of antileukemic activity were assessed. Bone marrow aspirates from 91 patients with newly diagnosed AML in whom karyotypes were successfully obtained were analyzed: (1) for spontaneous proliferative activity by 3H-thymidine (3H-TdR) incorporation; (2) proliferative response to GM-CSF by in vitro incubation of blasts for 48 h with or without GM-CSF (100 U/ml) followed by an additional 4-h exposure to 3H-TdR (0.5 microCi/ml); and (3) parameters of araC metabolism comprising 3H-araC uptake in vitro and the activities of polymerase alpha (poly alpha), deoxycytidine kinase (DCK) and deoxycytidine deaminase (DCD). According to the results of chromosome analyses four cytogenetic subgroups were discriminated: (I) normal karyotypes (n = 38); (II) favorable karyotypes [t8;21), t(15;17), inv(16)] (n = 16); (III) unfavorable karyotypes [inv (3), -5, 5q-, t(6;9), +8, t (9;11), complex abnormalities] (n = 20); (IV) karyotypes of unknown prognostic significance (n = 17). Proliferative activity of leukemic blasts was significantly higher in favorable karyotypes (group II) as compared to cases with unfavorable cytogenetics (group III) with median values and range for 3H-TdR uptake in group II of 2.48 pmol/10(5) cells (0.28-25.8) and in group III of 0.51 pmol/10(5) cells (0.04-7.6) (P = 0.0096). The respective values in group I and group IV were 0.7pmol/10(5) cells (0.0-6.7) and 0.98 pmol/10(5) cells (0.0-4.0), respectively. Inversely, response to GM-CSF, as defined by an increase in 3H-TdR incorporation >1.5- fold over control values after 48h of GM-CSF exposure, was significantly lower for patients with a favorable karyotype (group II) as compared to group I (P = 0.04) and group III (P = 0.013). No significant differences between karyotype groups I, II, III and IV were found for 3H-araC incorporation, nor for the activities of poly alpha, DCK and DCD. These data demonstrate differences in the biology of cytogenetic subgroups in AML which may partly explain the well established differences in clinical outcome.

Acute Disease↗

Patients with de novo acute myeloid leukaemia and complex karyotype aberrations show a poor prognosis despite intensive treatment: a study of 90 patients.

The clinical significance of complex chromosome aberrations for adults with acute myeloid leukaemia (AML) was assessed in 920 patients with de novo AML who were karyotyped and treated within the German AML Cooperative Group (AMLCG) trials. Complex chromosome aberrations were defined as three or more numerical and/or structural chromosome aberrations excluding translocations t(8;21)(q22;q22), t(15;17)(q22;q11-q12) and inv(16)(p13q22). Complex chromosome anomalies were detected in 10% of all cases with a significantly higher incidence in patients > or = 60 years of age (17.8% vs. 7.8%, P < 0.0001). Clinical follow-up data were available for 90 patients. Forty-five patients were < 60 years of age and were randomly assigned to double induction therapy with either TAD-TAD [thioguanine, daunorubicin, cytosine arabinoside (AraC)] or TAD-HAM (high-dose AraC, mitoxantrone). Twenty-one patients achieved complete remission (CR) (47%), 20 patients (44%) were non-responders and 9% of patients died during aplasia (early death). The median overall survival (OS) was 7 months and the OS rate at 3 years was 12%. Patients receiving TAD-HAM showed a significantly higher CR rate than patients receiving TAD-TAD (56% vs. 23%, P = 0.04). Median event-free survival was less than 1 month in the TAD-TAD group and 2 months in the TAD-HAM group, respectively (P = 0.04), with a median OS of 4.5 months vs. 7.6 months (P = 0.13) and an OS after 3 years of 7.6% vs. 19.6%. Forty-five patients were > or = 60 years of age: 28 of these patient were treated for induction using one or two TAD courses and 17 cases received TAD-HAM with an age-adjusted reduction of the AraC dose. The CR rate was 44%, 38% were non-responders and 18% experienced early death. The median OS was 8 months and the OS rate at 3 years was 6%. In conclusion, complex chromosome aberrations in de novo AML predicted a dismal outcome, even when patients were treated with intensive chemotherapy. Patients under the age of 60 years with complex aberrant karyotypes may benefit from HAM treatment during induction. However, long-term survival rates are low and alternative treatment strategies for remission induction and consolidation are urgently needed.

Acute Disease↗

Proliferative activity of leukaemic blasts and cytosine arabinoside pharmacodynamics are associated with cytogenetically defined prognostic subgroups in acute myeloid leukaemia.

The biological mechanisms responsible for the association of specific karyotypes with prognosis in acute myeloid leukaemia (AML) remain largely unclear. A prospective study was performed to evaluate how far cytogenetically defined prognostic subgroups of AML differ in their proliferative activity as a potential mechanism for differential sensitivities to S-phase-specific induction chemotherapy comprising cytosine arabinoside (AraC). One hundred and eighty-seven patients with de novo AML were included in the study; 25 patients with a favourable [inv(16), t(8;21), t(15;17)] karyotype, 99 with a normal karyotype, 29 with an unfavourable karyotype (-5, 5q-, -7, 7q-, complex aberrations) and 34 with cytogenetic aberrations of unknown prognostic significance (all others). The favourable group demonstrated the highest ex vivo proliferative activity (PA) (3.41 pmol/105 cells), significantly (P = 0.02) exceeding the unfavourable group with the lowest PA (0.72) and the group with a normal karyotype (1.06) or with karyotype of unknown significance (1.05) that both demonstrated an intermediate PA. Samples with a high PA (> median of the whole group) were more likely to produce interleukin 3, granulocyte macrophage colony-stimulating factor (GM-CSF), granulocyte CSF (G-CSF) (56%, 43% and 50%) than cells with a low PA (33%, 36% and 36%; n.s.). The effect of priming by exogenous GM-CSF or G-CSF was significantly more pronounced in samples with a low PA than in rapidly proliferating samples (P < 0.01). For the whole group, a high PA was closely associated with an increased incorporation of AraC triphosphate (AraCTP) into the DNA (P < 0.0001). Clinically, a high PA was associated with a better complete remission (CR) rate in the normal (95% versus 62%) and the unfavourable group (75% versus 33%). The significant differences in proliferative activity between cytogenetic subgroups of AML are associated with increased cytosine arabinoside pharmacodynamics and constitute one potential mechanism for the different response of cytogenetic subgroups to AraC-based induction therapy.

Adult↗

Conservation of microstructure between a sequenced region of the genome of rice and multiple segments of the genome of Arabidopsis thaliana.

The nucleotide sequence was determined for a 340-kb segment of rice chromosome 2, revealing 56 putative protein-coding genes. This represents a density of one gene per 6.1 kb, which is higher than was reported for a previously sequenced segment of the rice genome. Sixteen of the putative genes were supported by matches to ESTs. The predicted products of 29 of the putative genes showed similarity to known proteins, and a further 17 genes showed similarity only to predicted or hypothetical proteins identified in genome sequence data. The region contains a few transposable elements: one retrotransposon, and one transposon. The segment of the rice genome studied had previously been identified as representing a part of rice chromosome 2 that may be homologous to a segment of Arabidopsis chromosome 4. We confirmed the conservation of gene content and order between the two genome segments. In addition, we identified a further four segments of the Arabidopsis genome that contain conserved gene content and order. In total, 22 of the 56 genes identified in the rice genome segment were represented in this set of Arabidopsis genome segments, with at least five genes present, in conserved order, in each segment. These data are consistent with the hypothesis that the Arabidopsis genome has undergone multiple duplication events. Our results demonstrate that conservation of the genome microstructure can be identified even between monocot and dicot species. However, the frequent occurrence of duplication, and subsequent microstructure divergence, within plant genomes may necessitate the integration of subsets of genes present in multiple redundant segments to deduce evolutionary relationships and identify orthologous genes.

Arabidopsis↗

Sequence and analysis of chromosome 3 of the plant Arabidopsis thaliana.

Arabidopsis thaliana is an important model system for plant biologists. In 1996 an international collaboration (the Arabidopsis Genome Initiative) was formed to sequence the whole genome of Arabidopsis and in 1999 the sequence of the first two chromosomes was reported. The sequence of the last three chromosomes and an analysis of the whole genome are reported in this issue. Here we present the sequence of chromosome 3, organized into four sequence segments (contigs). The two largest (13.5 and 9.2 Mb) correspond to the top (long) and the bottom (short) arms of chromosome 3, and the two small contigs are located in the genetically defined centromere. This chromosome encodes 5,220 of the roughly 25,500 predicted protein-coding genes in the genome. About 20% of the predicted proteins have significant homology to proteins in eukaryotic genomes for which the complete sequence is available, pointing to important conserved cellular functions among eukaryotes.

Arabidopsis↗

MIPS: a database for genomes and protein sequences.

The Munich Information Center for Protein Sequences (MIPS-GSF), Martinsried, near Munich, Germany, continues its longstanding tradition to develop and maintain high quality curated genome databases. In addition, efforts have been intensified to cover the wealth of complete genome sequences in a systematic, comprehensive form. Bioinformatics, supporting national as well as European sequencing and functional analysis projects, has resulted in several up-to-date genome-oriented databases. This report describes growing databases reflecting the progress of sequencing the Arabidopsis thaliana (MATDB) and Neurospora crassa genomes (MNCDB), the yeast genome database (MYGD) extended by functional analysis data, the database of annotated human EST-clusters (HIB) and the database of the complete cDNA sequences from the DHGP (German Human Genome Project). It also contains information on the up-to-date database of complete genomes (PEDANT), the classification of protein sequences (ProtFam) and the collection of protein sequence data within the framework of the PIR-International Protein Sequence Database. These databases can be accessed through the MIPS WWW server (http://www. mips.biochem.mpg.de).

Arabidopsis↗

Isolated meningeal chloroma (granulocytic sarcoma)--a case report and review of the literature.

Isolated chloromas (granulocytic sarcomas) are rare tumors, most of them progressing to acute myeloblastic leukemia within months. There are still no conclusive treatment strategies for this entity; however, early antileukemic chemotherapy seems to lower the probability of developing systemic disease and prolong survival. We report on a patient with isolated meningeal chloroma, primarily misdiagnosed as a high-grade Non-Hodgkin's lymphoma. Two cycles of antileukemic induction chemotherapy were administered, followed by local irradiation and intensified consolidation therapy with autologous stem cell transplantation. After 20 months, he is still in complete remission.

Adult↗

Screening for MLL tandem duplication in 387 unselected patients with AML identify a prognostically unfavorable subset of AML.

Partial tandem duplications of the MLL gene have been associated with trisomy 11 in acute myeloid leukemia (AML) and recently, have also been reported for karyotypically normal AML. In order to test the incidence and prognostic importance of this molecular marker, we have analyzed eight cases of AML with trisomy 11 and 387 unselected consecutive cases with AML for partial duplications of the MLL gene. Patients with normal karyotypes and those with various chromosome aberrations were included. De novo as well as secondary leukemias including all FAB subtypes were analyzed. Performing a one-step RT-PCR with 35 cycles using an exon 9 forward primer and an exon 3 reverse primer partial tandem duplications of the MLL gene were demonstrated in 3/8 (37.5%) patients with trisomy 11. In addition, 13/387 (3.4%) of unselected cases revealed a tandem duplication. Ten of these 13 cases were cytogenetically normal, the other three cases had < or =2 additional chromosomal alterations. Sequencing of the RT-PCR products of all 16 positive cases revealed fusions of MLL exon 9/exon 3 (e9/e3) (six cases), e10/e3 (three cases), e11/e3 (four cases) or combinations of differentially spliced e10/e3 and e11/e3 (three cases) transcripts. The duplications were confirmed by genomic long range PCR and Southern blot hybridization. Twelve cases with the MLL duplication were de novo myeloid leukemia, one was a secondary AML after MDS, three were therapy-related AML (t-AML). Of the 16 MLL-duplication positive cases, seven were classified as FAB M2, two as M1, five as M4, one as M0, one as M5b. The mean age was 62.3 years for patients with MLL duplication vs 50.3 years for the control group. Of 15 adult patients, 12 received treatment. Of these, three were nonresponders, five had early relapse (< or =6 months), four relapsed between 7 and 12 months. Median survival and relapse-free interval of the MLL duplication positive group was significantly worse than those of an age-matched karyotypically normal control group. In conclusion, MLL tandem duplications (1) are less common than previously reported; (2) are preferentially observed in AML with normal karyotypes, but can also be found in the presence of chromosome alterations; (3) are not strongly associated with an FAB subtype; (4) were not observed with the prognostically favorable t(8;21), inv(16), and t(15;17), other recurrent translocations, or in complex karyotypes; and (5) identifies a subgroup of patients with an unfavorable prognosis.

Aged↗

Double induction strategy including high dose cytarabine in combination with all-trans retinoic acid: effects in patients with newly diagnosed acute promyelocytic leukemia. German AML Cooperative Group.

A prospective multicenter study was performed to investigate the clinical and molecular results of intensified double induction therapy including high-dose cytarabine (ara-C) in combination with ATRA in newly diagnosed acute promyelocytic leukemia (APL), followed by consolidation and 3 years maintenance therapy. Fifty-one patients, diagnosed and monitored from December 1994 to June 1999, were evaluated. The median age was 43 (16-60) years. The morphologic diagnosis was M3 in 40 (78%) and M3v in 11 (22%) patients. In 15 (30%) patients the initial white blood cell counts were > or =5 x 10(9)/l. The cytogenetic or molecular proof of the translocation t(15;17) was a mandatory prerequisite for eligibility. The diagnosis was confirmed by karyotyping in 46 and by RT-PCR of the PML/RARalpha transcript in 45 cases. The rate of complete hematological remission was 92% and the early death rate 8%. Monitoring of minimal residual disease by RT-PCR of PML/RARalpha (sensitivity 10(-4)) showed negativity in 29 of 32 (91%) evaluable cases after induction, in 23 of 25 (92%) after consolidation, and in 27 of 30 (90%) during maintenance, after a median time of 2, 4 and of 18 months after diagnosis, respectively. After a median follow-up of 27 months, the estimated actuarial 2 years overall and event-free survival were both 88% (79, 97), and the 2 years relapse-free survival 96% (90, 100). The high antileukemic efficacy of this treatment strategy is demonstrated by a rapid and extensive reduction of the malignant clone and by a low relapse rate. The results suggest that the intensity of the induction chemotherapy combined with ATRA is one of the factors which may have a critical influence on the outcome of APL. A randomized trial should assess the value of an induction therapy including ATRA and high-dose ara-C in comparison to standard-dose ara-C.

Adolescent↗