Treatment of patients with low-risk myelodysplastic syndromes using a combination of all-trans retinoic acid, interferon alpha, and granulocyte colony-stimulating factor

Used as single agents, ATRA, G-CSF, and IFN-alpha have shown a moderate benefit in patients with low-risk MDS, with a response rate of 10%. The aim of the present study was to evaluate the efficacy of a combination of these agents. The effect on hemoglobin (Hb), platelets, and absolute neutrophil count (ANC), as well as on transfusion frequency, was examined in 25 patients with MDS (11 RA, four RARS, eight RAEB, two CMML). The median age was 61 years (range 44-81), and the male/female ratio was 14/11. Treatment consisted of ATRA at 25 mg/m2/day p.o. for months 1, 3, 5, 7, 9, and 11, IFN-alpha at 1.5 MIU twice a week s.c. for 52 weeks, and, in patients with initial ANC <500/microl, G-CSF at 100-480 microg daily s.c. according to the degree of ANC. The duration of therapy was scheduled for 12 months. Two patients achieved ongoing CR (+19 months; +16 months), one patient with RA after 3 months and one with CMML after 7 months of treatment. In all patients, the mean ANC increased significantly from 1400+/-200/microl before the start of therapy to 3500+/-600/microl at the end of treatment (p=0.025). In two patients an increase of Hb was observed, and one patient ceased to require transfusions. In an additional patient with RA and 5q-syndrome, the platelet count normalized following administration of ATRA/IFN-alpha, increasing from 89,000/microl to 293,000/microl. The eight RAEB patients were nonresponders. We conclude that therapy with ATRA, IFNalpha, and G-CSF is effective in approximately 35% of low-risk MDS patients (in this study: six of 17) and may induce complete remission in individual cases.

Characterization of defective megakaryocytic development in patients with myelodysplastic syndromes

Megakaryocytic differentiation of progenitor cells was investigated in nine patients with low-risk myelodysplastic syndromes (MDS) (eight refractor anemia [RA] and one RA with ringed sideroblasts [RARS] and five patients with high-risk MDS (two RA with excess of blasts [RAEB] and three RAEB in transformation [RAEB-T]). Bone marrow-derived CD34+ cells were enriched to a purity of 87% +/- 2% (mean +/- SEM) and assayed in short-term suspension cultures in the presence of 10 ng/mL of PEGylated recombinant human megakaryocyte (MK) growth and development factor (PEG-rHuMGDF) and in addition to 50 ng/mL stem cell factor and 10 ng/mL interleukin-3. Cells of the megakaryocytic lineage were identified by flow cytometric analysis of CD42b (GP1b) and mature MKs by morphologic criteria. Transcription of c-mpl receptor-specific mRNA in the CD34+ cells of these patients was investigated by full-length reverse transcriptase polymerase chain reaction of the p form of c-mpl as well as of the alternative splice product c-mpl k. CD34+ cells from seven healthy bone marrow donors served as controls. Differentiation along the MK pathway was stimulated in five patients with RA. C-mpl mRNA was expressed in the CD34+ cells in all cases. In three low-risk patients the capacity for in vitro MK growth was absent or minimal even though mRNA for c-mpl receptor was detected in the CD34+ cells of this group as well. In patients with high-risk MDS, PEG-rHuMGDF stimulated in vitro MK growth from CD34+ cells in only one of five cases. As in the patients with low-risk MDS, c-mpl mRNA for both c-mpl p and c-mpl k splicing products was detected. These results indicate that the in vitro response to stimulation with c-mpl ligand discriminates between two groups of patients with low-risk MDS and that the observed defect in megakaryocytic development is unrelated to the level of c-mpl expression in both low-risk and high-risk MDS.

Fludarabine and epirubicin in the treatment of chronic lymphocytic leukaemia: a German multicenter phase II study

PURPOSE

Fludarabine has been reported to be the most effective single-agent in previously treated chronic lymphocytic leukaemia (CLL). Based on the in vitro synergism of fludarabine with anthracyclines and on results showing a higher efficacy of CHOP against COP we attempted to improve treatment results with a combination of fludarabine and an anthracycline.

PATIENTS AND METHODS

The aim of the multicenter study was to evaluate the rate and duration of remissions and investigate the toxic and immunosuppressive effects of fludarabine and epirubicin in the treatment of CLL in Binet stages B and C as first-line therapy or in first relapse. Thirty-eight patients were treated with fludarabine 25 mg/m2 on days 1-5 and epirubicin 25 mg/m2 on days 4 and 5.

RESULTS

The overall response rate (OR) was 82% (95% confidence interval (95% CI): 66%-92%) with a CR rate of 32% (95% CI: 18%-49%). For the 25 previously untreated patients the OR was 92% (95% CI: 74%-99%) including 40% CRs (95% CI: 21%-61%). Granulocytopenia grade 3 occurred in 23% of all evaluable cycles, and grade 4 in 17%. The median remission duration was 19 months (range 6-37 months).

CONCLUSION

The results show that the combination of fludarabine and epirubicin is tolerable and highly effective in the treatment of CLL. With the addition of epirubicin to fludarabine, it appears possible to achieve a higher response rate and a more rapid response, especially of nodal manifestations. This regimen can be administered in an outpatient facility except for the first cycle because of the risk of a tumour lysis. The possible benefit of the combination presented here in the treatment of CLL in comparison to single-agent fludarabine treatment is presently under study in a prospective randomized multicenter study.

Megakaryocytic growth factors: is there a new approach for management of thrombocytopenia in patients with malignancies?

C-mpl ligand acts primarily as a lineage-specific hematopoietic growth factor by promoting proliferation of megakaryocyte precursors and their differentiation into megakaryocytes and platelets. In addition to the ability of c-mpl ligand to support megakaryocytic development from CD34+ precursor cells, several lines of evidence also point to a stimulatory effect on hematopoietic stem cells. When recombinant thrombopoietin or pegylated megakaryocyte growth and development factor is administered to normal animals or humans, there is a dose-dependent increase in the platelet count. When administered following chemotherapy in animal models or humans, c-mpl ligands reduce the duration and sometimes the degree of thrombocytopenia. The issue of whether clinically relevant thrombocytopenia can be ameliorated has so far been more difficult to resolve. Because severe thrombocytopenia is not commonly seen with standard chemotherapy regimens, clinical studies examining c-mpl ligands for their ability to ameliorate chemotherapy-induced thrombocytopenia will focus on treatment of acute leukemias and bone marrow transplantation. The potential utility of c-mpl ligands for treatment of myelodysplastic syndromes, aplastic anemias, or in HIV infection, will have to be evaluated in the future. Possibly the greatest potential of thrombopoietic growth factors in the near future may be in transfusion medicine, to collect and to store platelets from healthy donors or in autologous settings.

Treatment of mantle-cell lymphomas with intermittent two-hour infusion of cladribine as first-line therapy or in first relapse

PURPOSE

Cladribine (2-chlorodeoxyadenosine, 2-CdA) has been reported to be effective in the treatment of low-grade lymphomas. The objective of this multicenter study was to evaluate the activity of cladribine in mantle-cell lymphomas as first-line therapy or in first relapse using an intermittent two-hour infusion of cladribine.

PATIENTS AND METHODS

A total of 47 courses, or an average of four courses per patient, were administered to 12 patients (seven untreated, five relapsed) with 5 mg/m2 cladribine given as an intermittent two-hour infusion over five consecutive days for a maximum of six cycles every four weeks.

RESULTS

Cladribine showed activity in patients with mantle-cell lymphomas, achieving a response rate of 58% (95% confidence interval (95% CI): 28%-85%). Myelosuppression was the major toxicity with 17% of grade 3 and 4 neutropenia. Thrombocytopenia was rare with only 2% of grade 3 and 4.

CONCLUSION

These results demonstrate single-agent activity of cladribine in mantle-cell lymphomas using the intermittent two-hour infusion dosage regimen. To further improve treatment results, cladribine should be combined with other agents active in mantle-cell lymphomas.

Growth factors in the treatment of acute lymphoblastic leukemia

The safety of G-CSF and GM-CSF in adult and pediatric patients with ALL has been well established. In addition, prophylactic administration of G-CSF was shown to significantly accelerate neutrophil recovery in most clinical trials. This was associated with a substantially reduced incidence and duration of febrile neutropenia and of severe infections in selected high risk patients receiving multiple treatment cycles, whereas the clinical benefit appears to be negligible in patients at low risk of infectious complications. There is currently insufficient evidence to support the use of GM-CSF as an adjunct to treatment for ALL outside of clinical trials. Apart from patient characteristics and type of CSF, it has become evident that scheduling of growth factor administration in relation to the type of chemotherapy, and use of different study end points influence the clinical efficacy of HGF administration. Although no studies have so far shown that use of growth factors is associated with reduced mortality, higher complete remission rates or superior survival, improvements in other clinical endpoints, e.g. infection rate, duration of i.v. antibiotics, and length of hospital stays were frequently perceived as clinically important and felt to contribute substantially to the patient's quality of life. It will become increasingly important to select those patients likely to benefit from growth factor support and to identify additional predictive criteria. Scheduling of CSFs, e.g. early versus delayed and prophylactic versus interventional administration, the type of growth factor used and the duration of administration need to be optimized in the context of specific treatment protocols. Although myeloid growth factors presently can not be expected to have a major impact on overall treatment outcome in patients with ALL, they facilitate important incremental improvement; in supportive care when appropriately applied. As the remaining open questions are resolved, clinical benefits may be achieved consistently and with a favorable cost benefit ratio.

L-tryptophan-related eosinophilia-myalgia syndrome possibly associated with a chronic B-lymphocytic leukemia

A female patient presenting with B-CLL and coincident eosinophilia-myalgia syndrome (EMS) after ingestion of L-tryptophan is described. The manifestations of EMS disappeared completely during treatment with cyclophosphamide/prednisone. and there was an intermittent clinical remission of CLL with absence of the monoclonal B-cell population. A few years later, the B-CLL relapsed, but without sign and symptoms of EMS. Whereas other eosinophilic syndromes such as eosinophilic fasciitis, panniculitis, or cellulitis Wells have been found to occur in relation to malignant underlying diseases, only a single patient with malignant fibrous histiocytoma following EMS has been described. There are no reports about an increased occurrence of B-CLL or other non-Hodgkin's lymphomas combined with or following EMS or related to L-tryptophan itself. The variant types of eosinophilic syndromes occurring due to malignant disorders, the differentiation from EMS, and the possible association between B-CLL and L-tryptophan-related EMS are discussed.

High efficiency gene transfer to human hematopoietic SCID-repopulating cells under serum-free conditions

Stable gene transfer to human pluripotent hematopoietic stem cells (PHSCs) is an attractive strategy for the curative treatment of many genetic hematologic disorders. In clinical trials, the levels of gene transfer to this cell population have generally been low, reflecting deficiencies in both the vector systems and transduction conditions. In this study, we have used a pseudotyped murine retroviral vector to transduce human CD34(+) cells purified from bone marrow (BM) and umbilical cord blood (CB) under optimized conditions. After transduction, 71% to 97% of the hematopoietic cells were found to express a low-affinity nerve growth factor receptor (LNGFR) marker gene. Six weeks after transplantation into immunodeficient NOD/LtSz-scid/scid (NOD/SCID) mice, LNGFR expression was detected in 6% to 57% of CD45(+) cells in eight of nine engrafted animals. Moreover, proviral DNA was detected in 8.3% to 45% of secondary colonies derived from BM cells of engrafted NOD/SCID mice. Our data show consistent transduction of SCID-repopulating cells (SRCs) and suggest that the efficiency of gene transfer to human hematopoietic repopulating cells can be improved using existing retroviral vector systems and carefully optimized transduction conditions.

Detection of karyotypic aberrations in acute myeloblastic leukaemia: a prospective comparison between PCR/FISH and standard cytogenetics in 140 patients with de novo AML

In 140 patients with de novo acute myeloid leukaemia (AML) standard cytogenetics were compared with RT-PCR for the detection of t(8;21), t(15;17) and inv(16) and fluorescence in situ hybridization (FISH) for numerical aberrations of chromosomes 7, 8, X and Y. RT-PCR detected 18 cases with t(8;21), 12 with t(15;17) and seven with inv(16). In two cases with t(8;21), two with t(15;17) and four with inv(16) these aberrations had not been detected by standard cytogenetics. There were no false negative PCR results. In 12 patients with these chromosomal changes, standard cytogenetics revealed additional chromosomal aberrations. In 16 patients sole numerical aberrations of the chromosomes 7, 8, X or Y were found by FISH. In these patients the sensitivity of FISH and standard cytogenetics was comparable. In 87 patients no aberrations could be found by PCR and FISH whereas in 24 of these patients standard cytogenetics revealed an abnormal karyotype. These data recommend the combination of standard cytogenetics and molecular techniques to improve the sensitivity for the detection of genetic lesions in AML. Once chromosomal markers have been identified by combined analysis these markers could be used to monitor residual disease during/after chemotherapy, by RT-PCR and/or FISH.

Recombinant human granulocyte and granulocyte-macrophage colony-stimulating factor (G-CSF and GM-CSF) administered following cytotoxic chemotherapy have a similar ability to mobilize peripheral blood stem cells

The availability of hematopoietic growth factors has greatly facilitated the mobilization and collection of peripheral blood stem cells (PBSC). It was the aim of this double-blind study to compare the PBSC-mobilizing efficacy of recombinant human G-CSF and GM-CSF when administered post-chemotherapy. Twenty-six patients with relapsed Hodgkin's disease were included in the study. Their median age was 31 years (range, 22-59) and 14 patients were males and 12 were females. Patients were pretreated with a median of eight cycles of cytotoxic chemotherapy, while 18 patients had undergone extended field irradiation. The patients received dexamethasone 24 mg days 1-7, melphalan 30 mg/m2 day 3, BCNU 60 mg/m2 day 3, etoposide 75 mg/m2 days 4-7, Ara-C 100 mg/m2 twice daily days 4-7 (Dexa-BEAM). Twelve patients were randomized to receive 5/microg/kg/day G-CSF and 14 patients to receive 5 microg/kg/day GM-CSF, both administered subcutaneously starting on day 1 after the end of Dexa-BEAM. Primary endpoints of the study were the number of CD34+ cells harvested per kg body weight on the occasion of six consecutive leukaphereses and the time needed for hematological reconstitution following autografting. Twenty-one patients completed PBSC collection, and six patients of the G-CSF group and nine of the GM-CSF group were autografted. No difference was observed with respect to the median yield of CFU-GM and CD34+ cells: 32.5 x 10(4)/kg vs 31.3 x 10(4)/kg CFU-GM, and 7.6 x 10(6)/kg vs 5.6 x 10(6)/kg CD34+ cells, for G-CSF and GM-CSF, respectively (U test, P= 0.837 and 0.696). High-dose chemotherapy consisted of cyclophosphamide 1.7 g/m2 days 1-4, BCNU 150 mg/m2 days 1-4, etoposide 400 mg/m2 days 1-4. All patients transplanted with more than 5 x 10(6) CD34+ cells/kg had a rapid platelet recovery (20 x 10(9)/l) between 6 and 11 days and neutrophil recovery (0.5 x 10(9)/1) between 9 and 16 days, while patients transplanted with less than 5 x 10(6)/kg had a delayed reconstitution, regardless of the kind of growth factor used for PBSC mobilization. In conclusion, our data indicate that in patients with Hodgkin's disease G-CSF and GM-CSF given after salvage chemotherapy appear to be not different in their ability to mobilize PBSC resulting in a similar time needed for hematological reconstitution when autografted following high-dose therapy.

Immunophenotypic and genotypic features, clinical characteristics, and treatment outcome of adult pro-B acute lymphoblastic leukemia: results of the German multicenter trials GMALL 03/87 and 04/89

In contrast to childhood acute lymphoblastic leukemia (ALL), the cell-biological features, clinical characteristics, and treatment outcome of CD10(-) pro-B ALL have not yet been determined in larger series of adult patients. Therefore, we studied 57 adult patients with newly diagnosed pro-B ALL (median age, 30 years) enrolled in two consecutive German multicenter ALL studies (03/87 and 04/89). Extensive immunophenotypic characterization of leukemic blasts could be performed on all patients, whereas adequate cytogenetic data were available in 33 cases and molecular studies in 18 cases, using reverse transcription-polymerase chain reaction to detect MLL-AF-4 transcripts. Twenty-two patients demonstrated a t(4;11)(q21;q23) and/or MLL-AF-4 rearrangements, and 6 patients had other structural abnormalities, including a t(9;22)(q34;q11) (N = 2). Nine patients had a normal karyotype. Patients with 11q23 abnormalities tended to be younger (median age, 29 years) and were characterized by male predominance (64%), hyperleukocytosis (median leukocyte count, 168 x 10(9)/L), and a frequent coexpression of CD65s (64%) as compared with patients with other cytogenetic abnormalities or a normal karyotype. Twelve of 16 (75%) pro-B ALL patients in study 03/87 and 30 of 41 (73%) in study 04/89 achieved a complete remission (CR). Sixteen of 30 patients in study 04/89 remain in continuous CR (CCR) in contrast to only 2 of 12 patients in study 03/87. Interestingly, all 7 patients treated with high-dose cytarabine and mitoxantrone as consolidation in study 04/89 remain alive and leukemia-free. One patient in study 03/87 and 8 in study 04/89 underwent autologous (N = 2) or allogeneic (N = 7) bone marrow transplantation (BMT). The median remission duration was 420 days for patients in study 03/87 and has not yet been reached in study 04/89. The median survival time of all pro-B ALL patients was 571 days in study 03/87 and 747 days in study 04/89. Among the 22 patients with a t(4;11) and/or MLL-AF-4 rearrangements, 17 achieved a CR and 8 are still in CCR, of whom 4 underwent an allogeneic BMT. Remission duration and overall survival did not differ significantly between pro-B ALL patients with 11q23 abnormalities and those with a normal karyotype or other structural abnormalities. These data indicate that intensification of postremission treatment may improve the prognosis of adult pro-B ALL, including patients with a t(4;11).

[Growth factors in oncology: effectiveness and prospects]

The hematopoietic growth factors G-CSF and GM-CSF stimulate the proliferation and differentiation of myeloid precursor cells leading to an accelerated granulocytic regeneration after chemotherapy and to a shortened duration of "febrile neutropenia". Criteria for the clinical application should be defined which take the advantage for the comfort of the patient and the economic aspect into account. The American Society for Clinical Oncology has published recommendations for the treatment with hematopoietic colony-stimulating factors, which are useful with the exception of the proposal to reduce the chemotherapy dose with the goal to save expensive CSF treatment. The use of CSF for treatment of afebrile and uncomplicated neutropenia should be reduced.

[Antibiotic therapy in leukopenia]

Intensified chemotherapy-induced long-term neutropenia is the main cause for morbidity and mortality of patients with hematologic malignancies. The successful management of neutropenia is based on hygienic procedures antimicrobial prophylaxis and therapy, and diagnostics. Until today, Co-Trimoxazole or fluoroquinolenes and oral amphotericine B are the prophylactic standard. The initial therapy of febrile neutropenia has to be started empirically before identification of causative pathogens or infectious foci. The febrile episodes should be treated with broad spectrum antibiotics (combinations or monotherapy) due to the spectrum of microorganisms or resistance situation at hospital. In case of non-response after 3-4 days the initial therapy should be modified, in addition to further antibacterial therapy the start with an antifungal drug has to be recommended. In patients with pulmonary infiltrates the early treatment with amphotericine B has been shown to be more advantageous than delayed antifungal therapy. Furthermore, the antibiotic therapy is based on proven microorganisms, susceptibility testing and infectious foci. The value of interventional treatment with G-CSF or GM-CSF is controversely discussed. An uncompromising handling of febrile neutropenia is necessary to reduce the mortality due to infections in patients with hematologic malignancies.

High rate of chromosome abnormalities detected by fluorescence in situ hybridization using BCR and ABL probes in adult acute lymphoblastic leukemia

The value of dual-color fluorescence in situ hybridization (FISH) with BCR and ABL probes for the detection of the Philadelphia (Ph) translocation and of other alterations involving ABL and/or BCR was evaluated in adult acute lymphoblastic leukemia (ALL). One hundred and four patients were studied prospectively using interphase nuclei FISH, chromosome analysis (CA), and PCR assays for the chimeric BRC/ABL transcript. FISH detected a Ph translocation in 24 cases (23.1%), as was confirmed by CA and/or PCR. FISH revealed a false positive diagnosis of a Ph translocation in four cases (5% false positive rate). Among 54 cases with combined FISH, CA and PCR assays, FISH failed to establish a correct diagnosis in 3.7%, PCR in 5.6%, and CA in 7.4%. The combination of two screening methods led to discrepant results in 9.3% (FISH + PCR), 11.1% (FISH + CA), or 13% (CA + PCR) of the cases. In seven of 80 (8.8%) Ph-negative patients, gain of BCR and/or ABL was identified. Overall, FISH detected alterations of the BCR and/or ABL genes with an incidence of 29.8% of the current study. Due to the possibility of false positive diagnosis of a Ph translocation using dual-color FISH the combination with chromosome and/or RT-PCR analyses is recommended in adult ALL patients.

Correction of respiratory burst activity in X-linked chronic granulomatous cells to therapeutically relevant levels after gene transfer into bone marrow CD34+ cells

Chronic granulomatous disease (CGD) is a disorder of the lymphohematopoietic system, whereby phagocytes of affected patients are unable to kill microorganisms. CGD is caused by a functional defect in the phagocytic nicotinamide adenine dinucleotide phosphatase (NADPH) oxidase (phox) enzyme complex, leading to a lack of microbicidal metabolites. As a therapeutic approach toward the predominant X-linked form of CGD, we have developed a bicistronic retroviral vector containing the coding sequences of gp91-phox and a cytoplasmically truncated version of the human low-affinity receptor for nerve growth factor (deltaLNGFR). Full reconstitution of superoxide-generating activity was achieved with this vector in a gp91-phox-deficient cell line. Using an optimized gene transfer protocol, up to 85% of the CD34+ cells obtained from the bone marrow of X-CGD patients were transduced. CD15+ cells differentiated in vitro from transduced X-CGD CD34+ cells showed correction of NADPH oxidase activity to 45-52% of normal levels whereas deltaLNGFR expression was found in 40-67% of the CD15+ cells. Moreover, immunoblots prepared from extracts of transduced CD15+ cells revealed gp91-phox protein levels similar to those found in neutrophils derived from normal CD34+ cells. Taking into consideration that superoxide production in only 5 to 10% of wild-type neutrophils is sufficient to protect X-CGD heterozygotes from serious infections, the results achieved in this study shows that for X-CGD patients a curative approach based on the genetic modification of hematopoietic stem/progenitor cells is feasible.

Piperacillin/tazobactam versus cefepime as initial empirical antimicrobial therapy in febrile neutropenic patients: a prospective randomized pilot study

The objective of the presented prospective, randomized study was to compare the efficacy of empirical antimicrobial monotherapy with piperacillin/tazobactam (PIP/TAZ) to cefepime (CEFP) for treatment of infections in neutropenic patients. From a total of 102 febrile episodes 100 were evaluable. The most frequent microorganisms were gram-negative, documented in 22% vs. 24% of the febrile episodes (gram-positives 18% vs. 16%, fungi 2% vs. 4%). The response rate was similar with 22/51 (43%) of episodes treated with PIP/TAZ vs. 19/49 (39%) with CEFP. Of the different infection types classified at the end of the febrile episodes, patients with fever of unknown origin (FUO) and primary bacteremias showed the best initial responses with 25/44 (57%) and 11/22 (50%). Lower initial response rates were found in pneumonias with totally 3/13 (23%) and other clinically documented infections with 2/21 (10%), without any difference between both groups. Gram positive infections showed a higher response with PIP/TAZ than with CEFP (4/9 vs. 0/8), gram negative responded less frequently (3/11 vs. 7/13). The median time until persistent defervescence was equal in both groups (2.5 vs. 2 days), likewise the response rates after the different steps of therapy modifications (change to imipenem or ceftazidim, or addition of gentamycin, vancomycin or amphotericin B). Totally, 96% of febrile episodes responded in both therapy arms. Overall, we found no significant differences in efficacy between the two therapeutic regimens. In conclusion, PIP/TAZ as well as CEFP might be a sufficient initial therapy for febrile neutropenia, but further randomized trials with larger patient numbers are necessary.

Meningeosis leukaemica in adult acute lymphoblastic leukaemia

This review addresses diagnosis of CNS involvement, incidence and treatment of CNS disease at time of diagnosis, prophylaxis and treatment of CNS relapse and risk factors for meningeal recurrence in adult acute lymphoblastic leukaemia (ALL). At the time of diagnosis meningeosis leukaemica is present in about 6% (1-10%) of the adult ALL patients with a higher incidence in ALL subgroups T-ALL (8%) and B-ALL (13 %). With the invention of early additional CNS directed therapy it no longer represents an unfavourable prognostic factor. In the absence of prophylaxis meningeal relapses occur in approximately one third of adults with ALL. A literature review including more than 4000 adult ALL patients showed for the different prophylactic treatment approaches the following CNS relapse rates: intrathecal therapy alone 13% (8-19%), intrathecal therapy and CNS irradiation 15% (6-22%), high dose chemotherapy 14% (10-16%), high dose chemotherapy and intrathecal therapy 8% (2-16%) and high dose chemotherapy, intrathecal therapy together with CNS irradiation 5% (1-12%). It became obvious that the early onset of intrathecal therapy and CNS irradiation and the continuation of intrathecal administrations throughout maintenance are essential. The most favourable results where achieved with high dose chemotherapy combined with intrathecal therapy and/or CNS irradiation. The majority of treatment regimens in adult ALL already include high dose chemotherapy in order to reduce the risk of bone marrow relapse. The outcome of patients with CNS relapse is still poor. Although a remission can be induced in the majority of patients (> 60%) it is usually followed by a bone marrow relapse and the survival is poor (< 5-10%). Bone marrow transplantation might be in adults at present the only curative approach.

Differential expression of bcl-2 and susceptibility to programmed cell death in lymphocytes of HIV-1-infected individuals

The bcl-2 protooncogene encodes an inner mitochondrial membrane protein that blocks programmed cell death. There is now increasing evidence that regulation of bcl-2 expression is a determinant of life or death in normal lymphocytes. In this study, we examined bcl-2 expression in lymphocytes from human immunodeficiency virus type 1 (HIV-1)-infected and healthy subjects by flow cytometry. bcl-2 expression was detected in more than 97% of peripheral blood lymphocytes in both healthy and HIV-infected individuals. It was consistently observed that CD4+ lymphocytes from HIV-1-infected individuals with less than 200 CD4+ cells/microliter expressed significantly less bcl-2 than healthy controls. In contrast, bcl-2 expression in CD8+ lymphocytes of these patients was significantly enhanced. No significant alteration of bcl-2 expression was found when lymphocytes of healthy individuals were polyclonally activated in the presence of various regulatory cytokines. Cells undergoing apoptosis showed significantly lower bcl-2 expression than viable cells. Staining of apoptotic cells revealed that lymphocytes from HIV-1-infected subjects were characterized by an increased susceptibility to programmed cell death which was not restricted to a particular lymphocyte subset. Despite significantly different bcl-2 expression in CD4+ and CD8+ lymphocytes of HIV-1-infected individuals with less than 200 CD4+ cells/microliter, no difference could be observed concerning their susceptibility to undergo apoptosis. Therefore, we conclude that sensitivity or resistance to in vitro induction of apoptosis does not directly correlate with bcl-2 expression.

Comparison of toxicity and outcome in patients with acute myeloid leukemia treated with high-dose cytosine arabinoside consolidation after induction with a regimen containing idarubicin or daunorubicin

The toxicity and outcome after high-dose ara-C/daunorubicin (HDara-C/DNR) consolidation therapy in de novo AML was compared in 11 patients who received an idarubicin-containing induction therapy (IDA; from June 1995 to March 1997) and 16 patients pretreated with daunorubicin (DNR; from July 1990 to May 1995) for induction. The DNR group consisted of two cohorts, one (n = 6) of patients who had received, as had the IDA group, two induction and one intermediate-dose ara-C consolidation courses, and another (n = 10) of patients who had been pretreated with one induction and one consolidation course prior to HDara-C/DNR. There was no difference in the relative dose between the three cohorts. Following HDara-C/DNR, the IDA-pretreated patients experienced a more prolonged myelosuppression during consolidation therapy compared with the DNR group. Duration of neutropenia (< 500 neutrophils/microl) following HDara-C/DNR was 31.2 +/- 16 days (mean +/- SEM) in the IDA group compared with 18.7 +/- 5 days in the DNR group (p < .001 Mann-Whitney U-test). The duration 'of thrombocytopenia (platelets < 25000/microl) was 34.8 +/- 20 days in the IDA group vs. 18.5 +/- 6 days in the DNR group (p < .005). The more prolonged myelosupression was associated with a longer duration of fever (18.9 +/- 24 vs. 6.9 +/- 5.2 days). A greater incidence, length (11 +/- 8 vs. 1.2 +/- 2 days), and severity of diarrhea were observed in the IDA-pretreated group. Three of 11 IDA patients experienced WHO grade III-IV diarrhea. In the IDA group two patients developed severe enterocolitis with Candida septicemia, and one of these patients died. One patient in the IDA group died during prolonged aplasia. In the DNR group 6/16 patients experienced grade I-II diarrhea. Two patients in each group died during consolidation therapy. The CR rate was 87% in the IDA group and 79% in the DNR group. Relapse-free survival after HDara-C is 50% at a median follow-up of 60 months in the DNR group and 45% after a median follow-up of 17 months in the IDA group. Whether the advantage of the superior response rate in the IDA-treated patients may be lost during HDara-C consolidation treatment due to increased toxicity remains to be proven in larger trials.

HFE codon 63/282 (H63D/C282Y) dimorphism in German patients with genetic hemochromatosis

Genetic hemochromatosis (GH) is closely associated with genes of the major histocompatibility complex (MHC) on chromosome 6. Recently, a candidate gene for GH, with structural similarities to MHC class I genes, designated HLA-H and presently named HFE, has been cloned. The HFE gene is localized telomeric to the MHC and several reports have indicated that the HFE gene is mutated in GH patients. In the present study we have analyzed the relationship of HFE gene variants and disease manifestation in GH patients and family members. Fifty-seven patients with GH, 73 family members and 153 healthy blood donors were studied for the amino acid dimorphism at codon 63 (His63Asp=H63D) and codon 282 (Cys282Tyr= C282Y) of the HFE gene. The codon 63 and 282 dimorphism were defined by PCR amplification of genomic DNA samples and restriction enzyme digestion using RsaI/SnaBI for C282Y and BclI/MboI for H63D. Ferritin, transferrin serum levels and total iron-binding capacity were determined prior to therapeutic intervention. The Tyr-282 substitution occurred in 53 (93%) of patients compared with 8 (5.2%) of controls (OR=169, P<0.0001). Fifty-one (90%) patients were Tyr-282 homozygous. In contrast, the Asp-63 substitution was present in 5 (8.8%) of the patients compared with 34 (22%) of controls (OR=0.39, P=NS) with none of the patients being homozygous. In Tyr-282 homozygous GH patients serum ferritin levels, transferrin saturation, liver iron and liver iron index were elevated significantly compared to Tyr-282-negative patients, whereas no difference was observed between Tyr/Cys-282 heterozygous and Tyr-282-negative patients.

Increase in Vdelta1+ gammadelta T cells in the peripheral blood and bone marrow as a selective feature of HIV-1 but not other virus infections

Dysregulation of T-cell receptor (TCR) alphabeta bearing lymphocytes and an increase in Vdelta1+ gammadelta T cells are typical features of HIV-1 infection. However, the role of gammadelta T cells remains unclear. Therefore, peripheral blood mononuclear cells (PBMC) of 103 HIV-1-infected patients were investigated with respect to expression of Vdelta1. These results were compared to the Vdelta1 expression of bone marrow mononuclear cells (BMMC). In contrast to healthy controls, Vdelta1+ cells dominated among both PBMC and BMMC in HIV-1-infected patients. Analysis of the coexpression of CD25, CD8, HLA-DR and CD45RO revealed a high prevalence of Vdelta1/CD45RO and Vdelta1/HLA-DR double-positive PBMC only in HIV-1-infected patients but not in healthy donors. Furthermore, analysis of the gammadelta TCR repertoire in patients infected with hepatitis B virus, hepatitis C virus, herpes simplex virus (HSV)-1 and HSV-2 showed that the selective enhancement of Vdelta1+ cells was restricted to HIV infection and not observed in other virus diseases. Our data provide further support for the involvement of gammadelta T cells in immunosuppression and progression of HIV infection.

Mechanism of gamma sigma T-cell-mediated inhibition of stem cell differentiation in vitro: possible relevance for myelosuppression in HIV-infected individuals

We investigated whether gamma delta T cells contribute to the suppression of myelopoiesis in HIV infection. Freshly isolated gamma delta T cells from HIV seropositive patients suppressed CFU-GM growth in vitro. Preactivation of gamma delta T cells with IL-2 and/or IL-15 further reduced the number of CFU-GM. Natural killer cells and to a lower extent CD4+ and CD8+ cells also inhibited CFU-GM growth. In contrast to gamma delta T cells, this effect was not dependent on IL-15 or IL-2 preactivation. Moreover, no enhanced inhibitory effect of CD56+ and CD4+ cells was observed in HIV+ subjects compared to HIV- donors. The myelosuppressive effect of supernatants of gamma delta T cells could be inhibited by antibodies against IFN-gamma or TNF-alpha. Accordingly, we found increased numbers of TNF-alpha or IFN-gamma-secreting CD8+ gamma delta T cells in HIV+ patients. We conclude that the increased fraction of activated gamma delta T cells producing myelosuppressive cytokines might contribute to the dyshematopoiesis frequently observed in HIV-infected individuals.

High expression of bcl-2 mRNA as a determinant of poor prognosis in acute myeloid leukemia

BACKGROUND

The bcl-2 oncoprotein is suggested to be directly involved in the emergence of drug resistance by disrupting or delaying the apoptotic program and promoting tumor survival.

PATIENTS AND METHODS

In order to define the clinical relevance of the bcl-2 mRNA expression in acute myeloid leukemia (AML) and its correlation to therapy outcome and prognosis, we analyzed 219 AML bone marrow (BM) samples, including 119 patients with de novo AML at presentation, 37 with AML following myelodysplastic syndrome (MDS), as well as 42 BM samples of AML in relapse and 21 in complete remission (CR) using RT-PCR. For performing quantitative measurements of bcl-2 mRNA, we developed a quantitative RT-PCR.

RESULTS

Bcl-2 mRNA was detectable in 133 of 156 (84%) patients at diagnosis and 40 of 42 (95%) at relapse. AML patients with high bcl-2 mRNA expression achieved lower CR rates than those with no or low expression. Concerning the long-term outcome, the overall (OS) and disease-free survival (DFS) was significantly worse in AML patients with high expression levels of bcl-2 mRNA. The three-year OS for all newly diagnosed AML patients was 49% and 10% (P = 0.028), respectively, and 71% and 15% (P = 0.0004) for patients < 60 years. Comparable significant differences were observed for the DFS. In AML following MDS and patients > 60 years, the bcl-2 expression was not associated with remission rate or survival.

CONCLUSIONS

The expression of bcl-2 mRNA may serve as a prognostic factor predicting remission outcome and long-term prognosis in AML.

Graft-versus-leukemia effects in T lineage and B lineage acute lymphoblastic leukemia

T and B lineage ALL cells express different levels of HLA-class II antigens, which may serve as targets for graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL). The object of this study was to determine whether GVL effects after HLA-identical sibling bone marrow transplantation differed in T and B lineage ALL. We studied 1132 patients with ALL of T lineage (n = 416) or of B lineage (cALLa+) (n = 716) transplanted in first (n = 605) or second (n = 527) remission with bone marrow from an HLA-identical sibling donor, between 1982 and 1992, and reported to the IBMTR by 165 teams. Cox proportional hazards regression models were used to determine the relative risk (RR) of relapse in patients with acute (grades II-IV) or chronic GVHD vs patients without GVHD. Acute and chronic GVHD were considered as time-dependent covariates. Patients transplanted in first and second remission were analyzed separately. GVHD decreased relapse risks to a similar extent in T and B lineage ALL. For first remission transplants, relative risks of relapse for patients with vs those without GVHD was 0.34 for T lineage ALL and 0.44 for B lineage ALL. Corresponding relative risks in second remission transplants were 0.54 and 0.61. This study confirms earlier findings of an antileukemia effect of GVHD in ALL. This effect was similar in T lineage and B lineage ALL, despite probable differences in HLA-class II antigen expression.