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The role of in vivo T-cell depletion on reduced-intensity conditioning allogeneic stem cell transplantation from HLA-identical siblings in patients with follicular lymphoma

Summary: Selective oral and systemic decontamination are widely discussed when it comes to the prophylaxis of bacterial and fungal infections in immunocompromised patients. The number of such patients is clearly rising due to the aggressiveness of modern medicine. Host defence is based on a variety of factors including the barrier function of mucosal surfaces as well as the phagocytic system provided by the blood. It seems helpful to distinguish between three different stages of immunodeficiency: “Minor immunodeficiency”, “immunodeficiency” (in a stricter sense), “major immunodeficiency”. When it comes to the choice of measures to be taken to protect the host, it is not only needed to consider the microbes already present but also the present state of defence mechanisms. When invasive fungal infections in particular have to be prevented, several drugs have to be discussed, As conventional antifun-gals have not met all expectations there is clear need for new drugs such as itraconazole.

The in vitro bone marrow growth of 2 patients with aprindine-induced agranulocytosis was studied. Granulocyte-macrophage committed stem cell (CFU-C) growth is inhibited by aprindine in a dose dependent manner. 50% inhibition of CFU-colony growth (TD50) was seen at 5.1 and 3.4 micrograms aprindine/ml medium respectively. The TD50 of control marrow CFU-C was 3.2 micrograms/ml. 100% inhibition was seen at 16 micrograms aprindine/ml, both in patients and controls. Pluripotential stem cell growth (CFU-GEMM) in control marrow was equally inhibited in a dose dependent manner by aprindine, though to a lesser extent (TD50: 9.1 micrograms/ml) and with relative sparing of pure megakaryocyte and erythroid colonies. Co-culturing of patients marrows with their respective acute phase serum did not inhibit CFU-C growth.

Dendritic cells (DC) are pivotal for T cell-mediated immunity. We investigated the early and terminal maturation of monocyte-derived DC (MoDC) in myelodysplastic syndromes (FAB subtypes refractory anemia (MDS-RA) or refractory anemia with ringed sideroblasts (MDS-RARS)). Immature MoDC were obtained by culture of monocytes with GM-CSF and IL-4 for 8 days. To obtain mature MoDC, TNF-alpha was added during the final three culture days. T cell proliferation and T cell cytokine secretion in mixed lymphocyte reactions (MLR) unveiled a strong reduction of allostimulatory capacity of mature but also of immature MoDC from MDS patients. Immature MoDC from MDS patients exhibited an almost normal immunophenotype, but secreted substantially less IL-12 and more IL-10 in response to LPS/IFN-gamma than normal controls. Terminal addition of TNF-alpha to GM-CSF/IL-4 treated monocytes failed to extinguish cytokine production by MDS MoDC and failed to induce the expected membrane upregulation of costimulatory and other ligands as in normal controls. While our data provide further support for previous studies that have indicated an impaired differentiation of immature towards mature MoDC, they also clearly demonstrate a qualitatively and quantitatively altered cytokine secretion at the level of immature MoDC, which may in part explain the reduced allostimulatory capacity of these cells. These alterations may contribute to immune modulation of the clinical phenotype of marrow failure in MDS, and may have to be considered when designing DC-based immunotherapeutic strategies for MDS.

Immune mechanisms have been shown to contribute to the process of myelodysplastic syndromes (MDS)-related bone marrow (BM) failure. The aim of this study was to evaluate the possible contribution of activated monocytes through CD40-CD40L(CD154) interactions with activated T helper cells. We demonstrated in 77 predominantly lower risk MDS patients that the CD40 receptor was expressed significantly higher on monocytes and that CD40L was expressed significantly higher on T helper cells in peripheral blood (PB) and BM. Increased levels of CD40 and CD40L were detected in the same patients. In addition, stimulation of the CD40 receptor on purified PB monocytes led to a significantly higher tumor necrosis factor alpha production in patients. Co-culture of BM mononuclear cells of 21 patients in the presence of a blocking CD40 monoclonal antibody (ch5D12) led to a significant increase in the number of colony-forming units. A correlation was seen between increased CD40 expression on monocytes with patients' age below 60 years and with the cytogenetic abnormality trisomy 8. These results demonstrate that CD40 expression on monocytes may identify a subgroup of MDS patients in whom immune-mediated hematopoietic failure is part of the disease process. As such, the CD40-CD40L-based activation of monocytes might be a target to counteract MDS-related BM failure. ispartof: Leukemia vol:21 issue:12 pages:2411-2419 ispartof: location:England status: published

In addition to stimulating erythropoiesis, erythropoietin (EPO) has several extra-haematopoietic functions including neuro- and cardioprotection. The mechanistic pathways by which EPO provides this tissue protective response remain to be fully elucidated. However, it is hypothesised that they involve an EPO receptor distinct from that activated in erythropoiesis. In vitro and in vivo studies have shown that EPO has the ability to cross the blood–brain barrier and provide neuroprotection by limiting damage to the central nervous system following injury. In vivo, the administration of recombinant EPO reduced brain injury associated with stroke, blunt trauma, cytotoxicity and experimental autoimmune encephalomyelitis, and prevented ischaemic injury to the spinal cord. Initial results from a preliminary clinical study in humans experiencing a stroke are promising. This study demonstrated that EPO treatment within 8 h of an ischaemic stroke was associated with a better clinical outcome at 1 month and r...

Purpose Epoetin therapy is associated with a slight increase in thromboembolic event (TEE) incidence, although causality is uncertain. This metaanalysis compared TEE incidence in patients with cancer-related anemia treated with epoetin beta versus a control group (placebo or standard treatment) and investigated the impact of hemoglobin (Hb) parameters on thromboembolic risk. Patients and Methods Patients from 9 randomized trials were pooled (epoetin beta group, n = 800; control group, n = 613). Adverse event reports were reviewed for all TEEs recorded during treatment and 28 days thereafter. Thromboembolic event incidence was compared between 2 groups, and standard statistical analyses were conducted to investigate the potential of Hb parameters to modulate thromboembolic risk. Results For epoetin beta, 5.9% of patients (n = 47) experienced ≥ 1 TEE versus 4.2% of controls (n = 26; not significant). Thromboembolic-related mortality rates were 1% in both groups. Thromboembolic event rates in patients stratified by tumor type were consistent with the overall population. For epoetin beta, greater baseline-adjusted Hb area under the concentration-time curve and greater Hb increases during the first 4 weeks of treatment significantly correlated with reduced risk of TEEs. Conversely, treatment in those with higher baseline Hb levels was associated with increased TEE risk. Conclusion When administered in accordance with European Organization for Research and Treatment of Cancer guidelines, epoetin beta did not appear to be associated with increased thromboembolic risk. Although risk of TEEs might be marginally increased in patients with cancer treated with epoetin beta, there is no increased risk of thromboembolic mortality.

Recent registry studies have established umbilical cord blood (UCB) transplantation as a safe and feasible alternative to bone marrow transplantation in adults when no sibling donor is available. There is, however, no gold standard to guide optimal treatment choices. We review here factors leading to the choice of the 'best available donor' and 'best available unit' in the case of UCB. For instance, it is clear that higher cell dose may partially overcome the negative impact of certain histocompatibility leukocyte antigen (HLA) disparities in UCB transplantation, leading us to choose the more closely HLA-matched unit with a cell dose >2.5 x 10(7)/kg. New approaches in adult UCB transplantation are systematically covered, with a quantitative appreciation of the evidence available to date. Reduced intensity conditioning, for example, broadens the range of potential recipients by reducing transplant-related mortality, but suffers from unproven risks and benefits long term. Potential advantages of multiple units over single unit transplants are discussed, with a particular emphasis on confounding factors that impact interpretation. The limited clinical results of ex vivo UCB expansion, the possible benefits of co-infusion of haploidentical cells and controversial issues (e.g. killer immunoglobulin-like receptor matching and alternative graft sources) are also addressed with a debate on the future of UCB transplantation. ispartof: Bone Marrow Transplantation vol:38 issue:2 pages:83-93 ispartof: location:England status: published

Summary Background The benefit of reperfusion therapies for ST-elevation acute myocardial infarction (STEMI) is limited by post-infarction left-ventricular (LV) dysfunction. Our aim was to investigate the effect of autologous bone marrow-derived stem cell (BMSC) transfer in the infarct-related artery on LV function and structure. Methods We did a randomised, double-blind, placebo-controlled study in 67 patients from whom we harvested bone marrow 1 day after successful percutaneous coronary intervention for STEMI. We assigned patients optimum medical treatment and infusion of placebo (n=34) or BMSC (n=33). Our primary endpoint was the increase in LV ejection fraction and our secondary endpoints were change in infarct size and regional LV function at 4 months' follow-up, all assessed by MRI. We assessed changes in myocardial perfusion and oxidative metabolism with serial 1-[ 11 C]acetate PET. Analyses were per protocol. This study is registered with clinicaltrials.gov, number NCT00264316. Findings Mean global LV ejection fraction 4 days after percutaneous coronary intervention was 46·9% (SD 8·2) in controls and 48·5% (7·2) in BMSC patients, and increased after 4 months to 49·1% (10·7) and 51·8% (8·8; OR for treatment effect 1·036, 95% CI 0·961–1·118, p=0·36). Compared with placebo infusion, BMSC transfer was associated with a significant reduction in myocardial infarct size (BMSC treatment effect 28%, p=0·036) and a better recovery of regional systolic function. Myocardial perfusion and metabolism increased similarly in both groups. We noted no complications associated with BMSC transfer and all but one patient in the BMSC group completed the 4 months' follow-up. Interpretation Intracoronary transfer of autologous bone marrow cells within 24 h of optimum reperfusion therapy does not augment recovery of global LV function after myocardial infarction, but could favourably affect infarct remodelling.

Mantle-cell lymphoma (MCL) is characterized by poor prognosis with a median survival of only 3 to 4 years. To improve clinical outcome, the European MCL Network initiated a randomized trial comparing consolidation with myeloablative radiochemotherapy followed by autologous stem cell transplantation (ASCT) to alpha-interferon maintenance (IFN alpha) in first remission. Patients 65 years of age or younger with advanced-stage MCL were assigned to ASCT or IFN alpha after achievement of complete or partial remission by a cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)-like induction therapy. According to the International Prognostic Index (IPI), 43% of patients had a low-risk, 41% a low-intermediate, 11% a high-intermediate, and 6% a high-risk profile. Sixty-two of 122 patients proceeded to ASCT and 60 received IFN alpha. Patients in the ASCT arm experienced a significantly longer progression-free survival (PFS) with a median of 39 months compared with 17 months for patients in the IFNa arm (P =.0108). The 3-year overall survival (OS) was 83% after ASCT versus 77% in the IFN group (P =.18). Early consolidation by myeloablative radiochemotherapy followed by ASCT is feasible and results in a significant prolongation of PFS in advanced-stage MCL. Longer follow-up is needed to determine the effect on OS. (c) 2005 by The American Society of Hematology.

Two siblings from a consanguineous family presented with a poikiloderma of limbs and face, plantar keratoderma, and toenail pachyonychia. Neutropenia and neutrophil dysfunction with impairment of the respiratory burst and bacterial killing resulted in frequent respiratory tract infections. A bronchocentric granulomatous pneumonia was a fatal complication. The clinical presentation is consistent with Clericuzio type poikiloderma with neutropenia. Literature review identified several additional probable patients. Genetic linkage analysis excluded the locus of the RECQL4 gene, mutations in which have been described in some patients with the Rothmund-Thomson poikiloderma syndrome. This report confirms the clinical and genetic identity of the Clericuzio type of poikiloderma with neutropenia syndrome.

Complete remission (CR) in patients with acute myeloid leukaemia (AML) is the primary endpoint for the evaluation of induction treatment and treatment strategies. However, the choice and application of the criteria for a haematological CR can often become a subject of debate because of regeneration more than 5% blasts may be present at the time of response evaluation; platelet and neutrophil recovery may be incomplete and marrow cellularity can vary. This study examined the individual parameters for CR in 1250 adult patients with de novo AML treated according to three successive study protocols. Patients with < or =5% blasts showed the best overall survival (OS) and the lowest relapse risk (RR). This was independent of blast cells present in the peripheral blood or bone marrow (BM) cellularity. In the same patient group, the presence of extramedullary leukaemia, incomplete platelet (

Summary The recent advent of an improved commercial serum enzyme-linked immunosorbent assay (ELISA) for the detection of circulating galactomannan (GM), a major constituent of Aspergillus cell walls, has contributed to the diagnosis of invasive aspergillosis (IA) in many haematology and transplant centres. However, the optimal threshold for positivity remains a matter of debate. We prospectively evaluated the impact of lowering the cut-off in 124 neutropenic episodes with a high pretest probability for IA. Two new cut-off points, lower than previously accepted, are proposed: (a) a ‘static’ cut-off at 0·8 and (b) a ‘dynamic’ cut-off at 0·5. A single assay with an optical density (OD) index ≥0·8 warrants the initiation of anti-Aspergillus therapy. A further lowering of the ‘static’ threshold seems not clinically feasible given the drop in positive predictive value (PPV). However, the demonstration of at least two sequential sera with an OD ≥0·5 (‘dynamic’ threshold) increased the specificity and the PPV to 98·6% and the efficiency to 98%. Applying both cut-offs to a subgroup of 21 ‘possible’ fungal infections further identified and upgraded six cases of IA. However, the clinical benefit of lower cut-offs (particularly for earlier diagnosis) depends upon the kinetics of antigenaemia and the intensity of serum sampling.

Detection of the FIP1L1-PDGFRA fusion gene or the corresponding cryptic 4q12 deletion supports the diagnosis of chronic eosinophilic leukemia (CEL) in patients with chronic hypereosinophilia. We retrospectively characterized 17 patients fulfilling WHO criteria for idiopathic hypereosinophilic syndrome (IHES) or CEL, using nested RT-PCR and interphase fluorescence in situ hybridization (FISH). Eight had FIP1L1-PDGFRA (+) CEL, three had FIP1L1-PDGFRA (-) CEL and six had IHES. FIP1L1-PDGFRA (+) CEL responded poorly to steroids, hydroxyurea or interferon-alpha, and had a high probability of eosinophilic endomyocarditis (n = 4) and disease-related death (n = 4). In FIP1L1-PDGFRA (+) CEL, palpable splenomegaly was present in 5/8 cases, serum vitamin B-12 was always markedly increased, and marrow biopsies revealed a distinctively myeloproliferative aspect. Imatinib induced rapid complete hematological responses in 4/4 treated FIP1L1-PDGFRA (+) cases, including one female, and complete molecular remission in 2/3 evaluable cases. In the female patient, 1 log reduction of FIP1L1-PDGFRA copy number was reached as by real-time quantitative PCR (RQ-PCR). Thus, correlating IHES/CEL genotype with phenotype, FIP1L1-PDGFRA (+) CEL emerges as a homogeneous clinicobiological entity, where imatinib can induce molecular remission. While RT-PCR and interphase FISH are equally valid diagnostic tools, the role of marrow biopsy in diagnosis and of RQ-PCR in disease and therapy monitoring needs further evaluation.

Intravenous fludarabine is a well-established therapy for the first-line treatment of chronic lymphocytic leukemia and the standard of care for second-line treatment. More recently, an oral formulation of fludarabine has been developed, with equivalent efficacy and tolerability to the intravenous formulation, but with improved convenience of administration and potentially greater cost effectiveness. In previously treated patients receiving oral fludarabine monotherapy, overall response rates of 46-51% were achieved, depending on the response criteria used. Oral fludarabine is also an effective first-line treatment, both as monotherapy (overall response 72-80%) and in combination with cyclophosphamide (overall response 80%). Infusion-related adverse effects are eliminated with oral administration. Importantly, WHO performance status is maintained or improved in more than 50% of patients. As oral fludarabine can be taken at home, administration costs are greatly reduced due to fewer physician and nursing interventions and less time spent in hospital. Oral fludarabine was approved first in the UK as second-line therapy for chronic lymphocytic leukemia and, based on its ease of administration and potentially greater cost effectiveness, is recommended in preference to the intravenous formulation by the UK National Institute for Clinical Excellence. The oral formulation is also now available in the majority of European countries. Therefore, with equivalent efficacy and tolerability to the intravenous preparation, oral fludarabine gives the hematologist an important new option in the management of chronic lymphocytic leukemia.

Gemtuzumab ozogamicin (Mylotarg) induces remission in approximately 30% of relapsed AML patients. We previously demonstrated that gemtuzumab infusion results in near-complete CD33 saturation in peripheral blood, and that saturating gemtuzumab levels result in continuous binding and internalization of gemtuzumab due to renewed CD33 expression. We now demonstrate that a high CD33-antigen load in peripheral blood is an independent adverse prognostic factor, likely due to peripheral consumption of gemtuzumab. Indeed, CD33 saturation in bone marrow is significantly reduced (40-90% saturation) as compared with CD33 saturation in corresponding peripheral blood samples (>90%). In vitro, such reduced CD33 saturation levels were strongly related with reduced cell kill. Apparently, high CD33-antigen loads in blood consume gemtuzumab and thereby limit its penetration into bone marrow. Consequently, CD33 saturation in bone marrow is reduced, which hampers efficient cell kill. Therefore, gemtuzumab should be administered at higher or repeated doses, or, preferably, after reduction of the leukemic cell burden by classical chemotherapy. ispartof: Leukemia vol:18 issue:5 pages:983-988 ispartof: location:England status: published

We assessed the activity and safety of liposomal nystatin, a broad-spectrum antifungal agent, for invasive aspergillosis in patients refractory to or intolerant of amphotericin B. Thirty-three patients were enrolled, received at least one dose of the study drug, and were evaluable for safety. Twenty-six patients had confirmed probable or definite aspergillosis and were fully eligible. Most patients had a hematological malignancy (53.8%) or hematopoietic stem cell transplantation (23.0%), were neutropenic (61.5%), and were refractory to previous amphotericin B (92.3%). The median duration of previous amphotericin B treatment was 16.5 days (range, 5 to 64 days). Aspergillosis was definite in 3 cases and probable in 23 cases. Liposomal nystatin was initiated at a dose of 4 mg/kg of body weight/day. Twenty-five patients were evaluable for response: a complete response was achieved for one patient, and a partial response was achieved for six. Thus, the overall response rate is 7 of 25 (28%; 95% confidence interval, 12 to 49%). Seventeen (68.0%) of the 25 evaluable patients died during therapy or within 1 month after the end of therapy. The primary cause of death was invasive aspergillosis for nine patients and underlying malignancy for eight patients. The most frequent side effects included chills, shivering, and fever, leading to discontinuation of therapy for two patients. Grade 1 decline in renal function was seen for 10 (30.3%) patients, and hypokalemia was seen for 13 (39.4%). We conclude that liposomal nystatin can be effective for salvage therapy of invasive aspergillosis. Infusion-related adverse events have been observed frequently.

Peripheral blood progenitor cells (PBPC) have been established as an alternative source of hematopoietic stem cells for allogeneic transplantation, but an increased incidence of both acute and chronic graft-vs-host disease (GVHD) has become apparent. We performed a prospective randomized trial comparing bone marrow transplantation (BMT) vs PBPC transplantation (PBPCT) using CD34(+) selection for T-cell depletion (TCD) in both study arms.Between January 1996 and October 2000, 120 patients with a diagnosis of acute leukemia, myelodysplasia, multiple myeloma, or lymphoma were randomized to receive either filgrastim-mobilized PBPC or BM from HLA-identical sibling donors after standard high-dose chemoradiotherapy. Patient characteristics did not differ between study arms.Recipients of PBPC received more CD3(+) T cells (median: 3.0 vs 2.0 x 10(5)/kg, p0.0001) and more CD34(+) cells (median: 3.6 vs 0.9 x 10(6)/kg, p0.0001). Neutrophil and platelet recoveries occurred significantly faster after PBPCT. The cumulative incidence of acute GVHD grades II-IV was 37% after BMT vs 52% after PBPCT and was most significantly (p=0.007) affected by the number of CD3(+) T cells in the graft. Acute GVHD appeared strongly associated with increased treatment-related mortality (TRM) in a time-dependent analysis. Higher numbers of CD34(+) cells were associated with less TRM. With a median follow-up of 37 months (range: 12-75), overall survival at 4 years from transplantation was 60% after BMT and 34% for recipients of PBPCT (p=0.04), which difference was largely due to increased GVHD and TRM in PBPC recipients receiving T-cell dosages greater than 2 x 10(5)/kg.Outcome following T cell-depleted PBPCT critically depends on the number of CD3(+) T cells, whereby high T-cell numbers may blunt a favorable effect of higher CD34(+) cell numbers.

Amifostine is a phosphorylated aminothiol that has besides anti-oxidative and cytoprotective properties, also survival- and growth-promoting effects on hematopoietic progenitor cells. Clinical studies have demonstrated that infusions with amifostine are able to increase erythro-, myelo-, and thrombopoiesis in some patients with myelodysplastic syndromes (MDS). Since clonal and non-clonal progenitors can coexist in early phase MDS, we have studied if amifostine exerts a selective growth-promoting effect on clonal or non-clonal cells. For this purpose, purified CD34(+) marrow progenitors from nine female MDS patients were grown in short- and long-term cultures. Clonality was studied on individual colonies using polymorphisms in the human androgen receptor assay (HUMARA) locus. Three patients had growth of residual non-clonal progenitors at baseline. Continuous exposure to 100nM amifostine exerted a growth-promoting effect on progenitors in 50% of the patients. HUMARA patterns of individual colony-forming unit granulocyte macrophage (CFU-GM; 5/9) and 5 week long-term culture-initiating cells (LTC-IC; 2/9) were compared without and with amifostine exposure. We did not observe preferential stimulation of clonal or non-clonal progenitors. Based on these results, the stimulation of committed and immature progenitor growth in MDS by amifostine, is non-selective and does not favor nor suppress the growth of residual non-clonal cells.

This open-label, prospective study was conducted to compare the impact of epoetin beta vs standard care on quality of life (QoL) in anaemic patients with lymphoid or solid tumour malignancies. A total of 262 anaemic patients (haemoglobin [Hb]or=11 g dl(-1)) were randomised to a 12-week treatment with s.c. epoetin beta (initial dose 150 IU kg(-1) three times weekly) or standard care. Transfusions were recommended for both groups at an Hb threshold of 8.5 g dl(-1). The primary efficacy variables were improvement in QoL as measured using the Short-Form-36 physical component summary (SF-36 PCS) score and the Functional Assessment of Cancer Therapy fatigue and anaemia subscales (FACT-F and FACT-An). A visual analogue scale (VAS) was also used as a global QoL measure. Clinical response was defined as aor=2 g dl(-1) increase in Hb level without need of transfusion after the initial 4 weeks of treatment. Baseline to final visit changes in SF-36 PCS, FACT-F and VAS scores were significantly greater with epoetin beta than with standard care (P0.05); changes in FACT-An subscale score tended to be greater with epoetin beta (P=0.076). Epoetin beta significantly increased Hb concentrations relative to standard care (responders: 47% vs 13%; P0.001). Levels of endogenous erythropoietin50 mIU ml(-1) were significantly predictive of response (OR 2.496, 95% CI: 1.21-5.13). Epoetin beta therapy significantly improves QoL compared with standard care in anaemic patients with solid tumours and lymphoid malignancies.

Idiopathic hypereosinophilic syndrome involves a prolonged state of eosinophilia associated with organ dysfunction. It is of unknown cause. Recent reports of responses to imatinib in patients with the syndrome suggested that an activated kinase such as ABL, platelet-derived growth factor receptor (PDGFR), or KIT, all of which are inhibited by imatinib, might be the cause.We treated 11 patients with the hypereosinophilic syndrome with imatinib and identified the molecular basis for the response.Nine of the 11 patients treated with imatinib had responses lasting more than three months in which the eosinophil count returned to normal. One such patient had a complex chromosomal abnormality, leading to the identification of a fusion of the Fip1-like 1 (FIP1L1) gene to the PDGFRalpha (PDGFRA) gene generated by an interstitial deletion on chromosome 4q12. FIP1L1-PDGFRalpha is a constitutively activated tyrosine kinase that transforms hematopoietic cells and is inhibited by imatinib (50 percent inhibitory concentration, 3.2 nM). The FIP1L1-PDGFRA fusion gene was subsequently detected in 9 of 16 patients with the syndrome and in 5 of the 9 patients with responses to imatinib that lasted more than three months. Relapse in one patient correlated with the appearance of a T674I mutation in PDGFRA that confers resistance to imatinib.The hypereosinophilic syndrome may result from a novel fusion tyrosine kinase - FIP1L1-PDGFRalpha - that is a consequence of an interstitial chromosomal deletion. The acquisition of a T674I resistance mutation at the time of relapse demonstrates that FIP1L1-PDGFRalpha is the target of imatinib. Our data indicate that the deletion of genetic material may result in gain-of-function fusion proteins.

Screening for galactomannan (GM) has been adopted by many European centers as part of the management plan for allogeneic stem cell transplant recipients. However, the temporal onset of GM antigenemia remains unknown. A series of allogeneic stem cell transplant recipients were monitored prospectively, and the relationship between antigenemia and other diagnostic triggers for initiation of antifungal therapy was analyzed. GM detection had a sensitivity of 94.4% and a specificity of 98.8%. Positive and negative predictive values were 94.4% and 98.8%, respectively. This statistical profile was better than that of other triggers, including unexplained fever, new pulmonary infiltrates, isolation of Aspergillus species, and abnormalities seen on computed tomography. Antigenemia preceded diagnosis on the basis of radiologic examination or Aspergillus isolation by 8 and 9 days in 80% and 88.8% of patients, respectively. Antigenemia preceded therapy in 83.3% of patients. Detection of GM was especially useful when patients were receiving steroid treatment or when coexisting conditions masked the diagnosis of invasive aspergillosis. Prospective screening for GM allows earlier diagnosis of aspergillosis than do conventional diagnostic criteria.

We analyzed the safety and efficacy of Mylotarg (gemtuzumab ozogamicin, an antibody-targeted chemotherapy consisting of a humanized anti-CD33 antibody linked to calicheamicin, a potent antitumor antibiotic) in the treatment of 101 patients > or =60 years of age with acute myeloid leukemia (AML) in untreated first relapse in three open-label trials. Mylotarg is administered as a 2-h intravenous infusion at 9 mg/m(2) for two doses with 14 days between doses. The overall remission rate was 28%, with complete remission (CR) in 13% of patients and complete remission with incomplete platelet recovery (CRp) in 15%. Median survival was 5.4 months for all patients and 14.5 months and 11.8 months for patients achieving CR and CRp, respectively. CD33 antigen is present on normal hematopoietic progenitor cells; thus, an expected high incidence of grade 3 or 4 neutropenia (99%) and thrombocytopenia (99%) was observed. The incidences of grade 3 or 4 elevations of bilirubin and hepatic transaminases were 24% and 15%, respectively. There was a low incidence of grade 3 or 4 mucositis (4%) and infections (27%) and no treatment-related cardiotoxicity, cerebellar toxicity, or alopecia. Mylotarg is an effective treatment for older patients with CD33-positive AML in first relapse and has acceptable toxicity.

Infections caused by Aspergillus species are an emerging cause of morbidity and mortality in a variety of immunocompromised patients, despite profound environmental protection and the widespread prophylactic use of agents with anti-Aspergillus activity. At the present time, no firm conclusions can be drawn on the use of chemoprophyla xis, mainly due to the lack of reliable, randomized trials. Therefore, universal prophylaxis should be discouraged and prevention should be targeted towards well-defined high-risk patients, although only as part of a properly designed clinical trial. The crude mortality rate of invasive aspergillosis remains unacceptably high and results at least partly from difficulties in obtaining a reliable diagnosis at an early stage of the disease. The concept of empirical antifungal therapy has been introduced in an effort to overcome these diagnostic obstacles, especially since the early implementation of antifungal therapy appears to be the crucial prerequisite to improve the detrimental outcome of established disease. However, the concept has not been sufficiently validated and is not devoid of significant risks and disadvantages. The implementation of sensitive and predictive new diagnostic tools, such as galactomannan detection, high-resolution pulmonary CT-scanning and detection of aspergillar DNA, may allow a more targeted pre-emptive approach, directed towards the high-risk patients and based upon a battery of clinical, radiological and microbiological clues, though without histopathological proof. The high mortality rate results also from shortcomings of the currently available therapeutic arsenal. Amphotericin B, flucytosine and itraconazole are associated with low success rates and are hampered by serious infusion- or drug-related toxicity, by hazardous drug-drug interactions, by pharmacokinet ic problems and by the development of resistance. In recent years, several companies have launched new compounds into preclinical and clinical trials. Some of these agents target the fungal cell wall in stead of the cell membrane. They exert their action through inhibition of the synthesis of critical compounds of that fungal cell wall, not present in mammalian cells (e.g. inhibitors of β-(1,3)-D-glucan synthesis). This article will focus on new therapeutic approaches (risk-adapted or targeted strategy) and upcoming antifungal agents with anti-Aspergillus activity, in particular voriconazole and caspofungin acetate.

PURPOSE: A prospective, multicenter, open-label phase II clinical trial was conducted to assess the efficacy and safety of oral fludarabine phosphate. Reference to an historical group of patients treated with the intravenous (IV) formulation allowed the investigators to compare the two formulations. PATIENTS AND METHODS: Efficacy was assessed using the International Workshop on Chronic Lymphocytic Leukemia (IWCLL) and National Cancer Institute (NCI) criteria for complete remission (CR), partial remission (PR), stable disease, or disease progression. Safety monitoring included World Health Organization (WHO) toxicity grading for all adverse events. RESULTS: Seventy-eight (96.3%) of 81 recruited patients with previously treated B-cell chronic lymphocytic leukemia (CLL) received 10-mg tablets of fludarabine phosphate to a dose of 40 mg/m2/d for 5 days, repeated every 4 weeks, for a total of six to eight cycles. According to IWCLL criteria, the overall remission rate was 46.2% (CR, 20.5%; PR, 25.6%). The comparative figures using NCI criteria were 51.3% (CR, 17.9%; PR, 33.3%). Overall, 30 incidents of severe adverse events were reported for 22 patients. WHO grade 3 or grade 4 hematologic toxicities included granulocytopenia (53.8%), leukocytopenia (28.2%), thrombocytopenia (25.6%), and anemia (24.4%). Gastrointestinal adverse events were more common with the oral formulation than previously reported with IV fludarabine phosphate. However, these events were generally mild to moderate. CONCLUSION: This study demonstrates that oral fludarabine phosphate has similar clinical efficacy to the IV formulation and a safety profile that is both predictable and essentially similar to that of the IV formulation.

SummaryCognate interactions between CD154 (CD40 ligand, CD40L) on activated T cells and its receptor CD40 on various antigen-presenting cells are involved in thymus-dependent humoral immune responses and multiple other cell-mediated immune responses. We have studied the regulation of CD154 expression in human T cells after activation with anti-CD3 and anti-CD28 antibodies or after pharmacological activation of protein kinase C with phorbol 12-myristate 13-acetate, and the calcium ionophore ionomycin. Under these conditions, transcription of the CD154 gene was rapidly induced without requiring de novo protein synthesis. Pharmacological inhibitors of NF-κB activation down-regulated CD154 mRNA and protein levels. Cyclosporin A, an inhibitor of NF-AT activation, acted similarly, and the effects of both inhibitors were additive. A potential NF-κB binding site is present within the CD154 promoter at positions −1190 to − 1181. In electrophoretic mobility shift assays, this sequence was specifically bound by NF-κB present in nuclear extracts from activated T cells. Furthermore, in transient co-transfection of Jurkat T cells, p65 activated the transcription of a reporter construct containing a multimer of this NF-κB binding site. These observations demonstrate a role of NF-κB transcription factors in the regulation of CD40L expression in activated primary human T cells.

The incidence of invasive fungal infection has increased in recent years. Most infections are caused by Candida albicans and Aspergillus spp. but the emergence of other fungal infections is changing the spectrum of disease. Immunosuppression and breakdown of anatomical barriers such as the skin are the major risk factors for fungal infections. Health care workers encounter at-risk patients in various settings, including AIDS clinics and intensive care, transplantation and oncology units. Patients with prolonged and deep neutropenia (haematological malignancy patients) are most at risk and are therefore most likely to receive prophylactic therapy. Practical measures can be taken to avoid exposing the patient to fungi (air filtration, regular hand washing, avoiding plants and flowers) and antifungal agents can be administered to prevent systemic fungal infection. Most fungal infections have non-specific symptoms; this makes recognition of the signs and symptoms of the disease important but also makes diagnosis difficult and empirical treatment necessary. Some antifungal agents have limitations but new formulations will improve therapy and play a key role in future antifungal strategies.

Item does not contain fulltext The purpose of this study was to evaluate the effect of alpha-IFN maintenance treatment after autologous stem cell transplantation (ASCT) for multiple myeloma in a retrospective registry analysis. 473 patients with multiple myeloma who received IFN maintenance treatment ASCT were compared with 419 patients who did not receive IFN-treatment. Patients who were evaluable for response and in complete or partial remission at 6 months after ASCT were eligible, after excluding patients with graft failure. Cox proportional hazards assumptions were checked and handled by stratification. The prognostic variables unevenly distributed between the two groups were statistically corrected for in the Cox analysis. 391 patients reached complete remission (CR) after ASCT (203 in the IFN group and 188 in the no-IFN group) and 501 were in partial remission (PR, IFN 270, no-IFN 231). Overall survival (OS) and progression-free survival (PFS) were significantly better in the IFN-group (OS, 78 vs 47 months, P = 0.007, and PFS, 29 vs 20 months, P = 0.006, respectively). The difference in OS and PFS was most strongly pronounced in the PR patients. 209 patients have died (IFN, 84; no-IFN, 125). Progressive myeloma was the cause of death in 94% of the IFN-treated patients and in 83% of the no-IFN group (P = NS). Thus, IFN maintenance treatment after ASCT was associated with better OS and PFS. Treatment seemed to be most beneficial in patients who did not achieve CR. The difference in median survival was as long as 2.5 years, and although part of this difference is attributable to differences in other prognostic factors, it might justify possible differences in quality-of-life due to adverse effects of interferon treatment.

The Wiskott-Aldrich syndrome protein (WASP; encoded by the gene WAS) and its homologs are important regulators of the actin cytoskeleton, mediating communication between Rho-family GTPases and the actin nucleation/crosslinking factor, the Arp2/3 complex. Many WAS mutations impair cytoskeletal control in hematopoietic tissues, resulting in functional and developmental defects that define the X-linked Wiskott-Aldrich syndrome (WAS) and the related X-linked thrombocytopenia (XLT). These diseases seem to result from reduced WASP signaling, often through decreased transcription or translation of the gene. Here we describe a new disease, X-linked severe congenital neutropenia (XLN), caused by a novel L270P mutation in the region of WAS encoding the conserved GTPase binding domain (GBD). In vitro, the mutant protein is constitutively activated through disruption of an autoinhibitory domain in the wild-type protein, indicating that loss of WASP autoinhibition is a key event in XLN. Our findings highlight the importance of precise regulation of WASP in hematopoietic development and function, as impairment versus enhancement of its activity give rise to distinct spectra of cellular defects and clinical phenotypes.

Item does not contain fulltext This study investigated the feasibility of allogeneic (alloSCT) and autologous stem cell transplantation (ASCT) as postconsolidation therapy for patients with myelodysplastic syndromes (MDSs) or acute myeloid leukemia after MDS. Patients with a histocompatible sibling were candidates for alloSCT and the remaining patients for ASCT. Remission-induction therapy consisted of 1 or 2 courses with idarubicin, cytarabine, and etoposide, followed by one intensive consolidation course with cytarabine and mitoxantrone. Initially, bone marrow cells were used for ASCT. Subsequently, mobilized blood stem cells were used in an attempt to shorten posttransplantation hypoplasia. With a median follow-up of 3.6 years the 184 evaluable patients showed a 4-year survival rate of 26% and a median survival of 13 months. The remission-induction chemotherapy induced complete remission (CR) in 100 patients (54%). The 4-year disease-free survival (DFS) rate was 29% and the median DFS was 12 months. Twenty-eight of 39 patients (72%) with a donor were allografted in CR-1, including 2 patients who underwent transplantation in CR-1 without a consolidation course. Thirty-six of 59 patients (61%) without a donor received ASCT in CR-1. The 4-year DFS rates in the group of patients with or without a donor were 31% and 27%, respectively. The 4-year survival rates from CR were 36% and 33%, respectively. This large prospective study shows the feasibility of both alloSCT and ASCT. This treatment approach leads to a relatively high remission rate, and the majority of patients in remission received the SCT in CR-1. The ongoing study investigates whether this approach is better than treatment with chemotherapy only.

The broad spectrum antifungal itraconazole is an effective and well tolerated agent for the prophylaxis and treatment of systemic fungal infections. The recent development of an itraconazole oral solution and an intravenous itraconazole solution has increased the options for the use of this drug and increased the oral bioavailability in a variety of at-risk patients. Reliable absorption of the itraconazole oral solution has been demonstrated in patients with HIV infection, neutropenic patients with haematological malignancy, bone marrow transplant recipients and neutropenic children. In clinical trials, itraconazole oral solution (5 mg/kg/day) was more effective at preventing systemic fungal infection in patients with haematological malignancy than placebo, fluconazole suspension (100 mg/day) or oral amphotericin-B (2 g/kg/day) and was highly effective at preventing fungal infections in liver transplant recipients. There were no unexpected adverse events with the itraconazole oral solution in any of these trials. In addition, intravenous itraconazole solution is at least as effective as intravenous amphotericin-B in the empirical treatment of neutropenic patients with systemic fungal infections, and drug-related adverse events are more frequent in patients treated with amphotericin-B. A large proportion of patients with confirmed aspergillosis also respond to treatment with intravenous itraconazole followed by oral itraconazole. The new formulations of itraconazole are therefore effective agents for prophylaxis and treatment of most systemic fungal infections in patients with haematological malignancy.

Summary: Central nervous system infection due to Torulopsis glabrata is very rare. The paper describes the case of a 22-year-old patient who died from multiple brain abscesses due to Torulopsis glabrata 3 months after a bone marrow transplantation, in spite of prophylaxis with ketoconazole and treatment with itraconazole and amphotericin B. Zusammenfassung: Eine Infektion des Zentralnervensystems mit Torulopsis glabrata ist nur auserst selten zu beobachten. Es wird berichtet Uber einen 22jahrigen Patienten, der drei Monate nach einer Knochenmarktransplantation, trotz prophylaktischer Behandlung mit Ketoconazol und Gabe von Itraconazol und Amphoterizin B, an multiplen Hirnabszessen infolge Torulopsis glabrata-Infektion starb.

Occupancy of CTLA-4 (cytotoxic T-lymphocyte antigen-4 or CD152) negatively regulates the activation of mouse T lymphocytes, as indicated by the fate of CTLA-4-deficient mice, by the impact of anti-CTLA-4 monoclonal antibodies (mAbs) on mouse T-cell activation in vitro and by the impact of CTLA-4 blockade on the course of experimental tumoral, autoimmune, alloimmune or infectious disease in this animal. The function of human CTLA-4, however, remains less clear. The expression and function of human CTLA-4 were further explored. CTLA-4 was expressed under mitogenic conditions only, its expression being, at least partially, dependent on the secretion of interleukin-2. Memory T cells expressed CTLA-4 with faster kinetics than naive T cells. The functional role of human CTLA-4 was assessed utilizing a panel of four anti-CTLA-4 mAbs that blocked the interaction between CTLA-4 and its ligands. These mAbs, in immobilized form, profoundly inhibited the activation of T cells by immobilized anti-CD3 mAb in the absence of anti-CD28 mAb, but co-stimulated T-cell activation in the presence of anti-CD28 mAb. Finally, and importantly, blockade of the interaction of CTLA-4 with its ligands using soluble anti-CTLA-4 mAbs, in intact form or as Fab fragments, enhanced T-cell activation in several polyclonal or alloantigen-specific CD80- or CD80/CD86-dependent assays, as measured by cytokine production, cellular proliferation or cytotoxic responses. It is concluded that interaction of CTLA-4 with its functional ligands, CD80 or CD86, can down-regulate human T-cell responses, probably by intracellular signalling events and independent of CD28 occupancy.

Efforts to improve the diagnosis of invasive aspergillosis (IA) have been directed towards the detection of fungal antigens, including galactomannan (GM). However, previous evaluations of GM detection have been hampered by a lack of proven cases of IA and by a nonserial study design. This prospective study assessed the diagnostic value of serial screening for circulating GM by using a recently developed sandwich enzyme-linked immunosorbent assay (ELISA) for prolonged-neutropenic and/or steroid-treated patients with hematological disorders. Serum GM levels were monitored twice weekly for 186 consecutive patients at increased risk for IA. The patients were stratified according to the likelihood of IA (proven, probable, possible, and no evidence of IA) by using stringent criteria. Proven IA was defined by characteristic histopathological findings together with a positive culture for Aspergillus species. Autopsy and culture from autopsy specimens was used to verify both positive and negative test results. A total of 2,172 serum samples were tested from 243 episodes (mean, 9 samples/episode). Based on the analysis of 71 patients with confirmed disease status (culture and histology), the sensitivity and specificity of serial GM monitoring were 92.6 and 95.4%, respectively. The positive predictive value was almost 93%, the negative predictive value was 95%, and the efficacy was 94%. False-positive reactions occurred at a rate of nearly 8%, although this figure might have been overestimated. Less than 1% of all tested sera were considered inconclusive. In more than half of the cases, antigenemia was detected before clinical suspicion of IA (median, 6 days before). Serial determination of serum GM by the sandwich ELISA technique is a sensitive tool for the diagnosis of IA in hematological patients at risk. This approach may substantially influence clinical management with regard to preemptive and empirical antifungal therapy.

Background: In march 1997 an international workshop introduced a new International Prognostic Scoring System (IPSS) for MDS. The goal of the present study was to apply the IPSS to a large group of MDS patients from one centre and to compare it to the FAB-classification. Patients: One hundred eighty-four MDS patients were included on the basis of similar criteria as used by the workshop but some of them (30) received AM L-type therapy. Results: The IPSS separated our patients into distinctive prognostic subgroups (P = 0.0001). Median survival was respectively 6.5, 2.6, 1.3 and 0.75 years for the low-risk (22% of patients), the intermediate-1-risk (INT-1) (46%), the intermediates-risk (INT-2) (25%) and the high-risk group (7%). The IPSS also discriminated within each of the FAB-catego-ries: RA patients (58 patients) were present in low-risk, INT-1-risk and INT-2-risk subgroups, RARS patients (23) were separated into low-risk and INT-1-risk subgroups. RAEB patients (53) were distributed predominantly between INT-1-risk and INT-2-risk groups, RAEB-t patients (23) between INT-2-risk and high-risk subgroups. CMML patients (27) were present in the low-risk, the INT-1-risk and the INT-2-risk group. Conclusions: Our results confirm the effectiveness of the IPSS in predicting clinical outcome in MDS patients and indicate that it is an improved method compared to the FAB-classification.

Translocation t(11;21)(q24;q11.2) is a rare but recurrent chromosomal abnormality associated with myelodysplastic syndrome (MDS) that until now has not been characterized at the molecular level. We report here results of a molecular cytogenetic analysis of this translocation in a patient with refractory anemia. Using FISH with a panel of 11q and 21q cosmid/YAC probes, we localized the chromosome 11 breakpoint at q23.3 in a region flanked by CP-921G9 and CP-939H3 YACs, distal to the HRX/MLL locus frequently involved in acute leukemias. The chromosome 21 breakpoint was mapped in a 800-kb fragment inserted into the CP-145E3 YAC at 21q11.2, proximal to the AML1 gene. It is noteworthy that in all four cases with a t(11;21) reported until now, a second der(11)t(11;21) and loss of normal chromosome 11 could be observed either at diagnosis or during the course of the disease. Since in our case heteromorphism was detected by FISH on the centromeric region of the two der(11), the second der(11) chromosome could be the result of a mitotic recombination that had occurred on the long arm of chromosome 11, rather than of duplication of the original der(11). Constancy of secondary karyotypic changes resulting in an extra copy of the putative chimeric gene at der(11), loss of 11 qter sequences, and partial trisomy 21 suggest that neoplastic progression of MDS cases with a t(11;21) may be driven by the same mechanism(s).

We describe two cases of acute myeloblastic leukemia, classified as M4 and M5 in the French-American-British nomenclature, with an 11q23 rearrangement at karyotypic analysis. The involvement of the MLL gene with two new partner loci on chromosome 10q22 and 8q24, respectively, was demonstrated by fluorescence in situ hybridization using a YAC clone B22B2L.

Chronic myelogenous leukemia (CML) is characterized by the Philadelphia (Ph) translocation and BCR/ABL gene rearrangement which occur in a pluripotent hematopoietic progenitor cell. Ph-negative (Ph-) hematopoiesis can be restored in vivo after treatment with -interferon or intensive chemotherapy, suggesting that normal stem and progenitor cells coexist with the Ph+ clone. We have previously shown that Ph- progenitors are highly enriched in the CD34(+)HLA-DR- fraction from early chronic phase (ECP) CML patients. Previous studies have suggested that the Ph-translocation represents a secondary clonal hit occurring in an already clonally mutated Ph- progenitor or stem cells, leaving the unanswered question whether Ph- CD34(+)HLA-DR- progenitors are normal. To show the clonal nature of Ph- CD34(+)HLA-DR- CML progenitors, we have compared the expression of BCR/ABL mRNA with X-chromosome inactivation patterns (HUMARA) in mononuclear cells and in CD34(+)HLA-DR+ and CD34(+)HLA-DR- progenitors in marrow and blood obtained from 11 female CML patients (8 in chronic phase and 3 in accelerated phase [AP] disease). Steady-state marrow-derived BCR/ABL mRNA-, CD34(+)HLA-DR- progenitors had polyclonal X-chromosome inactivation patterns in 2 of 2 patients. The same polyclonal pattern was found in the progeny of CD34(+)HLA-DR- derived long-term culture-initiating cells. Mobilization with intensive chemotherapy induced a Ph-, BCR/ABL mRNA- and polyclonal state in the CD34(+)HLA-DR- and CD34(+)HLA-DR+ progenitors from 2 ECP patients. In a third ECP patient, polyclonal CD34(+) cells could only be found in the first peripheral blood collection. In contrast to ECP CML, steady-state marrow progenitors in late chronic phase and AP disease were mostly Ph+, BCR/ABL mRNA+, and clonal. Further, in the majority of these patients, a Ph-, polyclonal state could not be restored despite mobilization with intensive chemotherapy. We conclude from these studies that CD34(+)HLA-DR- cells that are Ph- and BCR/ABL mRNA- are polyclonal and therefore benign. This population is suitable for autografting in CML. ispartof: Blood vol:93 issue:1 pages:284-92 ispartof: location:United States status: published

Substantial progress has been made in the understanding of the pathophysiology of the myelodysplastic syndromes. More refined prognostic classification systems have allowed more individualized treatment programs, leading to improved survival, but not at the expense of the quality of life of the patient. Recent data indicate that some high-risk myelodysplastic syndrome (MDS) patient categories, even some that only achieve partial remissions, may benefit from intensive cytotoxic treatment and may experience long-term survival. Newer chemotherapeutic regimens, eg, containing the mdr less sensitive Idarubicine, the purine analog fludarabine, or such hypomethylating agents as Decitabine, can lead to higher morphologic, cytogenetic, and molecular remission rates, providing a window of opportunity for the assessment of different forms of subsequent stem cell transplantation. Allogeneic stem cell transplantation from sibling donors remains the treatment of choice for younger intermediate and high risk patients with MDS. Much controversy, however, surrounds the applicability of this technique--certainly when using unrelated donors--as first line approach in younger low-risk patients with MDS. This has much to do with the often unacceptably high transplant related mortality rates. Autologous stem cell transplantation may provide a suitable alternative for those patients without a suitable sibling donor or for older patient categories. Peripheral blood progenitor cell collections and transplantations are feasible and carry a low transplant related morbidity and mortality. Prospective randomized studies are underway to assess the true value of intensified chemotherapy with stem cell support in MDS. Childhood MDS is a rare disease, and the data on intensified cytotoxic treatment and transplantation are scarce. However, preliminary data are encouraging.

Three-color flow cytometry immunophenotyping revealed significant increases of CD57+ and CD28- cells among both circulating CD4+ and CD8+ T lymphocytes of untreated hemato-oncological patients (n = 54) as compared to healthy donors (n = 55), with CD57 and CD28 expression on the patients' T cells being largely reciprocal. Marked expansion of CD57+ cells among circulating CD4+ T lymphocytes was frequently detected in patients with chronic leukemia of B cell origin (B-CLL, hairy cell leukemia) but not in patients with chronic myeloid leukemia, suggesting a causal relation with the tumor's major histocompatibility complex class II expression. Using immunomagnetic separation techniques, we further demonstrate that the patients' CD57+/CD28- T cells display a typical Th1-type cytokine secretion profile upon anti-CD3 stimulation, with a markedly higher secretion of the Th1-type cytokines IL-2, IFN-gamma, and TNF-alpha than their CD57-/CD28+ counterparts. Cytotoxic activity of circulating CD8+ T lymphocytes, measured ex vivo in an anti-CD3-redirected assay, was almost exclusively exerted by the CD57+/CD28- subset. Moreover, a marked cytotoxic activity was detected within CD4+CD57+ T cells from some B-CLL patients. Finally, the patients' CD57+/CD28- T cells displayed an increased tendency to apoptosis in culture. Collectively, our results indicate that the expanded CD57+/CD28- T cells in hemato-oncological patients represent differentiated effector cells, similar to their (quantitatively minor) counterpart in healthy donors. The reason for their expansion and their pathophysiologic significance, however, remains unclear.

The clonality of mature peripheral blood-derived myeloid and lymphoid cells and bone marrow haemopoietic progenitors from 18 females with myelodysplasia (MDS) (five refractory anaemia. RA: one RA with ringed sideroblasts. RARS: three chronic myelomonocytic leukaemia, CMML; four RA with excess of blasts. RAEB: five RAEB in transformation. RAEB-t) was studied by X-chromosome inactivation analysis. Using the human androgen-receptor (HUMARA) assay, we analysed the clonal patterns of highly purified immature CD34 + 38 - and committed CD34 + 38 + marrow-derived progenitors. and CD16 + 14 - granulocytes. CD14 + monocytes, CD3 + T and CD19 + B lymphocytes from peripheral blood. In high-risk patients (RAEB. RAEB-t). clonality analysis was performed before and after intensive remission-induction treatment. All patients. except one with RA, had predominance of a single clone in their granulocytes and monocytes. The same clonal pattern was found in CD34 + progenitor cells. In contrast. CD3 + T lymphocytes were polyclonal or oligoclonal in 14/18 patients. X-chromosome inactivation patterns of CD19 + B cells were highly concordant with CD3 + T cells except for two patients (one RA. one CMML) with monoclonal B and polyclonal T lymphocytes, therefore suggesting a clonal mutation in a progenitor common to the myeloid and B-lymphoid lineages or the coexistence of MDS and a B-cell disorder in these particular patients. After high-dose non-myeloablative chemotherapy. polyclonal haemopoiesis was reinstalled in the mature myeloid cells and immature and committed marrow progenitors in three of four patients achieving complete haematological remission. Therefore we conclude that most haematological remissions in MDS are associated with restoration of polyclonal haemopoiesis.

The purpose of this cooperative study was to evaluate the quantity and quality of Ph1-negative progenitor cells mobilized in the peripheral blood of patients with chronic myelogenous leukaemia soon after aplasia induced by chemotherapy. 32 patients ineligible for allografting who were cytogenetically refractory to interferon-alpha (IFN-alpha) were entered into this study. The chronic phase varied widely, with a median duration of 17 months (range 3-90 months). All patients were treated with intensive conventional chemotherapy regimens and recombinant human granulocyte colony-stimulating factor (rhuG-CSF, lenograstim). Peripheral blood progenitor cells (PBPC) were harvested by leukaphereses during early recovery from chemotherapy-induced aplasia. A total of 119 leukaphereses were performed. Median numbers of CD34+ cells and CFU-GM collected were 2.04 x 10(6)/kg and 2 9 x 10(4)/kg, respectively. There was a significant correlation between white cell count and number of CD34+ cells in the leukaphereses (P = 0.0001, r2 = 0.41, n = 104). A strict correlation between the number of CD34+ cells and CFU-GM in the leukapheretic product (P = 0.0001, r2 = 0.39, n = 110) was observed. 21% of evaluable patients (6/29) achieved a complete cytogenetic remission in the leukapheretic product and the other four patients achieved a major cytogenetic response for an overall response of 35% (10/22 patients). To date, 16 patients have been autografted and are alive. Five of them are Ph1-negative (three patients) or partially Ph1-negative (two patients). In conclusion, despite the high-risk characteristics of this study population, Ph1-negative PBPC were successfully mobilized in more than one-quarter of patients using a chemotherapy plus rhuG-CSF regimen. The importance of this achievement is increased by the current lack of other practical methods of rescuing Ph-negative cells in such patients.