BCL-2 Expression in AML Patients over 65 Years: Impact on Outcomes across Different Therapeutic Strategies.

BCL-2 overexpression has been associated with resistance to chemotherapy and reduced survival in acute myeloid leukemia (AML), but few data are available in elderly patients, a subset accounting for majority of AML cases and with dismal prognosis. We retrospectively analyzed 113 AML patients aged ≥65 years treated with 3 + 7 chemotherapy (n = 51) or hypomethylating agents (HMAs) (n = 62), evaluating the role of BCL-2 expression on complete remission (CR) and overall survival (OS). BCL-2 was expressed in 81 patients (72%), more frequently in those with unfavorable cytogenetic-molecular risk. CR was achieved in 34.5% cases, without differences according to BCL-2 expression or induction therapy. In the whole population 1-year OS was 39%, similar in BCL-2+ and BCL-2- cases. In BCL-2 positive patients OS was superior with HMAs (56% vs. 25% with 3 + 7; p = 0.02), while no advantage for HMA was found in BCL-2 negative cases (36% vs. 27% for 3 + 7). Therapy with HMAs was the only factor associated with longer OS in BCL-2+ AML by multivariable analysis. Use of HMAs, possibly in combination with BCL-2 inhibitors, appears to be particularly appealing in BCL2+ AML, where it is associated with superior survival.

Cytomegalovirus Prophylaxis versus Pre-emptive Strategy: Different CD4+ and CD8+ T Cell Reconstitution after Allogeneic Hematopoietic Stem Cell Transplantation.

Reconstitution of T cells after transplantation is a determinant of the long-term success of the procedure, and the correlation with T cell recovery and cytomegalovirus reactivation and disease is well known. We evaluated 110 patients who underwent transplantation: 55 received pre-emptive antiviral treatment, and in the other 55 patients, prophylaxis with letermovir was employed. A progressive statistically significant difference in T cell reconstitution between the 2 groups was observed, starting from day +60 with faster recovery in the pre-emptive group. Moreover, a higher incidence of cytomegalovirus reactivation was observed in prophylactic group after discontinuation of letermovir, and subsequent antiviral treatment has been necessary. Our findings confirm, as previously reported, that cytomegalovirus reactivation is a potent stimulator of T cell function.

Impact of Concomitant Aberrant CD200 and BCL2 Overexpression on Outcome of Acute Myeloid Leukemia: A Cohort Study from a Single Center

Objective: CD200 and BCL2 overexpression is independently associated with inferior survival in acute myeloid leukemia (AML), and these two factors are frequently co-expressed; however, no data are available on the role of concomitant aberrant CD200 and BCL2 expression on outcome of AML patients. We aimed to elucidate the prognostic role of CD200/BCL2 co-expression and its association with specific leukemia subsets. Materials and Methods: We analyzed 242 adult AML patients uniformly treated with intensive chemotherapy, evaluating the impact of CD200 and BCL2 expression on complete remission (CR), disease-free survival, and overall survival (OS). Results: CD200 and BCL2 were expressed in 139 (57.4%) and 137 (56.6%) cases, respectively, with 92 patients (38%) displaying double positivity (DP), 58 (24%) displaying double negativity (DN), and 92 patients expressing only either CD200 (n=47) or BCL2 (n=45). CR was achieved in 71% of cases, being less frequent in DP patients (60%) compared to other groups (76%-81%, p<0.001). In the whole population 3-year OS was 44%, being lower in DP patients (28%) than in patients with single CD200 or BCL2 expression (47%) or DN cases (60%; p=0.004). Other factors associated with worse OS were advanced age, CD34 positivity, secondary AML, and high white blood cell count at diagnosis; combining these 4 factors with CD200/BCL2 DP, we identified 6 groups with significantly different rates of survival (3-year OS ranging from 90% to 0%). Conclusion: Our data support a synergistic effect of CD200 and BCL2 in AML cells, conferring an enhanced survival capacity in a permissive microenvironment and resulting in worse prognosis.

Features, reason for testing, and changes with time of 583 paroxysmal nocturnal hemoglobinuria clones from 529 patients: a multicenter Italian study.

In this study, we aimed at disclosing the main features of paroxysmal nocturnal hemoglobinuria (PNH) clones, their association with presentation syndromes, and their changes during follow-up. A large-scale, cooperative collection (583 clones from 529 patients) of flow cytometric and clinical data was entered into a national repository. Reason for testing guidelines were provided to the 41 participating laboratories, which followed the 2010 technical recommendations for PNH testing by Borowitz. Subsequently, the 30 second-level laboratories adopted the 2012 guidelines for high-resolution PNH testing, both upon order by the local clinicians and as an independent laboratory initiative in selected cases. Type3 and Type2 PNH clones (total and partial absence of glycosyl-phosphatidyl-inositol-anchor, respectively) were simultaneously present in 54 patients. In these patients, Type3 component was sevenfold larger than Type2 (p < 0.001). Frequency distribution analysis of solitary Type3 clone size (N = 442) evidenced two discrete patterns: small (20% of peripheral neutrophils) and large (> 70%) clones. The first pattern was significantly associated with bone marrow failure and myelodysplastic syndromes, the second one with hemolysis, hemoglobinuria, and thrombosis. Pediatric patients (N = 34) showed significant preponderance of small clones and bone marrow failure. The majority of PNH clones involved neutrophils, monocytes, and erythrocytes. Nevertheless, we found clones made exclusively by white cells (N = 13) or erythrocytes (N = 3). Rare cases showed clonal white cells restricted only to monocytes (6 cases) or neutrophils (3 cases). Retesting over 1-year follow-up in 151 cases showed a marked clone size increase in 4 cases and a decrease in 13, demonstrating that early breaking-down of PNH clones is not a rare event (8.6% of cases). This collaborative nationwide study demonstrates a clear-cut difference in size between Type2 and Type3 clones, emphasizes the existence of just two classes of PNH presentations based on Type3 clone size, depicts an asymmetric cellular composition of PNH clones, and documents the possible occurrence of changes in clone size during the follow-up.

ABCG2, Cytogenetics, and Age Predict Relapse after Allogeneic Stem Cell Transplantation for Acute Myeloid Leukemia in Complete Remission.

Recent studies have shown that ABGG2 protein overexpression in acute myeloid leukemia (AML) may be associated with poor response to therapy and increased relapse risk. Few data are available in patients with AML undergoing allogeneic stem cell transplantation (SCT), particularly when in complete remission (CR). We analyzed 105 patients with AML who underwent allogeneic SCT in CR evaluating the role of ABCG2 and other pretransplantation features on subsequent transplantation outcomes. Factors negatively associated with leukemia-free survival (LFS) were unfavorable cytogenetics (3-year LFS 48% versus 80%, P = .0035) and ABCG2 positivity (65% versus 80%, P = .045). Three-year cumulative incidence of relapse (CIR) in the whole population was 20%; a higher incidence of relapse was associated with adverse cytogenetics (41% versus 16%, P = .018), ABCG2 overexpression (29% versus 15%, P = .04), and, marginally, age > 50 years (30% versus 14%, P = .06). We grouped patients according to the combination of these 3 risk factors: no patient relapsed within 3 years from SCT in the group without risk factors, whereas the 3-year CIR was 12% (95% confidence interval [CI], 2% to 25%) in the group with 1 risk factor and 47% (95% CI, 31% to 70%) in patients with 2 or 3 risk factors (P = .00005). In conclusion, allogeneic SCT does not seem to abrogate the negative prognosis associated with ABCG2 overexpression at diagnosis, specifically in terms of a higher relapse risk. ABCG2, age, and cytogenetics can predict AML relapse after SCT in patients who undergo transplantation while in CR.

Clinical impact of CD200 expression in patients with acute myeloid leukemia and correlation with other molecular prognostic factors.

CD200, a protein belonging to the immunoglobulin superfamily, has been associated with a poor prognosis in lymphoproliferative disorders and in acute leukemia. We studied the expression of CD200 in a series of 244 patients with diagnosis of acute myeloid leukemia (AML), to evaluate its impact on outcome and its possible association with other known prognostic factors. CD200 was found in 136/244 (56%) patients, in 41 of whom (30%) with high intensity of expression (MFI ≥ 11). CD200 was more frequent in secondary compared to de novo leukemia (p = 0.0006), in CD34 positive cases (p = 0.00001), in Bcl2 overexpressing cases (p = 0.01), in those wild-type Flt3 (p = 0.004) and with favorable or unfavorable compared to intermediate karyotype (p = 0.0003). CD200+ patients have a two-fold lower probability to attain complete remission, both in univariate (p = 0.006) and multivariate (p = 0.04) analysis. The negative impact of CD200 was found also in overall survival (p = 0.02) and was correlated with the intensity of expression of the molecule (p = 0.024). CD200 has an additive negative impact on survival in patients with unfavorable cytogenetic (p = 0.046) and in secondary leukemia (p = 0.05), and is associate with a worsening of outcome in patients with favorable biological markers, such as mutated NPM (p = 0.02), wild-type Flt3 (p = 0.034), negativity of CD34 (p = 0.03) and of CD56 (p = 0.03). In conclusion, CD200 is emerging as both a prognostic factor and a potential target of novel therapeutic approaches for AML, aiming to reverse the "do not eat me" signal of CD200 or to manipulate the suppressive immune microenvironment induced by CD200 binding to its receptor.

ABCG2 overexpression in patients with acute myeloid leukemia: Impact on stem cell transplantation outcome.

ABGG2 protein overexpression in acute myeloid leukemia (AML) has been associated with poor response to conventional chemotherapy and increased relapse risk. No data are available on the role of allogeneic stem cell transplantation (SCT) in reversing its negative prognostic role. We have reviewed the outcome of 142 patients with high risk AML who underwent allogeneic SCT in complete remission (n = 94) or with active disease (n = 48). Patients with ABCG2 overexpression at AML diagnosis have lower leukemia free survival (LFS) and increased cumulative incidence of relapse (CIR) compared with ABCG2- patients (5-year LFS 50% vs. 65%, P = 0.01; 5-year CIR 46% vs. 27%, P = 0.003). Five-year overall survival was not significantly different between ABCG2+ and ABCG2- patients (39% vs. 51%, P = 0.1). However, if we consider only disease-related deaths, ABCG2 maintains its negative role (64% vs. 78%, P = 0.018). The negative impact of ABCG2 overexpression was higher in patients undergoing SCT in CR compared with patients receiving transplant with active disease. Conditioning regimen did not abrogate the effect of ABCG2 overexpression, as CIR was higher in ABCG2+ patients receiving both myeloablative (44% vs. 22%, P = 0.018) or reduced intensity conditioning (50% vs. 32%, P = 0.03). In conclusion, ABCG2 overexpression at AML diagnosis identifies a subset of patients with poor outcome also after allogeneic SCT, mainly in terms of higher relapse rates. Prospective studies employing conditioning drugs or post-transplant strategies able to target ABCG2 are needed to maximize the curative potential of stem cell transplantation.

BAALC overexpression retains its negative prognostic role across all cytogenetic risk groups in acute myeloid leukemia patients.

Overexpression of brain and acute leukemia cytoplasmic (BAALC) gene confers poor prognosis in cytogenetically normal acute myeloid leukemia (AML) patients, while less defined is its role in AML with abnormal karyotype. We evaluated the effect of BAALC overexpression on outcome of 175 adult AML patients with different cytogenetic risks. Karyotype was favorable in 13, intermediate in 117 and unfavorable in 45 patients, respectively. Quantitative BAALC expression was determined by real-time PCR, with cut off value set at 50th percentile. BAALC was overexpressed in 87/175 (50%) patients, without association with cytogenetic status. High BAALC was associated with unmutated NPM (P = 0.006) and CD34 positivity (P < 0.0001). Complete remission (CR) was attained in 111 patients (63%), and was maintained at 5 years in 52 ± 7%. BAALC overexpression had a negative impact on CR achievement (P = 0.04), while did not influence relapse probability. Median survival was 22 months with a 5-years overall survival (OS) of 35%. Factors with a negative impact on OS were older age (P = 0.0001), unfavorable cytogenetic (P = 0.005), ABCG2 overexpression (P = 0.03) and high BAALC levels (P = 0.01). We observed a worse outcome in patients with high BAALC expression through all cytogenetic risk categories: 5-years OS was 100% vs. 71% in patients with favorable cytogenetics (P = 0.05), 55% vs. 40% in cases with intermediate karyotype (P = 0.04) and 34% vs. 23% in unfavorable cytogenetic subgroup (P = 0.02). BAALC overexpression identified AML patients with poor prognosis in all cytogenetic groups. Though relatively rare, BAALC positivity in patients with favorable or unfavorable karyotype significantly worsened survival.

Donor compatibility and performance status affect outcome of allogeneic haematopoietic stem cell transplant in patients with relapsed or refractory acute myeloid leukaemia.

We retrospectively analysed 78 patients with relapsed (n = 38), primary refractory (n = 34) or untreated (n = 6) acute myeloid leukaemia (AML) who underwent allogeneic HSCT at our Institution between 2002 and 2011, to verify outcome and to identify factors that can affect long-term outcome. Myeloablative conditioning regimens were used in 48 patients (24 siblings, 24 matched unrelated donor (MUD)), while 30 patients (18 siblings, 12 MUD) received reduced-intensity conditioning. Acute graft versus host disease (GVHD) developed in 37 (47 %) patients, while chronic GVHD occurred in 19 of the 65 evaluable patients (29 %). With a median follow-up time of 5 years, 13 of 78 patients (17 %) are alive and in complete remission (CR), while 64 have died. Cause of death was disease recurrence in 37 patients (58 %), infection in ten patients (16 %) and GVHD in six (9 %). One-year non-relapse mortality was 35 %. In multivariate analysis, performance status ≥80 % WHO and a full-matched donor were associated with a better outcome: these two variables allowed for risk stratification, identifying three groups with significantly different survival after transplant (P = 0.0001). Considering post-transplant variables, only CR at recovery and development of cGVHD were correlated with a longer survival. Our data confirm the capacity of allogeneic transplant to prolong survival in a significant proportion of extremely high-risk AML patients.

Concomitant ABCG2 overexpression and FLT3-ITD mutation identify a subset of acute myeloid leukemia patients at high risk of relapse.

BACKGROUND: ABCG2 protein overexpression and FLT3 internal tandem duplication (ITD) correlate with higher relapse rate and shorter disease-free survival (DFS) in acute myeloid leukemia (AML), but no data are available on the possible effect of concomitant presence of these 2 factors. METHODS: The authors analyzed the outcome of 166 cases of adult AML patients who were homogeneously treated with a fludarabine-based induction therapy. RESULTS: ABCG2 overexpression and FLT3-ITD were detected in 83 (50%) and 47 (28%) patients, respectively. A significant correlation was found between ABCG2 positivity and FLT3 mutation, with 33 (40%) ITD in 83 ABCG2-positive patients compared with 14 (17%) ITD in 83 ABCG2-negative patients (P = .002). Complete remission (CR) after induction therapy was achieved in 95 (57%) patients. Neither ABCG2 overexpression nor FLT3-ITD had any impact on achievement of CR. Relapse occurred in 42 of 95 (44%) patients at a median time of 28 months. Time to relapse was shortened in patients overexpressing ABCG2 (P = .0004). DFS was not affected by FLT3-ITD alone, but FLT3 mutation significantly worsened long-term outcome of ABCG2-positive patients. DFS at 1 and 3 years in patients with overexpression of both ABCG2 and FLT3-ITD was only 36% and 28%, respectively; in ABCG2-positive/FLT3-negative patients, DFS at 1 and 3 years was 65% and 48%, respectively; and in ABCG2-negative cases (regardless of FLT3 status), DFS at 1 and 3 years was greater than 85% and 75%. CONCLUSIONS: Concomitant overexpression of ABCG2 and FLT3-ITD is relatively frequent and identifies a subgroup of AML patients with a significantly worse prognosis. The possible interactions between these 2 prognostic factors need to be defined.

Fludarabine-based induction therapy does not overcome the negative effect of ABCG2 (BCRP) over-expression in adult acute myeloid leukemia patients.

Over-expression of multidrug resistance (MDR) proteins PGP and BCRP has a negative prognostic impact in acute myeloid leukemia (AML) patients. Inclusion of fludarabine in induction chemotherapy increases remission rate in PGP over-expressing cases. We investigated the role of BCRP in 138 adult AML patients receiving induction therapy with fludarabine. None of the MDR-related proteins influenced complete remission attainment. Conversely, high levels of BCRP significantly affected disease-free survival, as higher relapse rates (48.5% vs 28.5%) and earlier relapse occurred in BCRP+ patients. Also overall survival was affected by BCRP positivity, and survival significantly worsened in case of concomitant PGP and BCRP over-expression.

Quantitative assessment of WT1 gene expression after allogeneic stem cell transplantation is a useful tool for monitoring minimal residual disease in acute myeloid leukemia.

INTRODUCTION: WT1 overexpression is described in several oncological diseases including acute myeloid leukemia (AML). Quantification of WT1 in bone marrow samples may be useful as a marker of minimal residual disease (MRD) and may predict the relapse of AML after allogeneic hematopoietic stem cell transplant (HSCT). METHODS AND RESULTS: The quantitative expression of WT1 was measured in 38 AML patients (16 males and 22 females) at diagnosis, at the time of transplant and after the allogeneic HSCT (at precise time points). All cases showed high WT1 expression levels at diagnosis with a mean of 4189 (SD 3325) and a median of 3495 (range 454-13923) copies WT1/10(4)Abl. At transplant, 25 patients (66%) were in complete cytologic remission (CcR) and 13 (34%) had refractory or relapsed AML. Bone marrow samples from patients transplanted in CcR showed significantly lower WT1 expression levels during HSCT compared with the samples from patients with a relapsed or refractory AML (P = 0.004). After HSCT, a rapid decline in WT1 expression levels was observed in all patients who attained or maintained a condition of CcR. Six of 38 patients (13%) relapsed after HSCT and all of them had an increase in WT1 expression at/or before relapse. Five of these six patients died of leukemia and one was successfully reinduced with donor lymphocyte infusion (DLI) + chemotherapy with a rapid reduction of WT1 levels. Besides, we found a complete concordance between WT1 expression levels and other disease markers (when available). CONCLUSIONS: In our experience, there was a complete concordance between WT1 expression levels (measured by quantitative RT-PCR at precise time points) and status of AML before and after allogeneic HSCT. WT1 may be useful as a non-specific leukemia marker for monitoring MRD and as a predictor of AML clinical relapse. Based on these results, cases with increase of WT1 levels after HSCT and without graft vs. host disease may be candidate to discontinuation of immunosuppression and/or DLI therapy.

Gemtuzumab-ozogamicin in combination with fludarabine, cytarabine, idarubicin (FLAI-GO) as induction therapy in CD33-positive AML patients younger than 65 years.

INTRODUCTION: The addition of gemtuzumab-ozogamicin (GO) to an induction regimen including synergistic drugs, such as intermediate dose of cytarabine (Ara-C), idarubicin and fludarabine (FLAI), could reduce treatment failure in acute myeloid leukemia (AML) patients. Nevertheless, the role and safety of this antibody target-therapy in first-line chemotherapy in patients younger than 65 years has not yet been defined. PATIENTS AND METHODS: The primary goal of this prospective phase II pilot study was to evaluate the efficacy and the safety profile of FLAI plus GO as induction regimen. Thirty consecutive AML patients were included. All patients were younger than 65 with a median age of 53 years and CD33 expression exceeded 20% in all cases. The M/F ratio was 16/14 and 21/30 (70%) of patients were poor-risk at diagnosis. The induction regimen (FLAI-GO) included fludarabine (30mg/m(2)) and Ara-C (2g/m(2)) on days 1-5, idarubicin (10mg/m(2)) on days 1, 3, and 5 and GO (3mg/m(2)) on day 6. Hematopoietic stem cell transplant (HSCT) was planned for all high risk AML patients in first complete remission (CR) after consolidation with intermediate doses of Ara-C and idarubicin (IDAC-IDA). Cytogenetic, multidrug-resistance phenotype, FLT3 mutation status, and WT1 quantitative expression analyses were performed at diagnosis in all patients. WT1 expression and cytogenetic (in positive cases) analyses were performed after induction to detect and follow minimal residual disease. RESULTS: Patients were evaluated for response rate, treatment-related adverse events, overall survival and relapse free survival. After induction with FLAI-GO, CR rate was 90% (26 of 29 evaluable pts); one patient achieved partial remission and two were resistant. There was only one case of death during induction (DDI). After FLAI-GO, the mean value of WT1 dropped from 4200+/-2777 copies/10(4)ABL to 192+/-399 copies/10(4)ABL. The toxicity of FLAI-GO was acceptable; 57% of patients experienced transient and reversible GO infusion-related adverse events (especially fever and chills), but no cases of veno-occlusive disease occurred during CHT or after HSCT. After a median follow-up of 16 months (range 2-25), 24/30 (80%) patients are alive (24/24 in CR). The probability of 1-year OS and RFS was 90 and 85%, respectively. Allogeneic and autologus HSCT was performed in 19 (63%) and 4 (13%) patients, respectively. CONCLUSIONS: These preliminary results suggest that FLAI-GO is an effective and well tolerated induction regimen for CD33 positive AML patients younger than 65 years, with a high complete response rate, favourable safety profile, low DDI. These results encourage the testing of this regimen in a multicenter prospective trial.

The role of MDR-related proteins in the prognosis of adult acute myeloid leukaemia (AML) with normal karyotype.

Cytogenetic abnormalities are among the most important factors affecting the outcome of patients with acute myeloid leukaemia (AML), but approximately 40-50% of AML cases display a normal karyotype at diagnosis. Multidrug resistance (MDR) proteins overexpression is associated with worse prognosis in acute leukaemias, but its role in normal karyotype AML is less defined. We analysed the expression of P-glycoprotein (PGP), MDR-related protein (MRP) and lung resistance protein (LRP) in 135 adult patients with normal karyotype AML and its correlation with other biological features of the disease, to evaluate the impact of MDR proteins on response to therapy and on survival. Increased PGP expression was associated with lower rate of complete remission (CR; p = 0.006), similarly to advanced age. Cases overexpressing PGP displayed also a shorter event-free survival (EFS; 4 vs. 10 months, p = 0.035) and the increased expression of at least one MDR protein was associated with a reduced overall survival (OS; p = 0.038). Also age was predictive of worse prognosis. Our data confirm the prognostic role of MDR proteins, in particular of PGP, also in AML patients with normal karyotype at diagnosis. This finding could be used to stratify patients with different prognosis and to design risk-adapted therapeutic strategies.

Case-control study of multidrug resistance phenotype and response to induction treatment including or not fludarabine in newly diagnosed acute myeloid leukaemia patients.

One hundred and six patients aged /= 6) vs. 75% among the MDR-Pgp-negative (neg(ve)) ones (MFI < 6) (P = 0.16). Conversely, in the controls, the CR rate was 44% among the MDR-Pgp-pos(ve) patients vs. 67% among the MDR-Pgp-neg(ve) ones (P = 0.02). The 4-year disease-free survival (DFS) and overall survival (OS) of MDR-Pgp-pos(ve) cases were significantly longer than those of MDR-Pgp-pos(ve) controls (DFS, 28.1% vs. 6.5%, P = 0.004; OS, 33.5% vs. 9.6%, P = 0.01). This difference was not found among the MDR-Pgp-neg(ve) patients. By univariate (P = 0.007) and multivariate (P = 0.007) analysis, the MDR-Pgp-pos(ve) phenotype was negatively correlated with CR and it emerged as the most important independent negative prognostic factor, after cytogenetics. Our study confirms the prognostic impact of the MDR phenotype in AML and strongly suggests fludarabine-based induction treatments as a promising strategy for MDR-Pgp-pos(ve) AML patients. In this setting of patients, large prospective randomised studies should be planned.

Efficacy of liposomal daunorubicin and cytarabine as reinduction chemotherapy in relapsed acute lymphoblastic leukaemia despite expression of multidrug resistance-related proteins.

The treatment of relapsed adult acute lymphoblastic leukaemia (ALL) is frequently unsuccessful with current chemotherapy regimens, and often there is an overexpression of multidrug resistance (MDR)-related proteins. Liposomal encapsulation makes daunorubicin (DNR) less sensitive to the efflux effect of P-glycoprotein (PGP), and in vitro data indicate that liposomal-encapsulated DNR (Daunoxome-DNX) is more toxic than DNR against ALL cell lines. In this study, we assessed the in vivo and in vitro efficacy and toxicity of DNX plus cytarabine (Ara-C) as reinduction chemotherapy in 25 relapsed ALL patients (pts). The expression of MDR-related proteins (PGP, MRP1 and LRP) was also analysed. Of the 25 pts, 12 were males and 13 females; median age was 32 yr (range 18-58). Six cases were ALL T and 19 ALL B; eight pts were Ph+ (32%), and nine Bcr-Abl+ (36%). The expression of MDR-related proteins, and DNR and DNX retention and induction of apoptosis in leukaemic cells were evaluated in all cases. Seventeen of 25 (68%) pts were at first relapse and eight (32%) at second or subsequent relapse. The DNX was given in a dose of 80 mg/m(2)/d (days 1-3) in 11/25 pts (44%) and in a dose of 100 mg/m(2)/d (days 1-3) in 14/25 pts (66%). In all pts, Ara-C was administered in a dose of 2 g/m(2) (days 1-5). Twenty pts (80%) achieved a complete remission (CR) and two (8%) entered a partial remission (PR) for an overall response (OR) rate of 88% (22/25), with a tolerable toxicity and without significant cardiotoxicity. Before the start of DNX therapy, 18/25 (72%) cases overexpressed at least one MDR-related protein compared with 9/25 (36%) cases with MDR overexpression at diagnosis (P = 0.01). Taking into account the small number of cases, the response rate was not affected by MDR expression and the in vitro results also showed a higher uptake and apoptotic cell death by DNX compared with DNR. Twelve pts subsequently underwent allogeneic bone marrow transplantation (11 unrelated donor BMT, and one sibling BMT). The overall survival was 39% after 12 months. These data show the efficacy (OR rate 88% and CR rate 80%) of DNX plus Ara-C as reinduction therapy in very poor-risk ALL pts and the response rate seems not to be affected by MDR overexpression. Moreover, the high rate of remissions and the good clinical tolerance in heavily pretreated pts suggest a promising role of DNX in ALL chemotherapy regimens.

The prognostic value of P-glycoprotein (ABCB) and breast cancer resistance protein (ABCG2) in adults with de novo acute myeloid leukemia with normal karyotype.

Multidrug resistance is a major cause of treatment failure in acute myeloid leukemia (AML). P-glycoprotein (PGP) over-expression has an unfavorable prognostic significance, while the role of breast cancer resistance protein (BCRP) is less clear, especially in AML patients with a normal karyotype. We studied 73 consecutive AML patients with a normal karyotype. BCRP was over-expressed in 24 patients (33%) and was significantly co-expressed with PGP (13/24 vs 11/49, p=0.006) and with CD56. Only PGP, along with age and CD34, affected the achievement of complete remission (p=0.02), while BCRP-positive cases showed an increased risk of relapse (p=0.005) and a shorter disease-free survival (p=0.027). BCRP over-expression did not influence the achievement of remission, but significantly affected the duration of complete remissions. BCRP may, therefore, be regarded as a prognostic factor in patients with normal karyotype AML, for the design of risk-adapted post-remission therapy.

Epstein-Barr virus reactivation in a patient treated with anti-thymocyte globulin for severe aplastic anemia.

Epstein-Barr virus (EBV) infection and reactivation is an increasing complication in immune deficient patients, particularly after allogeneic hematopoietic stem cell transplantation (HSCT). Therapy with anti-thymocyte globulin (ATG) is associated with higher incidence of EBV-related disease in HSCT patients, but this risk is not documented in patients receiving ATG for severe aplastic anemia (SAA). We describe the case of a patient who developed an EBV infection, with the clinical features of an infectious mononucleosis, after immune suppression with cyclosporine and two courses of ATG for SAA.

Effect of amifostine on the cytotoxicity of daunorubicin and daunoxome in tumor and normal cells.

Anthracyclines are powerful cytotoxic agents, used as first-line treatment of leukemias and many other tumors, but host-tissue toxicity is their main dose-limiting factor. However, their therapeutic effects depend not only on the toxicity, hence on the dose, but also on drug resistance. Among the mechanisms that can account for cell sensitivity to anthracyclines, there is an overexpression of drug transport proteins, like the transmembrane P-glycoprotein (PGP), the multidrug- resistance-related protein (MRP) and the lung-resistance-related protein (LRP). Attempts to reduce the toxicity of chemotherapeutic agents without affecting their efficacy have been made using liposomal anthracyclines or cytoprotective agents, as Amifostine. The aim of this study was to evaluate and compare the toxic effects of Daunorubicin, in normal or liposomal formulation, used in combination with WR1065, the active metabolite of Amifostine, against normal and tumor cells. In conclusion these data show that the preincubation with WR-1065 does not inhibit the drug toxic effect on blast cells and on tumor cell lines, independently by their multidrug resistance phenotype, but has a cytoprotective effect on stem cells causing a drug cytotoxicity reduction of 10-20%. This advantage is even higher using the liposomal formulation of DNR. Therefore, Amifostine can offer a chance of protecting normal cells from the toxicity of anthracyclines, in normal or liposomal formulation. The combination of liposomal anthracyclines with Amifostine can confer further advantages in management of leukemic patients, especially the elderly where treatment toxicity is a main problem. These patients may be candidates for alternative therapeutic strategies and the combination of DNX and Amifostine is an attractive treatment for these cases where a low nonhematological toxicity is required.