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G Del Poeta

Publications and source records attributed to G Del Poeta.

At least 19 recordsLinked to original sources

The kinetics of reduction of minimal residual disease impacts on duration of response and survival of patients with acute myeloid leukemia.

UNLABELLED: We assessed by multiparametric flow cytometry the levels of minimal residual disease (MRD) in 100 adult patients with acute myelogenous leukemia (AML) achieving complete remission after intensive chemotherapy. The aim of the study was to determine the optimal threshold, in terms of residual leukemic cells, and the time point of choice, that is, post-induction (post-Ind) or post-consolidation (post-Cons), able to better predict outcome. By applying the maximally selected log-rank statistics, the threshold discriminating MRD- from MRD+ cases was set at 3.5 x 10(-4) residual leukemic cells, a level that allowed the identification of distinct subgroups of patients, both at post-Ind and post-Cons time points. Post-Cons MRD- patients had a superior outcome in terms of relapse rate, overall survival (OS) and relapse-free survival (RFS) (P<0.001, for all comparisons), regardless of the MRD status after induction. In particular, patients entering MRD negativity only after consolidation showed the same outcome as those achieving early negativity after induction. Multivariate analysis, including karyotype, age, MDR1 phenotype, post-Ind and post-Cons MRD levels, indicated that the post-Cons MRD status independently affected relapse rate, OS and RFS (P<0.001, for all comparisons). IN CONCLUSION: (1) the threshold of 3.5 x 10(-4) is valid in discriminating risk categories in adult AML and (2) post-Cons MRD assessment is critical to predict disease outcome.

Adolescent↗

Long-term observation of patients with anti-neutrophil cytoplasmic antibody-associated vasculitis treated with rituximab.

OBJECTIVE: Rituximab, a chimeric anti-CD20 monoclonal antibody, has been shown to be quite effective in the treatment of immune disorders resulting from autoantibodies. We prospectively studied the long-term effects of rituximab in 10 patients with anti-neutrophil cytoplasmic antibody (ANCA)-positive vasculitis refractory to conventional therapy (n=3) or in second or subsequent relapse (n=7). METHODS: The median age of patients was 53 yrs (range 38-70 yrs). Eight were classified as Wegener's granulomatosis, and two as microscopic polyangiitis. Clinical activity was assessed using the Birmingham Vasculitis Activity Score modification for Wegener's granulomatosis. Treatment consisted of intravenous infusions of rituximab given at the dose of 375 mg/m2 weekly for four consecutive weeks. RESULTS: All patients experienced a rapid clinical improvement following the administration of rituximab, with nine complete responses and one partial response at 6 months. With a median follow-up of 33.5 months (range 26-45 months), three patients have thus far relapsed. Retreatment with the monoclonal antibody at the same dose and schedule resulted in a new sustained response in all these patients. Rituximab therapy resulted in prolonged B-cell depletion. The ANCA titres decreased significantly in all patients, with eight out of 10 becoming ANCA-negative and three remaining ANCA-negative even after B-cell recovery. Infusion-related side effects were observed in one patient, but were of mild intensity and did not require discontinuation of treatment. CONCLUSIONS: Rituximab is an effective and well-tolerated treatment for patients with ANCA-associated vasculitis and should be strongly considered in severely affected patients who do not respond to standard therapy or in those in whom cytotoxic therapy bears a high risk of morbidity.

Adult↗

Graft failure due to hemolytic uremic syndrome recurrence.

The hemolytic uremic syndrome (HUS) is a severe disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. We herein report our experience with a 43-year-old female patient who underwent a second cadaveric kidney transplantation in February 2005, for adult-onset HUS. The first renal transplantation, which was performed in 1996, required removal after 3 weeks for probable recurrence of HUS. The immunosuppressive regimen for the second transplant included basiliximab, tacrolimus, mycophenolate mofetil, and steroids. On postoperative day (POD) 7, she received steroid treatment for an acute rejection episode with improved renal function. On POD 19 due to worsening renal function, a graft biopsy showed HUS recurrence, thus we instituted hemodialysis and then plasmapheresis treatments. At two months after transplantation, the patient continued under plasmapheresis treatment due to clinical evidence of HUS. On POD 80, cytomegalovirus infection was diagnosed and intravenous gancyclovir treatment started for 3 weeks. After 110 days from transplant, a deterioration in renal function was evident: the graft was swollen and painful with Doppler ultrasound showing patency of both the renal artery and vein but, low blood flow. After 2 weeks of hemodialysis, the patient underwent transplantectomy. In adult-onset HUS the recurrence rate reduces graft survival, particularly among patients undergoing second transplantation.

Adult↗

Pretransplant minimal residual disease level predicts clinical outcome in patients with acute myeloid leukemia receiving high-dose chemotherapy and autologous stem cell transplantation.

A total of 31 adult patients with AML entered in the EORTC/GIMEMA AML-10 trial, who received autologous stem cell transplantation (ASCT) after induction and consolidation chemotherapy, were prospectively evaluated for minimal residual disease (MRD) by multidimensional flow cytometry (MFC). Using a cutoff level of 3.5 x 10(-4) leukemic cells pre-ASCT, 12 patients (39%) were stratified to MRD high-risk group and 19 (61%) into MRD low-risk group. During follow-up, all patients who were in the high-risk group relapsed at a median time of 7 months; in the low-risk group, five patients relapsed at a median time of 11 months and 14 remained in remission for 56 (range 7-80) months (P=0.00004). Longitudinal MFC determinations post-ASCT showed increased MRD levels in three of the five patients who underwent subsequent relapse, while disease recurrence was unpredicted in the remaining two cases. The pre-ASCT MRD status was the factor most strongly associated with relapse risk in the multivariate analysis (P=0.0014). We conclude that: (1) pre-ASCT MRD status predicts successful outcome in patients receiving ASCT; (2) high-dose chemotherapy conditioning regimen followed by ASCT has no impact on the unfavorable prognostic value of high pre-ASCT MRD level; and (3) sequential MRD monitoring post-ASCT may allow the prediction of impending relapse.

Acute Disease↗

Clinical significance of CD38 expression in chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (B-CLL) follows heterogeneous clinical courses, and several biological parameters need to be added to the current clinical staging systems to predict which patients will experience an indolent or an aggressive outcome. This study analyzed CD38 expression by flow cytometry and soluble APO1/Fas (sAPO1/Fas), Bcl-2 (sBcl-2), and CD23 (sCD23) proteins by immunoenzymatic methods to evaluate their effect on the clinical course of 168 unselected B-CLL patients. Intermediate/high risk modified Rai stages were characterized by a higher CD38(+) B-cell number (P =.0002) and higher sCD23 levels (P <.0001). Moreover, CD38(+) B-cell percentages were significantly and directly associated both with beta(2)-microglobulin and sCD23 concentrations (P <.0001 and P =.002, respectively). Both a higher tumor burden (lymphadenopathy/splenomegaly) and a lymphocyte doubling time less than 12 months were significantly associated with higher CD38(+) percentages (P <.0001 and P =.0001, respectively). With regard to clinical outcome, progression-free survival was significantly longer (75% versus 37% at 5 years; P =.00006) in patients with lower CD38(+) B-cell percentages. Furthermore, the risk of partial or no response to fludarabine increased with increasing CD38 expression (P =.003), and a shorter overall survival (50% versus 92% at 8 years; P <.00001) characterized patients with more than 30% CD38(+) B-cell number. The predictive value of CD38 expression was maintained among the patients within the Rai intermediate risk group and was confirmed in multivariate analysis. Thus, the percentage of CD38(+) B cells appears to be an accurate predictor of clinical outcome and therefore could be used to indicate when more novel chemotherapeutic approaches are needed.

ADP-ribosyl Cyclase↗

New reciprocal translocation t(6;10) (q27;q11) associated with idiopathic myelofibrosis and eosinophilia.

Idiopathic myelofibrosis (IM), is a chronic myeloproliferative disorder (MPD) characterised by marrow fibrosis, extramedullary haematopoiesis and a leuco-erythroblastic picture of the peripheral blood. Cytogenetic data of IM is scarce: no specific karyotypic anomalies have been yet described. Trisomy 1q, del(13q), del(20q) and trisomy 8, appear in two-thirds of the cases with chromosome aberrations. We report on a 41-year-old patient diagnosed with IM associated with eosinophilia, bearing a novel translocation t(6;10)(q27;q11) as the sole chromosome anomaly. The patient, progressed to AML-M5a within 18 months from diagnosis. Recently new specific chromosomal translocations have been described in chronic MPD. These findings have allowed the classification of new syndromes with defined molecular abnormalities. The case we describe, because of the peculiar clinical features and the association with a previously unreported chromosomal translocation, might be a noteworthy addition.

Adult↗

The prognostic value of cytogenetics is reinforced by the kind of induction/consolidation therapy in influencing the outcome of acute myeloid leukemia--analysis of 848 patients.

We studied the impact of cytogenetics and kind of induction/consolidation therapy on 848 adult acute myeloid leukemia (AML) patients (age 15-83). The patients received three types of induction/consolidation regimen: standard (daunorubicin and cytosine arabinoside (3/7); two cycles); intensive (idarubicin, cytosine arabinoside and etoposide (ICE), plus mitoxantrone and intermediate-dose Ara-C (NOVIA)); and low-dose (low-dose cytosine arabinoside). CR patients under 60 years of age, if an HLA-identical donor was available received allogeneic stem cell transplantation (allo-SCT); otherwise, as part of the program, they underwent autologous (auto)-SCT. CR rates significantly associated with 'favorable' (inv(16), t(8;21)), 'intermediate' ('no abnormality', abn(11q23), +8, del(7q)) and 'unfavorable' (del (5q), -7, abn(3)(q21q26), t(6;9), 'complex' (more than three unrelated cytogenetic abnormalities)) karyotypes (88% vs 65% vs 36%, respectively; P = 0.0001). These trends were confirmed in all age groups. On therapeutic grounds, intensive induction did not determine significant increases of CR rates in any of the considered groups, with respect to standard induction. Low-dose induction was associated with significantly lower CR rates. Considering disease-free survival (DFS), multivariate analysis of the factors examined (including karyotype grouping) showed that only age > 60 years significantly affected outcome. However, in cases where intensive induction was adopted, 'favorable' karyotype was significantly related to longer DFS (P = 0.04). This was mainly due to the favorable outcome of t(8;21) patients treated with intensive induction. Patients receiving allo-SCT had significantly longer DFS (P = 0.005); in particular, allo-SCT significantly improved DFS in the 'favorable' and 'intermediate' groups (P = 0.04 and P = 0.048, respectively). In conclusion our study could provide some guidelines for AML therapy: (1) patients in the 'favorable' karyotype group seem to have a longer DFS when treated with an intensive induction/consolidation regimen, adopted before auto-SCT instead of standard induction; this underlines the importance of reinforcement of chemotherapy, not necessarily based on repeated high-dose AraC cycles. Allo-SCT, independently of induction/consolidation therapy, should be considered an alternative treatment; (2) patients in the 'intermediate' karyotype group should receive allo-SCT; (3) patients in the 'unfavorable' karyotype group should be treated using investigational chemotherapy, considering that even allo-SCT cannot provide a significantly longer DFS, but only a trend to a better prognosis.

Adolescent↗

Quantitative analysis of Fas and bcl-2 expression in hematopoietic precursors.

BACKGROUND AND OBJECTIVES: We investigated the expression of bcl-2 and CD95 (Apo1-/Fas) on CD34+ cells obtained from bone marrow (BM), mobilized peripheral blood (MPB), and umbilical cord blood (UCB) samples. The expression of bcl-2 and Fas was then compared with that of other markers usually associated with immaturity; functional tests using the agonistic antibody anti- Fas CH11 were also carried out. DESIGN AND METHODS: The analysis was performed by flow cytometry on purified CD34+ cells in a three (CD95 PE, CD34 APC and CD71 FITC) and in a four (CD38 PE, HLA-DR PerCP, CD34 APC and bcl-2 FITC) fluorescence assay. RESULTS: The results were expressed as mean fluorescence index (MFI); bcl-2 expression was significantly higher (p < 0.001) in BM (3.73 +/- 0.63) than in MPB (2.47 +/- 0.39) and UCB (2.38 +/- 0.58); Fas was significantly less expressed (p < 0.001) in UCB (1.27 +/- 0.78) than in MBP (3.63 +/- 2.19) and BM (4.56 +/- 1.69). CD34 expression was significantly (p < 0.001) brighter in UCB compared to in MBP and BM, while CD38 and CD71 were significantly (p = 0.005 and p < 0.001, respectively) more expressed in BM than in MPB and UCB. Fas values were directly correlated to CD38; both Fas and bcl-2 were directly related to CD71 and inversely to CD34. Culture assays showed that hematopoietic precursor cells from BM, MPB and UCB had a low susceptibility to undergo Fas-mediated apoptosis. INTERPRETATION AND CONCLUSIONS: In conclusion, bcl-2 and Fas are less expressed in UCB than in MPB and BM; early hematopoietic precursor cells are relatively resistant to CD95-triggered apoptosis; the observed correlation between Fas/bcl-2 and markers of immaturity suggests that they may be determinants of commitment in early hematopoietic precursors.

Adult↗

Level of minimal residual disease after consolidation therapy predicts outcome in acute myeloid leukemia.

We used flow cytometry to quantify minimal residual disease (MRD) in 56 patients with acute myeloid leukemia (AML) expressing a leukemia-associated phenotype. Thirty-four patients aged 18 to 60 years were entered into the AML-10 protocol (induction, consolidation, and autologous stem-cell transplantation [ASCT]), whereas 22 patients older than 60 years received the AML-13 protocol (induction, consolidation, and consolidation II). After induction, the level of MRD that was best associated with treatment outcome was 4.5 x 10(-4) residual leukemic cells. However, the outcome in patients with at least 4.5 x 10(-4) cells (n = 26) was not significantly different from that in patients with fewer leukemic cells (n = 30); there were 15 (58%) relapses in the first group and 12 (40%) relapses in the second. After consolidation, the most predictive MRD cutoff value was 3.5 x 10(-4) cells: 22 patients had an MRD level of 3.5 x 10(-4) cells or higher and 17 (77%) of these patients had relapse, compared with 5 of 29 patients (17%) with lower MRD levels (P <.001). An MRD level of 3.5 x 10(-4) cells or higher after consolidation was significantly correlated with poor or intermediate-risk cytogenetic findings, a multidrug resistance 1 (MDR1) phenotype, short duration of overall survival, and short duration of relapse-free survival (P =.014,.031,.00022, and.00014, respectively). In multivariate analysis, this MRD status was significantly associated with a high frequency of relapse (P <.001) and a short duration of overall (P =.025) and relapse-free survival (P =.007). ASCT did not alter the prognostic effect of high MRD levels after consolidation: the relapse rate after transplantation was 70%. Thus, we found that an MRD level of 3.5 x 10(-4) cells or higher at the end of consolidation strongly predicts relapse and is significantly associated with an MDR1 phenotype and intermediate or unfavorable cytogenetic findings. (Blood. 2000;96:3948-3952)

Actuarial Analysis↗

A novel t(11;12)(q23-24;q24) in a case of minimally-differentiated acute myeloid leukemia (AML-M0).

Acute myeloid leukemia with minimal signs of myeloid differentiation (AML-M0) is a recent addition to the FAB group classification. Chromosome data is scarce, but existing reports describe a high incidence of complex karyotypes and myelodysplastic syndrome-like chromosome alterations, while single chromosome translocations have rarely been reported. We describe the case of a 60-year-old woman diagnosed with AML-M0 with a novel translocation t(11;12)(q23-24;q24) as the sole karyotypic marker. Fluorescence in situ hybridization analysis to assess MLL gene splitting did not show rearrangement of this oncogene.

Acute Disease↗

A phase-II trial of all trans retinoic acid and low-dose cytosine arabinoside for the treatment of high-risk myelodysplastic syndromes.

Twenty-two patients with high-risk myelodysplastic syndrome (HRMDS) were treated with a 10-day course of oral all trans retinoic acid (45 mg/m2) and s.c. low-dose cytosine arabinoside (LDARAc) given at the dose of 20 mg twice per day. The courses were repeated monthly until response or progression, in the case of response, the therapy was administered until relapse. Morphologic diagnoses were refractory anemia with excess blasts (RAEB) in nine, RAEB in transformation (RAEB-t) in nine, and chronic myelomonocytic leukemia (CMMoL) in four patients; in all cases, bone-marrow blast infiltration was greater than 10% (median 20%, range 12-30%). When the international prognostic scoring system was applied, all the cases qualified as intermediate/high-risk categories. Nineteen patients were males and three were females; the median age was 69 years (range 25-90 years); three patients had previously been treated with conventional chemotherapy, and one of them had also undergone autologous bone-marrow transplantation. The criteria of response were defined as follows: (1) complete response: normalization of blood counts and bone-marrow blasts (<5%), and (2) partial response: decrease in bone-marrow blast infiltration by 50%, and two of the following parameters - improvement in hemoglobin level by 1.5 g/dl or decrease by 50% in transfusional requirement, increase by 50% in absolute neutrophil count, and increase by 50% in platelet count. Overall, 7 (32%) of 22 patients achieved a response, with 5 (23%) being classified as complete responders and 2 (9%) as partial responders. Fifteen (68%) patients did not achieve any response, and 14 died of progressive disease or infectious disease. The overall median survival was 8 months (range 1-27 months), whereas the median survival of responders was 16 months (range 8-27 months); the median duration of response was 11 months (range 2-21 months). Moderate to severe hematological toxicity and infections were the most common side effects. In conclusion, it seems that the association of ATRA and LDARA-C may be effective in approximately 30% of HRMDS patients. Optimizing this approach might be pursued by selecting, on a biological basis, those cases more likely to respond or by incorporating other differentiating agents or growth factors.

Administration, Oral↗

Acute leukemia following a previous malignancy: do acute lymphoid leukemia and acute myeloid leukemia have common risk factors?

INTRODUCTION: Within the framework of the GIMEMA Study Group, the characteristics of acute lymphoid leukemia and acute myeloid leukemia occurring in patients who have suffered a previous malignancy were studied. Assessment was also made of the clinical course, laboratory features and overall outcome of these conditions. MATERIALS AND METHODS: A four-year, multi-center retrospective study was conducted to evaluate the effect of treatment for previous hematological malignancy on the development of secondary leukemia. The study collected in the GIMEMA Archive of Adult Acute Leukemia 3934 new cases of acute leukemia (2964 AML, 901 ALL, 60 acute biphenotypic leukemia). Among these cases, data were evaluated from patients with a personal history of a previous malignancy, and included inquiring into demographic data, history of neoplastic diseases in the 1st degree relatives, type and treatment of the previous malignancy, latency until the development of a secondary acute leukemia diagnosis, laboratory features, treatment and outcome at the onset of secondary acute leukemia. RESULTS: Approximately 200 (5.1%) patients presented a previous malignancy. Twenty-one were affected by ALL and 179 by AML. The proportion of patients with secondary AML was higher than that of patients with secondary ALL (179/2964 vs 21/901, O.R. 2.69-95% C.I. 1.66-4.39, P<0.001). The median latency, from the onset of the previous malignancy to the development of secondary ALL was 27 months and to the development of secondary AML was 52 months (P<0.05). Furthermore, of patients who previously received chemotherapy more developed a second AML (66/127 sAML vs 5/21 sALL; O.R. 3.46-95% C.I. 1.10-11.56, P<0.01). CONCLUSION: In most cases, chemotherapy treatment for a previous malignancy can play a role in the development of secondary AML. In almost all cases of secondary ALL, the role of previous drugs does not appear to be relevant. On the basis of our analysis, performed systematically for the first time on a large adult series of acute leukemia, we conclude that in these patients a biological predisposition to cancer may be suspected.

Acute Disease↗

Autologous peripheral blood stem cell transplantation as first line treatment of multiple myeloma: an Italian Multicenter Study.

BACKGROUND AND OBJECTIVE: The outcome of patients with multiple myeloma (MM) has not changed markedly since the introduction of melphalan and prednisone. In recent years several studies have investigated the role of intensive therapy followed by infusion of autologous peripheral blood stem cells (PBSC) together with the administration of hematopoietic growth factors. In this study we evaluated the feasibility and efficacy of a PBSC transplantation program for patients with de novo MM in a multicenter setting. DESIGN AND METHODS: In a non-randomized controlled trial 52 patients with de novo MM from 6 Italian centers underwent a three phase treatment strategy including 3 cycles of VAD-like chemotherapy for initial debulking, followed by high-dose cyclophosphamide (HD-CY) and collection of PBSC, that were transplanted after a conditioning regimen with melphalan plus busulfan. Maintenance treatment was a conventional dose of interferon, given until relapse. Actuarial survival and response duration curves were plotted according to Kaplan and Meier's method; the groups were compared using the log rank test. Response rates were compared by the c(2) test; multivariate analysis was performed according to the stepwise regression model. RESULTS: Overall 39/52 (75%) of patients responded, with a complete remission (CR) rate of 31%. After a median follow-up of 55 months, median duration of event-free survival (EFS) and overall survival (OS) are 21 and 57 months, with 24% and 48% probabilities of being event-free and alive after 6 years, respectively. Among the group of 39 responders, CR was significantly associated with prolonged response and survival (2 deaths and 6 relapses/16 patients) as compared with PR (11 deaths and 15 relapses/23 patients), and remained the only significant variable also in a multivariate analysis. Myelosuppression did not protract beyond one week in transplanted patients; extra-hematologic toxicity was very low. INTERPRETATION AND CONCLUSIONS: This multicenter study confirms the feasibility of an aggressive approach to de novo MM patients. Additional confirmation is given of the increased rate of CR, and the significant prolonged survival observed in complete responders. In this experience the association melphalan plus busulfan was shown to be effective, at least as part of conditioning regimens, in the transplant strategy.

Adult↗

P-glycoprotein and terminal transferase expression identify prognostic subsets within cytogenetic risk classes in acute myeloid leukemia.

Clinical and biological features were assessed in 204 consecutive de novo adult acute myeloid leukemia (AML) patients who received intensive chemotherapy regimens. Multiparameter flow cytometric assays both of the multidrug resistance (MDR-1)-associated P-glycoprotein (PGP) using the UIC2 monoclonal antibody (MoAb), and of terminal transferase (TdT) were performed. Cytogenetic findings were obtained from 196 patients with high resolution banding. At onset, UIC2 and TdT positivities were detected in 58.5% and 24% of cases, respectively. There were strict correlations either between UIC2 negativity and FAB M3 or between TdT and FAB M0-M1 (P = 0.001 and < 0.0001, respectively). On the other hand, age was significantly associated with cytogenetic risk classes (P < 0.0001). CD34 positivity was highly correlated with TdT expression (P < 0.0001). Moreover, CD7 and CD11b were significantly represented in UIC2+ subset (P < 0.0001). Rhodamine 123 (Rh 123) efflux was significantly higher in 75 UIC2 positive patients compared to 65 UIC2 negative ones (P < 0.001). As regards to cytogenetics, TdT positivity was strongly related either to t(9;22) or single/associated anomalies of chromosome 7; on the other hand, most or all cases with t(8;21) or t(15;17) were UIC2 or TdT negative, respectively. The rate of first complete remission (CR) differed both between UIC2+ and UIC2- cases and between TdT+ and TdT- ones (40% versus 72%, P < 0.001; and 36% versus 61%, P = 0.001, respectively). The survival rates (Kaplan-Meier method) were significantly shorter either in UIC2+ or in TdT+ patients (P = 0.005 and = 0.011, respectively). UIC2 and TdT negative cases showed longer remission duration (P = 0.03 and = 0.22, respectively). The additional effect of UIC2 and TdT on prognosis allowed us to identify two subsets of patients, the first [UIC2- TdT-] at better and the second [UIC2+ TdT+] at worse clinical outcome compared to single UIC2 and TdT cases, concerning CR (P < 0.001), survival (P < 0.0001) and CR duration (P = 0.007). The combinations [UIC2+ TdT-] and [UIC2- TdT+] showed an intermediate clinical course. A strong difference was found between poor risk and intermediate/favorable risk cytogenetic classes with regard to CR rate (P < 0.0001), overall survival and CR duration (P < 0.001). Nevertheless, within the poor risk class, UIC2 positivity was able to identify patients at worst prognosis with regard to CR (P = 0.005), survival (P = 0.02) and CR duration (P = 0.015). On the other hand, UIC2 and TdT negativity allowed us to distinguish patients with longer survival (P = 0.012 and = 0.04, respectively) and CR duration (P = 0.04 and = 0.025, respectively) within the intermediate/favorable risk class. The independent prognostic value of UIC2, TdT and cytogenetic risk classes was confirmed in multivariate analysis. These results suggest that PGP and TdT expressions, together with cytogenetic findings, may represent a basic predictor of chemotherapeutic failure in AML.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Enumeration of CD34+ hematopoietic progenitor cells for clinical transplantation: comparison of three different methods.

Three different methods for determination of CD34+ cells in G-CSF-mobilized peripheral blood were compared. The methods were: the Milan/Mulhouse protocol, the ISHAGE guidelines for CD34+ cells enumeration and our own protocol. The procedure we have adopted is essentially a Milan/Mulhouse protocol-derived methodology combined with a multiparametric approach using the PAINT-A-GATE software analysis program. The samples were collected from 70 patients affected by acute leukemia, non-Hodgkin's lymphoma, Hodgkin's lymphoma, myeloma and breast cancer who were scheduled to receive autologous PBSC transplantation. PBSC collection was performed following mobilization with subcutaneous G-CSF at 5-10 microg/kg/day. A minimum target of 2 x 10(6)/kg CD34+ cells was considered an acceptable harvest to ensure a safe transplant. On average, three aphereses per patient were performed and a total of 204 apheresis samples were analyzed. Regression analysis of the percentage and absolute number of CD34+ cells, as calculated with each method, achieved an excellent correlation in spite of methodological differences. In fact, both CD34+dim and CD34+CD45- events were included in our gating strategy. In the setting of a triple staining associating CD34, CD38 and CD45, we identified a variable fraction of CD34+CD38+CD45- cells which would be otherwise undetected due to its CD45 negativity. To this end, we used a new technology referred to as laser-scanning cytometry (LSC) which allowed the isolation and morphological identification of CD34+CD45- cells. By comparing CD34+CD45+ and CD34+CD45- cells, we found that they share a common morphology, thus confirming the hypothesis that the latter are to be considered for CD34+ cell calculation. The median number of CD34+ cells/kg, as calculated by the three methods, was: 4.79 x 10(6)/kg (range 1-570) for the Milan/Mulhouse protocol, 3.9 x 10(6)/kg (range 0.8-498) for the ISHAGE one, and 5.17 x 10(6)/kg (range 2-599) for our protocol. The median time to ANC and PLT engraftment was 11 (range 9-24) and 20 (range 10-70) days, respectively. Our protocol achieved the best correlation between CD34+ cells/kg and time to ANC/PLT recovery according to the Spearman's rank test (r = -40 and P < 0. 015 for ANC, r= -46 and P = 0.005 for PLT). We conclude that (1) CD45 does not appear the ideal partner of HPCA-2 for determination of hematopoietic progenitors in mobilized peripheral blood; and (2) for clinical application, a single staining with 8G12 appears simple, reliable and feasible when rigorous procedures for sample preparation and acquisition are followed and an adequate software for multiparametric analysis is available.

Antigens, CD34↗