Time Of Hematological Recovery Research Articles

PF779 VIABILITY OF HEMATOPOETIC STEM CELLS FOLLOWING STORAGE AT −80OC WITH 5% DIMETHYLSULFOXIDE AND HEMATOLOGIC RECOVERY IN TRANSPLANTED MYELOMA PATIENTS

Background:Dimethylsulfoxide (DMSO) is a major intracellular cryoprotectant, used for cryopreservation of stem cells. It is toxic to both cells and patients at temperatures above 0oC. Reduction of this effect is achieved by either washing of cells after thawing or by reduction of DMSO during freezing and storage. The latter requires addition of extracellular cryoprotectants to the freezing media.Aims:We assessed the effect of low DMSO concentration and different hematocrits of the frozen cells on cell viability and hematologic recovery in patients, transplanted for multiple myeloma.Methods:Cells were non‐programmed frozen and stored at −80oC in a cryoprotectant solution achieving final concentrations of 5% DMSO, 3.6% of hydroxyethyl starch (HES, Weight average molecular weight 450 000 Da) and 3% of human serum albumin. The cell concentration in the frozen product for the first 77 patients (84 transplantations) varied between 100x106 and 250x106 cells/ml. In an attempt to reduce the amount of DMSO infused, for the rest of the patients (n = 172; 192 transplantations) we further decreased the volume of the freezing suspension by removal of the entire plasma.The average age of the transplanted patients was 55 (35 ‐ 71). The cells were bedside thawed at 37oC water bath. The average cell dose was 2,95x106/kg (1,3 – 9,2x106/kg).Results:Viability of the stem cells following thawing assessed by trypan blue exclusion was 95,34% (70–99). The hematocrit of the frozen cells had no effect on cell viability (94,80%(low) vs 95,52%(high)). The major complaints, if any, during stem cell infusion were coughing and an increase in nausea and vomiting induced by the prior conditioning.The average time for hematological recovery was 11,66 days (between 9 and 19) for the neutrophils, and 12,17 (between 9 and 20) days for the platelets. There was no significant difference in viability and hematologic recovery (11,86 and 12,60 vs 11,59 and 12,02) between patients receiving cells frozen with low or high hematocrit.Summary/Conclusion:Dimethylsulfoxide, despite its cryoprotective properties, is toxic for stem cells at temperatures above zero C and induces many side effects (cardiac, neurologic, respiratory, etc.) in the patients. To reduce those side effects we use lower DMSO concentration, high hematocrit resulting in lower volume of the frozen cell suspension, thus reducing the final quantity of DMSO to be infused to the patients. This does not affect the cell viability or the hematologic recovery of patients after transplantation. Our easily performed method for unprogrammed freezing of stem cells with final DMSO concentration 5% at −80oC is safe, well tolerated, and provides cryopreservation, which allows high viability and stable cell engraftment, while reducing the undesired side effects of DMSO.

PB2365 CELL DOSE AND HEMATOLOGIC RECOVERY AFTER AUTOLOGOUS STEM CELL TRANSPLANTATION FOR MULTIPLE MYELOMA

Background:The relation between the dose of the infused hematopoietic stem cells and the time of hematologic recovery after autologous transplantation has been investigated in different types of patients.Aims:We assessed the strength of this relation in patients with multiple myeloma, transplanted in our center.Methods:We analyzed the relation between different factors and the hematologic recovery in 277 transplantations performed on 249 patients (138 male and 111 female) with multiple myeloma, who underwent autologous transplants between 2005 and 2018. Twenty eight of them had second (tandem or not tandem) transplantation.The conditioning regimen consisted of Melphalan for most of the patients. The average age at the time of transplantation was 55 years (35 ‐ 71). Patients were transplanted with an average cell dose of 2,95 × 106/kg (1,30 – 9,20 × 106/kg) for the first transplantation and 2,36 × 106/kg (1,64 – 3,19 × 106/kg) for the second one (every patient received the same cell dose as for the first) with average cell viability 95,34 % (70 – 99%), with little difference between first and second transplantation.Results:The average time for hematological recovery was 11,60 (between 9 and 19) days for the neutrophils, and 12.11 (between 9 and 20) days for the platelets.We found no correlation between the cell dose and the hematological recovery. There was no difference in the hematopoietic recovery between the first and the second transplantation in the patients, who underwent tandem or two transplantations.Summary/Conclusion:Recovery time is considered by some to be a function of the effective stem cell number. We did not find such correlation, probably because in the analyzed group all the patients, except four of them, received a dose greater than 2 × 106/kg cell, which is accepted as a safe dose for autologous stem cell transplantation.

Intrabone Transplantation of a Single Cord Blood Unit Using Non-Irradiated Reduced-Intensity Conditioning

Intrabone Transplantation of a Single Cord Blood Unit Using Non-Irradiated Reduced-Intensity Conditioning

The prognostic value of hematogones in patients with acute myeloid leukemia.

In acute myeloid leukemia (AML), new prognostic tools are needed to assess the risk of relapse. Hematogones (HGs) are normal B-lymphocyte precursors that increase in hematological diseases and may influence remission duration in AML. HG detection was prospectively investigated in 262 AML patients to determine its prognostic value. Flow cytometric HG detection was performed in bone marrow aspiration after intensive chemotherapy at the time of hematological recovery. Patients with HGs in bone marrow samples had a significantly better relapse-free survival (RFS) and overall survival (OS) than patients without HGs (P = 0.0021, and P = 0.0016). Detectable HGs independently predicted RFS (HR = 0.61, 95%CI: 0.42 - 0.89, P = 0.012) and OS (HR = 0.59, 95%CI: 0.38 - 0.92, 0.019) controlling for age, ELN classification, the number of chemotherapy cycles to achieve CR, performance status, secondary AML and flow cytometric minimal residual disease (MRD). In intensively treated AML, individual determination of HGs could be useful to stratify the optimal risk-adapted therapeutic strategy after induction chemotherapy. Am. J. Hematol. 91:566-570, 2016. © 2016 Wiley Periodicals, Inc.

IL‐10 promoter polymorphisms influence susceptibility to aGvHD and are associated with proportions of CD4+FoxP3+ lymphocytes in blood after hematopoietic stem cell transplantation

Four hundred and ninety-five patients (390 and 105 grafted from unrelated and sibling (SIB) donors, respectively) and their donors were analyzed for the impact of interleukin-10 (IL-10) promoter genotype [rs18000896 (-1082 G/A), rs18000871 (-819 C/T) and rs18000872 (-592 C/A)] on the outcome of hematopoietic stem cell transplantation (HSCT). Patients having ACC haplotype were at a lower risk of acute graft versus host disease (aGvHD, grade > I) if transplanted from human leukocyte antigen (HLA) well-matched (10/10) unrelated donors (20/135 vs 39/117, P < 0.001, Pcorr = 0.002), which was not seen if patients were transplanted from either sibling (SIB) or poorly matched (<10/10) unrelated donors (MUD). In addition, GCC haplotype positive recipients of unrelated donor transplants tended to be more susceptible to aGvHD (68/199 vs 39/169, P = 0.019, Pcorr = 0.057). Multivariate logistic regression analysis in the MUD transplanted group showed that donor-recipient human leukocyte antigen (HLA) mismatch [odds ratio (OR) = 3.937, P = 0.001] and a lack of ACC haplotype in recipients (OR = 0.417, P = 0.013) played a significant role as independent risk factors of aGvHD grade > I. ACC carriers had higher proportions of FoxP3+ lymphocytes gated in CD4+ lymphocytes as compared with patients with other IL-10 haplotypes. It was seen at the time of hematological recovery (mean ± SEM: 3.80 ± 0.91% vs 2.06 ± 0.98%, P = 0.012) and 2 weeks later (5.32 ± 0.87% vs 2.50 ± 0.83%, P = 0.013); -592 C/A polymorphism was separately analyzed and it was found that AA homozygotes tended to have a higher incidence of aGvHD (8/15 vs 116/456, P = 0.034) and low proportions of FoxP3 CD4+ lymphocytes in blood (0.43 ± 0.22% vs 4.32 ± 0.71%, P = 0.051) measured 2 weeks after hematological recovery. Functional IL-10 polymorphism associated features influenced the risk of aGvHD with a positive effect of ACC on the pool of Treg in blood.

Occurrence Of Deep Vein Thrombosis and Pulmonary Embolism In Acute Promyelocytic Leukemia (APL) Patients

APL is a highly curable malignancy with cure rates in excess of 90% in most co-operative group trials. Population-based studies show that the survival is approximately 65-70% with up to 30% early deaths. The most common reasons of early deaths are bleeding, differentiation syndrome (DS) and infection. The bleeding seen in APL is due to disseminated intravascular coagulation (DIC) and is very unique to this disease. It can be very severe in some patients leading to fatal bleeding resulting in early deaths. APL can also induce a pro-coagulant state although much more rare than the bleeding condition. There have been reports of deep vein thrombosis in patients being treated for APL however most of the literature is in the form of case reports and there is very limited data on the incidence of thrombosis in APL. Here we report the incidence of DVT/PE in patients undergoing induction for APL at our institution. MethodsWe performed a retrospective chart review on patients diagnosed with APL who received induction between December 1, 2004 and July 30, 2013 at Georgia Regents University and also patients who were referred to us from surrounding treatment centers with whom we co-manage APL patients. Radiological evidence of deep vein thrombosis or pulmonary embolism by either ultrasound or CT scans was reviewed. ResultsForty-one patients with APL treated by our facility were reviewed. Seven patients died during induction and 1 patient refused treatment. Age range of the patients treated was 21-75 years. In the surviving 33 patients either treated or co-managed at our institution, 6 patients (18.2%) had thrombosis (DVT/PE). Age range of the patients with DVT was 30-70 years. 4 out of 6 patients that developed DVT were female. In three patients it was associated with a catheter in the same arm. 5 out of 6 patients had the thrombosis around the time of hematological recovery with one patient developing DVT early in the hospitalization. All patients were treated with anticoagulation and there were no deaths from DVT/PE. ConclusionsAcute deep vein thrombosis is felt to be a relatively uncommon presentation in APL. At our institution we found an increased incidence of DVT/PE mostly occurring around the time of hematological recovery. APL can also induce a pro-coagulant state and it is unclear as to why most of the patients had thrombotic episodes around the time of hematological recovery. There is also an increase in differentiation syndrome in the late stages of induction which might be cytokine mediated inflammation. This same process may also play a role in increased incidence of thrombotic episodes seen in this group of patients. We present this data to increase physician awareness regarding the possibility of DVT/PE in APL patients especially around the time of count recovery. We now routinely advocate the use of Venodynes in APL patients and are more rigorous with the implementation especially given our observation of increased incidence of DVT/PE. Disclosures:No relevant conflicts of interest to declare.

Low Blood Levels of Th17 Cells Are Seen in Patients with aGvHD and Associate with Rather Poor Survival Post HSCT,

Abstract 4079Alloreactivity strongly influences the course post HSCT being a primary force in pathomechanism of aGvHD, shapes the immunological reconstitution post-transplant and mounts graft vs leukemia effect. Therefore the understanding of the interplay between the main subsets of CD4 positive cells may help in understanding the mechanism which facilitates the activity of the immune system post HSCT. For that we investigated the presence of cells with a potential to generate IL-17, IFN-gamma and FoxP3 lymphocytes appearing in blood to post HSCT.The cytoplasmic expressions of IL-17A, FoxP3 and IFN-gamma were studied in stimulated PBMC (brefeldin A, Ionomycin and PMA) of alloHSCT patients (63 patients, median age: 43 yrs, range: 5.5 –60 yrs), 12 patients manifested aGvHD at the time of hematological recovery and in 17 patients aGvHD was clinically apparent after hematological reconstitution (from 17 to 93, median 31). The cells were labeled for CD4 (Becton Dickinson, San Jose, CA, USA) and intracellular IL-17A (e-biosciences, San Diego, CA, USA), FoxP3 and IFN-gamma (Becton Dickinson, San Jose, CA, USA) detection. All studied cases were genotyped for NOD2/CARD15 mutations: 104C-T (SNP8, Arg702W; rs.2066844), 2722G-C (SNP12, Gly908Arg; rs.2066845), and 3020insC (SNP13, Leu1007fsinsC; rs.2066847) with the use of RFLP-PCR technique.Patients post HSCT studied at the beginning of hematological recovery (1st observation point) had lower blood levels of IL-17 producing lymphocytes in CD4+ cells (Th17) independently whether they developed aGvHD at the hematological recovery or (later time) post-transplant as compared to those lacking aGvHD (median 0.090% (0.195%) vs 0.425%, p=0.019 (p=0.126)).Primarily low Th17 blood level in aGvHD cases normalized (increased) along the observation time, when a positive response to the therapy was noticed, being in one week intervals in the levels as follow (1st vs 2nd (3rd) time point: median 0.090% vs 0.355% (0.355%), p=0.049 (p=0.061)). Of note, patients lacking aGvHD at any time post HSCT had similar blood levels of Th-17 cells during 30 days post-transplant observation time.The first quartile of Th17 blood values of the whole group was 0.1% and this value was chosen as a cut-off point dividing the whole group into patients with low and higher blood Th17 levels. It became apparent that survival of patients having low Th17 blood levels at the beginning of hematological recovery, irrespective of the presence of absence of aGvHD, had poorer survival (2 yrs survival 30% vs 61%, p=0.045). When fatal cases were analyzed patients with low Th17 blood levels died rather due to aGvHD and those with higher levels due to infectious complications or relapse (7/10 vs 4/16, p=0.043).FoxP3+ cells and IFN-gamma producing lymphocytes were determined in blood of HSCT patients at the same time as it was done for Th17 cells. It was shown that the blood levels of FoxP3+ cells were well correlated with the levels of IFN-gamma producing cells (r=0.405, p=0.003) but not to the similar extent with Th17 cells (r=0.253, p=0.047).Th17 plays an important role in the mucous membrane barrier against microbial infections. Mutations in NOD2/CARD15 gene are described as a risk factor of aGvHD. We found that mutations in the NOD2/CARD15 gene is not more frequent in aGvHD cases but influences the level of Th17 in blood in such a way that patients with mutations had lower blood values of Th17 at the hematological recovery in the aGvHD group (median 0.080% vs 0.210%, p=0.051) as well as in the whole alloHSCT patient group (median 0.080% vs 0.310%, p=0.027).Conclusions:1.Th17 lymphocytes being lower at the beginning of aGvHD manifestation likely to marginalize at the sites of inflammation.2.Low levels of Th17 were associated with rather poor survival of HSCT pts with aGvHD as a primary cause of death.3.NOD2/CARD15 mutations associate with lower values of Th17 in blood.Supported by the grants N N402 430039 and N R13 0082 06 from the Polish Ministry of Science & Higher Education. Disclosures:No relevant conflicts of interest to declare.

Multi-Course of Moderate Dose Cytosine Arabinoside and Fludarabin in the Consolidation Therapy of Patients with De Novo Acute Myeloid Leukemia

Abstract 4251To investigate the long-term outcome of multi-course of moderate dose cytosine arabinoside and fludarabin in the consolidation therapy of patients with de novo acute myeloid leukemia (AML). Sixty-seven consecutive de novo AML patients, 38 males, 29 females, including M1 (5 cases), M2a (34 cases), M4 (11 cases), M5 (13 cases), M6 (2 cases), unclassified AML (1 cases), HAL (1 case), were enrolled in this retrospective analysis between 2006 to 2011. Their median age was 32.28 years (range 13–64 years). Cytogenetic analysis showed that 27 patients with normal karyotype, 11 patients with t(8; 21), 4 patients with inv(16), 16 patients with other karyotype. Forty-two cases were classified as low and intermediate risk groups based on karyotype analysis and fusion gene detection. Thirty-eight cases and twenth-nine cases achieved complete remission (CR) after one course and two course induction chemotherapy (such as cytarabine with idarubicin or daunorubicin and mitoxantrone etc), respectively.All patients received at least two-course consolidation therapy with moderate dose cytosine arabinoside (2g/m2) and fludarabin (30mg/m2) for 3 days (FA). Nineteen cases received two courses, 20 three courses, 20 four courses, 8 five courses and1 six courses. Quantitative RT-PCR and flow cytometry were used to detect minimal residual disease. Afterwards 3 patients underwent allogeneic stem cell transplantation. The median time for hematological recovery of neutrophils©ƒ500/microl and platelets©ƒ20,000/microl was 12 and 16 days, respectively. The median length of hospitalization was 18 days. Non-hematological toxicity consisted of mild gastrointestinal reaction and mild hepatic dysfunction, forty percent of patients experienced fever. There was no treatment-related mortality during consolidation. After follow up of 4–54 months, 10/19 (52.6%) cases were relapse-free survival (RFS) after two courses FA consolidation, 15/20 (75%) cases in three courses, 15/20 (75%) cases in four courses, respectively. 8 cases were all in RFS after five courses consolidation. 1 case was also in RFS after six courses FA consolidation. Three-year overall survival, event free survival and RFS was 67%, 67%, and 66%, respectively. Our results suggest that multi-course FA consolidation is effective in de novo AML patients with low-risk and moderate-risk diseases. To reduce the recurrence rate the number of courses should be increased. Non-hematological toxicity was mild and the toxicity is acceptable. Disclosures:No relevant conflicts of interest to declare.

TH17 CD4+ CELLS Disappear FROM BLOOD at the Onset of aGVHD

AbstractAbstract 2307IL-17 producing cells expand in the environment rich in IL-6 and TGF-beta. Our previous observation documented an increase in IL-6 and its reading protein CRP during the hematological recovery and later on at the time of frequent infectious complications. Therefore, HSCT patients are in a high risk of the expansion of Th17 lymphocytes which are potent pro-inflammatory lymphocytes. In this study we investigated the proportions of IL-17 producing cells in 7 days intervals beginning from hematological recovery covering the time of a risk of aGvHD and infectious complications post transplant. To illustrate the background to the generation of Th17+ lymphocytes serum CRP levels were measured and the manifestation of aGvHD was noted and followed. This study included also determination of NOD2/CARD15 gene mutation.The cytoplasmic expressions of IL-17A were studied in stimulated PBMC (brefeldin A, Ionomycin and PMA) of alloHSCT pts (58 pts, median age: 42 yrs, range; 1.0–64 yrs), 14 patients manifested aGvHD at the time of hematological recovery and in 13 patients with aGvHD was clinically apparent later time post HSCT (from 18 to 93, median 36). The cells were labeled for CD4 (Becton Dickinson, San Jose, CA, USA) and intracellular IL-17A (e-biosciences, San Diego, CA, USA) detection. Fifty six transplanted cases were genotyped for 2104C-T (SNP8, Arg702W; rs.2066844), 2722G-C (SNP12, Gly908Arg; rs.2066845), and 3020insC (SNP13, Leu1007fsinsC; rs.2066847) mutations with the use of RFLP-PCR technique.We found: (1) 14 pts with aGvHD seen at the time of hematological recovery (median 15.5 days, from 9 to 21 days post HSCT, when WBC > 500/ul and lymphocytes > 200/ul,) had lower percentages of IL-17A producing cells in CD4+ lymphocyte population as compared to those lacking aGvHD at the same stage of recovery (median 15 days, from 10 to 31), (0.29%±0.09 vs 0.78%±0.13, p=0.02, M-W U-Test). (2) 13 pts with aGvHD seen between 18 to 93 day post HSCT (median 36) had also lower percentage of IL-17A producing cells in CD4+ lymphocytes as compared to those lacking aGvHD and examined for the presence of IL-17A+ lymphocytes at the similar time post HSCT (median 35 day, from 27 to 43), (0.29±0.10 vs 0.99%±0.25, p=0.015 M-W U-Test), (2) manifestation of aGvHD at later time post HSCT allowed to examine the presence of IL-17A producing CD4+ lymphocytes prior to and then at the aGvHD manifestation. It was a significant decrease in proportions of IL-17A producing CD4+ lymphocytes at the day of aGvHD manifestation as compared to previous examinations performed 3 to 7 days before aGvHD became clinically apparent (1.02%±0.33 vs 0.29%±0.10, n=13, p=0.0009, Wilcoxon Test for pairs). Among these 13 pts 6 had only skin and 7 also gastrointestinal aGvHD, the latter pts had lower percentage of IL-17A producing CD4+ lymphocytes than those with only skin lesions (0.21%±0.08 vs 1.33%±0.47, for gut and skin aGvHD, respectively).3) 5 out of 56 (8.9%) transplanted cases were positive for at least one out of three major NOD2/CARD15 mutations (SNP8, SNP12 and SNP13), notably all 3 patients with gut manifestation and investigated for NOD2/CARD15 mutation had this gene mutated what was seen only in 4 out of 17 pts with skin symptoms (p=0.017 Fisher exact test). In the present observation no correlation was found between CRP elevation and the proportion of IL-17 producing cells in CD4+ lymphocytes. Conclusions;1. Apparent clinical manifestation of aGvHD associates with a low proportion of Th17 lymphocytes in blood, 2. This is rather an active process as Th17+ cells proportions decline in blood during 3 to 7 days prior to overt aGvHD. 3. Gut manifestation associates with significantly lower number of blood Th17+ lymphocytes than seen in pts with only skin lesions. 4. NOD2 mutation may constitute a risk factor of gut aGvHD.Supported by grant N R13 0082 06 from the Polish Ministry of Science & Higher Education. Disclosures:No relevant conflicts of interest to declare.

Treatment of Older Patients, 40 to 70 Years of Age, with Acute Lymphoblastic Leukemia According to a Chemotherapy Regimen That Includes a Novel Pre-Phase for Rapid Tumor Load Reduction. Results of the Dutch-Belgian HOVON-71 Study.

Abstract 2028Poster Board II-5 Background.Based on the dismal outcome of older patients with ALL and a promising pilot study in a single institution, HOVON started a multicenter phase 2 feasibility study to assess efficacy and safety of a novel chemotherapy regimen for patients between 40 and 70 years of age (younger patients being eligible for a pediatric treatment schedule in a parallel study). The innovative part of the study consisted of a relatively intensive “pre-induction” course for rapid reduction of the tumor load. Treatment schedule.The pre-induction course consisted of cytarabine 200 mg/m2 and etoposide 120 mg/m2 on day 1, and 8 and MTX 500 mg/m2 on day 4, and 11. This was followed on day 15 by an induction course of vincristine 1 mg/wk x 3, dexamethasone 8-12 mg/d x 21 depending on body weight, and adriamycine 40 mg (>60 yr: 30 mg)/m2/d on day 2-4 (ODA). After regeneration of the bone marrow, ODA was repeated once in patients with at least a partial remission. Subsequently, consolidation with cytarabine 1000 mg/m2/12 hr x 4 followed by asparaginase 6,000 IU/m2/d x 10 was given, and, finally, regular maintenance therapy for 30 cycles. Intrathecal prophylaxis consisted of weekly MTX 15 (>60 yr: 10) mg x 4 followed by monthly MTX 15 (> 60 yr: 10) mg x 6. Patients with t(9;22) also received imatinib 600 mg/d, except during asparaginase administration; patients in complete remission (CR) were eligible for nonmyeloablative allogeneic stem cell transplantation (SCT) using either sibling (sib) or matched unrelated donors (MUD). Results.Sixty patients, 27 males and 33 females, with a median age of 57 years (range 40–69) were enrolled; 40% were over 60 years. B-lineage ALL was present in 54. Median WBC count at diagnosis was 6.3 × 109/l (range 0.7-186). t(9;22) was present in 16 (34%) and t(4;11) in 4 (9%) of 47 patients with available karyotype or FISH data. Based on WBC, cytogenetics, and time to CR 31 patients (52%) were considered high risk and 29 (48%) standard risk. Fifty-one patients (85%) attained CR, 47 of them after the first ODA course. One patient was a nonresponder. Ten patients (17%) died during the early phases of intensive chemotherapy mainly due to infection. Moreover, treatment had to be withdrawn or delayed in 12 (20%) because of side effects such as grade 3-4 mucositis and infection. Seventeen patients underwent allo-SCT (10 sib, 7 MUD) in first CR. After a median follow-up of 21 months (range 15–37), 37 patients (62%) were alive; 13 (22%) relapsed, 6 of them after SCT. The 2-year EFS was 48% (95% CI 32-63%), 2-year DFS 51% (32-68%), and 2-year OS 61% (47-73%). Conclusion.Notwithstanding considerable toxicity including early mortality of 17%, this schedule produced high survival and low relapse rates, especially when considering the median age of 57 years and the relatively high number of high risk patients. The pre-induction course induced a rapid reduction of (circulating) blasts in all patients. Based on this phase 2 study a prospective randomized trial has recently been initiated. In order to reduce toxicity the protocol has been amended by replacing dexamethasone by prednisone, allowing time for hematological recovery after the pre-induction course, growth factor support, and optimizing antibiotic prophylaxis. Disclosures:No relevant conflicts of interest to declare.

Fludarabine, cytarabine, and G-CSF (FLAG) for the treatment of acute myeloid leukemia relapsing after autologous stem cell transplantation.

Twenty-six patients affected by acute myeloid leukemia (AML) who relapsed after autologous stem cell transplantation (ASCT) were treated with the FLAG regimen (fludarabine, cytarabine, and G-CSF). Their median age was 39 years (range 14-59). The median interval from achievement of CR to ASCT was 4 months (2-8). The conditioning regimen was BAVC (BCNU, amsacrine, VP-16, cytarabine) in eight patients, BuCy (busulfan, cyclophosphamide) in 13, and TBI-Cy (total body irradiation, cyclophosphamide) in five. Relapse occurred after a median of 7 months (2-18). ASCT had been performed in CR1 for 23 patients and in CR2 for three. Nineteen patients had been given bone marrow, seven peripheral blood stem cells collected following consolidation plus G-CSF. Overall, CR was obtained by 13 patients (50%), all remitters requiring a single course. The median time for hematological recovery of neutrophils >500/microl and platelets >20,000/microl was 24 and 30 days, respectively. The median duration of G-CSF administration was 25 days, while the median hospitalization was 31 days. There were four deaths in induction (15%), while nine patients (35%) were resistant. After achieving CR, two patients received allogeneic BMT, five a second ASCT, and four were consolidated with HD-ARA-C. Only two patients were judged unable to receive any further therapy. There were 14 documented infections, while nine patients experienced fever of unknown origin. WHO >2 nonhematological toxicity consisted of stomatitis (50%), hepatic dysfunction (11%), diarrhea (11%), and lethargy (4%). Median overall survival and disease-free survival were 6 and 13 months, respectively. Six patients are in CCR at present. We conclude that FLAG is effective in patients with AML who are relapsing after ASCT. The toxicity is acceptable, enabling most patients to receive further treatment, including second transplantation procedures.