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INTRODUCTION. Richter syndrome (RS), the transformation of chronic lymphocytic leukemia (CLL) into an aggressive lymphoma, is a rare but a life threatening complication. Complex karyotype (CK), defined by the presence of ≥3 chromosomal lesions, is a heterogeneous cytogenetic category associated with a shorter survival in CLL, but its impact on the evolution into a RS has not been investigated. Among CK cases, those with≥5 lesions (highCK) and those with major structural abnormalities [type-2 CK (CK2)] display a more aggressive clinical course. The aim of this study was to assess the impact of CK subtypes on the risk of CLL evolution into a RS. METHODS. We performed a retrospective study in 3 Italian CLL centers. Stimulated cytogenetic with CpG+IL2 was performed in 540 patients within the first year after CLL diagnosis. CK cases with unbalanced translocations, additions, insertions, derivative or marker chromosomes were classified as type-2 CK (CK2). Instead, high-CK cases were those presenting at least 5 chromosome abnormalities. An IGHV gene sequence homology ≥98% was considered as unmutated (U-IGHV), as opposed to mutated (M-IGHV). TP53 disruptions (TP53dis) included deletions and/or mutations. Time to Richter syndrome (TTRS) was calculated from CLL diagnosis to either histologically confirmed diffuse large B-cell lymphoma transformation or last known follow-up visit. Survival curves were compared with the log-rank test and p RESULTS. Among the 540 patients, the median age at diagnosis was 63±12 years, 61% were males, 76% were at Binet stage A, 52% were U-IGHV, 11% had TP53dis, 20% harbored a CK. According to the qualitative classification of CK subtypes, 78/107 (73%) were CK2, whereas, with regards to the number of chromosome lesions, 52/107 (49%) were classified as high-CK. High-CK was present in 63% of CK2 patients. Seventeen % of patients died and 5% developed a RS over a median follow-up of 7 years. Overall, the rate of RS after 5 and 10 years from the diagnosis of CLL was 2.6% and 12%. We observed that patients who developed a RS were more commonly at a more advanced Binet stage at CLL diagnosis (46% vs 23%, p=0.0113) and displayed more frequently an U-IGHV status (79% vs 56%, p=0.0191), TP53 abnormalities (32% vs 10%, p=0.0043), CK2 (46% vs 13%, p By univariate and multivariate analysis, the presence of a CK (overall), of a CK2 and of a high-CK subtypes were all significantly associated with a shorter TTRS, together with U-IGHV status, TP53dis, 11q- by FISH and Binet stage B-C. Patients with a CK2 (HR=5.6 p By integrating the statistically significant variables, we developed a hierarchical model based on HR values (Figure 1): 15% of patients were classified as high-CK and/or CK2, for whom the 10-year TTRS was 31% and the HR 13; 45% were U-IGHV/TP53dis/11q-/Binet B-C and showed a 10-year TTRS of 12% and the HR 3; 40% were M-IGHV without CK and TP53 wild-type, the 10-year TTRS was only 3%. This model was confirmed in multivariate analysis and internally validated (p CONCLUSIONS. We herein identified variables associated with a higher risk of developing a RS and recapitulated them into a RS scoring system. Remarkably, patients harboring a CK subtype at CLL diagnosis have the highest risk of developing a RS and should be carefully monitored during the clinical follow-up. Figure Disclosures Visentin: Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Rigolin:Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Mauro:Octopharma: Consultancy; Astrazeneca: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jannsen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Foà:Roche: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Speakers Bureau; Novartis: Speakers Bureau. Semenzato:Takeda: Honoraria; Roche: Honoraria; Abbvie: Honoraria. Cuneo:Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astra Zeneca: Honoraria; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Trentin:Takeda: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Octapharma: Membership on an entity's Board of Directors or advisory committees; Shire: Honoraria.

Introduction Persistence of leukemia stem cells (LSCs) in patients with Acute Myeloid Leukemia (AML) achieving complete remission (CR) after chemotherapy leads to disease recurrence and poor outcome. Therefore, the identification of LSCs driving resistance to therapy represents an important challenge. LSCs reside within the CD34+/CD38- cells and it has been recently demonstrated that co-expression of CD99 allows for separation of LSCs from functionally normal hematopoietic stem cells in AML. We showed that the presence of a CD123/CD99/CD25+ population within CD34+ cells strongly correlates with FLT3-ITD-positivity. The aim of this study was to deeply characterize the molecular profile of CD34+/CD123+/CD99+/CD25+ LSCs to shed light on the subclonal architecture of FLT3-ITD+ AML and to track the expansion of mutated clones. Methods Molecular status of FLT3-ITD and NPM1 were investigated at the DNA level in a cohort of 150 de novo AML patients at diagnosis and at relapse, using standard procedures. Clonal evolution of FLT3-ITD mutations was studied at diagnosis in 14 FLT3-ITD mutated AML on sorted bone marrow populations, purified by the Cytoflex High-Speed Cell Sorter using a sequential gating strategy, to separate CD34/CD123/CD99/CD25+ LSCs-, CD34+ precursors (CD123/CD99/CD25-) and T-lymphocytes. Moreover, to characterize the genetic profile of FLT3-ITD-mutated clones, DNA targeted sequencing was performed on 22 cell populations isolated from 7 AML patients, using the Oncomine™ Myeloid Research Assay panel on the Ion Torrent™ S5 sequencer. Results 39 of 150 AML cases were FLT3-ITD+, at a median allelic ratio (AR) of 0.36 (range 0.05-7.9). The FLT3-ITD AR was significantly higher within the rare LSCs compartment as compared to MNC (median AR: 0.78, range 0.42-19.3, vs 0.09, range 0.05-0.6m p1, while the number of LSCs do not seem to expand (Fig 1B). These data confirm that LSCs may persist at rare frequency during progression, still representing the treatment-resistant FLT3-ITD reservoir, driving disease relapse with expansion of more mature, FLT3-ITD positive populations. Aiming at shedding light on the molecular heterogeneity and subclonal structure of AMLs, using targeted NGS we compared the mutational profiles of MNCs to that of highly purified LSCs and/or to the CD34+/CD123-/CD25-/CD99- counterpart (n=7 patients). In 4 cases the same mutation pattern was present in both MNCs and LSCs. In 3 cases we found additional mutations in NRAS, BCOR and KRAS in MNCs, indicating acquisition of other transforming events during maturation (Fig 2A). Furthermore, the variant allele frequency (VAF) of mutations was similar in MNCs and LSCs (p=0.12), while FLT3-ITD and TKD burden was enriched in LSCs (p=0.03) (Fig 2B). Conversely, the NPM1 mutation burden remained almost stable in the different cell subsets (Fig 2C). In conclusion, our study shows that FLT3 mutations occur in early LSCs characterized by the CD34+/CD123+/CD99+/CD25+ immunophenotype, which represent the leukemic reservoir. These data may be the rational for CD99-targeted treatments in FLT3-ITD mutated AML to achieve durable disease eradication. Disclosures Venditti: Astellas: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy. Buccisano:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees.

INTRODUCTION. Complex karyotype (CK), defined by the presence of at least 3 chromosomal abnormalities, is a heterogeneous cytogenetic category associated with adverse prognosis in several hematologic malignancies. Recently, Rigolin et al. provided evidence that CK with major structural abnormalities (CK2) at chronic lymphocytic leukemia (CLL) diagnosis negatively impact on the time to first treatment (TTFT) and overall survival (OS) (Rigolin GM, BJH 2018). However, it is unknown whether the prognostic strength of CK could be implemented when combined with stable markers such as the IGHV mutational status. In the present study, we assessed the prognostic and predictive role of the combination of CK subtypes and IGHV status in a large CLL series. METHODS. Stimulated cytogenetics with CpG+IL2 was performed in 736 CLL patients in 3 referenced Italian hematological centers. According to Rigolin et al, CK2 cases included unbalanced translocations, addition, insertion, derivative and marker chromosomes. All other CK were classified as type 1 (CK1). An IGHV gene sequence homology >98% was considered as unmutated (U-IGHV), as opposed to mutated (M-IGHV). Treatment was initiated according to the iwCLL guidelines. TTFT and OS were calculated from diagnosis to first treatment or death, respectively, or last known follow-up. Survival curves were compared with the log-rank test and p RESULTS. We focused on 520 out of the 736 patients with cytogenetic and IGHV status assessed within 12 months from diagnosis. The median age at diagnosis was 63 years, 322 (62%) were males, 68% at Binet A stage, 45% U-IGHV, 48 harbored TP53 abnormalities, 99 a CK (28 CK1 and 71 CK2), 232 received at least one line of therapy (31% FCR, 16% BR, 8% ibrutinib, 5% chlorambucil-antiCD20, 40% other treatments) and 80 died over a median follow-up of 5.8 years. 71 (14%) harbored CK2, 214 (41%) CK1 or U-IGHV and 235 (45%) M-IGHV without CK2. The former group were characterized by a higher prevalence TP53 (38% vs 8% vs 3%, p The combination of these two markers also provides predictive information after first-line therapy (p CONCLUSIONS. In this study, we demonstrated that the combination of CK subtypes and IGHV status provides important prognostic and predictive data in CLL. Moreover, our model was not inferior to other commonly used prognostic scores. While patients with M-IGHV without any subtypes of CK showed an excellent outcome with chemoimmunotherapy, new alternative therapies should be explored for patients with CK2. Disclosures Visentin: janssen: Consultancy, Honoraria. Rigolin:Gilead: Research Funding. Mauro:abbvie: Other: board member; janssen: Other: board member. Foà:JANSSEN: Other: ADVISORY BOARD, Speakers Bureau; NOVARTIS: Speakers Bureau; INCYTE: Other: ADVISORY BOARD; CELTRION: Other: ADVISORY BOARD; ABBVIE: Other: ADVISORY BOARD, Speakers Bureau; AMGEN: Other: ADVISORY BOARD; GILEAD: Speakers Bureau; CELGENE: Other: ADVISORY BOARD, Speakers Bureau; ROCHE: Other: ADVISORY BOARD, Speakers Bureau. Cuneo:Roche: Other: advisory board, Speakers Bureau; Gilead: Other: advisory board, Speakers Bureau; Abbvie: Other: advisory board, Speakers Bureau; janssen: Other: advisory board, Speakers Bureau. Trentin:Gilead: Research Funding; Janssen: Research Funding; Abbvie: Honoraria; Roche: Membership on an entity's Board of Directors or advisory committees.

It is unclear whether karyotype aberrations that occur in regions uncovered by the standard fluorescence in situ hybridization (FISH) panel have prognostic relevance in chronic lymphocytic leukemia (CLL). We evaluated the significance of karyotypic aberrations in a learning cohort (LC; n = 64) and a validation cohort (VC; n = 84) of patients with chronic lymphocytic leukemia with “normal” FISH. An abnormal karyotype was found in 21.5% and 35.7% of cases in the LC and VC, respectively, and was associated with a lower immunophenotypic score (P = .030 in the LC, P = .035 in the VC), advanced stage (P = .040 in the VC), and need for treatment (P = .002 in the LC, P = < .0001 in the VC). The abnormal karyotype correlated with shorter time to first treatment and shorter survival in both the LC and the VC, representing the strongest prognostic parameter. In patients with chronic lymphocytic leukemia with normal FISH, karyotypic aberrations by conventional cytogenetics with novel mitogens identify a subset of cases with adverse prognostic features.

Eotaxin is a potent inducer of eosinophil chemotaxis and was considered as a selective ligand of the CC chemokine receptor 3 (CCR3), which is expressed on eosinophils, basophils, and Th2 lymphocytes. This study shows that eotaxin also interacts with CCR2 and CCR5 and can, thus, affect the responses of monocytes, which express both receptors. In human monocytes pretreatment with eotaxin decreased responsiveness to MCP-1, a selective ligand for CCR2, as well as to RANTES and MIP-1β, which bind to CCR5. Similar effects were obtained with transfected cells expressing CCR2 or CCR5, but here a difference became apparent: Eotaxin triggered CCR5 at a concentration of 100 nM but not CCR2 even at 1 μM, suggesting an antagonistic effect on this receptor. In agreement with this observation, eotaxin induced internalization of CCR5 but not of CCR2 in human monocytes and transfected cells. Binding studies showed that eotaxin displaces125 I-MCP-1 from monocytes in a concentration-dependent manner, and functional experiments showed that eotaxin inhibits MCP-1-induced chemotaxis and enzyme release. The results demonstrate that eotaxin is a CCR5 agonist and a CCR2 antagonist. The present findings suggest a role of eotaxin in the fine-tuning of cellular responses occurring at sites of allergic inflammation, in which both MCP-1 and eotaxin are produced.

Abstract 1811 The presence of chromosomal aberrations is a characteristic feature of multiple myeloma (MM). Recently, Avet-Loiseau et al reported that amp5q31.3 and del12p13.31, detected by high-density, single-nucleotide polymorphism arrays analysis correlate with prognosis in MM patients who were treated upfront with conventional chemotherapy (JCO 2009; 27:4585–90). The aim of our study was to evaluate the effect of these chromosomal abberations on survival of patients with newly diagnosed MM or with relapsed/refractory myeloma who were treated with novel agent-based regimens. We studied 172 MM patients who were treated in a single center in Athens (Greece) during a 4-year period (2007–2011); 76 were newly-diagnosed and were treated upfront with either bortezomib- or IMiD-based regimens and 96 had relapsed or refractory MM and were treated with the combination of lenalidomide and dexamethasone with or without bortezomib (RD vs. VRD) based on the presence of previous peripheral neuropathy (Dimopoulos et al, Leukemia 2010;24:1769–78). A combined methodological approach of G-banding karyotypic analysis and interphase fluorescence in situ hybridization (FISH) was performed in all patients. G-banding analysis was performed according to the European Cytogenetic Guidelines and Quality Assurance (ECA, 2006). The clonality criteria and the karyotypic description followed the recommendations of the International System for Human Cytogenetic Nomenclature (ISCN, 2009). FISH was performed according to the Recommendations for FISH in MM (European Myeloma Network) on uncultured BM, either on cytoplasmic immunoglobulin-enhanced cells (cIg-FISH) or on nuclei from purified CD138+ plasma cells. Commercially available DNA probes (Abott-VYSIS) were used for the detection of del17p, del13q, add1q21, t(4;14) and t(14;16). The probes RP11-96J7 and RP11-578N7 (labeled by Empire Genomics, NY, USA) were used to detect amp5q31 and del12p13. The frequency of the studied chromosomal abnormalities is depicted in the table. There was a strong correlation between the presence of amp5q31 with hyperdiploidy (p=0.012) but amp5q31 did not correlate with the presence of any other of the studied chromosomal aberrations. The presence of del12p13 was correlated with the presence of del13q (p=0.001), t(4;14) (p=0.009) and del17p (p=0.005). Add1q21 also correlated with del13q (p In patients with relapsed/refractory MM, who received either RD or VRD, the median overall survival was 19 months. Patients with amp5q31 had a median survival of 18 months (95% CI: 13–23 months) vs. 21 months of the others (95% CI: 8–35 months; p=0.737), while patients with del12p13 had a median survival of 27 months (95% CI: 0–57 months) vs. 19 months of the others (95% CI: 10–27 months; p=0.767). Of the other studied cytogenetic abnormalities, the presence of del17p (11 vs. 26 months; p=0.001), amp1q21 (12 vs. 26 months; p=0.001) and del13q by FISH (11 vs. 26 months; p=0.025), but not of t(4;14) (p=0.521), were associated with inferior overall survival. In patients with newly-diagnosed MM, the median overall survival was 57 months. The median survival of patients with amp5q31 was 46 months vs. 57 months of all others (p=0.315) and for patients with del12p13 has not been reached vs. 57 months of all others (p=0.379). In conclusion, amp5q31 and del12p13 are recurrent chromosomal abnormalities in MM. Amp5q31 is not associated with the presence of other genetic features, except hyperdiploidy. αmp5q31 or 12p13 was not predictive of survival ιn our series. However, further studies are needed in patients with newly diagnosed MM who receive novel agents upfront to validate the prognostic importance of amp5q31 and del12p13.TableCytogenetic abnormalityPatients at diagnosis (n=76)Relpased/refractory patients (n=96)p-valueamp5q3112 (15.7%)20 (20.8%)0.271amp5q31 as sole anomaly5 (6.5%)7 (7.2%)0.674del12p138 (10.5%)16 (16.6%)0.171del13q28 (36.8%)28 (29.1%)0.279del17p13 (17.1%)15 (15.6%)0.765add1q2115 (19.7%)26 (27%)0.303t(14;16)1 (1.3%)1 (1%)0.832t(4;14)4 (5.2%)10 (10.4%)0.221Hyperdiploidy/hypodiploidy10 (13.1%)/6 (7.8%)11 (11.4%)/13 (13.5%)0.301 Disclosures: No relevant conflicts of interest to declare.

Abstract 318 Introduction Coronary artery disease (CAD), along with its main complications, acute myocardial infarction (AMI) and congestive heart failure (CHF), remains a serious worldwide problem. Despite advances in medical and surgical treatments, CAD is still associated with a high mortality rate and markedly affects the quality of life of patients. The possibility to replace the scarring by inducing neoangiogenesis and possibly regeneration of injured myocardium is an attractive option to improve the prognosis of CAD patients. For this purpose, cytokine-induced mobilization of bone marrow stem cells (BMCs) into the peripheral blood might represents a potential pathway to activate the regenerative process. Some observations suggest that circulating BMCs may lodge in non-hematopoietic tissues such as muscle, liver and myocardium where the tissue injury or the local inflammation may promote stem cells migration. Thus, the association between cytokine induced BMCs migration and tissue injury, may induce tissue repair since the stem cells are usually attracted from the inflamed tissues. A phase II prospective study was performed combining BMCs migration, obtained by cytokines, and cardiac inflammation, induced by myocardial punctures. Results at early and long-term follow-up are here reported. Patients and methods BMCs mobilization was performed in 15 patients undergoing surgery for coronary artery bypass grafting (CABG) and/or mitral valve surgery and/or ventricular remodeling combined to multiple trans-myocardial punctures (Sen technique) in ungraftable non-viable fibrotic areas. BMC mobilization was induced by granulocyte colony stimulating factor (G-CSF) (Lenogastrim) given at 5 μgr/kg s.c. b.i.d. for 5 to 6 consecutive days, starting on day-3 before surgery along with granulocyte-macrophage colony stimulating factor (GM-CSF) (Molgramostim) at 2.5 μgr/kg s.c./day. Patients entered the study protocol on the basis of the following inclusion criteria: i. severe heart failure with left ventricular ejection fraction (EF) < 35%; ii. ineligibility to cardiac transplantation; iii. widespread myocardial ischemia with at least one area of akinetic and nonviable myocardium, detected by cardiac stress scintigraphy with Thallium; iv. presence of other combined surgical indications, including the requirement of surgery for CABG on areas other than nonviable scars; v. one or more previous myocardial infarction. The study protocol was approved by our local Institutional Review Board and Ethics Committee and all patients signed the informed written consent. Results Cytokine administration induced a variable increase in circulating CD34+ve cells in all patients, with peak values recorded between day +4 and day +6. There were no in hospital (0–30 days) deaths. All 15 patients were discharged from the ICU after a median of 2 days, while the overall in hospital stay was 10.5+4.2 days (range 7–21) and all patients were discharged in good clinical condition. There were two sudden deaths over the mid-term, at postoperative day +32 and +45: both patients had troublesome ECC weaning without other postoperative complications. Presently, at a median follow-up of 48 mos, four patients died, 11 patients are alive, one of them after heart transplantation. Among the 10 non-transplanted long-term survivors, there was a significant improvement of the NYHA class from 2,1±0,8 to 1,3±0,5 (p Disclosures: Off Label Use: G-CSF + GM-CSF in CAD.

Abstract 2429 Up to 80% of Chronic Lymphocytic Leukemia (CLL) harbour clonal chromosome aberrations having important clinical implications (i.e. 13q deletion, +12, 11q/ATM and 17p/TP53 deletions). 14q32/IGH rearrangements were recently found in 6–19% of CLL patients and were associated with therapy-demanding disease and inferior outcome. Whereas evidence was provided that some of the classical aberrations, such as 11q-, 17p-, may appear late in CLL clinical history, no information is presently available concerning 14q32/IGH translocations. The aim of this study was i) to analyze the incidence of 14q32/IGH translocations occurring at clonal evolution in CLL, ii) to analyze the clinicobiologic significance of late-appearing 14q32/IGH translocations. One hundred-five CLL cases seen at our institution in a 10-year period were submitted to FISH analysis at diagnosis or before 1st line treatment as part of routine diagnostic workup. In 47 patients with indolent disease (untreated or treated with 1 line without relapse, group 1) FISH analysis was repeated after 48–96 months (median 72). In 58 relapsed patients who started 2nd line treatment (group 2), FISH was performed sequentially before administration of the 2nd line and before each subsequent line of therapy. These 105 patients fulfilled the following criteria: a) diagnosis of bona fide CLL based on morphology and immunophenotyping (CD5/CD19+, CD23+ as minimal requirement), b) clinical records available for review, c) successful FISH analysis at diagnosis and during follow-up. Those cases with t (11;14)(q13;q32)/CCND1-IGH or other 14q32/IGH translocations present at diagnosis were excluded from this study. Sequential FISH studies were performed in all patients on peripheral blood (PB) samples using commercially available probes for the identification of deletions at 13q14, 11q22/ATM, 17p13/TP53, of trisomy 12 and of 14q32/IGH translocations. In 10 patients bone marrow (BM) aspiration and/or lymph node (LN) biopsy were studied by FISH as well. The patients were treated at disease progression as defined by NCI criteria. Refractory disease was defined by stable disease or progressive disease during treatment or disease progression within 6 months of from antileukemic treatment using fludarabine alone or in combination with other agents. Time to chemorefractoriness was measured from date of first line treatment to date of refractoriness to fludarabine containing regimen or date of last follow-up. Overall survival was measured from diagnosis to date of last follow-up or death and from initiation of first line treatment to the date of death or last follow-up. At diagnosis 39% of the cases had 13q-, 14% had +12, 7% had 11q- and 3% had 17p-. A late-appearing 14q32/IGH rearrangement was not detected among 47 patients in group 1, whereas 7/58 cases (12,1%) in group 2 showed a 14q32/IGH break in 16–25% of the cells. These 7 patients had the following aberrations at diagnosis: 13q- and 11q- in 1 case, 13q- in 2 cases; 11q- in 1 case, +12 in 2 cases, no aberrations 1 case. The 14q32 translocation appeared after a median time of 64 months (range 51–91). It was associated with the appearance of 17p- in 3/7 cases with one of these presenting also biallelic del13q. In two cases paired BM or LN sample and PB samples were available for FISH studies and the appearance of IgH translocation in the BM or in the LN sample preceded its appearance in PB by 13–58 months. All 7 cases with late appearing 14q32/IGH translocation developed chemorefractoriness to fludarabine regimen with a median TTC of 27 months (range 12–40 months), as compared with a TTC of 67 months (range 1–143 months) in 51 treated patients who did not develop the 14q32 translocation (p=0.0002). Overall survival did not differ significantly either when measured from diagnosis or from 1st line treatment in 7 patients with 14q32 translocation as compared with the appropriate control. We arrived at the following conclusions: i) a late-appearing 14q32/IGH translocation occurred at a relatively high incidence (12,1%) in patients with relapsing disease and not in patients with stable disease, ii) this aberration involved a minority of cells and, in approximately half of the cases, it was associated with other aberrations, reflecting complex clonal evolution, iii) in 2 assessable cases it first appeared first in the BM or LN; iv) the appearance of 14q32/IGH translocation was associated with shorter TTC. Disclosures: No relevant conflicts of interest to declare.

Between 1998 and 2002, 509 patients with AML (median age 46 yrs, range 15–60) were enrolled in the multicenter LAM99P study of the Italian GIMEMA group. To better evaluate the clinical impact of genetic characterization, all patients received a uniform protocol and diagnostic samples were centralised for cytogenetic and molecular studies. Therapy consisted of HU pre-treatment (2g/m2 for 5 days) followed by induction with DNR (50 mg/m2 d 1, 3, 5), cytarabine (100 mg/m2 d 1–10) and etoposide (100 mg/m2 d 1–5) and consolidation with cytarabine (500 mg/m2/q12 hrs d 1–6) and DNR (50 mg/m2 d 4–6). After consolidation, eligible patients with an identical HLA donor were to receive allogeneic SCT and the remaining peripheral blood autologous SCT. Cytogenetic and molecular genetic characterization (including analysis of major fusion genes, FLT3 and NPM status) was available in 397 (78%) patients. Compared to previous GIMEMA studies, the possibility to collect samples during the 5d of HU pretreatment considerably improved genetic characterization and in particular centralised karyotyping by overcoming the problem of sampling and shipment over the w-end. After induction, 269/397 (68%) patients achieved CR. For induction response, conventional K identified 3 distinct risk groups as follows: low risk (inv. 16 and t8;21), intermediate (normal K and other anomalies not comprised in the high risk group) and high risk (t3;3, inv.3, t9;22, 11q23, 5/7 abnormalities complex K,) with CR rates of 92%, 67% and 39%, respectively (P