ALBERT

Description: Background and aim: Inflammasome and pyroptosis overactivation have recently been associated as fundamental mechanisms in the ineffective hematopoiesis of myelodysplastic syndromes (MDS). Chronic myelomonocytic leukemia (CMML) shares histological and clinical characteristics with MDS but, within clinical differences, It stands out a high association with inflammatory/autoimmune diseases in which a disproportionate activation of inflamasome has been implicated. Our hypothesis is that CMML cases show a higher inflammasome activation with respect to the MDS subset, a relevant difference both in terms of potential therapeutic targets and pathogenic clues. The main objective is to confirm, describe and quantify these differences using high-performance and multi-gene/protein methods. Methods: We performed enhanced RNA-seq in bone marrow mononucleated cells of 27 CMML at diagnosis, 10 MDS and 9 controls (103 million average readings). We selected 116 genes related to the inflammasome and reviewed the differential expression between cases and controls. We evaluated by multiplex immunoassay the profile of 28 cytokines in peripheral blood in 35 CMML patients, 37 MDS and 8 controls. Subsequently, we studied whether these differentially expressed genes / cytokines showed differences in CMML depending on the mutational state of TET2, SRSF2 and ASXL1. Finally, we compared in vitro the degree of activation of inflamasome in the monocytoid component of 8 CMML patients versus 7 controls. Results: In the transcriptomic analysis of the inflamasome genes in patients with CMML, we found 30 of 116 differentially expressed genes compared with healthy controls. Of those 30 genes, 26 showed a pro-inflammatory function and, of them, 18 were up-regulated. Of the 4 differentially expressed genes with an anti-inflammatory function, 3 were significantly under-expressed in CMML patients. We highlight, due to the quantitative difference, the overexpression of two genes coding for monocyte chemotactic proteins, CCL7 and CCL2 (FC = 269.21, p = 0.032; FC = 11.79, p = 0.03) That pro-inflammatory transcriptional profile was not so evident in the cases of MDS: of the 29 differentially expressed genes with pro-inflammatory function, 18 were down-regulated. Subsequently, we designed a customized panel for proteomic analysis including 9 of the 30 differentially expressed genes in CMML. We found that, in a relevant percentage of cases, also proinflammatory cytokines derived from these differentially expressed genes were elevated (62.5%) in peripheral blood of patients, compared to healthy donors; pointing towards the key role of gene transcription in the definition of the pro-inflammatory sense of the proteomic dimension of inflammasome in CMML. Next, we found that those patients with CMML and somatic mutations of TET2 had a higher expression of CCL7 and CCL2 compared to patients with CMML wild type, with a tendency to significance in the first case and significant in the second (FC 11.9, p = 0.15; FC 7.8, p = 0.03). Finally, we conducted in vitro stimulation studies at diagnosis in patients with CMML confirming that the canonical activation of the NLRP3 inflammasome (increased production of IL-1β) is significantly enhanced with respect to control individuals. Conclusion: We describe for the first time, a hyperactivation in CMML, compared with MDS, of the components of the inflammasome. Hyperactivation associated in CMML to a gene transcriptional mechanism and related, in the case of the two most over-expressed genes, CCL2 and CCL7, to the presence of mutations in TET2. Our findings point to new therapeutic targets whose modulation could restore inefficient hemopoiesis and potential diagnostic and prognostic biomarkers in CMML. Disclosures Díez-Campelo: Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Jerez:Novartis: Honoraria; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

Description: Abstract 612 Background: Chromosome 5q deletion (del5q) is the most common cytogenetic abnormality in myelodysplastic syndrome (MDS). Although haplodeficiency of several genes may contribute to the disease phenotype, allelic deletion of the ribosomal protein S14 (RPS14) gene is a key effector of the hypoplastic anemia. Disruption of ribosome assembly arising from RPS14 deletion leads to nucleolar stress that triggers p53 activation. In a murine model of the human 5q- syndrome, TP53 inactivation was alone sufficient to rescue the hematologic phenotype, indicating that the molecular pathogenesis of del(5q) MDS is p53-dependent. The tumor suppressor TP53 gene is a key regulator of stem cell homeostasis and senescence. A well described single nucleotide polymorphism (SNP) located at codon 72 in the proline-rich, pro-apoptotic domain of TP53 has been linked to cancer and mutagen susceptibility, and treatment outcome. Substitution of a cytosine (‘C’ allele) for the more common guanine (‘G’ allele) results in translation of a proline rather than arginine residue at position 72, with diminished apoptotic potential. Given the pathogenetic role of p53 in del(5q) MDS, we hypothesized that homozygosity for the ‘C’ allele may be associated with disease predisposition. Methods: Bone marrow and blood samples were investigated from 118 del(5q) MDS patients, 102 non-del(5q) MDS patients, and 98 healthy controls. Genomic DNA was extracted and codon 72 of the TP53 gene was amplified by PCR. Forward and reverse Sanger sequencing was performed to determine genotype. Relationship to disease specific features at diagnosis including cytogenetic risk category, IPSS score, blast percentage, and age were investigated as well as the relationship to response to lenalidomide and AML transformation using SAS software (Version 9.2, SAS Institute Inc., Cary, NC, USA). Results: Genotype distribution significantly differed between del(5q) MDS patients (18% CC, 47% CG, and 35% GG), non-del(5q) MDS patients (9% CC, 58% CG, and 33% GG),and healthy controls (7% CC, 43% CG, and 50% GG) (p=0.01). The frequency of the homozygous CC genotype was 〉2x greater in del(5q) MDS (18%) compared to both non-del(5q) MDS (9%) and healthy controls (7%) (p=0.05). There was no significant frequency difference between non-del(5q) and healthy controls. Del(5q) MDS patients were 〉6 times more likely to carry the CC genotype vs. GG when compared to healthy controls [odds ratio (OR)=6.71, 95% CI: 1.56 to 28.86], whereas non-del(5q) patients were 〉3 times more likely to carry the CC genotype vs. GG when compared to healthy controls (OR=3.87, 95% CI: 0.66 to 22.71). The corresponding ‘C’ allele frequency was significantly greater among del(5q) MDS patients (41.7%) compared to healthy controls (28.6%) (p=0.006), and approached significance in non-del(5q) patients (37.8%) versus controls (p=0.06). There was no association between TP53 R72P genotype and cytogenetic risk group in either del(5q) (p=0.67) or non-del(5q) MDS patients (p= 0.60), IPSS (del5q, p=0.29; non-del5q, p=0.89), or response to lenalidomide (del5q, p=0.57; non-del5q p=0.89). Mean age at diagnosis was significantly (p=0.04) lower in del(5q) MDS (67.4 years; SD=11.1 years) compared to non-del(5q) MDS patients (70.8 years; SD=9.1years), although significant differences in age according to TP53 R72P genotype were not apparent in either MDS cytogenetic group (del5q, p=0.99; non-del5q, p=0.89). Conclusion: Our findings indicate that the TP53 R72P homozygous CC genotype occurs with significantly greater frequency in del(5q) MDS compared to both non-del(5q) MDS patients and healthy controls, suggesting that this polymorphism may play a key role in the pathogenesis of and predisposition to del(5q) MDS. Disclosures: Kurtin: Celgene: Honoraria. Maciejewski:Celgene: Research Funding; Eisai: Research Funding; Alexion: Consultancy. Nevill:Celgene: Honoraria. Karsan:Celgene: Research Funding. List:Celgene: Research Funding.

Description: Abstract 1861 Introduction: Total or partial Monosomy 7 (-7/del(7q)) is one of the most frequent cytogenetic abnormalities in MDS, occurring in about 11% of abnormal cases in patients (pts) with primary MDS. The cytogenetic module of the IPSS defines any abnormality of chromosome 7 as unfavourable and classifies them, combined with complex abnormalities, into the poor risk cytogenetic subgroup. However, in previous publications from other groups, the prognosis of isolated -7/del(7q) was described as intermediate. The aim of the present study was to re-analyze the prognostic impact of -7/del(7q) as a single anomaly based on a large, international MDS database which was previously presented at the 2009 ASH-meeting (Schanz et al. abstract #2772). Materials and Method: Patients with -7/del(7q), derived from the international MDS database were examined. The large international data collection contains 2901 patients with MDS, originating from the German-Austrian (GA)-, the International MDS Risk Analysis Workshop (IMRAW)- and the Spanish Cytogenetic Working group (GCECGH) and the International Cytogenetics Working Group of the MDS Foundation (ICWG). Inclusion criteria for the study were defined as follows: Primary MDS, age 〉=16, and bone marrow blasts

Description: Abstract 1750 Poster Board I-776 Chronic myelomonocytic leukemia (CMML) is a clonal disorder sharing features of both myelodysplastic syndromes (MDS) and chronic myeloproliferative disorders (MPD). The natural course of CMML is highly variable. Several small series have suggested the prognostic importance of different characteristics but a widely accepted prognostic scoring system for CMML is not available. The main aims of the study were to identify prognostic factors, including cytogenetic findings, for overall survival (OS) and acute leukemic (AL) transformation in a large series of patients with CMML and to develop an easily applicable prognostic scoring index for estimating outcome and planning treatment in the individual patient. Five hundred and seventy-two patients diagnosed of CMML according to FAB and WHO criteria in 25 centers belonging to the Spanish Registry of MDS were included in the study. Actuarial curves of OS and risk of AL evolution were built by Kaplan-Meier method and differences between curves compared with log-rank tests. Multivariate analyses of OS and risk of AL evolution were performed by Cox proportional hazards regression method. The weights assigned to the variables included in the final prognostic scoring system were based on the regression coefficients from the proportional hazards models. Median age was 73 yr and 397 (69%) were males. According to FAB criteria 61% of the patients had MDS-CMML (absolute WBC count '13 × 109/L) and 39% MPD-CMML and by WHO classification 86% were CMML-1 (blasts

Description: To develop a prognostic scoring system tailored for therapy-related myelodysplastic syndromes (tMDS), we put together a database containing 1933 patients (pts) with tMDS from Spanish, German, Swiss, Austrian, US, Italian, and Dutch centers diagnosed between 1975-2015. Complete data to calculate the IPSS and IPSS-R were available in 1603 pts. Examining different scoring systems, we found that IPSS and IPSS-R do not risk stratify tMDS as well as they do primary MDS (pMDS), thereby supporting the need for a tMDS-specific score (Kuendgen et al., ASH 2015). The current analysis focuses on cytogenetic information as a potential component of a refined tMDS score, based on this large, unique patient cohort. Of the 1933 pts, 477 had normal karyotype (KT), 197 had missing cytogenetics, while 467 had a karyotype not readily interpretable. Incomplete karyotype descriptions will be reedited for the final evaluation. Of the remaining 1269 pts the most frequent cytogenetic abnormalities (abn) were: -7, del(5q), +mar, +8, del(7q), -5, del(20q), -17, -18, -Y, del(12p), -20, and +1 with 〉30 cases each. Frequencies are shown in Table 1. Some abn were observed mostly or solely within complex KTs, such as monosomies, except -7. Others, like del(20q) or -Y, are mainly seen as single or double abn, while del(5q), -7, or del(7q) are seen in complex as well as non-complex KTs. The cytogenetic profile overlapped with that of pMDS (most frequent abn: del(5q), -7/del(7q), +8, -18/del(18q), del(20q), -5, -Y, -17/del(17p), +21, and inv(3)/t(3q) (Schanz et al, JCO 2011)), with notable differences including overrepresentation of complete monosomies, a higher frequency of -7 or t(11q23), and a more frequent occurrence of cytogenetic subtypes in complex KTs, which was especially evident in del(5q) occurring as a single abn in 16%, compared to 70% within a complex KT. IPSS-R cytogenetic groups were distributed as follows: Very Good (2%), Good (35%), Int (17%), Poor (15%), Very Poor (32%). Regarding the number of abn (including incomplete KT descriptions) roughly 30% had a normal KT, 20% 1, 10% 2, and 40% ≥3 abn, compared to pMDS: 55% normal KT, 29% 1, 10% 2, and 6% ≥3 abn. To be evaluable for prognostic information, abn should occur in a minimum of 10 pts. As a single aberration this was the case for -7, +8, del(5q), del(20q), del(7q), -Y, and t(11;varia) (q23;varia). Of particular interest, there was no apparent prognostic difference between -7 and del(7q); del(5q) as a single abn was associated with a relatively good survival, while the prognosis was poor with the first additional abn; t(11q23) occurred primarily as a single abn and was associated with an extremely poor prognosis, and prognosis of pts with ≥4 abn was dismal independent of composition (Table 1). To develop a more biologically meaningful scoring system containing homogeneous and prognostically stable groups, we will further combine subgroups with different abn leading to the same cytogenetic consequences. For example, deletions, unbalanced translocations, derivative chromosomes, dicentric chromosomes of 17p, and possibly -17 all lead to a loss of genetic material at the short arm of this respective chromosome affecting TP53. Further information might be derived from analyses of the minimal common deleted regions. For some abn, like del(11q), del(3p), and del(9q), this can be refined to one chromosome band only (table 1). Conclusion: Development of a robust scoring system for all subtypes of tMDS is challenging using existing variables. This focused analysis on the cytogenetic score component shows that favorable KTs are evident in a substantial proportion of pts, in contrast to historic data describing unfavorable cytogenetics in the majority of pts. Although complex and monosomal KTs are overrepresented, this suggests the existence of distinct tMDS-subtypes, although some of these cases might not be truly therapy-induced despite a history of cytotoxic treatment. The next steps will be to analyze the prognosis of the different groups, develop a tMDS cytogenetic score, and examine minimal deleted regions to identify candidate genes for development of tMDS, as well as to describe the possible influence of different primary diseases and treatments (radio- vs chemotherapy, different drugs) on induction of cytogenetic subtypes. Our detailed analysis of tMDS cytogenetics should reveal important prognostic information and is likely to help understand mechanisms of MDS development. Disclosures Komrokji: Novartis: Consultancy, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding. Sole:Celgene: Membership on an entity's Board of Directors or advisory committees. Sekeres:Celgene: Membership on an entity's Board of Directors or advisory committees; Millenium/Takeda: Membership on an entity's Board of Directors or advisory committees. Roboz:Cellectis: Research Funding; Agios, Amgen, Amphivena, Astex, AstraZeneca, Boehringer Ingelheim, Celator, Celgene, Genoptix, Janssen, Juno, MEI Pharma, MedImmune, Novartis, Onconova, Pfizer, Roche/Genentech, Sunesis, Teva: Consultancy. Steensma:Amgen: Consultancy; Genoptix: Consultancy; Janssen: Consultancy; Celgene: Consultancy; Millenium/Takeda: Consultancy; Ariad: Equity Ownership. Schlenk:Pfizer: Honoraria, Research Funding; Amgen: Research Funding. Valent:Amgen: Honoraria; Deciphera Pharmaceuticals: Research Funding; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Ariad: Honoraria, Research Funding; Deciphera Pharmaceuticals: Research Funding. Giagounidis:Celgene Corporation: Consultancy. Giagounidis:Celgene Corporation: Consultancy. Platzbecker:Celgene Corporation: Honoraria, Research Funding; TEVA Pharmaceutical Industries: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Janssen-Cilag: Honoraria, Research Funding; Amgen: Honoraria, Research Funding. Lübbert:Janssen-Cilag: Other: Travel Funding, Research Funding; Celgene: Other: Travel Funding; Ratiopharm: Other: Study drug valproic acid.

Description: Introduction: Several recent publications have advanced our knowledge of the prognostic significance of clonal cytogenetic abnormalities in MDS, yet the genetic risk assessment of the rare karyotypic aberrations in MDS patients (pts) remains unknown. Using the German-Austrian (G-A) Cytogenetics Database, we previously defined 24 cytogenetic prognostic subgroups; however, 12 subgroups characterized by non-complex (isolated or one additional abnormality only) karyotypes with del(9q), del(15q), t(15q), del(12p), −X, t(1q), t(7q), t(17q), −21, t(11q23), +19, t(5q) were observed infrequently (

Description: Abstract 4022 Introduction: The occurrence of cytogenetically-unrelated clones is a rare but recognized event in haematological malignancies that may appear at either presentation or in further progression of disease. As yet, little is known about the composition and prognostic relevance of unrelated clones in MDS and AML. The aim of this retrospective study was to analyze cases of unrelated clones in a large, multicentric and international study to further characterize their clinical relevance in myeloid disorders. Patients/Methods: A total of 95 patients with unrelated clones and their corresponding clinical data were collected from 10 different databases: MLL (n=30), German-Austrian-Swiss (16), Athens (11), City of Hope (10), Bobigny (6), Lund (5), Tokyo (5), Spanish (4), IMRAW (3), and Dortmund (2). 77 pts. (81.1%) had a diagnosis of primary MDS, 5 (5.3%) t-MDS, 9 (9.5%) de novo AML, and 4 (4.2%) AML following MDS. Abnormalities detected FISH only were excluded. Unrelated clones were defined as two abnormal clones that were not evolvable from each other. Overall survival and the risk of AML transformation was calculated. For comparison MDS cases without unrelated clones were included from the international MDS database, including 2901 pts. with primary MDS. Result: Two unrelated clones were seen in 80 pts. (84%), three in 14 (15%) and five in 1 patient (1%). The majority of cases showed one aberration per clone (84.5%). The most frequent single aberration was +8 (43.2%), followed by del(5q) (28.4%). Other anomalies were -7/del(7q) (14.7%), -Y (12.6%), del(20q) (9.5%), +21 (7.4%), i(17q) (5.3%) and del(9q) (5.3%). Complex aberrations were identified in 3/95 cases (3.2%) only. Patients with unrelated clones showed an overrepresentation of +8 (p

Description: Introduction: Since its implementation in 2012, the IPSS-R (Greenberg et al., 2012), defines the latest standard in risk stratification of patients with Myelodysplastic Syndromes (MDS). However, the prognostic impact of rare abnormalities remains unclear as yet because the number of these aberrations was too low to allow a valid statistical analysis. Hence, rare abnormalities were coalesced in one group in the IPSS and IPSS-R and, due to the unknown prognosis of these abnormalities, classified as prognostically intermediate. The main goal of the study presented here was to analyse the type, frequency and prognosis of rare single abnormalities in a large cohort of patients with primary, untreated MDS and integrate them in the existing IPSS-R in order to refine its predictive power. Methods: The data set analyzed was derived from the IPSS-R database and extended by additional data from European centers. In total, 7245 patients with primary, untreated MDS were included. Of these, we identified 410 (6%) pts. with rare single abnormalities. An aberration was defined as rare when it occurred in less than 10 patients in the cytogenetic scoring system that was the basis for the IPSS-R (Schanz et al., 2012). Additionally, further cytogenetic abnormalities not considered in this score were detected. A specific cytogenetic subgroup was defined as having at least n=5 cases with the same abnormality. Survival analyses was performed in cytogenetic subgroups with a minimum number of n=10 exclusively. The participating centers (in numerical order) were: Spain (n=110; 26.8%), MD Anderson Cancer Center (69; 16.8%), Düsseldorf (44; 10.8%), IMRAW (41; 10.0%), France (32; 7.8%), Pavia (21; 5.1%), Vienna (19; 4.6%), Japan (13; 3.2%), Vienna Medical University (12; 2.9%) Italy (11; 2.7%), Cleveland (10; 2.4%), Dundee (9; 2.2%), Brazil (8; 2.0%), Netherlands (5; 1.2%), Czech (2, 0.5%), Freiburg (1; 0.2%), Innsbruck (1; 0.2%), Sweden (1; 0.2%), and Russia (1; 0.2%). The median overall- (OS) and AML-free survival (AFS) was calculated for any specific cytogenetic subgroup. Results: Rare single abnormalities detected were: der(1;7)(n=24; 5.9%), partial or total monosomy 13 (22; 5.4%), partial or total monosomy 9 (22; 5.4%), +21 (20; 4.9%), +mar (14; 3.4%), del(3p) (12; 2.9%), total or partial monosomy 21 (11; 2.7%), total or partial monosomy X (11; 2.7%), total or partial monosomy 18 (10; 2.4%), +1/+1q (10; 2.4%), del(17p) (9; 2.2%), total or partial monosomy 14 (9; 2.2%), total or partial monosomy 16 (9; 2.2%), total or partial monosomy 6 (9; 2.2%), total or partial monosomy 1 (8; 2.0%), t(11q23;varia) (7; 1.7%), total or partial monosomy 19 (6; 1.5%), +11/+11q (6; 1.5%), +13 (6; 1.5%), +14 (6; 1.5%), del(5p) (5; 1.2%), total or partial monosomy 2 (5; 1.2%), +15 (5; 1.2%) and +X (5; 1.2%) The remaining 159 patients (38.7%) showed very rare abnormalities occurring in less than 5 patients each. The median overall survival as well as the AML-free survival in each category will be presented in detail. Furthermore, a multivariate model including all relevant confounders and a proposal to integrate these abnormalities in the cytogenetic module of the IPSS-R will be suggested. Conclusions: In order to overcome the problem of their extremely low frequency, knowledge about rare single abnormalities in MDS can only be gained by large, international cooperative projects. The present study was performed to identify and comprehensively analyze rare abnormalities occurring in MDS, uninfluenced by therapy or additional abnormalities. The results will lead to a further refinement of the cytogenetic prognostic classification in patients with MDS. The study was supported by a grant from the European Leukemia Net (ELN) Disclosures Schanz: Novartis: Honoraria, Other: Travel Grant; Celgene: Honoraria, Research Funding; Alexion: Other: Travel Grant; Lilly: Other: Travel Grant. Sole:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Fenaux:Amgen: Honoraria, Research Funding; Celgene Corporation: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Valent:Novartis: Consultancy, Honoraria, Research Funding; Ariad: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria; Pfizer: Honoraria; Celgene: Honoraria. Ohyashiki:Kyowa Kirin KK: Honoraria; Novartis Pharma KK: Honoraria, Research Funding, Speakers Bureau; Celegen KK: Consultancy, Honoraria, Research Funding, Speakers Bureau; Jansen Pharma KK: Honoraria, Research Funding, Speakers Bureau; Chugai Pharna KK: Research Funding; Bristol Meyer Squib KK: Research Funding; Taiho Yakuhin KK: Research Funding; Asahikasei: Research Funding; Teijin Pharma KK: Research Funding; Alexion Pharma KK: Research Funding; Asteras: Research Funding; Shinbaio Pharma KK: Honoraria; Toyama Kagaku KK: Speakers Bureau; MSD KK: Honoraria; Nippo Shinyaku KK: Speakers Bureau; Sumitomo Dainippon: Membership on an entity's Board of Directors or advisory committees. Sekeres:Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; TetraLogic: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees.

Description: Background: De-ubiquitinating enzyme BAP1, functionally related to ASXL1, is mutated in various hereditary cancers and its deletion is associated with the appearance of myelodysplastic/myeloproliferative features in mice. BRCA1 is known to drive homologous recombination, playing a critical role in preserving genomic integrity. Finding an impaired DNA-damage via in chronic myelomonocytic leukemia (CMML) would open the synthetic lethality strategy to MDS/MPN diseases, moreover if the already targeted hypermethylation mechanism is not involved. Methods: BAP1 and BRCA1 expressions levels were quantified by RT-qPCR. Methylation detection was performed on 57 CMML patients and 27 controls using Methylation Cancer Panel I from Illumina (San Diego, CA) interrogating 2 CpG sites at the 5´promoter region of BAP1. We developed a sandwich-type ELISA assay to measure the grade of ubiquitination of BRCA1. Fifty micrograms of total protein from blood-sorted monocytes, granulocytes and lymphocytes lysate of 19 patients were used. Total BRCA1 was captured in precoated microtiter and an anti-mono and poly ubiquitin conjugates monoclonal antibody (HRP-linked FK2) was added. A second ELISA assay determines the nanogrames of BRCA1 protein quantity in those 50 µg of sample lysate. It allows to determine the ratio of ubiquitylated BRCA1 light units/total BRCA1 (uBRCA1/BRCA1), which measures in a quantitative manner the percentage of BRCA1that is ubiquitylated in a given sample. Results: Samples of 175 patients were included in the study: CMML=61; MDS=34; AML=50; CML=30 and 10 controls. CMML showed the lowest values (65% compared with the controls), significantly lower than the other groups, except for CML patients: CMML vs MDS, p=0.001; CMML vs AML, p