ALBERT

Description: Introduction: As showed in a recent study of our group, considering bone marrow (BM) blasts from nonerythroid cellularity (NECs) improves the prognostic evaluation of MDS (Arenillas et al, J Clin Oncol 2016). By enumerating blasts from NECs, 12% of MDS patients diagnosed within WHO categories with less than 5% BM blasts were reclassified into higher-risk categories and showed a poorer overall survival than did those who remained in the initial categories. Refractory anemia with ring sideroblasts (RARS) and refractory cytopenia with multilineage dysplasia and ring sideroblasts (RCMD-RS) have shown an special good outcome in different studies. As MDS with ring sideroblasts (MDS-RS) usually present a high percentage of BM erythroblasts, considering BM blasts from NECs could imply a risk overestimation of this subset of patients. Aim: we evaluated the relevance of considering BM blasts from NECs or from total nucleated cells (TNCs) on classification and prognostication of the group of patients diagnosed with MDS-RS. Methods: We retrospectively analyzed 3,924 de novo MDS diagnosed according to WHO 2001 and 2008 classifications from the MDS Spanish registry. 1,045 patients presented less than 5% BM blasts from TNCs and equal or greater than 15% BM ring sideroblasts, fulfilling current definition for RARS (WHO 2001 and 2008) and RCMD-RS (WHO 2001). Moreover 1,233 patients with equal or greater than 5% BM ring sideroblasts and less than 5% BM blasts were analyzed in order to explore the future definition of WHO 2016, that considered as MDS-RS those patients with 5%-

Description: INTRODUCTION: Chronic lymphocytic leukemia (CLL)-like monoclonal B cell lymphocytosis (MBL) is considered a precursor of CLL. It is found in 5-10% of elderly healthy individuals and shows a progression rate to CLL requiring therapy of 1.1% per year. A balance between microenvironmental factors and intrinsic properties of the emerging B cell clone may be decisive for the transition from MBL to CLL, although biomarkers of progression remain unknown. The objective is to describe biological markers (B cell gene expression profiles and serum cytokine levels) that predict progression from MBL to CLL. METHODS: Gene expression profiles of clonal B cells from 14 MBL subjects (median age: 76 years, clonal B cells: 0.5-4.3 x109/L) were evaluated. With a median follow-up from analysis of 59 months (range: 10-77), 3 cases (21.4%) had progressed to CLL Binet stage A at last follow-up (clonal lymphocytosis 〉5x109/L, range: 6.2-7.9). Clonal B cells (CD19+CD5+) were isolated from peripheral blood by immunomagnetic methods (Miltenyi Biotec). Extracted RNA (RIN〉7) was hybridized to GeneChip Human Gene 2.0 ST arrays (Affymetrix). Gene expression profiles were compared between MBL cases that progressed to CLL (P-MBL, n=3) and non-progressive MBL cases (NP-MBL, n=11). Differential gene expression was evaluated employing linear models for microarrays in R, and genes with P1.5 or 5x109/L, range: 6.4-17.3). Clonal B cells and cytokine levels were compared between P-MBL (n=5) and NP-MBL (N=36). For cytokine levels, the optimal cut-off values to stratify MBL cases according to their progression risk were assessed using the maxstat R package, whereas for clonal B cells a cut-off value of 3.9 x109/L was considered according to the results obtained by Kostopoulos et al (Blood Cancer J, 2017). The effect of different covariates on progression-free survival was evaluated using log-rank test. Cox proportional hazards regression models were performed to assess their independent prognostic value. P

Description: Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous category of lymphoid tumors that comprises different clinical forms not fully recognized in the WHO classification. In this regard, extranodal (EN) DLBCLs have particular clinicobiological features and outcome, sometimes related to the specific site where the lymphoma arises. Nowadays, rituximab plus chemotherapy (CT) is the gold-standard in the treatment of DLBCL. However, the superiority of rituximab-CT (R-CT) over CT alone has not been addressed for all the clinical subsets of the disease and, in fact, the clinical role of the new therapies might be different for primary nodal or EN DLBCLs. The aim of this study was to assess the impact of rituximab in patients suffering from nodal or EN DLBCL. Two-hundred and thirty non-immunocompromised patients (112M/118F; median age, 61 years) diagnosed with CD20+DLBCL in a single institution between 1997 and 2006 (five years before and after establishing R-CT as the standard treatment in DLBCL) and treated with adriamycin-containing regimens were the subject of the present study. The series included 148 primary nodal and 82 EN DLBCL. Patients with primary CNS lymphoma were excluded and lymphomas arising at Waldeyer ring were considered as nodal DLBCL. The main EN sites were GI (n=26), bone (n=13), soft tissue (n=13), lung/pleura (n=9), liver (n=9), and other (n=12). Main clinico-biological and evolutive variables were analyzed. One hundred nineteen patients received only CT and 111 R-CT. Eighty-seven cases with available information were assigned to germinal center B-cell-like (GCB) (41%) or non-GCB (59%) groups according to the Hans method (Blood2004;103:275–82) based on CD10, BCL6 and MUM1 expression. Main initial features, including the primary nodal or EN origin, international prognostic index (IPI), and GCB/non-GCB categories were similar for CT and R-CT groups. No correlation was observed between the GCB/non-GCB groups and the primary site of the tumor, although nodal lymphomas more frequently expressed MUM1 than EN (69% vs. 31%, respectively; p=0.01). CR rate and 5-year overall survival (OS) according to the treatment arm (CT vs. R-CT) is detailed for the whole series and for the nodal and EN groups in the table and OS curves depicted in the figure. In the whole series, variables predicting poor OS in the multivariate analysis were high-risk IPI (RR 2.5; p

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: Abstract 4005 Background and objective: the cytogenetic risk classification defined by the 1997 IPSS remains the most widely used to assess the prognostic impact of karyotype in the MDS. Recently, the German-Austrian MDS Study Group (Haase, Ann Hematol 2008; 87:515) has proposed a new, more comprehensive cytogenetic risk classification. Our aim was to assess the prognostic performance of the Haase's cytogenetic classification, as compared to that defined by the IPSS, and what would be its contribution to the IPSS and WPSS. Methods: MDS patients seen at our center after 1986 were eligible for inclusion if they had a cytogenetic study performed at diagnosis that could be scored according to both the IPSS and the Haase's criteria. The prognostic performance was assessed by the Harrell's concordance index and the R2 explained variation (the closer both statistics to 1 the better the prognostic performance). Results: 327 out of 494 patients seen after 1986 met the eligibility criteria. Median age was 73 (range: 16–97) years and 55% were women. The 2001 WHO categories were refractory anemia (RA, 6%), RA with ringed sideroblasts (RARS, 2%), refractory cytopenia with multilineage dysplasia (RCMD, 54%), RCMD with ringed sideroblasts (RCMD-RS, 11%), RA with excess of blasts (RAEB-1, 11%; RAEB-2, 14%), and del(5q) (2%). According to the IPSS cytogenetic classification, 232 (71%) patients were in the low risk group, 46 (14%) in the intermediate, and 49 (15%) in the high risk group. According to Haase's criteria, 239 (73%) patients were in the good prognosis group, 26 (8%) in the int-1, 25 (8%) in the int-2, and 37 (11%) in the poor prognosis group. Agreement between both karyotype-based risk classifications was high (Kendall's tau=0.92; Kruskal's gamma=0.99). At the study closing date, median survival for the whole series was 4.1 years, 160 (49%) patients had died and 27 (8%) were lost to follow-up. Median survival (95% CI) in years according to the IPSS cytogenetic classification was 5.2 (4.2-6.4) for the low risk group, 3.8 (1.7-5.0) for the intermediate, and 0.9 (0.7-1.1) for the high risk group. Median survival (95% CI) in years according to Haase's criteria was 5.2 (4.1-6.4) for the good prognosis group, 3.9 (1.6-not reached) for the int-1, 3.1 (0.9-3.8) for the int-2, and 0.8 (0.6-1.9) for the poor prognosis group. There was no statistically significant difference in survival between the int-1 and Int-2 groups. Grouping the Int-1 and Int-2 into a single intermediate risk category yielded a median survival of 3.5 (1.7-4.4) years, which was significantly different from that of good and poor risk groups (p=0.014 and p=0.0001, respectively). The figure shows the concordance and R2 statistics for both cytogenetic classifications as well as those of the IPSS and the WPSS had they been based on the Haase's score, as compared to the standard ones. For this latter analysis, the Haase's int-1 and int-2 categories were grouped together. Conclusion: The new cytogenetic risk classification was comparable to that defined by the IPSS with regard to prognostic performance and did not improve the discriminatory power of the IPSS or the WPSS. Disclosures: No relevant conflicts of interest to declare.

Description: Introduction: Based on the 2008 World Health Organization classification (WHO 2008), erythroleukemia is defined by the presence of ≥50% erythroid precursors in bone marrow (BM) and ≥20% myeloblasts in the non-erythroid cell population. Multilineage dysplasia is almost always present with high rates of MDS-like cytogenetic abnormalities, specially complex karyotypes. Therefore an extensive comparison with myelodysplastic syndromes (MDS) with ≥50% erythropoesis seems crucial to elucidate whether erythroleukemia and MDS with erythroid hyperplasia should be considered as different biological entities. Aim: To elucidate this issue, the outcome and cytogenetic alterations of erythroleukemia patients were studied and compared to MDS patients with ≥50% erythropoesis with

Description: Introduction: The MDS are a group of clonal hematopoietic disorders characterized by blood cytopenias and increased risk of transformation into acute myeloid leukemia (AML). The MDS predominate in old people (median age at diagnosis 〉 70 years) so that a fraction of the observed mortality would be driven by age-related factors shared with the general population rather than the MDS. Distinguishing between the MDS-related and unrelated mortality rates will help better assessment of the population health impact of the MDS and more accurate prognostication. This study was aimed at quantifying the MDS-attributable mortality and its relationship with the IPSSR risk categories. Methods: The database of the GESMD was queried for patients diagnosed with primary MDS after 1980 according to the WHO 2001 classification. Patients with CMML, younger than 16 years or who lacked the basic demographic or follow-up data were excluded. Relative survival and MDS-attributable mortality were calculated by the cohort method and statistically compared by Poisson multivariate regression as described by Dickman (Stat Med 2004; 23: 51). Three main parameters were calculated: the observed (all-cause) mortality, the MDS-attributable mortality (both as percentage of the initial cohort), and the fraction of the observed mortality attributed to the MDS. Results: In total, 7408 patients met the inclusion criteria and constitute the basis for this study. Among these patients, 5307 had enough data to be classified according to the IPSSR. Median age was 74 (IQR: 16-99) years and 58 % were males. The most frequent WHO categories were RAEB, type I or II (29% of cases), RCMD (28%), and RA with ring sideroblasts (16%). Most patients (72%) were classified within the very low and low risk categories of the IPSSR. At the study closing date (December 2014), 1022 patients had progressed to AML, 3198 had died (974 after AML) and 3210 were censored alive. The median actuarial survival for the whole series was 4.8 (95% CI: 4.6-5.1) years and 30% of patients are projected to survive longer than 10 years. The overall MDS-attributable mortality at 5 years from diagnosis was 39%, which accounted for three-quarters of the observed mortality (51%, figure). The corresponding figures at 10 years for the MDS-attributable and observed mortality were 55% and 71%, respectively. According to the IPSSR, the 5-year MDS-attributable mortality rates was 19% for the very low risk category, 39% (low risk), 70% (intermediate risk), 78% (high risk), and 92% (very high risk). On average, the incidence rate ratio for the MDS-attributable mortality increased 1.9 times (95% CI: 1.7-2.3, p

Description: INTRODUCTION: Although specific prognostic models for Chronic Myelomonocytic Leukemia (CMML) exist, few are based on large series of patients. Since its publication in 2002, the MD Anderson prognostic score (MDAPS) has been the most powerful prognostic tool for CMML. Due to the recent emergence of the CMML-specific prognostic scoring system (CPSS) and the Mayo prognostic model, we compared the three scores to assess their usefulness in our series. These three indexes, and not those based on clinical and molecular variables (Mayo Molecular Model and GFM prognostic score), were selected as the most easy-to-apply in normal clinical practice. AIM: 1) To assess the prognostic impact on overall survival (OS) and leukemia-free survival (LFS) of the variables composing the scores: MDAPS, CPSS and Mayo prognostic model; 2) To test the capability of the scores to detect the high-risk CMML patients; 3) To detect the index with the best predictive value for mortality and leukemia transformation, and 4) To implement a new score after selecting the best variables of the three indexes in terms of OS prognostic information. PATIENTS AND METHODS: From January 1997 to August 2013 a retrospective analysis including 146 patients diagnosed with CMML was performed in Hospital Clínic of Barcelona (n=134) and Hospital Germans Trias i Pujol (n=12). The median age was 76 years (range 27-96 years) and 63% were males. One-hundred and twenty-nine (88%) had a CMML-1, 17 (12%) a CMML-2, 102 (70%) a CMML-MD and 44 (30%) a CMML-MP. The median follow-up for surviving patients was 24.5 months and the median OS was 20 months (range 0-159 months). The prognostic impact in terms of OS and LFS of each of the variables that compose the indexes were studied by a univariate survival analysis (Kaplan-Meier; Log-Rank). A multivariate analysis (Cox model) was performed to assess the independent impact of the variables that showed significance in the univariate analysis in order to select the ones with the best prognostic information. The global prognostic scores were analyzed by univariate and multivariate analyses. In addition, ROC curves and the concordance index (C-index) were implemented to select the score with the best predictive power for mortality or leukemia transformation. RESULTS: All the variables that compose the MDAPS (hemoglobin level 〈 12 g/dl, absolute lymphocyte count 〉 2.5 x 109/L, presence of circulating immature myeloid cells (IMCs) and BM blasts ≥ 10%), the CPSS (CMML-MD vs. CMML-MP, CMML-1 vs. CMML-2, RBC transfusion dependency and the Spanish cytogenetic risk classification) and the Mayo prognostic model (absolute monocyte count 〉 10x109/L, presence of IMCs, hemoglobin 〈 10 g/dl and platelet count 〈 100 x 109/L) showed prognostic value on OS with the exception of circulating IMCs. Regarding LFS, only CPSS variables, BM blast ≥ 10% and an absolute monocyte count 〉 10x109/L had an impact. When the scores were applied, all showed an impact on OS and retained their significance in multivariate analysis. By using ROC curves and C-index, CPSS (ROC area: 0.80, CI 95%: 0.72-0.88; C-index: 0.73) showed a slightly better predictive value for mortality. Variables composing the three indexes were compared in a multivariate analysis and only CPSS parameters and platelets 〈 100 x 109/L retained their significance. Based on these findings, by adding platelet count information to CPSS, a new score was implemented (CPSS-P) showing the best risk stratification in our series (Figure 1). CONCLUSIONS: The present study reinforces the validity of CPSS, the MDAPS and the Mayo prognostic model for the assessment of CMML patients. Moreover, by including the platelet count information to the CPSS improved the prediction capacity for OS and LFS in our series. It is of importance to remark that platelet count information could help to better stratify CMML patients, being of special value in the subset of patients with normal karyotype. Figure 1. Associations Between Genetic Mutations and Clinical or Demographic Parameters Figure 1. Associations Between Genetic Mutations and Clinical or Demographic Parameters Disclosures No relevant conflicts of interest to declare.

Description: Background Therapy-related Myelodysplastic Syndromes (t-MDS) are those MDS occurring after cytotoxic and/or radiation therapy administered for a prior neoplastic or non-neoplastic disorder. Their prognosis is generally very poor. The commonly used risk prognostic models for MDS (IPSS and IPSS-R) are not validated in this entity as they were developed after the exclusion of therapy-related cases (Greenberg et al. Blood 1997; Greenberg et al. Blood 2012). Aims The main aims of this study are: a) to report clinical findings and overall survival on 233 patients with t-MDS, and to compare them with a large series of de novo cases; b) to test if IPSS-R is applicable to t-MDS patients. Patients and methods The study is based on the Spanish Registry for MDS, a retrospective database that includes more than 10000 cases. The investigators were asked to fill in a questionnaire regarding prior disease (PD) and prior therapy in those cases reported to be t-MDS. Herein are described the clinical features and overall survival of the first 233 cases with the required information, and compared with patients with de novo MDS from a single center series (n=725). Log Rank test was applied to asses IPSS-R in t-MDS group. Results The 233 reported patients were diagnosed between January 1993 and February 2014. The series includes 104 women (44,6%) and 129 men (55,4%). One hundred and two patients (43.9%) had a primary hematologic malignancy, 119 (51%) had a solid tumor, and 12 (5.1%) received cytotoxic therapy for autoimmune disorders. Ninety eight patients (42.6%) received only chemotherapy (CT), 45 (19.6%) received only radiotherapy (RT), 44 (19.1%) received combined modality treatment (CMT), and 43 (18.6%) received an autologous stem cell transplantation (ASCT). The median time of latency between PD and diagnosis in t-MDS group was 4.56 years (range: 0.03-29.63) in patients previously treated with CT or CMT, significantly lower than the observed after RT (8.54; range 0.83-23.02) or ASCT (8.64; range 2.87-28.32) groups (p=0.023 and p Disclosures No relevant conflicts of interest to declare.

Description: INTRODUCTION: CXCL9, CXCL10 and CXCL11 (CXCL9-10-11) are closely related cytokines that specifically bind to their receptor CXCR3. They act inducing chemotaxis, proliferation and/or cytotoxicity of CD4+ Th1 and cytotoxic T cells, which express CXCR3. Although the CXCL9-10-11/CXCR3 axis promotes immune activation, their pro- or anti-tumor effects in chronic lymphocytic leukemia (CLL) remain controversial. The aims of this study are: 1. To investigate serum levels of CXCL9-10-11 and the protein expression of their receptor CXCR3, as well as Th1 and cytotoxic gene expression signatures and protein expression of the cytotoxic molecules granzyme B and perforin in peripheral blood (PB) CD4+ T cells of controls, CLL-like monoclonal B-cell lymphocytosis (MBL) and CLL Binet stage A patients. 2. To assess the correlations between all previous parameters. 3. To evaluate Th1, cytotoxic and PD1+ T cell populations during disease progression. METHODS: Samples from 52 MBL subjects, 61 untreated CLL patients (Binet stage A/B [CLL-A/CLL-B]: 53/8) and 31 age-matched controls were employed. Serum levels (pg/mL) of CXCL9-10-11 were measured in 24 controls, 41 MBL and 44 CLL-A patients using Human CXCL9/MIG Quantikine ELISA Kit (R&D Systems) and U-PLEX Platform (Meso Scale Discovery). In addition, cryopreserved PB mononuclear cells from 8 controls, 11 MBL, 10 CLL-A and 8 CLL-B were studied by flow cytometry. Anti-CD3, anti-CD4, anti-granzyme B, anti-perforin, anti-CXCR3 and anti-PD1 antibodies, FVS510 and Fixation/Permeabilization Kit were used for cell staining (BD Biosciences). Protein expression of CXCR3, granzyme B, perforin and PD1 (measured as percentage of positive cells in PB CD4+ T cells) was assessed using FACSCanto II cytometer (BD Biosciences). In addition, purified CD4+ cells from PB (purity≥90%) were isolated by immunomagnetic methods (Miltenyi Biotec) to analyze gene expression in 9 controls, 13 MBL and 14 CLL-A patients. Extracted RNA (RIN〉7) was hybridized to GeneChip Human Gene 2.0 ST arrays (Affymetrix). Differential gene expression was evaluated with linear models in R, and genes with P-value1.5 were considered differentially expressed. Linear regression and Pearson correlations were calculated to evaluate the relationship between the different components of the CXCL9-10-11/CXCR3 axis (Figure 1). P-values0.8 for 6/7 genes). Significant positive correlations were also observed between CXCR3 protein expression and cytotoxic genes as well as granzyme B protein (Table 2). Protein expression of CXCR3 and cytotoxic molecules were similarly increased in the different stages of the disease. However, CLL-B patients displayed an increased percentage of CD4+ T cells expressing PD1 (around 7% in MBL and CLL-A versus 16% in CLL-B), although significance was not achieved (Table 1). CONCLUSIONS: 1. The increased levels of the different components of the CXCL9-10-11/CXCR3 axis in MBL and CLL-A, together with the strong correlations observed, point to an important activation of this molecular pathway in the first stages of the disease. 2. Correlations between CXCR3 and Th1/cytotoxic genes/proteins suggest that the increased Th1/cytotoxic features of CD4+ T cells in MBL and CLL-A are triggered by CXCL9-10-11/CXCR3 stimulation, and might be considered as a potential target for CLL immunotherapy. 3. The lower percentage of PD1+ CD4+ T cells in MBL/CLL-A may allow efficient effector Th1/cytotoxic responses at these stages of the disease. ACKNOWLEDGEMENTS. PI11/01621, PI15/00437, 2017/SGR437, Fundació La Caixa, Fundación Española de Hematología y Hemoterapia (FEHH). Disclosures Gimeno: Abbvie: Speakers Bureau; JANSSEN: Consultancy, Speakers Bureau. Rai:Genentech/Roche: Membership on an entity's Board of Directors or advisory committees; Pharmacyctics: Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Membership on an entity's Board of Directors or advisory committees; Cellectis: Membership on an entity's Board of Directors or advisory committees. Abrisqueta:Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: Travel, Accommodations, expenses, Speakers Bureau; Abbvie: Consultancy, Honoraria, Other: Travel, Accommodations, expenses, Speakers Bureau; Roche: Consultancy, Honoraria, Other: Travel, Accommodations, expenses, Speakers Bureau. Bosch:Acerta: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Kyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda: Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AstraZeneca: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd/Genentech, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.