ALBERT

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: 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.

Description: Background. Dysregulated NK-cell responses have been reported in chronic lymphocytic leukemia (CLL) patients, but little is known about the NK cell compartment in CLL-like monoclonal B cell lymphocytosis (MBL). Human cytomegalovirus (HCMV) infection induces an adaptive reconfiguration of the NK cell compartment characterized by the differentiation and persistent expansion of a subset displaying the CD94/NKG2C NK receptor (NKR). Moreover, a deletion of the NKG2C (KLRC2) gene has been reported to modulate the magnitude of the NK cell repertoire redistribution. Little is known about the expression of NKG2C in CLL and MBL patients. Aims. To analyse the distribution of NKR, with special attention to NKG2C, in MBL and CLL patients, assessing the relation of the NK cell immunophenotype with clinical features. Methods. The study cohort included 61 patients, 24 were diagnosed with clinical MBL and 37 were treatment-naïve CLL (32/37 Binet A). The expression of NKG2C, NKG2A, ILT2 (LIR1, LILRB1), CD161, CD57 and KIRs (identified with a cocktail of monoclonal antibodies) was assessed by flow cytometry in peripheral blood NK cells. The NKG2C (KLRC2) genotype was analysed in a larger representative MBL/CLL cohort (n=135). Results. The proportions of NK cells were reduced in CLL patients compared to MBL (median 5.5% vs. 10%; P=0.003), whereas their absolute numbers were increased (median 0.85x109/L vs. 0.57x109/L; P=0.002). No significant differences between MBL and CLL were detected regarding the distribution of the different NKR: NKG2C (median: 2.7 vs. 5.9%, respectively), NKG2A (31.4 vs. 30.8%), ILT2 (18.0 vs.15.8%), KIRs (54.4 vs. 52.7%), CD161 (16.1 vs. 16.4%) and CD57 (40.4 vs. 38.9%). Though a reduced NKG2C expression was noticed in both entities, it was specially marked in patients with a greater (〉30x109 cells/L) lymphocytosis (1.4 vs. 7.7%, P=0.016). The proportions of NKG2C+ NK cells in HCMV+ patients (85%, 47/55) as compared to HCMV- individuals were not significantly different (6.3% vs. 2.9%, respectively). HCMV+ patients showed a significantly lower NKG2C expression when compared with two independent age-matched cohorts of HCMV+ non-CLL/-MBL individuals, including 43 non-metastatic breast cancer patients (4.2% vs. 15.3% , P