Ibrutinib impairs the phagocytosis of rituximab-coated leukemic cells from chronic lymphocytic leukemia patients by human macrophages

We have read with great interest the recent article of Kohrt, H.E. et al1 showing that Ibrutinib prevented NK cell mediated cytotoxicity of antibody-coated CLL cells in vitro. They also found that the concurrent treatment with Ibrutinib and rituximab or trastuzumab reduces the therapeutic efficacy of both anti-CD20 antibodies in a mouse model, while the sequential treatment with Ibrutinib and rituximab restored its anti-lymphoma activity. Since macrophages are the most important effector cells in CD20-directed cytotoxicity in murine models2,3 and they probably play a key role in human anti-CD20 therapy4,5, we determined whether Ibrutinib interferes the capacity of human macrophages to mediate phagocytosis of rituximab-coated CLL cells. To address this issue, macrophages differentiated from healthy peripheral blood monocytes were treated with or without Ibrutinib for 30 minutes and then cultured for 1, 2 or 3 hours with CFSE-labeled CLL cells or rituximab-coated CFSE-labeled CLL cells. Then, cells were tripsinized and the proportion of macrophages that have taken up CFSE-labeled CLL cells (CFSE+ macrophages) were scored by flow cytometry and verified using confocal microscopy, as previously described6. As expected, we found that the cultures with rituximab-coated CLL cells showed the highest percentage of CFSE+ macrophages, which increase in a time dependent manner (open circles in Figure 1A). Ibrutinib was able to reduce these values in all the times evaluated (solid circles in Figure 1A). Low percentages of CFSE+ macrophages were obtained in cultures with uncoated CLL cells, which were not modified by Ibrutinib (open and solid squares in Figure 1A). In addition, we found that Ibrutinib diminishes the percentage of CFSE+ macrophages in the cultures with rituximab-coated cells in a dose dependent manner (Figure 1B), which was not associated to a decreased viability of the macrophages (not shown). Moreover, the inhibitory effect of Ibrutinib was not limited to rituximab since comparable results were obtained when campath-coated CFSE-labeled CLL cells were employed (Figure 1C). Similar results were found when macrophages from CLL patients were used: mean±SE of the % of CFSE+ macrophages: 26.8 ± 2.1 vs, 17.3 ± 2.7 vs 10.8 ± 0.7 for rituximab-coated CFSE-labeled CLL cells alone, with 0.5μM or 5μM of Ibrutinib (n= 6). Representative dot plots are shown in Figure 1D. The results obtained by flow cytometry analysis were validated by confocal microscopy quantifying the number of macrophages that engulfed at least one tumor target cell (Figure 1E). A representative experiment is shown in Figure 1F. In addition, by performing a binding assay at 4oC, we confirmed that Ibrutinib did not reduce the binding of rituximab-coated CFSE-labeled CLL cells to macrophages (Figure 1G). Interestingly, while the presence of Ibrutinib during the assay impairs the phagocytosis of rituximab-coated CLL cells, when Ibrutinib was washed out, macrophages recovered their phagocytic capacity in a time-dependent manner (Figure 1H). In conclusion we found that the presence of Ibrutinib impairs the phagocytosis of rituximab-opsonized CLL cells by human macrophages, which was restored when the inhibitor was removed from the cultures. Our results, and those obtained by Kohrt et al1 suggest that the sequential administration of Ibrutinib followed by rituximab, and not the concurrent treatment of the patients with these agents, might enhance their anti-tumor activity in vivo.Fil: Borge, Mercedes. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Almejún, María Belén. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Cátedra de Microbiología, Parasitología e Inmunología; ArgentinaFil: Podaza, Enrique Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Colado, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fernández Grecco, Horacio. Sanatorio Municipal Dr. Julio Méndez; ArgentinaFil: Cabrejo, María. Sanatorio Municipal Dr. Julio Méndez; ArgentinaFil: Bezares, Raimundo F.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos ; ArgentinaFil: Giordano, Mirta Nilda. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Gamberale, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentin

The effect of the proteasome inhibitor bortezomib on acute myeloid leukemia cells and drug resistance associated with the CD34+ immature phenotype

[Background]: Proteasome inhibition represents a promising novel anticancer therapy, and bortezomib is a highly selective reversible inhibitor of the proteasome complex. Acute myeloid leukemia (AML) is an immnunophenotypically heterogeneous group of diseases, with CD34+ cases being associated with drug resistance and poor outcome. We investigated the effects of bortezomib on the growth and survival of AML cells. [Design and Methods]: We studied the in vitro activity and mechanism of action of bortezomib on both cell lines and fresh cells from 28 AML patients including CD34+ and CD34- cases. [Results]: Bortezomib showed potent anti-AML activity (IC50 < 50 nM), which was greater than that of conventional agents (doxorubicin, cytarabine and fludarabine). Moreover, synergistic effects were observed when bortezomib was adminstered in combination with doxorubicin and cytarabine. Mechanistically, bortezomib induced accumulation of cells in the G2/M phase, with up-regulation of p27, together with cell death through an increase in the mitochondrial outer membrane permeability involving caspase-dependent and -independent pathways. The apoptotic activity of bortezomib on fresh CD34 + blast cells from patients was similar to that observed on CD34 - blast cells. Importantly, bortezomib was significantly more active than doxorubicin in the immature CD34+ cells, while there were no differences in its action on CD34- cells. [Conclusions]: Bortezomib induces apoptosis in acute myeloid leukemia cells in vitro. Whether this drug might be useful in the treatment of patients with acute myeloid leukemia can be established only in ad hoc clinical trials. ©2008 Ferrata Storti Foundation.We thank Johnson and Johnson Pharmaceutical Research and Development (JJPRD).Peer Reviewe

Chronic lymphocytic leukemia cells increase neutrophils survival and promote their differentiation into CD16 high CD62L dim immunosuppressive subset

Reprogramming of neutrophils by malignant cells is well-described for many types of solid tumors, but data remain scarce for hematological diseases. Chronic lymphocytic leukemia (CLL) is characterized for a deep immune dysregulation mediated by leukemic cells that compromises patient´s outcome. Murine models of CLL highlight the relevance of myeloid cells as tumor-driven reprogramming targets. In our study, we evaluated neutrophil reprogramming by CLL cells. We first show that the proportion of the CD16high CD62Ldim neutrophil subset in peripheral blood of CLL patients is increased compared to age-matched healthy donors (HD). In vitro, neutrophils from HD cultured in the presence of CLL cells or conditioned media (CM) from CLL cells exhibited a longer lifespan. Depletion of G-CSF and GM-CSF from CM partially reversed the protective effect. In addition, the proportion of viable neutrophils that displayed a CD16high CD62Ldim phenotype was increased in the presence of CM from CLL cells, being TGF-β/IL-10 responsible for this effect. Altogether, our results describe a novel mechanism through which CLL cells can manipulate neutrophils.Fil: Podaza, Enrique Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Risnik, Denise Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Colado, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Elías, Esteban Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Almejún, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fernandez Grecco, Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Bezares, Raimundo Fernando. Sanatorio Municipal "Dr. Julio Mendez"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Dr. Teodoro Álvarez"; ArgentinaFil: Borge, Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Gamberale, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Giordano, Mirta Nilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin

Autologous t-cell activation fosters ABT-199 resistance in chronic lymphocytic leukemia: Rationale for a combined therapy with SYK inhibitors and anti-CD20 monoclonal antibodies

Fil: Elías, Esteban Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Almejún, María Belén. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Colado, Ana. Academia Nacional de Medicina de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Cordini, Gregorio. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Vergara Rubio, Maricef. Academia Nacional de Medicina de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Podaza, Enrique Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Risnik, Denise Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Cabrejo, María. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Fernández Grecco, Horacio. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Bezares, Raimundo Fernando. Universidad de Buenos Aires; ArgentinaFil: Custidiano, María Del Rosario. Sanatorio Municipal Dr. Julio Méndez; ArgentinaFil: Sánchez Ávalos, Julio César Américo. Sanatorio Municipal Dr. Julio Méndez; ArgentinaFil: Vicente, Ángeles. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Dr. Teodoro Álvarez"; ArgentinaFil: Garate, Gonzalo Martín. Instituto Alexander Fleming; ArgentinaFil: Borge, Mercedes. Instituto Alexander Fleming; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Giordano, Mirta Nilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina. Hospital Alemán; ArgentinaFil: Gamberale, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina. Hospital Aleman; Argentin

Neutrophils from chronic lymphocytic leukemia patients exhibit an increased capacity to release extracellular traps (NETs)

Chronic lymphocytic leukemia (CLL) is characterized by immune defects that contribute to a high rate of infections and autoimmune cytopenias. Neutrophils are the first line of innate immunity and respond to pathogens through multiple mechanisms, including the release of neutrophil extracellular traps (NETs). These web-like structures composed of DNA, histones, and granular proteins are also produced under sterile conditions and play important roles in thrombosis and autoimmune disorders. Here we show that neutrophils from CLL patients are more prone to release NETs compared to those from age-matched healthy donors (HD). Increased generation of NETs was not due to higher levels of elastase, myeloperoxidase, or reactive oxygen species production. Instead, we found that plasma from CLL patients was able to prime neutrophils from HD to generate higher amounts of NETs upon activation. Plasmatic IL-8 was involved in the priming effect since its depletion reduced plasma capacity to enhance NETs release. Finally, we found that culture with NETs delayed spontaneous apoptosis and increased the expression of activation markers on leukemic B cells. Our study provides new insights into the immune dysregulation in CLL and suggests that the chronic inflammatory environment typical of CLL probably underlies this inappropriate neutrophil priming.Fil: Podaza, Enrique Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Sabbione, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Risnik, Denise Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Borge, Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Almejún, María Belén. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Colado, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fernández Grecco, Horacio. Servicio de Hematología, Sanatorio Municipal Dr. Julio Méndez; ArgentinaFil: Cabrejo, María del Rosario. Servicio de Hematología, Sanatorio Municipal Dr. Julio Méndez; ArgentinaFil: Bezares, Raimundo F.. Servicio de Hematología, Hospital Municipal Dr. Teodoro Alvarez; ArgentinaFil: Trevani, Analía Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina; ArgentinaFil: Gamberale, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Giordano, Mirta Nilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin

Expression and function of cathelicidin hCAP18/LL-37 in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of clonal Bcellsin peripheral blood and lymphoid tissues 1. Circulating CLL cells are non-dividing Blymphocytes, but a significant fraction of the clone proliferates in lymphoid tissues wherethey receive a plethora of signals from the microenvironment that promote their survivaland expansion 2. Cathelicidins are a family of proteins with antibacterial functions mainlyexpressed by neutrophils, macrophages and epithelial cells 3. In humans, the only memberof this family, hCAP18, is encoded by the gene CAMP. The cleavage of hCAP18 generatesthe antimicrobial peptide LL-37, which has been recently implicated in the promotion oftumor growth, through direct stimulation of malignant cells, initiation of angiogenesis andrecruitment of immune cells 4. In this study, we investigated the role of hCAP18/LL-37 inCLL.Fil: Podaza, Enrique Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Palacios, Florencia. The Feinstein Institute for Medical Research. Karches Center for Oncology Research; Estados UnidosFil: Croci Russo, Diego Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Risnik, Denise Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Yan, Xiao J.. The Feinstein Institute for Medical Research. Karches Center for Oncology Research; Estados UnidosFil: Almejún, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Colado, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Elías, Esteban Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Borge, Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Morande, Pablo Elías. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Bezares, Raimundo F.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Dr. Teodoro Álvarez"; ArgentinaFil: Fernández Grecco, Horacio. Sanatorio Municipal Dr. Julio Méndez. Servicio de Hematología; ArgentinaFil: Rabinovich, Gabriel Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Gamberale, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Chiorazzi, Nicholas. The Feinstein Institute for Medical Research. Karches Center for Oncology Research; Estados UnidosFil: Giordano, Mirta Nilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin

Sphingosine Kinase 1 Participates In The Activation, Proliferation And Survival Of Chronic Lymphocytic Leukemia Cells

Sphingosine kinases (SKs) have received the most attention as important enzymes in cancer biology. They participate in the regulation of bioactive sphingolipid metabolism by producing sphingosine-1 phosphate (S1P) which mediates several biological functions, including cell growth, differentiation, cell survival, migration, and angiogenesis among other tasks.1 S1P generation depends on the conversion of sphingosine to S1P, in a reaction catalyzed by two isoforms of SKs, SK1 and SK2, and its levels are tightly controlled via a rapid degradation by intracellular S1P lyases (S1PL) or dephosphorylated by S1P phosphatases.1 Once produced, S1P may function as an intracellular second messenger and/or can be exported outside the cells, where it binds to specific S1P receptors (S1PRs) and initiates downstream signaling pathways, in a paracrine or autocrine manner, in a process known as “inside-out” signaling.Fil: Almejún, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Borge, Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Colado, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Elías, Esteban Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Podaza, Enrique Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Risnik, Denise Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: de Brasi, Carlos Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Stanganelli, Carmen Graciela. Academia Nacional de Medicina de Buenos Aires. Instituto de Investigaciones Hematológicas "Mariano R. Castex"; ArgentinaFil: Slavutsky, Irma Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Cabrejo, María. Ciudad Autónoma de Buenos Aires. Sanatorio Municipal "Dr. Julio Méndez"; ArgentinaFil: Fernández Grecco, Horacio. Ciudad Autónoma de Buenos Aires. Sanatorio Municipal "Dr. Julio Méndez"; ArgentinaFil: Bezares, Raimundo Fernando. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Dr. Teodoro Álvarez"; ArgentinaFil: Cranco, Santiago. Instituto Alexander Fleming; ArgentinaFil: Burgos, Rubén Ángel. Instituto Alexander Fleming; ArgentinaFil: Sánchez Ávalos, Julio César Américo. Instituto Alexander Fleming; ArgentinaFil: Oppezzo, Pablo. Instituto Pasteur de Montevideo; UruguayFil: Giordano, Mirta Nilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Gamberale, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin

Genomic complexity and IGHV mutational status are key predictors of outcome of chronic lymphocytic leukemia patients with TP53 disruption.

The clinical course of chronic lymphocytic leukemia (CLL) is extremely heterogeneous and while some patients achieve a normal lifespan, others succumb to the disease shortly after diagnosis. Recurrent chromosomal aberrations as detected by chromosome banding analysis (CBA) or fluorescent in situ hybridization (FISH) have a reproducible prognostic power in terms of response to therapy and survival.1–3 In particular, patients whose tumor cells harbor 17p deletions (17p-) are considered to have a shorter survival and, hence, high-risk CLL. This poor prognosis is, however, not universally true for all patients with 17p- CLL. Indeed, we and others have observed that some clinical-biological features, such as presence of B symptoms, advanced clinical stage, size of the 17p- clone, β2-microglobulin (β2M) concentration and IGH mutational status have a significant impact on the outcome of this subgroup of patients.4,5 Novel molecular studies have helped in the understanding of 17p- CLL. On one hand, TP53 mutations are present in more than 80% of cases with 17p deletion and in around 5% of patients without 17p deletion.6,7 On the other hand, next generation sequencing studies have revealed novel genetic aberrations such as NOTCH1 and SF3B1 mutations that have a negative impact on survival.8–10 Finally, genomic complexity, as defined by karyotyping1 or copy number (CN) arrays, has also been independently associated with disease transformation and poor outcome in patients with CLL.11,12 The aim of this study was to evaluate the prognostic value of concomitant molecular abnormalities in patients with CLL and TP53 aberrations as diagnosed by FISH, CBA or DNA sequencing

Basophil-lineage commitment in acute promyelocytic leukemia predicts for severe bleeding after starting therapy

Severe hemorrhagic events occur in a significant fraction of acute promyelocytic leukemia patients, either at presentation and/or early after starting therapy, leading to treatment failure and early deaths. However, identification of independent predictors for high-risk of severe bleeding at diagnosis, remains a challenge. Here, we investigated the immunophenotype of bone marrow leukemic cells from 109 newly diagnosed acute promyelocytic leukemia patients, particularly focusing on the identification of basophil-related features, and their potential association with severe bleeding episodes and patient overall survival. From all phenotypes investigated on leukemic cells, expression of the CD203c and/or CD22 basophil-associated markers showed the strongest association with the occurrence and severity of bleeding (p ≤ 0.007); moreover, aberrant expression of CD7, coexpression of CD34+/CD7+ and lack of CD71 was also more frequently found among patients with (mild and severe) bleeding at baseline and/or after starting treatment (p ≤ 0.009). Multivariate analysis showed that CD203c expression (hazard ratio: 26.4; p = 0.003) and older age (hazard ratio: 5.4; p = 0.03) were the best independent predictors for cumulative incidence of severe bleeding after starting therapy. In addition, CD203c expression on leukemic cells (hazard ratio: 4.4; p = 0.01), low fibrinogen levels (hazard ratio: 8.8; p = 0.001), older age (hazard ratio: 9.0; p = 0.002), and high leukocyte count (hazard ratio: 5.6; p = 0.02) were the most informative independent predictors for overall survival. In summary, our results show that the presence of basophil-associated phenotypic characteristics on leukemic cells from acute promyelocytic leukemia patients at diagnosis is a powerful independent predictor for severe bleeding and overall survival, which might contribute in the future to (early) risk-adapted therapy decisions.This work was supported by the Fundación Científica de la Asociación Española Contra el Cáncer (AECC, Madrid, Spain) and the Fundación Rafael del Pino (Madrid, Spain) and both CIBERONC (CB16/12/00400, CB16/12/00233, CB16/12/00480) and grant PI16/00787 from Instituto de Salud Carlos III (Ministerio de Economía y Competitividad, Madrid, Spain)

Proposed global prognostic score for systemic mastocytosis: a retrospective prognostic modelling study

[Background]: Several risk stratification models have been proposed in recent years for systemic mastocytosis but have not been directly compared. Here we designed and validated a risk stratification model for progression-free survival (PFS) and overall survival (OS) in systemic mastocytosis on the basis of all currently available prognostic factors, and compared its predictive capacity for patient outcome with that of other risk scores.[Methods]: We did a retrospective prognostic modelling study based on patients diagnosed with systemic mastocytosis between March 1, 1983, and Oct 11, 2019. In a discovery cohort of 422 patients from centres of the Spanish Network on Mastocytosis (REMA), we evaluated previously identified, independent prognostic features for prognostic effect on PFS and OS by multivariable analysis, and designed a global prognostic score for mastocytosis (GPSM) aimed at predicting PFS (GPSM-PFS) and OS (GPSM-OS) by including only those variables that showed independent prognostic value (p<0·05). The GPSM scores were validated in an independent cohort of 853 patients from centres in Europe and the USA, and compared with pre-existing risk models in the total patient series (n=1275), with use of Harrells' concordance index (C-index) as a readout of the ability of each model to risk-stratify patients according to survival outcomes.[Findings]: Our GPSM-PFS and GPSM-OS models were based on unique combinations of independent prognostic factors for PFS (platelet count ≤100 × 109 cells per L, serum β2-microglobulin ≥2·5 μg/mL, and serum baseline tryptase ≥125 μg/L) and OS (haemoglobin ≤110 g/L, serum alkaline phosphatase ≥140 IU/L, and at least one mutation in SRSF2, ASXL1, RUNX1, or DNMT3A). The models showed clear discrimination between low-risk and high-risk patients in terms of worse PFS and OS prognoses in the discovery and validation cohorts, and further discrimination of intermediate-risk patients. The GPSM-PFS score was an accurate predictor of PFS in systemic mastocytosis (C-index 0·90 [95% CI 0·87–0·93], vs values ranging from 0·85 to 0·88 for pre-existing models), particularly in non-advanced systemic mastocytosis (C-index 0·85 [0·76–0·92], within the range for pre-existing models of 0·80 to 0·93). Additionally, the GPSM-OS score was able to accurately predict OS in the entire cohort (C-index 0·92 [0·89–0·94], vs 0·67 to 0·90 for pre-existing models), and showed some capacity to predict OS in advanced systemic mastocytosis (C-index 0·72 [0·66–0·78], vs 0·64 to 0·73 for pre-existing models).[Interpretation]: All evaluated risk classifications predicted survival outcomes in systemic mastocytosis. The REMA-PFS and GPSM-PFS models for PFS, and the International Prognostic Scoring System for advanced systemic mastocytosis and GPSM-OS model for OS emerged as the most accurate models, indicating that robust prognostication might be prospectively achieved on the basis of biomarkers that are accessible in diagnostic laboratories worldwide.Carlos III Health Institute, European Regional Development Fund, Spanish Association of Mastocytosis and Related Diseases, Rare Diseases Strategy of the Spanish National Health System, Junta of Castile and León, Charles and Ann Johnson Foundation, Stanford Cancer Institute Innovation Fund, Austrian Science Fund