Venetoclax in association with decitabine as effective bridge to transplant in a case of relapsed early T‐cell lymphoblastic leukemia

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A case of acquired factor XIII deficiency secondary to plasmablastic lymphoma

Acquired factor XIII (FXIII) deficiency is an extremely rare and potentially fatal bleeding disorder. Immune-mediated FXIII deficiency is due to the development of anti-FXIII autoantibodies which may develop with concomitant conditions that cause immune dysregulation such as malignancies or autoimmune disorders. Clinical presentation includes delayed post-operative bleeding or spontaneous soft tissue hematomas and/or cerebral bleeding. Since screening coagulation laboratory tests (prothrombin time, activated partial thromboplastin time, and fibrinogen) are typically normal, acquired FXIII deficiency is likely to be overlooked and underdiagnosed. The management of immune-mediated FXIII deficiency is based on hemostatic therapy, autoantibody removal and eradication of the underlying etiology; however, no treatment guidelines are still available. Here we report a case of acquired FXIII deficiency associated with plasmablastic lymphoma, in order to raise awareness of this rare bleeding disorder and consent prompt life-saving management

Circulating CD34+/CD38-/CD26+ Leukemia Stem Cells along Chronic Myeloid Leukemia progression: differences between Chronic, Accelerated and Blast Phase

In Chronic Myeloid Leukemia (CML) patients, CD34+/CD38-/CD26+ cell population represents a “CML specific” Leukemia Stem Cell (LSC) compartment. Indeed, preliminary studies showed that the expression of CD26 discriminates bone marrow CML Leukemic Stem Cells (LSCs) from nor-mal Hematopoietic Stem Cells (HSCs) or from LSCs of other myeloid neoplasms. We were first to demonstrate that at diagnosis CD34+/CD38-/CD26+ cells are easily measurable also in Peripheral Blood (PB) and that residual circulating CD26+LSCs persist, with a fluctuating trend, in most pa-tients in optimal response during treatment with Tyrosine Kinase Inhibitors (TKIs) and even after successful TKI discontinuation. These data corroborate and confirm the possibility of using flow-cytometry CD26+ evaluation as an important diagnostic tool that, combined with molecular biology and cytogenetic, could provide a rapid diagnosis of Chronic Phase (CP) CML starting from a simple PB sample. Yet, few data are available regarding the behavior of CD26+LSCs during Accelerated Phase (AP) or Blast Phase (BP) CML and the role, if any, this peculiar staminal cell compartment may play in disease progression. In the present study we compared the presence and phenotypic characteristics of circulating CD26+LSCs in CP CML patients at diagnosis, during AP and in cases of progression to lymphoid BP, inquiring a possible role of these cells during dis-ease evolution

Genetic predisposition and induced pro-inflammatory/pro-oxidative status may play a role in increased atherothrombotic events in nilotinib treated chronic myeloid leukemia patients

Several reports described an increased risk of cardiovascular (CV) events, mainly atherothrombotic, in Chronic Myeloid Leukemia (CML) patients receiving nilotinib. However, the underlying mechanism remains elusive. The objective of the current cross-sectional retrospective study is to address a potential correlation between Tyrosine Kinase Inhibitors (TKIs) treatment and CV events. One hundred and 10 chronic phase CML patients in complete cytogenetic response during nilotinib or imatinib, were screened for CV events and evaluated for: traditional CV risk factors, pro/anti-inflammatory biochemical parameters and detrimental ORL1 gene polymorphisms (encoding for altered oxidized LDL receptor-1). Multivariate analysis of the whole cohort showed that the cluster of co-existing nilotinib treatment, dyslipidaemia and G allele of LOX-1 polymorphism was the only significant finding associated with CV events. Furthermore, multivariate analysis according to TKI treatment confirmed IVS4-14 G/G LOX-1 polymorphism as the strongest predictive factor for a higher incidence of CV events in nilotinib patients. Biochemical assessment showed an unbalanced pro-inflammatory cytokines network in nilotinib vs imatinib patients. Surprisingly, pre-existing traditional CV risk factors were not always predictive of CV events. We believe that in nilotinib patients an induced "inflammatory/oxidative status", together with a genetic pro-atherothrombotic predisposition, may favour the increased incidence of CV events. Prospective studies focused on this issue are ongoing

Residual peripheral blood CD26+leukemic stem cells in chronic myeloid leukemia patients during TKI therapy and during treatment-free remission

Chronic myeloid leukemia (CML) patients in sustained “deep molecular response” may stop TKI treatment without disease recurrence; however, half of them lose molecular response shortly after TKI withdrawing. Well-defined eligibility criteria to predict a safe discontinuation up-front are still missing. Relapse is probably due to residual quiescent TKI-resistant leukemic stem cells (LSCs) supposedly transcriptionally low/silent and not easily detectable by BCR-ABL1 qRT-PCR. Bone marrow Ph+ CML CD34+/CD38− LSCs were found to specifically co-express CD26 (dipeptidylpeptidase-IV). We explored feasibility of detecting and quantifying CD26+ LSCs by flow cytometry in peripheral blood (PB). Over 400 CML patients (at diagnosis and during/after therapy) entered this cross-sectional study in which CD26 expression was evaluated by a standardized multiparametric flow cytometry analysis on PB CD45+/CD34+/CD38− stem cell population. All 120 CP-CML patients at diagnosis showed measurable PB CD26+ LSCs (median 19.20/μL, range 0.27–698.6). PB CD26+ LSCs were also detectable in 169/236 (71.6%) CP-CML patients in first-line TKI treatment (median 0.014 cells/μL; range 0.0012–0.66) and in 74/112 (66%), additional patients studied on treatment-free remission (TFR) (median 0.015/μL; range 0.006–0.76). Notably, no correlation between BCR-ABL/ABLIS ratio and number of residual LSCs was found both in patients on or off TKIs. This is the first evidence that “circulating” CML LSCs persist in the majority of CML patients in molecular response while on TKI treatment and even after TKI discontinuation. Prospective studies evaluating the dynamics of PB CD26+ LSCs during TKI treatment and the role of a “stem cell response” threshold to achieve and maintain TFR are ongoing

Cardiovascular toxicity in patients with chronic myeloid leukemia treated with second-generation tyrosine kinase inhibitors in the real-life practice: Identification of risk factors and the role of prophylaxis

No abstract availabl

The Polycomb BMI1 Protein Is Co-expressed With CD26+ in Leukemic Stem Cells of Chronic Myeloid Leukemia

The Polycomb gene BMI1 expression exerts a negative predictive impact on several hematological malignancies, such as acute and chronic myeloid leukemia (CML), myelofibrosis, and follicular lymphoma. As already demonstrated in CML, BMI1 is responsible for the resistance to the tyrosine kinase inhibitors (TKIs) in a BCR-ABL1-independent way. Even if, it is unknown where BMI1 in CML is expressed (in progenitors or more mature cells). We decided, therefore, to evaluate if and where the BMI1 protein is located, focusing mainly on the CD34+/CD38-/CD26+ CML progenitors. To begin we measured, by flow cytometry, the proportion of CD34+/CD26+ cells in 31 bone marrow samples from 20 CML patients, at diagnosis and during treatment with imatinib. After that the bone marrow blood smears were stained with antibodies anti-CD26, BCR-ABL1, and BMI1. These smears were observed by a confocal laser microscope and a 3D reconstruction was then performed. At diagnosis, CD34+/CD26+ cells median value/μL was 0.48; this number increased from diagnosis to the third month of therapy and then reduced during treatment with imatinib. The number and behavior of the CD26+ progenitors were independent from the BCR-ABL1 expression, but they summed up what previously observed about the BMI1 expression modulation. In this work we demonstrate for the first time that in CML the BMI1 protein is co-expressed with BCR-ABL1 only in the cytoplasm of the CD26+ precursors; on the contrary, in other hematological malignancies where BMI1 is commonly expressed (follicular lymphoma, essential thrombocytemia, acute myeloid leukemia), it was not co-localized with CD26 or, obviously, with BCR-ABL1. Once translated into the clinical context, if BMI1 is a marker of stemness, our results would suggest the combination of the BMI1 inhibitors with TKIs as an interesting object of research, and, probably, as a promising way to overcome resistance in CML patients