Consecutive Liver and Bone Marrow Transplantation for Erythropoietic Protoporphyria: Case Report and Literature Review.

BACKGROUND: Erythropoietic protoporphyria (EPP) is a rare inherited disease of heme biosynthesis resulting in the accumulation of protoporphyrin, characterized by liver failure in a minority of cases. Although liver transplant (LT) is the therapeutic strategy for advanced hepatic disease, it does not correct the primary defect, which leads to recurrence in liver graft. Thus, hematopoietic stem cell transplantation (HSCT) is an approach for treating EPP. METHODS: We aim to describe the first sequential LT and HSCT for EPP performed in Latin America, besides reviewing the present-day literature. RESULTS: The patient, a 13-year-old female with a history of photosensitivity, presented with symptoms of cholestatic and hepatopulmonary syndrome and was diagnosed with EPP. Liver biopsy demonstrated cirrhosis. She was submitted to a successful LT and showed improvement of respiratory symptoms. However, she had disease recurrence on the liver graft. She underwent a myeloablative HSCT using a matched unrelated donor, conditioning with BuCy (busulfan and cyclophosphamide), and GvHD (graft vs. host disease) prophylaxis with ATG (thymoglobulin), tacrolimus and methotrexate. Neutrophil engraftment occurred on D+18. She has presented mixed chimerism, but normalization of PP levels, being 300 days after HSCT, in good state of health and normal liver function. CONCLUSIONS: Consecutive LT and HSCT for EPP is a procedure that has been described in 10 cases in the literature and, even though these patients are a highly diversified population, studies have shown favorable results. This concept of treatment should be considered in patients with established liver disease.

Peripheral blood persistence and expansion of transferred non-genetically modified Natural Killer cells might not be necessary for clinical activity.

Natural killer (NK) cells are innate lymphocytes that react without previous exposition to virus infected or malignant cells and stimulate adaptive immune response to build a long-lasting immunity against it. To that end, tissue resident NK cells are predominantly regulatory as opposed to cytotoxic. In the hematopoietic stem cell transplant (HSCT) setting, which curative potential relies on the graft versus leukemia effect, NK cells are known to play a significant role. This knowledge has paved the way to the active investigation on its anti-tumor effect outside the stem cell transplant scenario. Based on the relevant literature on the adoptive transfer of non-genetically modified NK cells for the treatment of relapsed/refractory acute leukemia and on our own experience, we discuss the role of donor cell peripheral blood persistence and expansion and its lack of correlation with anti-leukemia activity.

Prophylaxis in hemophilia

Hemophilia is an inherited X-linked coagulopathy defined by a deficiency or abnormality in the clotting function of factor VIII (Hemophilia A) or factor IX (Hemophilia B). Prophylaxis ­ the regular administration of therapeutic products to maintain hemostasis and prevent bleeding ­ is the mainstream of treatment. Addressing the development and scientific evidence for administrating prophylaxis is the goal of this review. Prophylaxis is the therapeutic modality of choice for people with severe hemophilia, being considered, in principle, a lifelong treatment. It should have an early onset, ideally as a primary, or at least secondary. Even lifelong tertiary prophylaxis seems to offer benefit, although further studies are still lacking. Individualized strategies should lead to an optimization of the dilemma between better joint outcomes versus involved costs.

Hemophilia: a biography on therapeutical approaches

The history of hemophilia is ancient, with descriptions dated to the 2nd century AD. The first modern narratives appeared in 1800s, when total blood transfusion was the only available treatment and life expectancy was remarkably low. Advances occurred with the use of plasma and cryoprecipitate, but only the discovered of factor concentrates revolutionized the treatment. The implantation of prophylaxis allowed hemophilic patients to prevent bleeding and the development of chronic arthropathy, although with a significant burdensome with the regular infusions. In the past 20 years, this field has witnessed major improvements, including the development of gene therapy and other pharmacological approaches.

The proteomic and particle composition of human platelet lysate for cell therapy products.

Following health agencies warning, the use of animal origin supplements should be avoided in biological products proposed as therapy in humans. Platelet lysate and several other growth factors sources are alternatives to replace fetal calf serum, the current gold standard in clinical-grade cell culture. However, the platelet supplement's content lacks data due to different production methods. The principle behind these products relays on the lysis of platelets that release several proteins, some of which are contained in heterogeneous granules and coordinate biological functions. This study aims to analyze the composition and reproducibility of a platelet lysate produced with a standardized method, by describing several batches' protein and particle content using proteomics and dynamic light scattering. Proteomics data revealed a diversified protein content, with some related to essential cellular processes such as proliferation, morphogenesis, differentiation, biosynthesis, adhesion, and metabolism. It also detected proteins responsible for activation and binding of transforming growth factor beta, hepatocyte growth factor, and insulin-like growth factor. Total protein, biochemical, and growth factors quantitative data showed consistent and reproducible values across batches. Novel data on two major particle populations is presented, with high dispersion level at 231 ± 96 d.nm and at 30 ± 8 d.nm, possibly being an important way of protein trafficking through the cellular microenvironment. This experimental and descriptive analysis aims to support the content definition and quality criteria of a cell supplement for clinical applications.

Adoptive immunotherapy with double-bright (CD56bright /CD16bright ) expanded natural killer cells in patients with relapsed or refractory acute myeloid leukaemia: a proof-of-concept study.

Patients with acute myeloid leukaemia (AML) have a five-year survival rate of 28·7%. Natural killer (NK)-cell have anti-leukaemic activity. Here, we report on a series of 13 patients with high-risk R/R AML, treated with repeated infusions of double-bright (CD56bright /CD16bright ) expanded NK cells at an academic centre in Brazil. NK cells from HLA-haploidentical donors were expanded using K562 feeder cells, modified to express membrane-bound interleukin-21. Patients received FLAG, after which cryopreserved NK cells were thawed and infused thrice weekly for six infusions in three dose cohorts (106 -107 cells/kg/infusion). Primary objectives were safety and feasibility. Secondary endpoints included overall response (OR) and complete response (CR) rates at 28-30 days after the first infusion. Patients received a median of five prior lines of therapy, seven with intermediate or adverse cytogenetics, three with concurrent central nervous system (CNS) leukaemia, and one with concurrent CNS mycetoma. No dose-limiting toxicities, infusion-related fever, or cytokine release syndrome were observed. An OR of 78·6% and CR of 50·0% were observed, including responses in three patients with CNS disease and clearance of a CNS mycetoma. Multiple infusions of expanded, cryopreserved NK cells were safely administered after intensive chemotherapy in high-risk patients with R/R AML and demonstrated encouraging outcomes.

Bone Marrow Mesenchymal Stem Cells in Acute-on-Chronic Liver Failure Grades 2 and 3: A Phase I-II Randomized Clinical Trial.

Introduction: Acute-on-chronic liver failure (ACLF) is an acute liver decompensation in cirrhotic patients, which leads to organ failures and high short-term mortality. The treatment is based on the management of complications and, in severe cases, liver transplantation. Since specific treatment is unavailable, we aimed to evaluate the safety and initial efficacy of bone marrow mesenchymal stem cells (BM-MSC) in patients with ACLF Grades 2 and 3, a population excluded from previous clinical trials. Methods: This is a randomized placebo-controlled phase I-II single center study, which enrolled 9 cirrhotic patients from 2018 to 2020, regardless of the etiology. The control group (n = 5) was treated with standard medical therapy (SMT) and placebo infusion of saline. The intervention group (n = 4) received SMT plus 5 infusions of 1 × 106 cells/kg of BM-MSC for 3 weeks. Both groups were monitored for 90 days. A Chi-square test was used for qualitative variables, and the t-test and Mann-Whitney U test for quantitative variables. The Kaplan-Meier estimator was used to build survival curves. In this study, we followed the intention-to-treat analysis, with a significance of 5%. Results: Nine patients with a mean Child-Pugh (CP) of 12.3, MELD of 38.4, and CLIF-C score of 50.7 were recruited. Hepatitis C and alcohol were the main etiologies. The average infusion per patient was 2.9 and only 3 patients (2 in control and 1 in the BM-MSC group) received all the protocol infusions. There were no infusion-related side effects, although one patient in the intervention group presented hypernatremia and a gastric ulcer, after the third and fifth infusions, respectively. The survival rate after 90 days was 20% (1/5) for placebo versus 25% (1/4) for the BM-MSC. The patient who completed the entire MSC protocol showed a significant improvement in CP (C-14 to B-9), MELD (32 to 22), and ACLF (grade 3 to 0). Conclusion: BM-MSC infusion is safe and feasible in patients with ACLF Grades 2 and 3.

Epidemiological characteristics of hemophilia in the pre-primary prophylaxis era: a historical cohort

Introduction: Epidemiological studies on hemophilia in the Brazilian population are historically scarce. Despite the continuous effort made by the National Program of Inherited Bleeding Disorders to map this condition, little information is available, especially on the period prior to program conception. Therefore, the present study aims to assess the epidemiological, serological, and clinical characteristics of patients with hemophilia in the state of Rio Grande do Sul, Brazil. Methods: A total of 455 patients had their medical records reviewed from January 1, 2003 to December 31, 2007. Results: We observed a remarkable prevalence of hepatitis C virus (HCV) infection in patients with both hemophilia A and B, and this prevalence significantly increased along with age (p < 0.001). No positive anti-HCV results were observed among children younger than 5 years old. There was a significant correlation between the severity of hemophilia and the number of arthropathies in all age categories. Considering the presence of inhibitors, a significant difference was observed between age groups, as older patients had higher inhibitor titers. There was a significant correlation between mean coagulation factor consumption and the number of arthropathies in patients over 5 years old. Conclusions: This profile analysis of patients with hemophilia reflects a gradual improvement in treatment safety and efficiency, as well as the need for continued investment in this population. (AU)

An Experimental Study Comparing the Expansion of Peripheral Blood Natural Killer (NK) Cells Cultured with Artificial Antigen-Presenting Cells, in the Presence or Absence of Bone Marrow Mesenchymal Stem Cells (MSCs).

NK cells have been seen as potential agents in adoptive immunotherapy for cancer. The main challenge for the success of this approach is to obtain a great quantity of activated NK cells for adoptive transfer. The present study had aimed to evaluate the effect of a feeder layer of irradiated MSCs in the in vitro expansion of NK cells. MSCs were obtained from the bone marrow (BM) cells remaining in the bag and filter used in the transplantation of hematopoietic stem cells. NK cells were obtained from peripheral blood (PB) of healthy volunteers. NK expansion and activation were stimulated by culture with artificial antigen-presenting cells (aAPCs) and IL-2, in the presence or absence of BM-MSCs. NK cell proliferation, phenotypic expression and cytotoxic activity were evaluated. Both culture conditions showed high NK purity with predominance of NK CD56brightCD16+ subset post expansion. However, cultures without the presence of MSCs showed higher NK proliferation, expression of activation markers (CD16 and NKG2D) and related cytotoxic activity. In this experimental study, the presence of a feeder layer of irradiated BM-MSCs interfered negatively in the expansion of PB-NKs, limiting their growth and activation. Further investigation is needed to understand the mechanisms of NK-MSC interaction and its implications.

What happens to intolerant, relapsed or refractory chronic myeloid leukemia patients without access to clinical trials?

ABSTRACT Objective: To assess clinical outcomes of intolerant, relapsed or refractory patients who could not be treated with new tyrosine kinase inhibitors or experimental therapies. Methods: A retrospective cohort of 90 chronic myeloid leukemia patients in all phases of the disease treated with imatinib mesylate as their first TKI therapy, and with dasatinib or nilotinib as the next line of therapy. We evaluated clinical outcomes of these patients, with special focus on the group that needed more than two therapy lines. Results: Thirty-nine percent of patients were refractory or intolerant to imatinib. An 8-year overall survival rate of the patients who went through three or more lines of treatment was significantly lower, compared to those who were able to maintain imatinib as their first-line therapy (83% and 22%, respectively p < 0.01). Decreased overall survival was associated with advanced-phase disease (p < 0.01), failure to achieve major molecular response in first-line treatment (p < 0.01) and interruption of first-line treatment due to any reason (p = 0.023). Failure in achieving complete cytogenetic response and major molecular response and treatment interruption were associated with the progression to the third-line treatment. Conclusion: The critical outcome observed in relapsed, intolerant or refractory chronic phase CML patients reflects the unmet need for this group of patients without an alternative therapy, such as new drugs or experimental therapies in clinical trials. Broader access to newer treatment possibilities is a crucial asset to improve survival among CML patients, especially those refractory or intolerant to first-line therapies.

What happens to intolerant, relapsed or refractory chronic myeloid leukemia patients without access to clinical trials?

OBJECTIVE: To assess clinical outcomes of intolerant, relapsed or refractory patients who could not be treated with new tyrosine kinase inhibitors or experimental therapies. METHODS: A retrospective cohort of 90 chronic myeloid leukemia patients in all phases of the disease treated with imatinib mesylate as their first TKI therapy, and with dasatinib or nilotinib as the next line of therapy. We evaluated clinical outcomes of these patients, with special focus on the group that needed more than two therapy lines. RESULTS: Thirty-nine percent of patients were refractory or intolerant to imatinib. An 8-year overall survival rate of the patients who went through three or more lines of treatment was significantly lower, compared to those who were able to maintain imatinib as their first-line therapy (83% and 22%, respectively p<0.01). Decreased overall survival was associated with advanced-phase disease (p<0.01), failure to achieve major molecular response in first-line treatment (p<0.01) and interruption of first-line treatment due to any reason (p=0.023). Failure in achieving complete cytogenetic response and major molecular response and treatment interruption were associated with the progression to the third-line treatment. CONCLUSION: The critical outcome observed in relapsed, intolerant or refractory chronic phase CML patients reflects the unmet need for this group of patients without an alternative therapy, such as new drugs or experimental therapies in clinical trials. Broader access to newer treatment possibilities is a crucial asset to improve survival among CML patients, especially those refractory or intolerant to first-line therapies.

Correction to: Monitoring of intracerebellarly-administered natural killer cells with fluorine-19 MRI.

There was a typo in author Andrew Wahba's name in the initial online publication. The original article has been corrected.

Monitoring of intracerebellarly-administered natural killer cells with fluorine-19 MRI.

PURPOSE: Medulloblastoma (MB) is the most common malignant brain tumor in children. Recent studies have shown the ability of natural killer (NK) cells to lyse MB cell lines in vitro, but in vivo successes remain elusive and the efficacy and fate of NK cells in vivo remain unknown. METHODS: To address these questions, we injected MB cells into the cerebellum of immunodeficient mice and examined tumor growth at various days after tumor establishment via bioluminescence imaging. NK cells were labeled with a fluorine-19 (19F) MRI probe and subsequently injected either intratumorally or contralaterally to the tumor in the cerebellum and effect on tumor growth was monitored. RESULTS: The 19F probe efficiently labeled the NK cells and exhibited little cytotoxicity. Fluorine-19 MRI confirmed the successful and accurate delivery of the labeled NK cells to the cerebellum of the mice. Administration of 19F-labeled NK cells suppressed MB growth, with the same efficacy as unlabeled cells. Immunohistochemistry confirmed the presence of NK cells within the tumor, which was associated with induction of apoptosis in tumor cells. NK cell migration to the tumor from a distal location as well as activation of apoptosis was also demonstrated by immunohstochemistry. CONCLUSIONS: Our results show that NK cells present a novel opportunity for new strategies in MB treatment. Further, 19F-labeled NK cells can suppress MB growth while enabling 19F MRI to provide imaging feedback that can facilitate study and optimization of therapeutic paradigms.

Donor characteristics and hematopoietic stem cell transplantation outcome: experience of a single center in Southern Brazil.

BACKGROUND: Hematopoietic stem cell transplantation is a curative treatment for many patients with hematological disorders. Donor-recipient genetic disparity, especially involving the human leukocyte antigen system is a critical factor for transplant outcome. OBJECTIVE: To evaluate retrospectively donor characteristics and correlations with the occurrence of acute and chronic graft-versus-host disease, disease-free survival and overall survival in a Brazilian population submitted to allogeneic hematopoietic stem cell transplantation between 1994 and 2012 in a single center. RESULTS: Three hundred and forty-seven consecutive transplantations were included. Related transplants (81.2%) were significantly more common than unrelated transplants (18.7%); donor and recipient median ages were 34 (range: 1-61) and 33 (range: 3-65) years respectively with donor HLAs being matched for 333 (95.9%) patients. Donor gender, cytomegalovirus status and ABO incompatibility did not influence the five-year overall survival. In univariate analyses, overall survival was negatively influenced by the presence of acute graft-versus-host disease (33% vs. 47%, respectively; p-value = 0.04), unrelated transplant (41.5% vs. 50.9%, respectively; p-value = 0.045) and donors aged over 40 years (41% vs. 52%, respectively; p-value = 0.03). Older donors were associated with a higher rate of acute (52% vs. 65.8%; p-value = 0.03) and chronic graft-versus-host disease (60% vs. 43%, respectively; p-value = 0.015). In multivariate analyses, acute graft-versus-host disease [relative risk (RR): 1.8; 95% confidence interval (CI): 1.1-29; p-value = 0.008] and older donors (RR: 1.6; 95% CI 1.11-2.24; p-value = 0.013) were associated with higher transplant-related mortality. CONCLUSIONS: In transplant patients, to have a donor older than 40 years of age seems to significantly increase the incidence of acute and chronic graft-versus-host disease and transplant-related mortality with no impact on disease-free survival and overall survival. In spite of the rather small cohort of patients, these findings are similar to what is described in the literature suggesting that a younger donor should be chosen whenever possible.

Donor characteristics and hematopoietic stem cell transplantation outcome: experience of a single center in Southern Brazil

ABSTRACT Background: Hematopoietic stem cell transplantation is a curative treatment for many patients with hematological disorders. Donor-recipient genetic disparity, especially involving the human leukocyte antigen system is a critical factor for transplant outcome. Objective: To evaluate retrospectively donor characteristics and correlations with the occurrence of acute and chronic graft-versus-host disease, disease-free survival and overall survival in a Brazilian population submitted to allogeneic hematopoietic stem cell transplantation between 1994 and 2012 in a single center. Results: Three hundred and forty-seven consecutive transplantations were included. Related transplants (81.2%) were significantly more common than unrelated transplants (18.7%); donor and recipient median ages were 34 (range: 1-61) and 33 (range: 3-65) years respectively with donor HLAs being matched for 333 (95.9%) patients. Donor gender, cytomegalovirus status and ABO incompatibility did not influence the five-year overall survival. In univariate analyses, overall survival was negatively influenced by the presence of acute graft-versus-host disease (33% vs. 47%, respectively; p-value = 0.04), unrelated transplant (41.5% vs. 50.9%, respectively; p-value = 0.045) and donors aged over 40 years (41% vs. 52%, respectively; p-value = 0.03). Older donors were associated with a higher rate of acute (52% vs. 65.8%; p-value = 0.03) and chronic graft-versus-host disease (60% vs. 43%, respectively; p-value = 0.015). In multivariate analyses, acute graft-versus-host disease [relative risk (RR): 1.8; 95% confidence interval (CI): 1.1-29; p-value = 0.008] and older donors (RR: 1.6; 95% CI 1.11-2.24; p-value = 0.013) were associated with higher transplant-related mortality. Conclusions: In transplant patients, to have a donor older than 40 years of age seems to significantly increase the incidence of acute and chronic graft-versus-host disease and transplant-related mortality with no impact on disease-free survival and overall survival. In spite of the rather small cohort of patients, these findings are similar to what is described in the literature suggesting that a younger donor should be chosen whenever possible.

A simple protocol for transfecting human mesenchymal stem cells.

OBJECTIVES AND RESULTS: Mesenchymal stromal cells (MSCs) are potential targets for cell and gene therapy-based approaches against a variety of different diseases. The MSCs from bone marrow are a promising target population as they are capable of differentiating along multiple lineages and have significant expansion capability. These characteristics make them strong candidates for delivering genes and restoring organ systems function. However, as other primary cells, MSCs are difficult to transfect. In order to standardize a simple protocol for transfection of MSCs, we conducted a series of experiments and achieved a protocol that does not require the use of viral particles or specific expensive equipment. CONCLUSION: MSCs transfection at early passages using a ratio lipid/DNA of 3.0 µL/µg with Lipofectamine 3000® yields good transfection efficiencies for human MSCs (up to 26%) and is rapid, simple, and safe.

Comparison of cyclophosphamide-thalidomide-dexamethasone to bortezomib-cyclophosphamide-dexamethasone as induction therapy for multiple myeloma patients in Brazil.

OBJECTIVE/BACKGROUND: Chemotherapy followed by autologous hematopoietic stem cell transplantation (HSCT) remains the standard treatment for multiple myeloma (MM). Thalidomide or bortezomib may be combined with cyclophosphamide and dexamethasone, in what are known as the CTD and VCD protocols, respectively. The objective of this study was to evaluate the clinical characteristics and response rates obtained with CTD and VCD, observing whether the inclusion of bortezomib to treat MM patients in Brazil increases therapeutic efficiency. METHODS: Forty-three MM patients treated with induction protocols CTD and VCD between January 2010 and March 2015 were included. The parameters analyzed were staging, frequency of comorbidities prior to treatment, response rates obtained at each induction cycle, progression-free survival, and overall survival of patients. RESULTS: Very good partial response and complete response obtained with the VCD protocol were superior, compared with the CTD treatment. The presence of comorbidities was similar in the two groups, except kidney failure, which prevailed in the VCD group. Also, 78.3% and 48.3% of patients treated with the VCD and CTD protocols underwent autologous HSCT, respectively. In patients given the VCD protocol, 45.5% had complete response before autologous HSCT. Among those given CTD, this number was only 7.1% (p=0.023). Disease progression after autologous HSCT did not differ between the two groups. CONCLUSION: VCD afforded better responses than the CTD protocol, and improved patient condition before autologous HSCT. However, more studies are necessary including more patients and addressing various clinical conditions, besides the analysis of cost-effectiveness of these treatments.

Comparison of human mesenchymal stromal cells from four neonatal tissues: Amniotic membrane, chorionic membrane, placental decidua and umbilical cord.

BACKGROUND: Mesenchymal stromal cells (MSCs) are being investigated as a potential alternative for cellular therapy. This study was designed to compare the biological characteristics of MSCs isolated from amniotic membrane (A-MSCs), chorionic membrane (C-MSCs), placental decidua (D-MSCs) and umbilical cord (UC-MSCs) to ascertain whether any one of these sources is superior to the others for cellular therapy purposes. METHODS: MSCs were isolated from amniotic membrane, chorionic membrane, umbilical cord and placental decidua. Immunophenotype, differentiation ability, cell size, cell complexity, polarity index and growth kinetics of MSCs isolated from these four sources were analyzed. RESULTS: MSCs were successfully isolated from all four sources. Surface marker profile and differentiation ability were consistent with human MSCs. C-MSCs in suspension were the smallest cells, whereas UC-MSCs presented the greatest length and least width. A-MSCs had the lowest polarity index and UC-MSCs, as more elongated cells, the highest. C-MSCs, D-MSCs and UC-MSCs exhibited similar growth capacity until passage 8 (P8); C-MSCs presented better lifespan, whereas insignificant proliferation was observed in A-MSCs. DISCUSSION: Neonatal and maternal tissues can serve as sources of multipotent stem cells. Some characteristics of MSCs obtained from four neonatal tissues were compared and differences were observed. Amniotic membrane was the least useful source of MSCs, whereas chorionic membrane and umbilical cord were considered good options for future use in cell therapy because of the known advantages of immature cells.

Characterization of Patients with Chronic Myeloid Leukemia Unresponsive to Tyrosine Kinase Inhibitors Who Underwent Allogeneic Hematopoietic Stem Cell Transplantation.

Background: Tyrosine kinase inhibitors (TKIs) were the first drugs to use an intracellular signaling molecule as a therapeutic target. Unresponsiveness to TKIs limits therapeutic options, making allogeneic hematopoietic stem cell transplantation (HSCT) the only option leading to molecular remission. The aim of this study is to characterize CML patients unresponsive to first- and/or second-generation TKI therapy who underwent HSCT and to describe the main factors associated with treatment failure. Subjects and Methods: Twenty one CML patients who underwent allogeneic HSCT and had previously used first- and/or second-generation TKIs from January 2005 to May 2014. Results: Of the 21 patients, 52.4% were male, with a median age of 49 years (23-65 years) and 85.7% had chronic phase CML at the time of diagnosis; 28.6% showed inadequate treatment adherence to TKI therapy. Thirteen patients were resistant and eight were intolerant to TKIs; additionally, nine did not have T315I mutation. Ten transplantations involved related donors, and more than a half of patients (11) died, three of which due to graft failure. Most patients who survived transplantation were in the chronic phase of disease at the time of HSCT. Conclusion: The population was composed mainly of young age patients at diagnosis, male, white, and coming from areas in the state of Rio Grande do Sul other than Porto Alegre and metropolitan region. Low adherence to TKI therapy may be related to unresponsiveness to treatment, especially in patients with acquired resistance, or this low adherence, together with the presence of molecular changes, may have led to the need for HSCT.