The Role of Azacitidine in the Treatment of Elderly Patients with Acute Myeloid Leukemia: Results of a Retrospective Multicenter Study.

OBJECTIVE: In this study, we aimed to investigate the efficacy and safety of azacitidine (AZA) in elderly patients with acute myeloid leukemia (AML), including patients with >30% bone marrow (BM) blasts. MATERIALS AND METHODS: In this retrospective multicenter study, 130 patients of ≥60 years old who were ineligible for intensive chemotherapy or had progressed despite conventional treatment were included. RESULTS: The median age was 73 years and 61.5% of patients had >30% BM blasts. Patients received AZA for a median of four cycles (range: 1-21). Initial overall response [including complete remission (CR)/CR with incomplete recovery/partial remission] was 36.2%. Hematologic improvement (HI) of any kind was documented in 37.7% of all patients. HI was also documented in 27.1% of patients who were unresponsive to treatment. Median overall survival (OS) was 18 months for responders and 12 months for nonresponders (p=0.005). In the unresponsive patient group, any HI improved OS compared to patients without any HI (median OS was 14 months versus 10 months, p=0.068). Eastern Cooperative Oncology Group performance status of <2, increasing number of AZA cycles (≥5 courses), and any HI predicted better OS. Age, AML type, and BM blast percentage had no impact. CONCLUSION: We conclude that AZA is effective and well tolerated in elderly comorbid AML patients, irrespective of BM blast count, and HI should be considered a sufficient response to continue treatment with AZA.

Ex vivo evaluation of the effect of regulatory T cells on the anti-tumor activity of bortezomib in multiple myeloma.

Multiple myeloma (MM) is a hematologic cancer characterized by malignant proliferation of plasma cells and their precursors. Immunosuppressive CD4+CD25+Foxp3+ regulatory T (Treg) cells are increased in the peripheral blood of patients with MM. On the basis of this finding, we sought to evaluate the ex vivo effect of CD4+CD25+Foxp3+ Treg cells on the anti-tumor effect of the proteosome inhibitor bortezomib on MM cells. We collected peripheral blood and bone marrow aspiration samples from 20 patients with newly diagnosed MM and isolated CD4+CD25+Foxp3+ Treg cells from peripheral blood mononuclear cells. The bone marrow mononuclear cells were cultivated in RPMI at 37°C and 5% CO2 for 72 hours. The LD50 doses of bortezomib, isolated Treg cells, and their combination were added. After 24 hours, the viability of CD138+ myeloma cells was evaluated by WST-1. We compared the anti-tumor effect of bortezomib alone and in combination with Treg expansion and statistically analyzed the measured differences with respect to the clinical parameters of the patients. Treg cells had varied effects on bortezomib, increasing, decreasing, or not changing its anti-tumor effect. The increased in vitro anti-tumor effect of bortezomib after Treg cell expansion was correlated in patients who did not develop bortezomib resistance in vivo (p = 0.022). These patients with in vivo non-bortezomib-resistant MM also responded to Treg expansion with decreased cell viability (p = 0.024). Our data indicate that the ex vivo expansion of Treg cells increased the cytotoxic effect of bortezomib in clinically sensitive cases.

IPSET-Thrombosis Better Identifies Thrombosis-Free Survival: A Turkish Cohort.

INTRODUCTION: Essential thrombocythemia (ET) is the most common of the myeloproliferative neoplasms. For better predicting the occurrence of thrombotic events, an International Prognostic Score of Thrombosis for ET (IPSET-Thrombosis) was recently developed. We aimed to investigate the validity of IPSET-Thrombosis in a Turkish patient cohort and to compare the efficacy of IPSET-Thrombosis and conventional risk scoring systems in predicting thrombosis-free survival. PATIENTS AND METHODS: We retrospectively evaluated the clinical characteristics and risk factors for thrombosis in 112 Turkish patients. Median thrombosis-free survival and Harrell C concordance indexes were calculated for both conventional and IPSET-Thrombosis. RESULTS: Median age of 112 patients included in the study was 61 (range, 27-90) years at the time of diagnosis. When patients were stratified according to the conventional risk stratification system, 43.8% of patients were in the low-risk group and 56.2% in the high-risk group. A total of 22.4% of low-risk and 42.9% of high-risk patients had at least one thromboembolic event. When patients were stratified according to the IPSET-Thrombosis, 33% were in the low-risk group, 26.8% in the intermediate-risk group, and 40.2% in the high-risk group. Considering IPSET-Thrombosis risk groups, 5.4% of low-risk, 26.7% of intermediate-risk, and 66.2% of high-risk patients had at least one thromboembolic event. Regarding IPSET-Thrombosis risk groups, 10-year thrombosis-free survival was 86.8% for low-risk, 39.4% for intermediate-risk, and 32.9% for high-risk groups (P < .001). Harrell C concordance indexes of conventional and IPSET-Thrombosis were 0.60 and 0.77, respectively. CONCLUSION: By validating the reproducibility of IPSET-Thrombosis in Turkish ET patients, we found that IPSET-Thrombosis identifies thrombosis-free survival better than the conventional risk stratification system.

Renal and neurological response with eculizumab in a patient with transplant associated thrombotic microangiopathy after allogeneic hematopoietic progenitor cell transplantation.

Transplantation-associated thrombotic microangiopathy (TA-TMA) is a challenge after allogeneic hematopoietic progenitor cell transplantation, considering the diagnostic uncertainties and lack of established treatment. We report a 43-year-old male patient who was diagnosed as TA-TMA after allogeneic progenitor cell transplantation for a progressive ALK negative anaplastic large cell lymphoma and responded to eculizumab with dramatically improving neurological status and renal function. Rapid neurological and renal recovery achieved after eculizumab could support a possible relationship between complement activation and TA-TMA. Eculizumab should be a reasonable treatment approach in patients with TA-TMA after allogeneic hematopoietic progenitor cell transplantation.

Nilotinib Does Not Alter the Secretory Functions of Carotid Artery Endothelial Cells in a Prothrombotic or Antithrombotic Fashion.

BACKGROUND: There have been concerns about the possible prothrombotic effects of nilotinib, especially in patients having cardiovascular risk factors. The potential mechanism behind the increased risk of thromboembolic events is still not clear. OBJECTIVES: In this study, we aimed to evaluate possible harmful effects of nilotinib on endothelial cells. To this aim, we examined proliferative capacity and secretory functions of healthy human carotid artery endothelial cells (HCtAECs) in response to nilotinib. METHODS: 3-(4,5-Dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation method was used to determine antiproliferative effects of nilotinib on HCtAECs. The HCtAECs were incubated with 5, 10, and 100 nmol/L doses of nilotinib for 72 hours. Then, in order to assess the endothelial function, levels of nitric oxide (NO), von Willebrand factor (vWF), tissue plasminogen activator, plasminogen activator inhibitor 1 (PAI-1), and endothelin 1 (ET-1) were evaluated using enzyme-linked immunosorbent assay from tissue culture supernatants. RESULTS: There were slight but statistically significant decreases in cell proliferation in response to nilotinib. Nilotinib increased the secretion of t-PA, PAI-1, and vWF in a dose-dependent manner when compared with the untreated control group. The ET-1 secretion was lower in 5 nmol/L and higher in 10 and 100 nmol/L nilotinib-treated cells as compared to untreated cells. Regarding NO secretion, lower levels were observed in 5 and 10 nmol/L, and higher levels were detected in 100 nmol/L nilotinib-treated cells as compared to untreated control group cells. CONCLUSION: Considering the results obtained in our study, nilotinib does not affect the functions of endothelial cells either in a prothrombotic or an antithrombotic fashion, despite a dose-dependent decline in cell viability.

Successful hematopoietic engraftment with gray platelets after allogeneic hematopoietic stem cell transplantation from gray platelet syndrome donor.

Gray platelet syndrome (GPS) is a rare inherited disorder characterized by the absence of α-granules and their constituents. It may be present with thrombocytopenia and bleeding tendency. Platelets have a large and gray appearance under light and electron microscope. A 19-year old female patient with her second relapse acute lymphoblastic leukemia had to be consolidated with allo-hematopoietic stem cell transplantation (HSCT) after achieving remission with induction chemotherapy. The only available and one mismatch compatible donor was her brother, who was previously diagnosed as GPS. Allogeneic HSCT was performed from her brother in spite of GPS, and successful neutrophil and platelet engraftment achieved at the 12th and 42nd day of reinfusion, consecutively. The engrafted and circulating thrombocytes were large and gray and had little or no α-granules under electron microscope. The patient was well with no major bleeding event and increased need for thrombocyte replacement until developing bronchiolitis obliterans organizing pneumonia and respiratory distress syndrome. Thereafter death occurred. This is the first case of successful thrombocyte engraftment with documented gray thrombocyte megakaryopoiesis after allogeneic HSCT from a GPS donor. The only noteworthy issue was the slight prolongation of engraftment.