bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hereditary Deficiencies of Protein C or Protein S Confer Increased Risk of Arterial Thromboembolic Events at Young Age. Results from a Large Family Cohort Study
Authors: Mahmoodi Bakhtawar Khan , Brouwer Jan-Leendert P. , Veeger Nic J.G.M. , van der Meer Jan 
Published: April 2020

Abstract
Introduction: Hereditary deficiencies of protein S, protein C or antithrombin are strong risk factors for venous thromboembolism (VTE). Whether these deficiencies are associated with arterial thromboembolism (ATE) and whether history of VTE in these subjects predisposes to subsequent ATE has yet to be determined.
Methods: Based on pedigree analysis we enrolled a total 552 subjects (52% women; mean age, 46±17 years), belonging to 84 different kindreds, in this retrospective family-cohort study. Detailed information on previous episodes of VTE, ATE, anticoagulants use and atherosclerosis risk factors (i.e. diabetes, hypertension, hyperlipidemia, and smoking) were collected. In addition to the index deficiencies participants were also tested for other thrombophilic defects; including factor V Leiden, prothrombin G20210A, increased FVIII and lupus anticoagulants. Primary study outcome was objectively verified symptomatic ATE. As the assumption for proportional hazards for the final model was not met over the entire observation period, we opted for a piecewise Cox model with a cut off point set at 55 years of age.
Results: Of 552 subjects (mean age±SD, 46±17 years; 52% women), 308 had either protein S (35%), protein C (39%) or antithrombin deficiency (26%). Age, atherosclerosis risk factors and other thrombophilic defects were similar (P&gt;0.23) between deficient and non-deficient subjects. A total of 44 arterial thromboembolic events had occurred, corresponding to an overall annual incidences of 0.34% (95% CI, 0.23–0.49) in deficient and 0.17% (0.09–0.28) in non-deficient subjects, hazard ratio 2.3 (1.2–4.5; P=0.01). However, the risk hazards varied over lifetime; while risk of ATE conferred by these deficiencies was 5.4 (1.6–18.4; P=0.006) before age 55 years, it was 1.3 (0.6–2.9; P=0.51) thereafter. After adjusting for atherosclerosis risk factors and clustering of ATE within families, deficient subjects had 4.7-fold (1.5–14.2; P=0.007) higher risk of ATE before age 55 years, versus 1.1 (0.5–2.6; P=0.84) thereafter, compared to non-deficient family members. For separate deficiencies these were 4.6 (1.1 – 18.3), 6.9 (2.1 – 22.2) and 1.1 (0.1 – 10.9) in protein S-, protein C- and antithrombin-deficient subjects, respectively, before age 55 years. History of VTE was not related to subsequent ATE, hazard ratio 1.1 (0.5 – 2.2).
Conclusions: Compared to non-deficient family members, subjects with protein S or protein C deficiencies but not antithrombin deficiency have an increased risk for ATE before age 55 years, independent of prior VTE. After age 55 years conventional atherosclerosis risk factors accounted for ATE. In thrombophilic families, deficiencies of protein S and protein C should be considered in atherothrombotic risk assessment before age 55 years.
Growth Factor Deprivation Combined with Prolonged Inhibition of BCR-ABL Does Not Eradicate Functional CML Stem Cells
Authors: Hamilton Ashley , Helgason Gudmundur V , Allan Elaine , Alcorn Michael J. , Nicolini Franck E , Blair Allison , Schemionek Mirle , Koschmieder Steffen , Brunton Valerie G , Holyoake Tessa L 
Published: April 2020

Abstract
Chronic myeloid leukaemia (CML) is a myeloproliferative disorder that originates in a haemopoietic stem cell (HSC) and is characterised by the BCR-ABL oncogene. We have previously shown that cancer stem cells exist in all patients with newly diagnosed CML. These cells are primitive, quiescent, transplantable in NOD/SCID mice and insensitive to the tyrosine kinase inhibitor (TKI) imatinib. This intrinsic resistance may in part be explained by high expression of BCR-ABL in the most primitive cells. Our overall aim was to achieve complete and prolonged inhibition of BCR-ABL within CML CD34+ cells in vitro, using the highest clinically achievable concentration of a novel dual Src/ABL TKI, dasatinib, in serum free medium in the absence of growth factors. The drug was replenished every 3 days and cells remaining at 12 days were analysed. Despite growth factor deprivation combined with 12 days continuous treatment with dasatinib 150nM, 10% of the starting CD34+ cells were recovered. CFSE stained CML cells showed that treatment with dasatinib resulted in a “backing up” of cells within the undivided cell population and earlier cell divisions, demonstrating that dasatinib, like imatinib, is anti-proliferative. Inhibition of P-CrkL and hence BCR-ABL was maximal at the earliest time-point (day 4) and in the cells that were able to proliferate through several divisions, likely the most mature cells. Cells which remained undivided/quiescent and maintained expression of stem cell markers, CD34 and CD133, demonstrated significantly elevated levels of P-CrkL, as compared to the mature cycling populations. Following drug washout, the remaining viable cells achieved 5-fold expansion when cultured in growth factors for 7 days. Moreover, these cells were able to form colonies following culture in LTCIC assays, which were BCR-ABL positive by FISH and did not show gene mutation. Retrospective studies which assessed the efficacy of TKI treatment times and concentrations also showed that transient dasatinib exposure for 1 hour at 150nM, resulted in a ~80% reduction of viable CML cells when assessed 72 hours later and was as effective as 72 hours continuous exposure at concentrations as high as 1000nM. Our next approach will be to combine BCR-ABL knock-down using shRNA with dasatinib to fully inhibit BCR-ABL in the stem cell population in an effort to determine whether these cells are dependent on BCR-ABL for survival and proliferation.
Imatinib Is a Substrate for Various Multidrug Resistance Proteins
Authors: Czyzewski Krzysztof , Styczynski Jan 
Published: April 2020

Abstract
An increasing resistance to imatinib is an emerging problem in patients with chronic myeloid leukemia. The aim of the study was assessing possible mechanisms of cellular drug resistance in imatinib-resistant derivates of chronic myeloid leukemia K-562 cell line. A parental K-562 and its imatinib-resistant derivate cell lines were used. Cell lines were tested for cytotoxicity of imatinib, cytarabine, busulfan and etoposide. Multidrug resistance proteins expression, rhodamine retention and daunorubicin accumulation were measured for each cell line. Imatinib was cytotoxic to all tested groups of cells. Exposition of K-562 cell line to low concentrations of imatinib caused an increase of IC50 value of imatinib, while exposition of K-562 cell line to higher concentrations of imatinib decreased IC50 value of imatinib. There was a high correlation between PGP, MRP1 and LRP expression and IC50 for imatinib and etoposide. All tested cell lines were highly resistant to cytarabine. Rhodamine retention alone and in the presence of cyclosporine was the lowest in imatinib-resistant K-562R-0.1 cell line, what suggest high PGP activity in this cell line. Daunorubicin accumulation was the highest in parental K-562 cell line and it decreased in imatinib-resistant cell lines, which were characterized by high PGP, MRP1 and LRP expression. These data suggest that imatinib is a substrate for multidrug resistance proteins, and an increased expression of PGP, MRP1 and LRP play a role in resistance to imatinib in chronic myeloid leukemia.
Effect of Imatinib Mesylate on Platelet Aggregation Abnormalities in BCR-ABL + CML Patients
Authors: Mogalluru Upendra srinivas , Mahapatra Manoranjan , Pati Hara prasad , Saxena Renu 
Published: April 2020

Abstract
Bleeding and thrombotic events complicate the clinical course of chronic myeloproliferative disorders (CMPDs). A spectrum of platelet aggregation abnormalities have been described in CML. Clonal involvement of megakaryocytopoiesis is regarded as the main origin of these abnormalities. Effects of cytoreductive drugs on platelet aggregation abnormalities have been studied which showed no significant corrective effect. Effect of Imatinib mesylate on platelet aggregation abnormalities has not been studied so far. Our study aims at assessing the effect of imatinib mesylate on platelet aggregation abnormalities in BCR-ABL positive CML patients. A total of 50 newly diagnosed BCR-ABL positive CML patients and 30 normal healthy volunteers were enrolled in the study. BCR-ABL by RT-PCR and Platelet aggregation parameters by CHRONOLOG aggregometer using arachidonic acid (AA), collagen, adrenaline (ADR), adenosine diphosphate (ADP) and ristocetin as agonists were measured both at diagnosis and after a minimum of 3 months of imatinib therapy. Platelet aggregation parameters measured for each agonist were Degree of aggregation (DOA) and Rate of Aggregation (ROA). DOA was calculated by increase of transmissions for 1 minute/total maximum transmissions in 2 minutes measurement of platelet aggregation and expressed as percentage. ROA was calculated as the number of 1mm squares under the platelet aggregation curve in 60 seconds. These parameters were calculated for each agonist for all patients and controls and their mean ± 2SD were analyzed. Forty-eight cases were in chronic phase (CP), accelerated (AP) and blast phase (BP) constituted one each. DOA and ROA parameters in 39/48(81%) cases in CP and both AP and BP cases measured with ADP, AA, and ADP as agonists in the pre-imatinib phase showed a statistically significant lower values compared to healthy controls. 3/48 (6%)CP cases showed hyper aggregation with ADR and 6/48(13%) showed normal aggregation parameters. In the post-imatinib phase, aggregation parameters normalized in 32/39 CP cases. AP and BP cases showed persistently lower values. No significant difference is noted in parameters measured using ristocetin and collagen as agonists when compared among pre and post imatinib phases and controls. The normalization of aggregation parameters may be attributed to either partial or complete suppression of clonal abnormal megakaryocytopoiesis and restoration of normal megakaryocytopoiesis by imatinib mesylate therapy in BCR-ABL positive CML.
Dasatinib in the Treatment of CML Patients Aged &gt; 60 Years Resistant/Intolerant to Imatinib
Authors: Latagliata Roberto , Breccia Massimo , Stagno Fabio , De Matteis Silvia , Annunziata Mario , Carmosino Ida , Cannella Laura , Napoleone Laura , Vozella Federico , Sica Simona , Di Raimondo Francesco , Ferrara Felicetto , Alimena Giuliana 
Published: April 2020

Abstract
Dasatinib is a 2nd generation tyrosine-kinase inhibitor active in CML patients resistant or intolerant to Imatinib; at present there is no data on its toxicity and efficacy in elderly patients. To highlight this issue, 37 patients treated with Dasatinib when aged &gt; 60 years were retrospectively evaluated. There were 21 males and 16 females, median age at Dasatinb was 69.3 years (IR 64.9–73.0), Sokal Risk at diagnosis was low in 13 patients, intermediate in 14, high in 5 and not valuable in 5. Twenty-two patients (59.4%) were primary resistant, 4 (10.8%) intolerant and 11 (29.8%) secondary resistant to Imatinib; all but 2 patients were in CP when Dasatinib was started. Median time from diagnosis to Dasatinib treatment was 99.2 months (IR 56.8–124.5); 25/37 patients (67.5%) have been pretreated with IFN ± Ara-C before Imatinib, all patients received Imatinib at standard dose (400 mg/day) followed in 20/37 (54%) by Imatinib at increased dose (600–800 mg/day) with an overall median period of Imatinib treatment of 52.8 months (IR 26.2–60.9). In addition, 7/37 patients (18.9%) received other 2nd line treatment (3 with Nilotinib, 2 with Imatinib + HU and 2 with other drugs) before Dasatinib. Starting dose of Dasatinib was 140 mg/day in 18 patients and 100 mg/day in 19 patients, respectively. After a median period of treatment of 9.4 months (IR 3.0–19.1) all patients were evaluable for toxicity; among 18 patients receiving 140 mg, grade 3–4 haematological and extra-haematological toxicities were reported in 14 (77.7%) and 6 (33.3%) patients, respectively; among 19 patients receiving 100 mg, grade 3–4 haematological and extra-haematological toxicities were reported in 4 (21.0%) and 1 (5.2%) patients, respectively. Pleuro-pericardial effusions occurred in 3 patients, all treated with 140 mg as starting dose. Overall, 3/37 patients (all treated with 140 mg) discontinued permanently Dasatinib due to early toxicity; a dose reduction was needed in 17/37 patients [16/18 (88.8%) treated with 140 mg and 1/19 (5.2%) with 100 mg]. As to response, 28 patients were considered evaluable (≥ 6 months of treatment) and 9 considered as too early; five patients (17.9%) did not have any response (including 3 patients with early Dasatinib discontinuation for toxicity) and 23 (82.1%) achieved Complete Haematological Response (CHR). Furthermore, 11/28 patients (39.2%) achieved a Cytogenetic Response (CyR) (Major CyR in 4 and Complete CyR in 7) and 4/28 patients (14.2%) achieved a molecular response. In conclusion, Dasatinib, when employed at the current recommended starting dose of 100 mg/day; seems effective and very well tolerated also in heavily pretreated elderly subjects; these results are encouraging also for a future use of this drug in early chronic phase elderly patients.
Evidence for Increased Bone Marrow Lymphoplasmocytoid Cells and SDF1 Secretion in imatinib Treated CML. Relationship with Clinical/hemathological Response
Authors: Pierri Ivana , Catellani Silvia , Olcese Francesca , Grasso Raffaella , Colombo Nicoletta , Gobbi Marco , Poggi Alessandro , Zocchi Maria Raffaella 
Published: April 2020

Abstract
Tyrosine kinase inhibitors, such as imatinib mesylate (Gleevec, Novartis, formerly known as STI571) are confirmed to be the first line treatment of Chronic Myelogenous Leukemia (CML) and of a rare form of gastroenteric stromal cancer. It has been reported that in the latter case, the response to the drug in vivo is mainly due to immunocompetent cells, able to produce cytokines with antineoplastic activity. In this study, peripheral blood and bone marrow of 20 CML patients were studied, prior and during treatment with imatinib, to assess morphologic, phenotypic, cytogenetic and biomolecular patterns. Plasma from BM and PB was also tested to evaluate (by ELISPOT and real time polymerase chain reaction) cytokines able to induce B lymphocytes differentiation, and/or proliferation, such as interleukin (IL)-4, IL-6 (ligand for CD126), IL-3, IL-10 or IL-21 together with chemokines MCP-1, SDF-1, IP-10 and IL-8. In 14 out of 20 CML patients a significant increase in the percentage of BM lymphoplasmocytoid cells was observed on imatinib treatment with &gt;10% (range 8–12%) of CD20+CD126+cells. Among this population, two third of cells coexpressed IgM and one third was IgD+, moreover a lower fraction of IgM+CD126+CD20− (3–4%) or IgD+CD126+CD20− (2–3%) cells was found too. In all these patients SDF1 increased in the BM plasma after imatinib (from 10–80pg/ml to 150–450pg/ml) and its receptor CXCR4 was up-regulated on CD20+CD126+cells. In 4 patients the amount of IP-10 in BM plasma and the expression of its receptor CXCR3 were also increased. No significant modification in transcription and secretion of IL-3, IL-4, IL-6, IL-10, IL-21, IL-8 or MCP1 were observed. The lasting 6 patients had&lt;5% of CD20 +CD126+ lymphocytes (range2–4%), 2/3 coexpressing IgM and 1/3 coexpressing IgD. Every patients with increased number of CD126+ B lymphocytes achieved hemathologic remission, 7 of them complete cytogenetic and biomolecular remission. On the other hand, among the patients with low or undetectable CD20+CD126+cells, 2 obtained only hemathological remission. In the 2 relapsed patients, BM CD20+CD126+ lymphocytes decreased from 11% and 8% to 7 and 5%, respectively, with undetectable IgM+ CD126+CD20− or IgD+ CD126+CD20− cells. The increased production of SDF-1, following imatinib administration, might increase BM lymphoplasmocitoid cells, thanks to the double proliferative/chemotactic effect of the cytokine on B cells, with redistribution and in situ differentiation of CD20+ CD126+ lymphocytes. These findings shed some light on the possibility that, even in CML, immunological events may play a role in disease control;moreover they could be useful in monitoring disease outcome.
Late Responders to Imatinib: Is Timing of Achievement of Complete Cytogenetic and Molecular Responses the Same in Previously Treated as Compared to the Newly Diagnosed CML Patients?
Authors: Scholl Vanesa , Bitencourt Roberta , Moellmann Arthur , Hassan Rocio , Rocha Moises , Dobbin Jane , Zalcberg Ilana 
Published: April 2020

Abstract
Appropriate monitoring of the effect of tyrosine kinase (TK) therapy is a relevant issue for CML therapeutic strategy. Although cytogenetics is the gold-standard method for response evaluation, serial quantification of BCR-ABL levels by real time PCR (RQ-PCR) has shown accuracy in predicting therapeutic response. Optimal cytogenetic (CCyR) and molecular (MMR) responses for newly diagnosed chronic phase (CP) CML patients were defined within 12 and 18 months of Imatinib (IM) therapy. However, patients not achieving optimal responses (OpRes) within these times are classified as “late responders”. We evaluated a group of 142 patients (4 year follow up) treated with IM as 2nd line. Patients were classified in 3 groups according to previous treatment: IFN (n=90), SCT (n=11) and HU/IFN ≤3 months (n=41, considered as without treatment). BCR–ABL levels were measured every 3 months, at least 5 times/patient during follow-up. A laboratory-specific conversion factor of 1.33 was generated to convert the BCR-ABL/ABL% values to an International Scale (IS). At the moment, 90 patients are being followed (69 CP, 11 AP). Cytogenetics results were available in 80/90 cases, and 63/80 (79%) (55 CP, 8 AP) achieved CCyR. After 12 months of IM treatment, 30/63 cases (48%) obtained CCyR (early responders), and 33/63 (52%) were late responders. When 18 months were considered as a cut-off time to achieved OpRes, 46 (73%) were considered early and 17 (27%) late responders. Molecular data were available for 74 patients; 45/74 (61%) (40 CP, 5 AP) achieved MMR, and 20 (27%) also showed Complete MR. 10/45 cases (22%) were early responders, and 35/45 (78%) late at 18 months of IM. When evaluating at 24 months, 17 (38%) were early and 28 (62%) were late responders. When only CP patients that achieved CCyR (n=55) and MMR (n=40) were considered, these proportions were maintained. Attainment of CCyR/MMR was similar between patients with and without previous treatment (p=0,26;p=0,09). However, we found a delay in the timing of OpRes achievement in comparison with previous related work analyzing patients in 1st line IM. Thus, to achieve similar frequencies of CCyR/MMR obtained from the use of 1st line IM, previously treated patients needed an extension time of 6 months. Thus we suggest for the patients treated with IM as 2nd line a threshold of 18 months for CCyR and 24 for MMR for the establishment of the OpRes. This swap concept might be important in countries such as Brazil that postponed the introduction of IM as 1st line therapy for CML.
Imatinib Plasma Levels Correlate with Molecular Response in CML Patients
Authors: Rozmanova Sarka , Friedecky David , Polynkova Adriana , Faber Edgar , Rohon Peter , Adam Tomas , Jarosova Marie , Indrak Karel 
Published: April 2020

Abstract
Measurement of imatinib plasma levels is recommended for CML patients on Glivec therapy with suboptimal response or failure. Recently, reports suggesting that imatinib plasma levels correlate both with cytogenetic and molecular response of the patient and may be used for routine management of the treatment were published. We have introduced the examination of imatinib plasma levels into our laboratory follow-up of CML patients in 2007. All patients have signed informed consent before sampling. New capillary electrophoretic method was developed for determination of imatinib plasma levels. Plasma samples were deproteinated by methanol, evaporated, resuspended and directly analyzed. Separation was performed in buffer consisting of 50 mmol/L citrate adjusted with γ-amino-n-butyric acid to pH 4.0. Imatinib was quantified by UV detection in the range 250 – 270 nm (limit of detection is 10 nmol/L). BCR-ABL transcript levels were monitored by TaqMan-based real-time quantitative PCR, the baseline value of BCR-ABL/ABL% was 60%. Here we report comparison of plasma drug levels in CML patients with optimal and suboptimal molecular response. Total 238 samples from 100 CML patients were examined. Patients with major and complete molecular response (n = 68) and patients with suboptimal molecular response (n = 35) were chosen for the final comparison. The actual sample was eligible for analysis providing patient had been treated with standard dose 400 mg daily for at least one year, there was no other evident cause of the suboptimal response (presence of additional cytogenetic abnormalities or BCR/ABL mutation) and the sample was taken 24±6 hours after the ingestion of the drug. Other medication, the actual duration of the therapy (providing it was longer than one year), time interval between the dose and the meal ingestion, weight, body-mass index, body surface area and co-morbidity of patients were not taken into the account. All patients in the suboptimal group have achieved the complete cytogenetic response. Three patients in the suboptimal group have progressed, while there were any such patients in the optimal group. The results showed considerable inter-individual variability between the patients. However, the imatinib plasma levels found in the optimal group significantly higher (median of 2.34 umol/l; range of 0.46 – 6.23) than in the suboptimal group (median of 1.75 umol/l; range of 0.84 – 4.63) p &lt; 0.003. Moreover, patients with negativity in real-time quantitative PCR testing showed a trend for even higher drug plasma levels (median of 3.18 umol/l; range of 0.46 – 6.23, n = 36) p &lt; 0.001. We can conclude that higher imatinib plasma levels are associated with better molecular response to therapy and laboratory measurements may be used for modification of the imatinib dosage.
DC-Based Vaccines Show in-Vitro Activity against Chronic Myeloid Leukemia Cells
Authors: Tan Yuen-Fen , Cheong Soon-Keng , Leong Chooi-Fun , Fadhilah SAW 
Published: April 2020

Abstract
Chronic Myeloid leukemia is a common myeloproliferative disease. Despite recent advances in targeted therapy, only 7–12% of patients achieve molecular remission. Leukemic cells arrange multiple mechanisms to avoid recognition by the immune system. Dendritic cells (DC) are professional antigen presenting cells of the immune system playing a crucial role in the induction of anti-tumor responses. The use of DC is an attractive immunotherapeutic strategy against cancers, especially in minimal residual disease state. In this study, DC vaccine against chronic myeloid leukemia was generated and evaluated in-vitro. Monocytes were isolated and enriched from peripheral blood. These monocytes were subsequently cultured in RPMI medium supplemented with GM-CSF and IL-4 to induce them to become DC. These DC were then co-cultured with tumor lysates obtained from CML cell line in culture medium supplemented with GM-CSF, IL-4 and TNF alpha to become DC-based CML vaccine. The generated DC-based CML vaccines retained their DC morphology, showed strong expression of CD 86 and HLA-DR, and were negative for CD14. Mixed lymphocyte reaction indicated that the generated DC-based CML vaccines were capable of inducing proliferative responses to allogeneic lymphocytes. DC-based CML vaccines were shown to stimulate T cells to express DC-ligands, ie CD28 and CD154, as well as HLA-DR, CD71 and CD 25. In addition, the stimulated T cells were cytotoxic to CML cells used to prepare tumor lysates.