Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023473 (chronic myeloid leukemia)
 18,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We herein report the findings of a 47-year-old Japanese female with chronic myeloid leukemia (CML) with a cryptic BCR-ABL1 transcript on chromosome 9 and a derivative chromosome 22 unrelated to BCR-ABL1. Although she achieved and continued to demonstrate a major molecular response to imatinib treatment following interferon-alpha, there was persistence of a derivative chromosome 22. A detailed chromosome/molecular studies, including serial karyotyping analysis, finally resulted in the karyotyping at the disease onset to be 47,XX,+del(22)(q11.2), with two genetic evens, namely a cryptic BCR-ABL1 transcript on chromosome 9 and derivative chromosome 22 unrelated to BCR-ABL1. This CML case with these two rare genetic events thus raises diagnostic issues such as the difficulty in making a concise evaluation of the chromosomal/molecular events and an accurate disease prognosis, as well as the difficulty in determining the disease remission status after treatment.
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PMID:Persistence of derivative chromosome 22 after achieving a major molecular response in chronic myeloid leukemia with a cryptic BCR-ABL1 fusion gene. 1999 64

Therapy with the tyrosine kinase inhibitor (TKI) represents the current standard first-line therapy for the management of patients with chronic myeloid leukemia (CML). Although most patients respond satisfactorily to imatinib, a subset of patients develops resistance mainly because of the acquisition of mutations within the kinase domain of BCR-ABL1 that impair the ability of TKIs to block the activity of the enzyme. Moreover, BCR-ABL1 transcripts can be detected in most patients by molecular techniques, underscoring the limitations of imatinib to eradicate minimal residual disease. Although the resistance conferred by most BCR-ABL1 mutations can be overcome with the use of second-generation TKIs such as nilotinib, dasastinib, bosutinib, or bafetinib, the T315I mutation, which represents a common resistance pathway in CML, remains unassailable to TKI therapy. We herein discuss current research efforts in 2 areas of vital importance in CML research, the management of patients with imatinib-resistant mutations, with particular emphasis on those carrying T315I, and the eradication of residual disease.
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PMID:The next generation of therapies for chronic myeloid leukemia. 2000 9

For adult patients who present with chronic myeloid leukemia (CML) in chronic phase it is now generally agreed that initial treatment should start with the tyrosine kinase inhibitor (TKI) imatinib at 400 mg daily. Five years after starting imatinib about 60% of these patients will be in complete cytogenetic response (CCyR), still taking imatinib; an appreciable proportion of these will have achieved a major molecular response, defined as a 3-log reduction in the level of BCR-ABL1 transcripts in their blood. The patients in CCyR seem to have a very low risk of relapse to chronic phase or of progression to advanced phase. Other patients may be resistant to imatinib or may experience significant side effects that require change of therapy. The best method of monitoring responding patients is to enumerate Philadelphia chromosome-positive marrow metaphases at 3-month intervals until CCyR and to perform RQ-PCR for BCR-ABL1 transcripts at 3-month intervals after starting imatinib. The recommendations for defining "failure" and "sub-optimal response" proposed by the European LeukemiaNet in 2006 have proved to be a major contribution to assessing responses in individual patients and are now being updated. Patients who fail imatinib may respond to second-generation TKIs, but allogeneic stem cell transplantation still plays an important role for eligible patients who fare badly with TKIs. Patients who present in advanced phases of CML should be treated initially with TKI alone or with TKI in conjunction with cytotoxic drugs, but their overall prognosis is likely to be much inferior to that of those presenting in early chronic phase.
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PMID:Initial treatment for patients with CML. 2000 31

Targeted therapy in the form of selective tyrosine kinase inhibitors (TKI) has transformed the approach to management of chronic myeloid leukemia (CML) and dramatically improved patient outcome to the extent that imatinib is currently accepted as the first-line agent for nearly all patients presenting with CML, regardless of the phase of the disease. Impressive clinical responses are obtained in the majority of patients in chronic phase; however, not all patients experience an optimal response to imatinib, and furthermore, the clinical response in a number of patients will not be sustained. The process by which the leukemic cells prove resistant to TKIs and the restoration of BCR-ABL1 signal transduction from previous inhibition has initiated the pursuit for the causal mechanisms of resistance and strategies by which to surmount resistance to therapeutic intervention. ABL kinase domain mutations have been extensively implicated in the pathogenesis of TKI resistance, however, it is increasingly evident that the presence of mutations does not explain all cases of resistance and does not account for the failure of TKIs to eliminate minimal residual disease in patients who respond optimally. The focus of exploring TKI resistance has expanded to include the mechanism by which the drug is delivered to its target and the impact of drug influx and efflux proteins on TKI bioavailability. The limitations of imatinib have inspired the development of second generation TKIs in order to overcome the effect of resistance to this primary therapy. (Clin Cancer Res 2009;15(24):7519-27).
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PMID:Mechanisms of Resistance to Imatinib and Second-Generation Tyrosine Inhibitors in Chronic Myeloid Leukemia. 2000 52

Imatinib is considered standard therapy for patients with chronic myelogenous leukemia (CML), inducing a high rate of hematologic and cytogenetic responses. Despite these excellent results, several patients develop resistance to imatinib. Mechanisms of resistance are varied and include BCR-ABL1 kinase domain mutations, decreased entry of imatinib into cells, acquisition of secondary genetic changes and activation of alternate signaling pathways. Second-generation tyrosine kinase inhibitors (TKI) (dasatinib, nilotinib) were developed as an alternative for patients that develop resistance or are intolerant to imatinib. Dasatinib is a dual Abl/Src kinase TKI that is structurally unrelated to imatinib and is approved for therapy of all phases of CML in patients who are resistant or intolerant to imatinib. Nilotinib is a compound related to imatinib that has greater specificity and improved binding characteristics, and has clinical activity in the setting of imatinib failure. Resistance to multiple TKIs does occur, particularly in patients with the T315I mutation. Several new agents are in development including new TKIs, aurora kinase inhibitors and homoharringtonine.
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PMID:Advances in treatment of chronic myelogenous leukemia--new treatment options with tyrosine kinase inhibitors. 2001 7

Patients with chronic myeloid leukemia (CML) infrequently present in blast crisis (BC). While most BC are of myeloid origin, megakaryocytic BC is rare, especially at the time of CML diagnosis. We describe the first pediatric patient presenting with megakaryocytic leukemia and having BCR-ABL1 translocation as the single chromosomal abnormality. Clinical features were more suggestive of CML in megakaryocytic blast crisis than Philadelphia chromosome positive de novo AML. The patient was treated with AML-directed chemotherapy and imatinib mesylate followed by umbilical cord blood stem cell transplantation. The patient was in complete molecular response 16 months after stem cell transplantation.
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PMID:Megakaryocytic blast crisis at presentation in a pediatric patient with chronic myeloid leukemia. 2023 13

During follow-up of leukocyte counts in 20 consecutive patients (age range 29-81 years) treated with dasatinib, 9 patients (7 chronic myeloid leukemia in chronic phase, 2 Philadelphia chromosome-positive acute lymphoid leukemia in complete remission) developed lymphocytosis (>3,000/microl). Peripheral blood smears revealed a population of large granular lymphocytes. Large granular lymphocytosis (LGL) was first noted between 1 and 8 months after initiation of dasatinib, and it has persisted up to 33 months from the onset of LGL in one patient. Peak numbers of large granular lymphocytes ranged from 2,915 to 17,425/microl. The occurrence of LGL might interfere with achieving molecular response (MR, real-time quantification of major BCR-ABL1 mRNA less than 50 copies/microg RNA) in our small cohort; 8 (89%) of 9 patients with LGL attained MR, while only 6 (55%) of 11 patients without LGL eventually achieved MR. With respect to the relationship between LGL and pleural effusion (PE), 3 (27%) of 11 patients without LGL developed PE, while 5 (56%) of 9 patients with LGL developed PE. Moreover, the mean peak number of LGL was 9,215/microl, which was much higher than the mean peak number (4,635/microl) of LGL in patients without PE. These results may suggest possible association of both events in our cohorts.
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PMID:Clinical features of dasatinib-induced large granular lymphocytosis and pleural effusion. 2040 52

In a proportion of patients with chronic myeloid leukemia (CML) being treated with dasatinib, we recently observed large granular lymphocyte (LGL) expansions carrying clonal T-cell receptor (TCR) gamma/delta gene rearrangements. To assess the prevalence and role of clonal lymphocytes in CML, we collected samples from patients (n = 34) at the time of diagnosis and during imatinib and dasatinib therapies and analyzed lymphocyte clonality with a sensitive polymerase chain reaction-based method of TCR gamma and delta genes. Surprisingly, at CML diagnosis, 15 of 18 patients (83%) had a sizeable clonal, BCR-ABL1 negative lymphocyte population, which was uncommon in healthy persons (1 of 12; 8%). The same clone persisted at low levels in most imatinib-treated patients. In contrast, in a distinct population of dasatinib-treated patients, the diagnostic phase clone markedly expanded, resulting in absolute lymphocytosis in blood. Most patients with LGL expansions (90%) had TCR delta rearrangements, which were uncommon in patients without an LGL expansion (10%). The TCR delta clones were confined to gammadelta(+) T- or natural killer-cell compartments and the TCR gamma clones to CD4(+)/CD8(+) alphabeta(+) fractions. The functional importance of clonal lymphocytes as a part of leukemia immune surveillance and the putative anergy-reversing role of dasatinib require further evaluation.
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PMID:Mono/oligoclonal T and NK cells are common in chronic myeloid leukemia patients at diagnosis and expand during dasatinib therapy. 2068 61

An 18-year-old male underwent an allogeneic hematopoietic stem cell transplantation (allo-HSCT) for chronic myeloid leukemia (CML) in the first late chronic phase. On day 132, he was readmitted to the hospital with nausea, vomiting and nodular lesions on endoscopy. A diagnosis of granulocytic sarcoma of the stomach was made. Bone marrow cytogenetic analysis for the Philadelphia chromosome and nested polymerase chain reaction for BCR-ABL1 were both negative. Immunosuppression was abruptly discontinued, and by day 180, all gastric lesions had completely disappeared. However, there were histological signs of graft-versus-host disease. The patient developed progressive anorexia and elevated hepatic enzymes, which prompted the reintroduction of cyclosporine. Considering the risk of another relapse, imatinib mesylate (IM) 600 mg/day was started. The patient Is condition improved, and there was no evidence of disease recurrence at 36 months after relapse. Relapse of CML is the commonest cause of treatment failure after allo-HSCT. On rare occasions, a localized extramedullary presentation is seen. Unless properly treated, other extramedullary relapse sites and/or marrow infiltration usually occur. Withdrawal of immunosuppression, along with IM therapy seems to be an acceptable approach in this setting.
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PMID:Granulocytic sarcoma of the stomach: relapse after hematopoietic stem-cell transplantation for chronic myeloid leukemia. 2054 44

Treatment of CML with the tyrosine kinase inhibitor (TKI) imatinib mesylate results in the emergence of point mutations within the kinase domain (KD) of the BCR-ABL1 fusion transcript. The introduction of next-generation TKIs that can overcome the effects of some BCR-ABL1 KD mutations requires quantitative mutation profiling methods to assess responses. We report the design and validation of such quantitative assays, using pyrosequencing and mutation-specific RT-PCR techniques, to allow sequential monitoring and illustrate their use in tracking specific KD mutations (e.g. G250E, T315I, and M351T) following changes in therapy. Pyrosequencing and mutation-specific RT-PCR allows sequential monitoring of specific mutations and identification of rapid clonal shifts in response to kinase inhibitor therapy in CML. Rapid reselection of TKI-resistant clones occurs following therapy switch in CML.
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PMID:Rapid clonal shifts in response to kinase inhibitor therapy in chronic myelogenous leukemia are identified by quantitation mutation assays. 2055 6


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