Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lymphocytic neoplasm involving the heart is not common and usually presents with pericardial effusion or focal myocardial infiltration. Myocardial infarctions due to leukemic infiltration of the coronary arteries are rarely reported. We present the case of a 52-year-old Guatemalan man with a one-year history of untreated T-cell prolymphocytic leukemia. He was admitted to our hospital for chemotherapy and evaluation of a pulmonary cavitary lesion by wedge resection. During sedation, the patient experienced acute respiratory failure and hypovolemic shock, from which he could not be resuscitated. Autopsy revealed that leukemic cells extensively infiltrated the aorta, myocardium, and coronary arteries. The lumina of the 3 major coronary artery branches showed 70% to 95% stenosis, with multifocal remote myocardial infarctions. Tumor cells were also detected in the lungs and other organs. The acute cardiorespiratory insufficiency secondary to leukemia-particularly the extensive infiltration of the coronary arteries and myocardium, and the multiple myocardial infarctions-eventually resulted in cardiac death.
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PMID:T-cell prolymphocytic leukemia with extensive cardiovascular infiltrate leading to multiple myocardial infarctions and cardiac death. 2559 28

There is a rich history behind the extinct entity 'T-cell chronic lymphocytic leukemia (T-CLL)' and the now-established replacement, small-cell variant of T-cell prolymphocytic leukemia (T-PLL-sv). Herein, we review the history of the events, observations, and discussions that led to this replacement. We also provide a systematic analysis of all previously reported cases of T-PLL-sv as well as our four new additional cases. Despite the higher frequency of a normal karyotype and perhaps an overrepresented CD4(-) CD8(-) immunophenotype among these patients (compared to T-PLL in general) as well as bland morphology (that makes them superficially appear more similar to B-CLL), we argue that the current World Health Organization (WHO)-based classification as T-PLL-sv is adequate and should continue for the time being. Morphologically, T-PLL-sv represents approximately one-fifth of all T-PLL cases. However, morphology alone does not determine the clinical course and should not be the basis for clinical decision making and prognostication. We propose a clonal evolution model in which mature T-cell leukemias classified in the past as T-CLL are perhaps T-PLL diagnosed early in the course of the disease. Future research using next-generation sequencing, comparative genomic hybridization, and molecular array studies, including serial analyses of individual cases over time, is needed to better identify this rarely diagnosed, inherently controversial form of T-cell leukemia.
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PMID:T-cell chronic lymphocytic leukemia or small-cell variant of T-cell prolymphocytic leukemia: a historical perspective and search for consensus. 2584 34

T-cell prolymphocytic leukaemia (T-PLL) is an aggressive leukaemia. The primary genetic alteration in T-PLL are the inv(14)(q11q32)/t(14;14)(q11;q32) leading to TRD/TRA-TCL1A fusion, or the t(X;14)(q28;q11) associated with TRD/TRA-MTCP1 fusion. However, additional cooperating abnormalities are necessary for emergence of the full neoplastic phenotype. Though the pattern of secondary chromosomal aberrations is remarkably conserved, targets of the changes are largely unknown. We analysed a cohort of 43 well-characterized T-PLL for hotspot mutations in the genes JAK3, STAT5B and RHOA. Additionally, we selected a subset of 23 T-PLL cases for mutational screening of 54 genes known to be recurrently mutated in T-cell and other haematological neoplasms. Activating mutations in the investigated regions of the JAK3 and STAT5B genes were detected in 30% (13/43) and 21% (8/39) of the cases, respectively, and were mutually exclusive. Further, we identified mutations in the genes encoding the epigenetic regulators EZH2 in 13% (3/23), TET2 in 17% (4/23) and BCOR in 9% (2/23) of the cases. We confirmed that the JAK-STAT pathway is a major mutational target, and identified epigenetic regulators recurrently mutated in T-PLL. These findings complement the mutational spectrum of secondary aberrations in T-PLL and underscore the potential therapeutical relevance of epigenetic regulators in T-PLL.
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PMID:Genes encoding members of the JAK-STAT pathway or epigenetic regulators are recurrently mutated in T-cell prolymphocytic leukaemia. 2691 88

Leukemia cutis describes the infiltration and dissemination of neoplastic leukemic cells into the epidermis, dermis, or subcutis, resulting in clinically identifiable cutaneous lesions. Depending on the type of leukemia, a wide range of clinical and histopathological findings may be encountered. This report describes a patient with a rosacea-like eruption as a unique clinical presentation of T-cell prolymphocytic leukemia.
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PMID:Rosacea-Like Leukemia Cutis: A Case Report. 2704 35

Six thymocyte suspensions, 10 normal blood CD4(+) CD8(-) lymphocyte-enriched fractions and leukaemic cells from 24 patients with CD4(+) mature T-cell lymphoid malignancy (five Sezary Syndrome, six adult T-cell leukaemia-lymphoma and 13 cases of T-cell prolymphocytic leukaemia) were examined in this study for the expression of membrane HLA-ABC by CD45RA (2H4) and CD45RO (UCHL1) subpopulations. These analyses showed that the main increase in HLA-ABC expression by normal CD4(+) CD8(-) blood lymphocytes (mean 490 to 760 FITC units) paralleled the loss of membrane 2H4 whilst the acquisition of UCHL1 was not associated with any significant change in HLA-ABC staining intensity. The sequence of 2H4 differentiation by normal thymocytes, based on the observed increasing levels of HLA-ABC staining intensity appeared to be (a) CD1a (+) 2H4(-) UCHL1(+) (25 HLA-ABC fluorescent units), (b)CD1a(-)2H4(int)UCHL1(+) (134 units), and (c) CD 1a(-) 2H4 (+) UCHL1 (-) (197 units). Quantitative estimates of membrane HLA-ABC expression by leukaemic T-cells revealed marked heterogeneity between individual cases irrespective of diagnostic subgroup. Based on the lower observed limits for normal CD4(+) 2H4(+) (318 units) and CD4 (+) 2H4(-) (478 units) fractions, 14% and 38% respectively of the leukaemic 2H4(+) and 2H4(-) components examined showed reduced HLA-ABC expression. Two cases showed very low membrane HLA-ABC levels that were within the range observed for normal CD1a(-) thymocytes. In contrast, HLA-ABC staining intensities exceeding that of corresponding normal CD4(+) 2H4(+) (710 units) and CD4(+) 2H4(-) (1286 units) subpopulations were seen in a high proportion (65%) of leukaemic 2H4 (+) components, with only 14% of 2H4(-) fractions showing raised levels and, in two cases, these staining intensities exceeded three times the normal observed limits. In addition to the quantitative differences in HLA-ABC expression, a remarkably consistent (81% of evaluable cases) feature of the leukaemic T-cells was that the 2H4(-)UCHL1(+) subpopulation in CD4(+) malignancies had a lower HLA-ABC level than the 2H4(+)UCHL1 subpopulation. This was in marked contrast to normal post-thymic T-cells where increasing HLA-ABC expression was seen with increasing UCHL1 (or decreasing 2H4) staining. These results suggest that leukaemic T-cells have an aberrant intra-thymic and post-thymic sequence of 2H4/UCHL1 expression which has become 'uncoupled' from CD1a/HLA-ABC expression.
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PMID:T-Cell Membrane CD45RA (2H4) and CD45RO (UCHL1) Determinants: II, Aberrant HLA-ABC Expression by CD45RA and CD45RO Cell Subpopulations of Mature CD4(+) T-Cell Leukaemias. 2746 16

T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive neoplasm of mature T-cells with an urgent need for rationally designed therapies to address its notoriously chemo-refractory behavior. The median survival of T-PLL patients is <2 years and clinical trials are difficult to execute. Here we systematically explored the diversity of drug responses in T-PLL patient samples using an ex vivo drug sensitivity and resistance testing platform and correlated the findings with somatic mutations and gene expression profiles. Intriguingly, all T-PLL samples were sensitive to the cyclin-dependent kinase inhibitor SNS-032, which overcame stromal-cell-mediated protection and elicited robust p53-activation and apoptosis. Across all patients, the most effective classes of compounds were histone deacetylase, phosphoinositide-3 kinase/AKT/mammalian target of rapamycin, heat-shock protein 90 and BH3-family protein inhibitors as well as p53 activators, indicating previously unexplored, novel targeted approaches for treating T-PLL. Although Janus-activated kinase-signal transducer and activator of transcription factor (JAK-STAT) pathway mutations were common in T-PLL (71% of patients), JAK-STAT inhibitor responses were not directly linked to those or other T-PLL-specific lesions. Overall, we found that genetic markers do not readily translate into novel effective therapeutic vulnerabilities. In conclusion, novel classes of compounds with high efficacy in T-PLL were discovered with the comprehensive ex vivo drug screening platform warranting further studies of synergisms and clinical testing.
Leukemia 2018 03
PMID:Discovery of novel drug sensitivities in T-PLL by high-throughput ex vivo drug testing and mutation profiling. 2880 27

T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive T-lymphoid malignancy usually refractory to current treatment strategies and associated with short overall survival. By applying next-generation functional testing of primary patient-derived lymphoma cells using a library of 106 US Food and Drug Administration (FDA)-approved anticancer drugs or compounds currently in clinical development, we set out to identify novel effective treatments for T-PLL patients. We found that the B-cell lymphoma 2 (BCL-2) inhibitor venetoclax (ABT-199) demonstrated the strongest T-PLL-specific response when comparing individual ex vivo drug response in 86 patients with refractory hematologic malignancies. Mechanistically, responses to venetoclax correlated with protein expression of BCL-2 but not with expression of the BCL-2 family members myeloid cell leukemia 1 (MCL-1) and BCL-XL in lymphoma cells. BCL-2 expression was inversely correlated with the expression of MCL-1. Based on the ex vivo responses, venetoclax treatment was commenced in 2 late-stage refractory T-PLL patients resulting in clinical responses. Our findings demonstrate first evidence of single-agent activity of venetoclax both ex vivo and in humans, offering a novel agent in T-PLL.
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PMID:First-in-human response of BCL-2 inhibitor venetoclax in T-cell prolymphocytic leukemia. 2921 97

Prolymphocytic leukemias (PLLs) are rare mature lymphoid disorders of B- and T-cell subtypes with distinct features and an aggressive clinical course. PLL represents only 2% of all mature lymphocytic leukemias in adults. T-PLL represents 20% of all PLLs cases. T-cell prolymphocytic leukemia (T-PLL) is more rare and more rapidly progressive and aggressive than B-PLL; it is generally resistant to conventional chemotherapy, and historically the median survival has been about 7 months. Clinicians will often only see a case of T-PLL once every 5 to 10 years, which makes recognition of the disorder difficult. The prognosis is poor and there is no curative therapy. We report a 77-year-old male patient with de novo T-PLL presenting with WBC count of 1,115,000. We will discuss the clinical, morphologic, immunophenotypic and cytogenetic features of this rare entity. A distinctive hematologic aspect of T-PLL is a rapidly rising white blood cell count with a doubling time of weeks to months. The key morphologic feature in the diagnosis of T-PLL is a population of more than 55% prolymphocytes in the peripheral blood. The diagnosis can be made on peripheral blood by flow cytometry where a monoclonal lymphocyte population will show positivity for T-cell markers. T-PLL is characterized by complex chromosomal abnormalities, which suggests that chromosomal aberrations might occur progressively during the course of the disease, thus explaining the aggressive nature of this condition. The main challenge as a clinician treating T-PLL is to deliver long-term disease-free survival. The most important predictor of outcome is response to alemtuzumab therapy (Campath). Knowledge of the disrupted pathways and mechanisms underlying activation and proliferation in T-PLL has raised the possibility of developing future and promising treatment approach that targets these pathways and signals by the use of future molecule inhibitors. T-PLL is a rare disease and careful attention should be given to correctly diagnose this T-cell leukemia. Physicians should be aware of this unusual entity. With the advent of alemtuzumab, although much progress has been made in the treatment of this disease, autologous or allogeneic hematologic stem cell transplant (HSCT) still remains the only hope for cure.
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PMID:A patient with white blood cell counts more than a million: A diagnostic and therapeutic challenge. 2923 32

Genomic analysis of cancer offers the hope of identifying new treatments or aiding in the selection of existing treatments. Rare leukemias pose additional challenges in this regard as samples may be hard to acquire and when found the underlying pathway may not be attractive to drug development since so few individuals are affected. In this case, it can be useful to identify common mutational overlap among subsets of rare leukemias to increase the number of individuals that may benefit from a targeted therapy. This chapter examines the current mutational landscape of large granular lymphocyte (LGL) leukemia with a focus on STAT3 mutations, the most common mutation in LGL leukemia to date. We examined the linkage between these mutations and autoimmune symptoms and disorders, in cases of obvious and suspected LGL leukemia. We then summarized and compared mutations in a set of other rare leukemias that also have JAK/STAT signaling pathway activation brought about by genomic changes. These include T-cell acute lymphoblastic leukemia (T-ALL), T-cell prolymphocytic leukemia (T-PLL), cutaneous T-cell lymphoma (CTCL), select peripheral T-cell lymphoma (PTCL), and adult T-cell leukemia/lymphoma (ATLL). Though STAT3 activation is common in these leukemias, the way in which it is achieved, such as the activating cytokine pathway and/or the co-mutational background, is quite diverse.
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PMID:Genomics of LGL leukemia and select other rare leukemia/lymphomas. 3158 20

T-cell prolymphocytic leukemia (T-PLL) is a rare and poor-prognostic mature T-cell leukemia. Recent studies detected genomic aberrations affecting JAK and STAT genes in T-PLL. Due to the limited number of primary patient samples available, genomic analyses of the JAK/STAT pathway have been performed in rather small cohorts. Therefore, we conducted-via a primary-data based pipeline-a meta-analysis that re-evaluated the genomic landscape of T-PLL. It included all available data sets with sequence information on JAK or STAT gene loci in 275 T-PLL. We eliminated overlapping cases and determined a cumulative rate of 62.1% of cases with mutated JAK or STAT genes. Most frequently, JAK1 (6.3%), JAK3 (36.4%), and STAT5B (18.8%) carried somatic single-nucleotide variants (SNVs), with missense mutations in the SH2 or pseudokinase domains as most prevalent. Importantly, these lesions were predominantly subclonal. We did not detect any strong association between mutations of a JAK or STAT gene with clinical characteristics. Irrespective of the presence of gain-of-function (GOF) SNVs, basal phosphorylation of STAT5B was elevated in all analyzed T-PLL. Fittingly, a significant proportion of genes encoding for potential negative regulators of STAT5B showed genomic losses (in 71.4% of T-PLL in total, in 68.4% of T-PLL without any JAK or STAT mutations). They included DUSP4, CD45, TCPTP, SHP1, SOCS1, SOCS3, and HDAC9. Overall, considering such losses of negative regulators and the GOF mutations in JAK and STAT genes, a total of 89.8% of T-PLL revealed a genomic aberration potentially explaining enhanced STAT5B activity. In essence, we present a comprehensive meta-analysis on the highly prevalent genomic lesions that affect genes encoding JAK/STAT signaling components. This provides an overview of possible modes of activation of this pathway in a large cohort of T-PLL. In light of new advances in JAK/STAT inhibitor development, we also outline translational contexts for harnessing active JAK/STAT signaling, which has emerged as a 'secondary' hallmark of T-PLL.
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PMID:JAK/STAT-Activating Genomic Alterations Are a Hallmark of T-PLL. 3176 51


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