Bleeding and Thrombosis in Chronic Myeloproliferative Disorders: Relation of Platelet Disorders to Clinical Aspects of the Disease

1989 ◽  
Vol 19 (5) ◽  
pp. 251-259 ◽  
Author(s):  
A. Wehmeier ◽  
R.E. Scharf ◽  
S. Fricke ◽  
W. Schneider
1996 ◽  
Vol 16 (02) ◽  
pp. 151-163 ◽  
Author(s):  
W. Schneider ◽  
A. Wehmeier

SummaryMegakaryocytes are part of clonal hematopoiesis in chronic myeloproliferative disorders and are responsible for most of the clinical complications in this disease. About 30-40% of patients with polycythemia vera (PV) and essential thrombocythemia (ET) suffer from thrombotic complications, and microcirculatory disorders are common. Spontaneous bleeding mainly from the gastrointestinal tract is another complication that is especially prevalent in myelofibrosis and advanced stages of chronic myeloid leukemia.In vivo, the bone marrow is hypercellular and the concentration of megakaryocytes increased with characteristic morphological abnormalities. Megakaryocytes are enlarged and ploidy is increased in PV and ET but small mononuclear cells with decreased ploidy are a feature of CML. Despite spontaneous growth in cul-ture, megakaryocytes in chronic MPD are hypersensitive to added interleukin-3, interleukin-6 and GM-CSF.Platelets released from these megakaryocytes show abnormal morphology and ultrastructure, reflected in loss of storage granules and organelles, increased volume distribution and low buoyant density. Uptake, storage and secretion of platelet dense granule constituents is abnormal, and the plasma levels of platelet specific proteins which may also include growth factors for fibroblasts are elevated. At high platelet counts, spontaneous aggregation is observed, whereas agonist-induced aggregation in vitro with adrenaline, ADP and collagen is often defective. Platelet thromboxane generation may be stimulated, and production along the lipoxygenase pathway is decreased. Abnormalities of glycoprotein receptors and decreased fibrinogen binding have been reported but their clinical significance is uncertain. Several observations suggest that not only receptor defects but ineffective intracellular signalling may be responsible for platelet function abnormalities.No single underlying defect has been discovered that could explain this variety of pathological findings. Moreover, a combination of intrinsic megakaryocyte abnormalities and increased susceptibility of platelets to activation makes it difficult to differentiate secondary phenomena from effects of clonal hematopoiesis. How-ever, there are some clinical guidelines for therapy.Most elderly patients will be treated with cytoreductive therapy. Alkylating drugs and 32P have been shown to be leukemogenic, but even hydroxyurea may have a 10% incidence of leukemia induction after long-term therapy. Therapy with platelet-inhibitory drugs is often not sufficient to control thrombosis, and may aggravate a bleeding tendency, so that younger patients with PV and ET are increasingly treated with anagrelide or interferon alpha (A-IFN). Anagrelide is a quinazolin derivative that specifically inhibits megakaryocytopoiesis, while A-IFN may suppress clonal hematopoiesis by an unknown mechanism.


2002 ◽  
Vol 69 (3) ◽  
pp. 159-163 ◽  
Author(s):  
C. Musolino ◽  
L. Calabro' ◽  
G. Bellomo ◽  
F. Martello ◽  
B. Loteta ◽  
...  

2019 ◽  
Vol 59 (4) ◽  
pp. 188-94
Author(s):  
Sri Mulatsih ◽  
Adnina Hariningrum ◽  
Ignatius Purwanto ◽  
Rizki Oktasari

Background A hospital-based cancer registry can be used as a guide to decision-making. Considering the limited cancer registry data in the population, the Yogyakarta Pediatric Cancer Registry (YPCR) is one of the pioneers of hospital-based pediatric cancer registries in Indonesia. The YPCR was started in 2000 in Dr. Sardjito Hospital. Objective To describe the characteristics of childhood cancer and the outcomes by analyzing overall survival (OS) and event-free survival (EFS) based on data from Yogyakarta Pediatric Cancer Registry. Methods Data were collected from the YPCR for the period of 2000 to 2016. Childhood cancers were classified into 12 groups based on the 3rd edition International Classification for Childhood Cancer (ICCC). Incidence, frequency, and distribution of cases were grouped by sex, age, and patients’ place of residence. Incidence was further analyzed using SPSS software. Kaplan-Meier test was used to analyze OS and EFS. Results Within the study period, 2,441 children aged 0-18 years were diagnosed with cancer. The highest incidence was found in the 1-5-year age group. The most common diagnoses found were leukemia, myeloproliferative disorders, and myelodysplastic disease (58%); lymphoma and reticuloendothelial neoplasm (8%); retinoblastoma (6%); soft tissue and other extra-osseous sarcomas (5%); as well as neuroblastoma and other peripheral nervous cell tumors (5%). The OSs of acute lymphoblastic leukemia (ALL), high risk ALL (HR-ALL), and standard risk (SR-ALL) were 31.8%, 18.5%, and 43.9%, respectively. The EFSs of ALL, HR-ALL, and SR-ALL were 23.9%, 14.7%, and 32.4%, respectively. For solid tumors, the OS was 13.7% and EFS was 6.4%. Conclusion The number of new cases of childhood cancer has increased in the last few years. The Yogyakarta Pediatric Cancer Registry (YPCR), which serves as a hospital-based pediatric cancer registry, has an important role to evaluate clinical and non-clinical aspects of childhood cancer.


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