PubMed Health⌕ Search

Biomedical subjects

Alvin Zipursky

Publications and source records attributed to Alvin Zipursky.

11 recordsLinked to original sources
PubMed2006

A prospective study of the natural history of transient leukemia (TL) in neonates with Down syndrome (DS): Children's Oncology Group (COG) study POG-9481.

A unique transient leukemia (TL) has been described in newborns with Down syndrome (DS; or trisomy 21 mosaics). This leukemia has a high incidence of spontaneous remission; however, early death and subsequent development of acute megakaryoblastic leukemia (AMKL) have been reported. We prospectively evaluated 48 infants with DS and TL to determine the natural history and biologic characteristics of this disease, identify the clinical characteristics associated with early death or subsequent leukemia, and assess the incidence of subsequent leukemia. Blast cells associated with TL in DS infants exhibited FAB M(7) morphology and phenotype. Most infants (74%) had trisomy 21 (or mosaicism) as the only cytogenetic abnormality in the blast cells. Most children were able to spontaneously clear peripheral blasts (89%), normalize blood counts (74%), and maintain a complete remission (64%). Early death occurred in 17% of infants and was significantly correlated with higher white blood cell count at diagnosis (P < .001), increased bilirubin and liver enzymes (P < .005), and a failure to normalize the blood count (P = .001). Recurrence of leukemia occurred in 19% of infants at a mean of 20 months. Development of leukemia was significantly correlated with karyotypic abnormalities in addition to trisomy 21 (P = .037). Ongoing collaborative clinical studies are needed to determine the optimal role of chemotherapy for infants at risk for increased mortality or disease recurrence and to further the knowledge of the unique biologic features of this TL.

Bilirubin↗
PubMed2006

Long-term results of an ultra low-dose cytarabine-based regimen for the treatment of acute megakaryoblastic leukaemia in children with Down syndrome.

Children with acute megakaryoblastic leukaemia (AMKL) and Down syndrome (DS) show a favourable response to chemotherapy, probably due to increased sensitivity of the leukaemic blasts to cytarabine. In contrast, dose-intensive approaches have resulted in disproportionate treatment-related mortality in this group. The survival of children with AMKL and DS was retrospectively compared following treatment with a low-dose chemotherapy protocol, consisting of cytarabine (10 mg/m2/dose), retinylpalmitate and vincristine or standard chemotherapy. Event-free (67 +/- 11%) and overall survival (77 +/- 10%) at 5 years were not significantly different in both groups. Further reduction of treatment intensity in AMKL of children with DS, therefore, appears feasible.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

Congenital abnormalities and childhood cancer.

BACKGROUND: The examination of specific characteristics of neoplasms diagnosed in children have suggested that a significant proportion can be attributed to a genetic mutation or genetic predisposition. Although the study of a genetic predisposition to cancer in children remains in the early stages, congenital abnormalities could provide essential information for mapping predisposing lesions in children with cancer. METHODS: In the current study, 2 large cohorts of children with and without congenital abnormalities were followed for the occurrence of cancer and death up to 18 years. Through this study, the risk of developing cancer by age at diagnosis, effects of birth characteristics on cancer risk, and possible associations between specific anomalies and tumor types were examined. RESULTS: Based on the follow-up of 90,400 children, the risk of developing cancer during the first year of life was found to be nearly 6 times higher in children with anomalies (rate ratio [RR] of 5.8; 95% confidence interval [95% CI], 3.7-9.1). Children with birth defects were found to be at a higher risk for developing leukemia (RR of 2.7; 95% CI, 2.1-3.6), tumors of the central nervous system (RR of 2.5; 95% CI, 1.8-3.4), sympathetic nervous system tumors (RR of 2.2; 95% CI, 1.4-3.4), and soft tissue sarcomas (RR of 1.9; 95% CI, 1.0-3.5). Among children with birth defects, children with Down syndrome, nervous system anomalies, and anomalies of the urinary system had the highest incidence rates of cancer. In the presence of birth defects, other factors such as birth weight, gestational age, age of the mother, and birth order were not found to be associated significantly with the risk of cancer. CONCLUSIONS: The significant relative risks found in the current study provided evidence of links between the presence of abnormalities and the development of cancer. Some "cancer-prone" abnormalities were identified in the current study. Such anomalies may be markers of other exposures or processes that increase the risk of developing cancer.

Adult↗
PubMed2005

Origins of leukaemia in children with Down syndrome.

Transient megakaryoblastic leukaemia is found in 10% of newborns with Down syndrome, characterized by constitutional trisomy 21. Although in most cases the leukaemic cells disappear spontaneously after the first months of life, irreversible acute megakaryoblastic leukaemia develops in 20% of these individuals within 4 years. The leukaemic cells typically harbour somatic mutations of the gene encoding GATA1, an essential transcriptional regulator of normal megakaryocytic differentiation. Leukaemia that specifically arises in the context of constitutional trisomy 21 and somatic GATA1 mutations is a unique biological model of the incremental process of leukaemic transformation.

Cell Transformation, Neoplastic↗
PubMed2003

GATA1 mutations in transient leukemia and acute megakaryoblastic leukemia of Down syndrome.

Children with constitutional trisomy 21 (Down syndrome) have an approximately 500-fold increased risk of developing acute megakaryoblastic leukemia (AMKL), a form of acute myeloid leukemia. Unique to newborn infants with Down syndrome is a transient leukemia (TL), also referred to as transient myeloproliferative syndrome, that undergoes spontaneous remission in the majority of cases but in approximately 20% is followed by AMKL later in life. Recently mutations of the gene encoding the hematopoietic transcription factor GATA1 were shown to be specific for AMKL of Down syndrome. Here, we demonstrate that GATA1 mutations are present in blasts of TL and show the identical GATA1 mutation in sequential samples collected from a patient during TL and subsequent AMKL. These findings suggest a model of malignant transformation in Down syndrome AMKL in which GATA1 mutations are an early event and AMKL arises from latent TL clones following initial apparent remission.

Cell Transformation, Neoplastic↗
PubMed2002

Incidence and treatment of potentially lethal diseases in transient leukemia of Down syndrome: Pediatric Oncology Group Study.

Transient leukemia (TL or transient myeloproliferative disorder) occurs in approximately 10% of newborn infants with Down syndrome. The disorder is characterized by the presence of megakaryoblasts in the peripheral blood; most cases resolve spontaneously within the first 3 months of life, and the child is well thereafter. However, there are cases in which a severe, potentially lethal form of disease develops, manifesting as hepatic fibrosis or cardiopulmonary failure. Hitherto, the incidence of these severe forms of the disease has not been reported. A prospective study of TL was conducted by the Pediatric Oncology Group (POG Study 9481) in which 48 children with TL were identified. Life-threatening disease occurred in nine patients (19%); seven had hepatic fibrosis and two had cardiopulmonary failure. Five children died of the disease within the first 3 months of life, none of whom received antileukemic therapy. One patient died on day 31 after receiving minimal therapy within 1 day of death. Three children received low-dose cytosine arabinoside (Ara-C) (0.4-1.5 mg/kg every 12 hours for 5 or 7 days). In all these patients, the disease resolved. It is concluded that potentially lethal disease is relatively common in TL, and the available evidence suggests that these diseases are responsive to low-dose Ara-C therapy.

Child↗
PubMed2002

Telomerase and the benign and malignant megakaryoblastic leukemias of Down syndrome.

The most common form of leukemia in Down syndrome patients is megakaryoblastic leukemia. There are two forms of the disease. Transient leukemia (TL) is a form of megakaryoblastic leukemia that occurs in newborns with Down syndrome and usually disappears spontaneously within the first 3 months of life. Acute megakaryoblastic leukemia (AMKL) occurs in Down syndrome children within the first 4 years of life and is fatal without treatment. The megakaryoblasts of TL and AMKL are indistinguishable by light and electron microscopy; yet, TL is benign and AMKL is malignant. One of the hallmarks of many malignancies is the expression of telomerase. It is therefore hypothesized that the transient, benign form of megakaryoblastic leukemia (TL) would not contain telomerase activity, whereas telomerase would be demonstrable in the malignant form of the disease. Telomerase activity was determined in the blood and/or bone marrow aspirates in 29 cases of AMKL and 34 cases of TL. The authors found telomerase activity in 15 of 29 (52%) cases, of AMKL and in only 4 of 34 (12%) cases of TL (P < 0.001). Furthermore, three of the four telomerase-positive TL cases were particularly severe, of which two were fatal. Telomerase activity is found frequently in the leukemic cells of the malignant form of megakaryoblastic leukemia but rarely in the benign form of the disease (TL). Observations provide evidence that telomerase may be a critical factor for the malignant conversion of leukemic cells.

Bone Marrow↗