Life-threatening complications of transient abnormal myelopoiesis in neonates with Down syndrome

Clonal Myeloproliferative Disorders in Patients with Down Syndrome-Treatment and Outcome Results from an Institution in Argentina

Children with Down syndrome (DS) are at an increased risk of developing clonal myeloproliferative disorders. The balance between treatment intensity and treatment-related toxicity has not yet been defined. We analyzed this population to identify risk factors and optimal treatment. This single-center retrospective study included 78 DS patients <16 years-old with Transient Abnormal Myelopoiesis (TAM, n = 25), Acute Myeloblastic Leukemia (DS-AML, n = 41) of which 35 had classical Myeloid Leukemia associated with DS (ML-DS) with megakaryoblastic immunophenotype (AMKL) and 6 sporadic DS-AML (non-AMKL). Patients with DS-AML were treated according to four BFM-based protocols. Classical ML-DS vs. non-DS-AMKL were compared and the outcome of ML-DS was analyzed according to treatment intensity. Only four patients with TAM required cytoreduction with a 5-year Event-Free Survival probability (EFSp) of 74.4 (±9.1)%. DS-AML treatment-related deaths were due to infections, with a 5-year EFSp of 60.6 (±8.2)%. Megakaryoblastic immunophenotype was the strongest good-prognostic factor in univariate and multivariate analysis (p = 0.000). When compared ML-DS with non-DS-AMKL, a better outcome was associated with a lower relapse rate (p = 0.0002). Analysis of administered treatment was done on 32/33 ML-DS patients who achieved CR according to receiving or not high-dose ARA-C block (HDARA-C), and no difference in 5-year EFSp was observed (p = 0.172). TAM rarely required treatment and when severe manifestations occurred, early intervention was effective. DS-AML good outcome was associated with AMKL with a low relapse-rate. Even if treatment-related mortality is still high, our data do not support the omission of HDARA-C in ML-DS since we observed a trend to detect a higher relapse rate in the arm without HDARA-C.

Plasma TGF-β1 Levels Are Elevated in Down Syndrome Infants with Transient Abnormal Myelopoiesis

Infants with Down syndrome (DS) are at risk of developing a transient myeloproliferative disorder during the neonatal period, known as transient abnormal myelopoiesis (TAM). It is characterized by clonal myeloproliferation and is typically self-limiting. However, TAM can be a life-threatening disorder, when complicated by liver fibrosis. Here, we evaluated cytokine profiles in two male DS infants having TAM with or without liver dysfunction. The first patient, Patient 1, had hyperleukocytosis with cholestatic liver dysfunction, coagulopathy, and increased counts of blasts and was treated with exchange transfusion (ExT) due to the serious general condition. In Patient 1, serum interleukin (IL)-8 and plasma transforming growth factor (TGF)-β1 levels were markedly elevated before ExT (1,518.2 pg/mL and 17,635 pg/mL, respectively). After ExT, serum IL-8 and plasma TGF-β1 levels decreased to 40.7 pg/mL and 6,847 pg/mL, respectively. However, Patient 1 died on day 56 due to cholestatic liver dysfunction; namely, this patient represents fatal TAM. The second patient, Patient 2, had hyperleukocytosis with increased counts of blasts without liver dysfunction and was treated with cytarabine. In Patient 2, plasma TGF-β1 levels, but not plasma IL-8, were elevated (9,068 pg/mL and 28 pg/mL, respectively). Patient 2 was discharged on day 47. In summary, plasma TGF-β1 levels were elevated in the two DS infants with TAM, regardless of the presence or absence of hepatic fibrosis. Importantly, fatal TAM is assoicated with the elevated serum level of IL-8. We thus propose that IL-8 may be involved in the pathogenesis of liver fibrosis.

Risk factors for early death in transient myeloproliferative disorder without phenotypic features of Down syndrome: a case report and literature review

Not only in newborns with Down syndrome, but newborns without phenotypic features of Down syndrome also develop transient myeloproliferative disorder (TMD). In these cases, trisomy 21 and related chromosomal abnormalities are either constitutionally mosaic or limited to blood cells. Risk factors for early death of these patients are unknown so far. We here report a fatal case of TMD without phenotypic features of Down syndrome and review literature to identify risk factors associated with early death. Not only are gestational age and white blood cell count risk factors for early death in TMD with Down syndrome, but they also appear to be risk factors in TMD without Down syndrome.

Treatment and prognostic impact of transient leukemia in neonates with Down syndrome

Approximately 10% of the neonates with Down syndrome (DS) exhibit a unique transient leukemia (TL). Though TL resolves spontaneously in most patients, early death and development of myeloid leukemia (ML-DS) may occur. Prognostic factors as well as treatment indication are currently uncertain. To resolve that issue, we prospectively collected clinical, biologic, and treatment data of 146 patients with TL. The 5-year overall survival (OS) and event-free survival (EFS) were 85% plus or minus 3% and 63% plus or minus 4%, respectively. Multivariate analysis revealed a correlation between high white blood cell (WBC) count, ascites, preterm delivery, bleeding diatheses, failure of spontaneous remission, and the occurrence of early death. Treatment with cytarabine (0.5-1.5 mg/kg) was administered to 28 patients with high WBC count, thrombocytopenia, or liver dysfunction. The therapy had a beneficial effect on the outcome of those children with risk factors for early death (5-year EFS, 52% +/- 12% vs 28% +/- 11% [no treatment]; P = .02). Multivariate analysis demonstrated its favorable prognostic impact. A total of 29 (23%) patients with TL subsequently developed ML-DS. Patients with ML-DS with a history of TL had a significantly better 5-year EFS (91% +/- 5%) than those without documented TL (70% +/- 4%), primarily due to a lower relapse rate. A history of TL may therefore define a lower-risk ML-DS subgroup. This study was registered at www.clinicaltrials.gov as no. NCT 00111345.

Acute megakaryoblastic leukemia in Down syndrome

Children with Down syndrome (DS) have a 10- to 20-fold increased risk of developing acute leukemia. An estimated 10% of newborns with DS develop Transient Myeloproliferative Disease (TMD) or Transient Leukemia (TL), a clonal accumulation of megakaryoblasts that resolves spontaneously within months. Acute megakaryoblastic leukemia (AMKL) develops in approximately 20% of cases of TMD/TL by 4 years of age. Both the blasts of AMKL and TMD/TL in DS harbor somatic mutations of GATA1, an essential transcriptional regulator of megakaryocytic differentiation. The distinct phenotypes of megakaryoblastic leukemia in DS are a unique biological model of the incremental process of leukemic transformation.

Pro-inflammatory cytokinemia is frequently found in Down syndrome patients with hematological disorders

Down syndrome (DS) patients are frequently complicated with infections, autoimmune phenomena and hematological disorders, including transient abnormal myelopoiesis (TAM) in infancy and acute megakaryoblastic leukaemia (AMKL) in later life. In this study, serum levels of cytokines from 23 TAM and 15 AMKL patients were examined using the highly sensitive microsphere fluorescence system. Statistical differences between DS neonates with or without TAM were found in IL-1beta [median 7.0 pg/ml (0.34-271.6) verses 0.05 pg/ml (0.0-2.4), p=0.034], TNF-alpha [8.11 pg/ml (0.1-253.0) verses 0.41 pg/ml (0.1-1.5), p=0.041], and IFN-gamma [20.0 pg/ml (0.14-406.3) verses 1.5 pg/ml (0.14-5.79), p=0.036]. Moreover, abnormal inflammatory cytokinemia was also found in myelodysplastic syndrome (MDS) and AMKL with DS. These abnormal cytokinemia may have a role in the pathophysiology of TAM, MDS and AMKL in DS, especially in liver fibrosis or myelofibrosis.

Four cases of fetal hypoechoic hepatomegaly associated with Trisomy 21 and transient abnormal myelopoiesis

OBJECTIVE

Our objective was to determine the clinical significance of fetal hypoechoic hepatomegaly and serial change of liver sizes.

METHODS

The liver sizes of four fetuses with hypoechoic hepatomegaly were serially estimated by liver length, as measured from the dome of the right hemidiaphragm to the tip of the right lobe.

RESULTS

All cases were associated with trisomy 21 or transient abnormal myelopoiesis (TAM). Two cases were trisomy 21 with TAM, one case was a phenotypically normal newborn, who had developed TAM during the fetal period, and the last case was trisomy 21 without TAM. In the last case, it is speculated that TAM had developed and regressed completely before birth. Two cases, whose hepatomegaly had improved before birth, showed good prognosis and the other two cases, in whom improvement had not been observed, resulted in death after birth by liver failure.

CONCLUSION

These experiences show that one of the differential diagnoses of hypoechoic hepatosplenomegaly is TAM and that the change of live size is a predictor of prognosis.

Prenatal sonographic findings and hematological abnormalities in fetuses with transient abnormal myelopoiesis with Down syndrome

OBJECTIVES

To determine relevant prenatal findings of transient abnormal myelopoiesis (TAM) that have important prognostic implications.

METHODS

The prenatal and postnatal medical records of all cases with confirmed TAM associated with Down syndrome were reviewed retrospectively, with emphasis on prenatal sonographic findings, fetal blood analysis, neonatal outcomes, and causes of death.

RESULTS

From January 1992 to December 2005, seven cases were confirmed postnatally as having TAM associated with Down syndrome. Sonography demonstrated hydrops with hepatomegaly in four, and isolated hepatomegaly in two of these seven cases. There were no findings suggestive of cardiac failure in cases of hydrops. Fetal blood analysis revealed elevated liver enzyme levels in six cases and hypoalbuminemia in four cases. Comparison of sonographic findings with fetal blood findings demonstrated an association between hydrops and hypoalbuminemia. Four of the seven cases were fatal. All fatal cases were associated with hydrops and the main cause of death was coagulopathy due to liver failure, which may have resulted from infiltration of the liver by blast cells.

CONCLUSIONS

Fetal TAM is associated with hepatomegaly and elevated liver enzyme levels. The prenatal finding with prognostic implications is hydrops, which may result from hypoalbuminemia due to liver failure.

Clinical manifestations of hematologic and oncologic disorders in patients with Down syndrome

Hematologic abnormalities are common in individuals with Down syndrome (DS). Increased erythrocyte mean corpuscular volume (MCV) is frequently found among DS infants and remains elevated throughout life in two-thirds of patients, making interpretation of red cell indices for diagnosis of nutritional anemias or bone marrow failure disorders more challenging. Transient myeloproliferative disorder (TMD) associated with pancytopenia, hepatosplenomegaly, and circulating immature WBCs, is found almost exclusively in DS infants with an incidence of approximately 10%. In most cases, TMD regresses spontaneously within the first 3 months of life, but in some children, it can be life threatening or even fatal. Despite the high rate of spontaneous regression, TMD can be a preleukemic disorder in 20-30% of children with DS. The types of malignancy, response to therapy, and clinical outcome in children with DS are also unique. There is an increased risk of leukemia with an equal incidence of lymphoid and myeloid leukemia. Acute megakaryocytic leukemia (AMKL) subtype is the most common form of acute myeloid leukemia (AML) in this setting, and is uncommon in children without DS. Somatic mutations of the gene encoding the hematopoetic growth factor GATA1 have been shown to be specific for TMD and AMKL in children with DS. Myelodysplastic syndrome can precede AML. Children with DS and leukemia are more sensitive to some chemotherapeutic agents such as methotrexate than other children which requires careful monitoring for toxicity. Although the risk for leukemia is higher in individuals with DS, these patients have a lower risk of developing solid tumors, with the exception of germ cell tumors, and perhaps retinoblastoma and lymphoma.

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.