Hematopoietic dysplasia and marrow hypocellularity in children: a preleukemic condition

Allogeneic bone marrow transplantation in children with myelodysplastic syndrome or juvenile myelomonocytic leukemia: the Seattle experience

The purpose of this study was to evaluate the role of allogeneic bone marrow transplantation (BMT) in children with myelodysplastic syndrome (MDS). In total, 94 consecutive pediatric patients with MDS received an allogeneic BMT from 1976 to 2001 for refractory anemia (RA) (n=25), RA with ringed sideroblasts (RARS) (n=2), RA with excess blasts (RAEB) (n=20), RAEB in transformation (RAEB-T) (n=14), juvenile myelomonocytic leukemia (JMML) (n=32) or chronic myelomonocytic leukemia (CMML) (n=1). The estimated 3-year probabilities of survival, event-free survival (EFS), nonrelapse mortality and relapse were 50, 41, 28 and 29%, respectively. Patients with RA/RARS had an estimated 3-year survival of 74% compared to 68% in those with RAEB and 33% in patients with JMML/CMML. In multivariable analysis, patients with RAEB-T or JMML were 3.9 and 3.7 times more likely to die compared to those with RA/RARS and RAEB (P=0.005 and 0.004, respectively). Patients with RAEB-T were 5.5 times more likely to relapse (P=0.01). The median follow-up among the 43 surviving patients is 10 years (range 1-25). We conclude that allogeneic BMT for children with MDS is well tolerated and can be curative.

Clinical and morphological features of paediatric myelodysplastic syndromes: a review of 34 cases

BACKGROUND

The clinical and morphological spectrum of myelodysplastic syndromes (MDS) during childhood has not yet been completely documented. We herein present the clinical features and morphological data from peripheral blood (PB), bone marrow aspirates (BMA) and bone marrow biopsies (BMB) of a series of paediatric MDS patients, with particular emphasis on their specific morphological characteristics and their diverse underlying genetic background.

PATIENTS AND METHODS

Thirty-four patients with MDS (median age 8.45 y) were consecutively diagnosed and treated during a period of 15 y (1988-2002). Diagnosis was based on clinical manifestations, morphology of PB, BMA and BMB, and cytogenetic analysis of BM cells. Clonogenic methylcellulose cell cultures were performed in 23/34 patients. Patients were categorized into group A [26 primary/de novo MDS, i.e. refractory anaemia (RA) 18, RA with excess of blasts (RAEB) 2, RAEB in transformation (RAEB-t) 6] and group B (8 secondary MDS, i.e. RA 4, RAEB 1, RAEB-t 3). Treatment options varied according to protocols active during the period of the study and the availability of a suitable BM donor. Survival probabilities were estimated using the Kaplan-Meier method.

RESULTS

Dysplastic features of the erythroid, myeloid and megakaryocytic lineage were detected at BMA in 85%, 50% and 90% of the patients, respectively, while decreased cellularity was found at BMB in 21/34 patients (60%). RA patients of group A presented at BMB significant hypocellularity (14/18) as a prominent finding due to decrease of the myeloid (13/18 patients) and/or the megakaryocytic (14/18 patients) lineage. Hypocellularity in RA was accompanied by dysplasia of the erythroid (17/18 patients) and megakaryocytic (16/18 patients) lineage, the presence of abnormal localization of immature precursors (ALIP, 8/18 patients), fibrosis (5/18) and stromal changes (11/18). Chromosomal aberrations were revealed in 17/34 patients, of which monosomy 7 was present in seven. Cell cultures demonstrated abnormal myeloid and/or erythroid in vitro clonal growth pattern in all the examined patients. An associated disorder or inherited disease, was identified in 14/26 patients (54%) with primary MDS. Cumulative survival of group A patients was 44.2% (RA 66.6%, RAEB/RAEBt 14.6%; p = 0.001), and of the whole group 42.4%, at 14 y.

CONCLUSIONS

Hypocellularity of significant degree is a constant and prominent feature among paediatric MDS, especially those with RA. A large variety of associated disorders underlies the clinical appearance of paediatric MDS, reflecting their marked heterogeneity. RA represents the prominent subtype during childhood (69% in this study), and it appears to have the best prognosis, while prognosis of RAEB/RAEBt remains extremely poor.

Transient abnormal myelopoiesis in Noonan syndrome

An infant affected by Noonan syndrome and presenting with abnormal hemopoiesis is described. Cytogenetic analysis, molecular studies, and in vitro culture assays ruled out myelodysplasia or other hematologic malignancies but were consistent with transient abnormal myelopoiesis. At present, 3 years and 10 months after diagnosis, the patient shows a normal hematologic picture. Supportive treatment in such patients, unless refractory cytopenias or overt leukemia develops, is emphasized.

Myelodysplastic syndromes in children. A critical review of the clinical manifestations and management

The FAB group has defined myelodysplasia in adults but direct application of this categorization to children has been controversial. Consequently, to outline the natural history of the disease better we have retrospectively analysed case reports and series published in English between 1982 and 1996. This study also included children with juvenile chronic myelomonocytic leukaemia (JCML) and monosomy 7 (Mo7). 340 patients were described in 27 publications. The mean presentation age was 5.91 (SD 5.04) years, and 34.9% were female. Constitutional alterations were described in 68 (20%) where refractory anemia (RA) and RA with excess of blasts (RAEB) predominated and were associated with a significantly longer survival. Among all patients progression to higher forms of MDS was noted in 61 (18%). Cytogenetic anomalies were detected in 59% of 227 children, and in 67 it was to Mo7. Amid those with Mo7, the clinical and laboratory characteristics as well as survival, closely followed their FAB type. Of the treatment options described, survival was significantly higher in those who underwent bone marrow transplant (BMT) (46.9%; P = 0.00021). Among children with JMML (CMML/JCML) not receiving a BMT, time to death was shortest in those best described as JCML (absence of constitutional and karyotypic derangement, thrombocytopenia and elevated Hb F). We conclude that children with constitutional abnormalities survive longer, Mo7 disorders are clinically and morphologically heterogeneous and should not be grouped into a single entity and that CMML and JCML may have biological differences. Finally, BMT remains the treatment of choice for those with primary MDS, as intensive chemotherapy is no better than supportive measures.

Myelodysplastic syndrome associated with Griscelli syndrome

Myelodysplastic syndrome (MDS) in children has been reported to be associated with various constitutional anomalies; however, it has not been described previously in patients with Griscelli syndrome (GS). In this report, we present a case with GS and refractory anemia with an excess of blasts. We believe that careful evaluation of peripheral blood and bone marrow could increase the number of patients who are found to have GS-associated MDS.

[Myelodysplastic syndromes in children, Groupe d'étude des myélodysplasies de l'enfant de la Société d'hématologie et d'immunologie pédiatrique (SHIP)]

Myelodysplastic syndromes (MDS) in children constitute a heterogeneous disorder, including 'primary' MDS and MDS associated with constitutional abnormalities. The Franco-American-British (FAB) cytological classification for adults can be applied for childhood in 50 to 100% of the cases. The transformation into acute myeloblastic leukemia often occurs, but stabilisation or spontaneous regression of the disease may also be observed. The therapeutic decision is difficult because there is no predictive factor of the course of the disease. Allogenic bone marrow transplantation is the best curative option when treatment is necessary.

Myelodysplasia and deficiency of uridine diphosphate-galactose 4-epimerase

A 4-year-old girl known to have peripheral uridine diphosphate-galactose 4-epimerase deficiency was examined for bruising and thrombocytopenia. She had dysplastic peripheral blood and bone marrow changes, with a global platelet function defect. Uridine diphosphate-galactose-4-epimerase participates in a metabolic pathway that provides substrates for posttranslational glycosylation of secreted and membrane glycoproteins, including hematopoietic growth factors and their receptors; there may be a causal relationship between the two disorders.

Myelodysplastic syndromes in childhood: description of seven cases

Seven children with a primary myelodysplastic syndrome were seen at our center over a 9-year period. Two presented with refractory anemia, three with refractory anemia with excess of blasts, and two with refractory anemia with excess of blasts in transformation. All children received supportive therapy, including blood transfusions in five of them. Three patients developed acute myeloid leukemia and were treated with intensive chemotherapy, followed by allogeneic or autologous marrow transplantation in the two responders. All three died of either infection or progressive disease. The other four patients are still alive a median of 71 months (range 38-130) after diagnosis. These results confirm the difficulties in managing patients with myelodysplastic syndromes.

Severe aplastic anemia in a patient with primary immunodeficiency

This paper reports the case of a 6 year old boy with primary immunodeficiency disease, whose marrow cells showed dyshematopoietic features, that was subsequently transformed to severe aplastic anemia. He was first diagnosed as having congenital immunodeficiency comprising deficiency of immunoglobulin A (IgA), IgG2 and IgG4, depressed mitogen responses, lymphopenia with inverted CD4/CD8 ratio and an increased proportion of T-cell receptor gamma/delta-bearing cells. Cytogenetic study of the peripheral blood showed a normal karyotype of 46,XY, but that of the marked hypoplastic marrow demonstrated one cell with monosomy 7 and another with trisomy 8 in the 20 cells examined.

Myelodysplastic syndromes in childhood--classification, epidemiology, and treatment

Much of the applied terminology of myelodysplastic syndromes (MDS) in childhood is confusing and not mutually exclusive. It is therefore proposed that the FAB classification of MDS is used in children in order to improve diagnostic precision and to facilitate epidemiologic, clinical, and therapeutic comparisons. The true incidence of childhood MDS is unknown but the rate may approximate the incidence of acute myelogenous leukemia. A pooled analysis of eight larger series representing 110 children less than 15 years old at diagnosis with de novo MDS classified according to the FAB recommendations showed that the more aggressive subtypes dominated, which partly may reflect that the less advanced cases are underdiagnosed. The median age at presentation was 6.0 years. The male/female ratio was 1.6. Monosomy 7 was the most frequent cytogenetic abnormality. The median survival was 13 months and the probability of survival three years from diagnosis was 16%. Spontaneous remission may be observed very infrequently. Allogeneic bone marrow transplantation (BMT) represents the only potentially curative treatment. The survival rate three years after BMT is about 50%. Major differences between childhood and adult MDS exist with respect to the distribution of FAB subgroups, the rate of progression, and the cytogenetic findings. The literature on MDS in children is still sparse and there is an obvious need for more studies designed to determine the incidence, clinical and laboratory characteristics, the natural course, and the efficacy of contemporary treatment options.

Childhood acute lymphocytic leukemia with a preleukemic phase: report of an associated translocation and review of the literature

A fourteen month old boy presented with hepatosplenomegaly and pancytopenia. An extensive evaluation, including bone marrow aspiration and biopsies of both liver and lymph nodes, revealed a polyclonal B cell proliferation consistent with a reactive process, with no evidence of leukemia. After receiving transfusions of red cells and platelets, his blood counts recovered. Five weeks later, he returned with an elevated white blood count and bone marrow findings diagnostic of acute lymphocytic leukemia. The leukemic blasts contained a novel chromosomal translocation, t(5;14) (q34;q12). We describe the clinical, immunophenotypic and cytogenetic features of this case, review the literature of acute lymphocytic leukemia associated with a preleukemic phase, and discuss the relationship of this clinical entity to the 5q-abnormality associated with myelodysplasia.

Primary myelodysplastic syndrome in children: the clinical experience in 33 cases

We describe the clinicomorphological features in 33 cases of primary myelodysplastic syndrome classified according to the FAB classification which presented to a single centre over a 12 year period. Presenting features were typically related to pancytopenia although hepatosplenomegaly and granulocytic sarcomas were far more prevalent than in the adult population. Morphological assessment of the peripheral blood and the bone marrow showed seven patients had refractory anaemia (RA), 13 patients had RA with excess of blasts (RAEB), nine patients had RAEB in transformation (RAEB-t) and four patients had chronic myelomonocytic leukaemia (CMML). The overall mean survival was short (9.9 months) in all the subgroups and the leukaemic transformation rate was high. None of the patients scored 0-1 according to the Bournemouth Scoring System; four patients scored 2 whereas 29 patients scored 3 to 4. We conclude that unlike adults, the myelodysplastic syndromes in children run an aggressive clinical course, irrespective of the FAB subtype, and the pathogenesis of these diseases in paediatric practice warrants scientific scrutiny. Intensive chemotherapy such as the one used in de novo-AML lead to complete remission in some children and these early results suggest that this should be the treatment of choice in paediatric MDS.

Childhood myelodysplastic syndromes: clinical features, cytogenetics and prognosis

Sixteen children with myelodysplastic syndrome as defined by the French-American-British co-operative group are presented. The mean age was 10.5 (2.5 to 16) years, with a male predominance. All patients belonged to the more aggressive subtypes of myelodysplastic syndromes. Seven patients presented with refractory anaemia with excess blasts, six had refractory anemia with excess blasts in transformation, and three had chronic myelomonocytic leukemia. Cytogenetic analysis done in 7 of the 16 patients, revealed karyotype abnormalities involving chromosomes 7, 8 and 17. One patient with Down's syndrome had karyotype of 47, XY, +21 (major clone) and 46, XY (minor clone). Five of these patients evolved to acute leukemia. The mean duration of survival was 5.5 months. Aggressive chemotherapy as a primary line of treatment induced remission in five out of six patients. Predominance of aggressive types of myelodysplastic syndromes in children and their good but short-lived response to aggressive chemotherapy suggests the need for early bone marrow transplantation following chemotherapy.

Bone marrow dysfunctions preceding acute leukemia in children: a clinical study

This is a review of preleukaemic states in children. In a prospective series of 109 children with AML the overt disease was preceded by MDS in 22 cases. Ten of these patients had Down's syndrome. Advanced FAB groups were represented in the series. An important subgroup is the bone marrow monosomy 7 syndrome. Cytogenetic anomalies are common in MDS, and multiple and complicated abnormalities develop in nearly all patients with progressing disease. Some children die before transformation to overt ANLL. Transformation usually occurs, few children survive. With cytostatic treatment the risk of irreversible aplasia is great. The choice of schedule should therefore be carefully considered. Bone marrow transplantation has proved beneficial in a number of cases, but these are still quite few. The dysfunction of the bone marrow preceding ALL is due to transient aplastic anaemia--spontaneous remission--overt ALL, often FAB type L1, immunophenotype CALLA. The ALL reacts to the same treatment as de novo ALL of the same type and the prognosis is the same.

Growth hormone therapy and leukaemia

Following an initial report from Japan in 1987, 15 growth hormone (GH)-deficient patients developed leukaemia during or following GH treatment. Nearly all available pituitary and biosynthetic growth hormones have been used. In 14 of these 15 patients GH treatment was initiated in 1975 or later with doses between 4.5 and 18IU/m2 per week. The therapy period was between 0.17 and 8.0 years. Leukaemia occurred 0.2-11 years after the start of GH treatment. GH affects normally and abnormally growing blood cells in vitro and in animal experiments, but the clinical data in humans do not indicate GH induction of tumour growth. Seven out of the 14 patients under discussion had an additional increased leukaemia risk. Two other patients had been treated only for a very short time. Though no clear evidence of a strikingly augmented leukaemia incidence in GH-treated patients is found worldwide, the available data call for increased attention.

A dysmorphic child with myelodysplasia characterized by a duplication of 1q and multiple duplications of 3q

Multiple inserted duplications of bands 3q21 through 3q27 and a duplication of the chromosome 1 long arm are reported in a karyotypically altered clone from a dysmorphic child with myelodysplasia.

Acute myelogenous leukaemia in children

Acute myelogenous leukaemia in childhood is considerably more resistant to chemotherapy than the acute lymphocytic leukaemias. Recently, more aggressive therapy has improved the outlook for children with this difficult form of leukaemia. Long-term disease-free survival of children achieving remission has been reported to be more than 40% in some studies. This paper reviews both the present concept of leukaemogenesis as well as some of the more recent therapeutic studies on childhood AML.

Preleukemic syndromes and other syndromes predisposing to leukemia

The myelodysplastic and myeloproliferative syndromes are syndromes in childhood that may precede leukemia. Clinical and biologic features are reviewed in this article. Although rare, they offer an unique opportunity to observe the evolution of leukemia and give clues that are helping us to understand the leukemogenic process.

Cytogenetics of childhood preleukemia

Chromosome studies were done on ten children with childhood preleukemia characterized by anemia, thrombocytopenia, blasts in the circulation, and hypercellular marrow with excess blasts. The syndrome was clinically similar to adult preleukemia (myelodysplastic disorder). A chromosomally abnormal clone was found in the marrow in five patients: three with monosomy 7; one with a chromosome No. 21 replaced by two isochromosomes for 21q; and one with multiple alterations including an extra, abnormal chromosome No. 7. It was not apparent that a karyotypic change indicated a worse prognosis. The observed chromosome abnormalities appeared to overlap less with those in acute nonlymphocytic leukemia occurring de novo than is the case in adults, perhaps reflecting differing contributions of genetic and environmental factors to the pathogenesis of the disease at different ages.