Hyperdiploidy with 58-66 chromosomes in childhood B-acute lymphoblastic leukemia is highly curable: 58951 CLG-EORTC results.

The aim of our study was to analyze the factors contributing to heterogeneity of prognosis in patients with hyperdiploidy>50 chromosomes (HD>50), a group of B-cell precursor acute lymphoblastic leukemia with favorable outcome. The 541 HD>50 patients registered prospectively in the 58951 European Organisation for Research and Treatment of Cancer (EORTC) Children's Leukemia Group (CLG) trial, identified by karyotype (446 patients) and by DNA index (DI) (490 patients), had a 6-year event-free survival (EFS) of 89.0% (standard error [SE] = 1.5%) and a 6-year overall survival (OS) of 95.9% (SE = 0.9%). The strongest prognostic factor was the modal number of chromosomes (MNC): the 6-year EFS of 51-53, 54-57, and 58-66 MNC groups were 80%, 89%, and 99%, respectively (P < .0001). Ploidy assessed by DI was also a favorable factor: the higher the DI, the better the outcome. The 6-year EFS of the 3 subgroups of DI < 1.16/≥1.16-<1.24/≥1.24 were 83%, 90%, and 95%, respectively (P = .009). All usual combinations of trisomies (chromosomes 4, 10, 17, 18) were significant favorable factors but had lower EFS when MNC was lower than 58. In multivariate analysis, MNC remained the strongest factor. Consequently, the best indicator for excellent outcome was ploidy assessed by karyotype because patients with 58-66 chromosomes stood every chance of being cured (OS of 100% at 6-year follow-up) with less-intensive therapy. This trial was registered at www.clinicaltrials.gov as #NCT00003728. Registered: http://www.eortc.org/, http://clinicaltrials.gov/show/NCT00003728.

Myelodysplasia and leukemia of Fanconi anemia are associated with a specific pattern of genomic abnormalities that includes cryptic RUNX1/AML1 lesions.

Fanconi anemia (FA) is a genetic condition associated with bone marrow (BM) failure, myelodysplasia (MDS), and acute myeloid leukemia (AML). We studied 57 FA patients with hypoplastic or aplastic anemia (n = 20), MDS (n = 18), AML (n = 11), or no BM abnormality (n = 8). BM samples were analyzed by karyotype, high-density DNA arrays with respect to paired fibroblasts, and by selected oncogene sequencing. A specific pattern of chromosomal abnormalities was found in MDS/AML, which included 1q+ (44.8%), 3q+ (41.4%), -7/7q (17.2%), and 11q- (13.8%). Moreover, cryptic RUNX1/AML1 lesions (translocations, deletions, or mutations) were observed for the first time in FA (20.7%). Rare mutations of NRAS, FLT3-ITD, MLL-PTD, ERG amplification, and ZFP36L2-PRDM16 translocation, but no TP53, TET2, CBL, NPM1, and CEBPα mutations were found. Frequent homozygosity regions were related not to somatic copy-neutral loss of heterozygosity but to consanguinity, suggesting that homologous recombination is not a common progression mechanism in FA. Importantly, the RUNX1 and other chromosomal/genomic lesions were found at the MDS/AML stages, except for 1q+, which was found at all stages. These data have implications for staging and therapeutic managing in FA patients, and also to analyze the mechanisms of clonal evolution and oncogenesis in a background of genomic instability and BM failure.

Wide diversity of PAX5 alterations in B-ALL: a Groupe Francophone de Cytogenetique Hematologique study.

PAX5 is the main target of somatic mutations in acute B lymphoblastic leukemia (B-ALL). We analyzed 153 adult and child B-ALL harboring karyotypic abnormalities at chromosome 9p, to determine the frequency and the nature of PAX5 alterations. We found PAX5 internal rearrangements in 21% of the cases. To isolate fusion partners, we used classic and innovative techniques (rolling circle amplification-rapid amplification of cDNA ends) and single nucleotide polymorphism-comparative genomic hybridization arrays. Recurrent and novel fusion partners were identified, including NCoR1, DACH2, GOLGA6, and TAOK1 genes showing the high variability of the partners. We noted that half the fusion genes can give rise to truncated PAX5 proteins. Furthermore, malignant cells carrying PAX5 fusion genes displayed a simple karyotype. These data strongly suggest that PAX5 fusion genes are early players in leukemogenesis. In addition, PAX5 deletion was observed in 60% of B-ALL with 9p alterations. Contrary to cases with PAX5 fusions, deletions were associated with complex karyotypes and common recurrent translocations. This supports the hypothesis of the secondary nature of the deletion. Our data shed more light on the high variability of PAX5 alterations in B-ALL. Therefore, it is probable that gene fusions occur early, whereas deletions should be regarded as a late/secondary event.

Cryptosporidiosis in children with acute lymphoblastic leukemia on maintenance chemotherapy.

Cryptosporidium is recognized as a cause of diarrhea associated with a high mortality in immunocompromised patients. We report on 2 pediatric cases of cryptosporidiosis during maintenance chemotherapy of acute lymphoblastic leukemia. The patients presented severe diarrheas, 1 of them was complicated by a cholangitis. Withdrawal of immunosuppressive treatments and adjunction of an adequate antiparasitic treatment cured the Cryptosporidium infection in both cases.

Childhood near-tetraploid acute lymphoblastic leukemia: an EGIL study on 36 cases.

OBJECTIVES: Patients with near-tetraploid (karyotype: 81 - 103 chromosomes) acute lymphoblastic leukemia (NT-ALL) constitute about 1% of childhood ALL and data reported on them are limited and controversial. The aim of the study was to enlarge the knowledge on these rarely occurring ALL. METHODS: The members of the European Group for Immunophenotyping of Leukemias (EGIL) searched retrospectively their databases for NT-ALL patients. RESULTS: We collected data of 36 European children from seven European countries with NT-ALL diagnosed since 1992. All patients reached complete remission (CR) after induction chemotherapy. Their blasts were negative for peroxidase and BCR-ABL1. Ten children were diagnosed as T-cell ALL (T-ALL) EGIL categories (T-I n=2, T-II n=2, T-III n=3, T-IV n=3) and four displayed various structural chromosomal abnormalities. Eight of 10 T-ALL remained in 1st CR; one died in CR from sepsis and one is alive in 2nd CR. Median survival was 88 (7-213) months. B-cell precursor (BCP) ALL was diagnosed in 26 children. Thirteen were positive for ETV6-RUNX1 and are alive in 1st CR for 32-147 months. Ten children were ETV6-RUNX1 negative and remained in 1st CR for 16-163 months. One girl with hypodiploid and NT metaphases and ETV6-RUNX1-negative BCP-ALL and one of two boys with NT-BCP-ALL not examined for ETV6-RUNX1 died of infection after stem cell transplantation in 2nd/3rd CR. Secondary myelodysplastic syndrome developed in two patients with NT-BCP-ALL. CONCLUSIONS: Our data demonstrate immunophenotypic, cytogenetic, and molecular heterogeneity of NT-ALL and favorable prognosis of most NT-ALL across different immunophenotypic and/or genetic ALL subtypes.

Successful salvage chemotherapy for isolated central nervous system (CNS) relapse in Burkitt lymphoma: monocentric experience of 3 pediatric patients.

Short-term intensive chemotherapy regimens have substantially improved the prognosis of pediatric patients with Burkitt lymphoma (BL), which now has an excellent overall outcome. However, central nervous system (CNS) involvement at diagnosis remains a poor prognostic factor, and progressive or relapsed disease in the CNS is associated with even worse outcomes. We report 3 boys aged 4, 7, and 12 years treated under the French Société Française d'Oncologie Pédiatrique LMB 89/96 protocols who presented, respectively, with CNS-/bone marrow+ stage-IV BL; CNS+ stage-IV BL; and stage-I BL. Each experienced an isolated CNS relapse, which was treated with CNS-directed salvage chemotherapy. All 3 are alive after 11 years of median follow-up, indicating that this chemotherapy regimen can be curative in pediatric BL with isolated CNS relapse.

High frequency of CD34+CD38-/low immature leukemia cells is correlated with unfavorable prognosis in acute myeloid leukemia.

AIM: To evaluate the importance of the CD34+CD38- cell population when compared to the CD34+CD38+/low and CD34+CD38+/high leukemic cell sub-populations and to determine its correlations with leukemia characteristics and known prognostic factors, as well as with response to therapy and survival. METHODS: Two hundred bone marrow samples were obtained at diagnosis from 200 consecutive patients with newly diagnosed acute myeloid leukemia (AML) were studied between September 2008 and December 2010 at our Institution (Hematology Department, Lyon, France). The CD34/CD38 cell profile was analyzed by multiparameter flowcytometry approach using 8C panels and FACS CANTO and Diva software (BD Bioscience). RESULTS: We analyzed CD34 and CD38 expression in bone marrow samples of 200 AML patients at diagnosis, and investigated the prognostic value of the most immature CD34+CD38- population. Using a cut-off value of 1% of CD34+CD38- from total "bulk leukemic cells" we found that a high (> 1%) level of CD34+CD38- blasts at diagnosis was correlated with advanced age, adverse cytogenetics as well as with a lower rate of complete response after induction and shorter disease-free survival. In a multivariate analysis considering age, leukocytosis, the % of CD34+ blasts cells and the standardized cytogenetic and molecular risk subgroups, a percentage of CD34+CD38- leukemic cells > 1% was an independent predictor of DFS [HR = 2.8 (1.02-7.73), P = 0.04] and OS [HR = 2.65 (1.09-6.43), P = 0.03]. CONCLUSION: Taken together, these results show that a CD34/CD38 "backbone" for leukemic cell analysis by multicolour flowcytometry at diagnosis provides useful prognostic information.

Abnormalities of the long arm of chromosome 21 in 107 patients with hematopoietic disorders: a collaborative retrospective study of the Groupe Français de Cytogénétique Hématologique.

Chromosome 21 is frequently rearranged in hematopoietic malignancies. In order to detect new chromosomal aberrations, the Groupe Français de Cytogénétique Hématologique collected a series of 107 patients with various hematologic disorders and acquired structural abnormalities of the long arm of chromosome 21. The abnormalities were subclassified into 10 groups, according to the location of the 21q breakpoint and the type of abnormality. Band 21q22 was implicated in 72 patients (excluding duplications, triplications, and amplifications). The involvement of the RUNX1 gene was confirmed in 10 novel translocations, but the gene partners were not identified. Eleven novel translocations rearranging band 21q22 with bands 1q25, 2p21, 2q37, 3p21, 3p23, 4q31, 6p24 approximately p25, 6p12, 7p15, 16p11, and 18q21 were detected. Rearrangements of band 21q11 and 21q21 were detected in six novel translocations with 5p15, 6p21, 15q21, 16p13, and 20q11 and with 1p33, 3q27, 5p14, 11q11, and 14q11, respectively. Duplications, triplications, amplifications, and isodicentric chromosomes were detected in eight, three, eight, and three patients, respectively. The present study shows both the wide distribution of the breakpoints on the long arm of chromosome 21 in hematopoietic malignancy and the diversity of the chromosomal rearrangements and the hematologic disorders involved. The findings invite further investigation of the 21q abnormalities to detect their associated molecular rearrangements.

Acute megakaryoblastic leukaemia: a national clinical and biological study of 53 adult and childhood cases by the Groupe Français d'Hématologie Cellulaire (GFHC).

Since the WHO classification of haematological malignancies recommended the description of global entities, we performed a national M7-AML study to correlate morphological, immunological and cytogenetic features, and to find new clinically relevant M7 entities. This study is based on accurate morphological and immunological study to select pure megakaryoblastic proliferations and to eliminate megakaryocytic participation in haemopathies. We collected 53 cases: 23 adults and 30 children. We confirm the wide heterogeneity of adult M7. In adults, the cytogenetic abnormalities are frequently those of secondary leukaemia while a few patients have a previous history and morphological features of dyshaematopoiesis; their outcome is very poor. Among children, besides the well-known Down syndrome M7, we in particular, studied ten t(1;22) M7 and one OTT-MAL transcript positive case with normal karyotype presenting specific features. We were already aware of their younger age, female and tumoral presentation, but we also found a lower percentage of bone marrow blasts, sometimes without any megakaryoblastic bone marrow involvement, but always, with a dysmegakaryocytopoiesis associated with micromegakaryocytes. They are generally good responders to intensive AML chemotherapy with very long disease-free survivals (DFS). Accordingly, OTT-MAL transcript study, in infant M7 with normal karyotype, is recommended and we feel that this entity should be added to the WHO AML classification.

Two cases of varicella zoster virus meningitis found in pediatric patients after bone marrow transplantation despite valaciclovir prophylaxis and without skin lesions.

Two cases of varicella zoster virus (VZV) meningitis are described in an 18-year-old girl and an 18-year-old boy. They occurred, respectively, 9 days and 9 months after allogeneic bone marrow transplantation. VZV nucleic acid was detected in the cerebrospinal fluid during the 1st week of illness. This recurrence occurred despite valaciclovir prophylaxis and without skin lesions. The two patients received aciclovir intravenously and immunoglobulins infusion. They responded to treatment and their clinical state improved rapidly.

Human herpesvirus 6 infection and transient acquired myelodysplasia in children.

BACKGROUND: To demonstrate that primary human herpesvirus 6 (HHV-6) infection in childhood can cause hematopoietic dysplasia that mimics a myelodysplastic syndrome (MDS) in severe cases. PROCEDURE: Seven immunocompetent children, who presented at admission with concomitant cytopenias in blood and morphologic features of dysplasia in bone marrow, were evaluated. Diagnosis of acute HHV-6 infection was secondary made by detection of HHV-6 DNA in plasma, bone marrow, or cerebrospinal fluid and measurement of plasma antibody titers. Peripheral blood and bone marrow aspirate smears were examined at diagnosis and during follow-up. Morphologic recognition of myelodysplasia was made according to the recommendations of the Third MIC Cooperative Group. RESULTS: Anemia was the most frequent cytopenia (five of seven cases). Bi- or tri-lineage dysplasia was observed in the marrow samples. Granulocytic and erythroid cells were always affected with dysgranulopoiesis and dyserythropoiesis scores equal to or higher than 3. Myelodysplasia was not due to a clonal disorder and disappeared gradually within 1 or 2 months. CONCLUSIONS: Our results indicate that severe HHV-6 infection may induce reversible myelodysplastic changes. These findings contribute to elucidate the pathogenicity of HHV-6 and furthermore suggest that HHV-6 infection must also be considered as a cause of dysplasia in the differential diagnosis of MDS.

Thrombocytosis and toxocariasis: report of two pediatric cases.

We report two cases of visceral larva migrans (VLM) syndrome by Toxocara in children. The biological presentation was unusual and characterized by persistent secondary thrombocytosis (>1,000 x 10(9)/L) mimicking an essential thrombocythemia and variable hypereosinophilia syndrome. Both children had non-specific symptoms including abdominal pain, skin rash, and fever. The diagnosis was confirmed by serology. The children were treated with either thiabendazole or albendazole, resulting in normalization of eosinophil and platelet counts.

Cytogenetic profile of childhood and adult megakaryoblastic leukemia (M7): a study of the Groupe Français de Cytogénétique Hématologique (GFCH).

To draw the cytogenetic profile of childhood and adult acute megakaryoblastic leukemia (M7), the Groupe Français de Cytogénétique Hématologique collected 53 cases of M7 (30 children and 23 adults). Compared to other acute myeloid leukemias, M7 is characterized by a higher incidence of abnormalities, a higher complexity of karyotypes, and a different distribution of abnormalities among children and adults. Nine cytogenetic groups were identified: normal karyotypes (group 1), patients with Down syndrome (group 2), numerical abnormalities only (group 3), t(1;22)(p13;q13) or OTT-MAL transcript (group 4), t(9;22)(q34;q11) (group 5), 3q21q26 (group 6), -5/del(5q) or -7/del(7q) or both (group 7), i(12)(p10) (group 8), and other structural changes (group 9). Groups 1, 2, 3, and 4 were exclusively composed of children (except one adult in group 3), whereas groups 5, 6, 7, and 8 were mainly made up of adults. The main clinical and hematologic features of these groups were described. No new recurrent abnormality was identified, but mapping of all breakpoints allowed us to specify several possible hot spots of rearrangement: 17q22-23, 11q14-21, 21q21-22, and 16q21-22-23. Although 90.5% of cases had no documented antecedent hematologic disorder or exposure to chemotherapy or radiotherapy, the morphologic and the cytogenetic findings indicated that M7 might be a secondary leukemia more often than suggested by preceding history, particularly among adults. The concurrent analyses of morphologic and cytogenetic data also led us to assume that the initial precursor involved might be more immature in adult than in childhood M7.

CD4(+), CD56(+) DC2 acute leukemia is characterized by recurrent clonal chromosomal changes affecting 6 major targets: a study of 21 cases by the Groupe Français de Cytogénétique Hématologique.

CD4(+), CD56(+) DC2 malignancies constitute a novel disease entity, which has recently been shown to arise from a transformed lymphoid-related plasmacytoid dendritic cell (DC2). Diagnosis is primarily based on a particular immunophenotype with tumor cells expressing CD4 and CD56 antigens in the absence of common lymphoid or myeloid lineage markers. Little is currently known about the cytogenetic features of this disease entity. In this setting, the Groupe Français de Cytogénétique Hématologique (GFCH) initiated a cytogenetic study of 18 adults and 3 children with CD4(+), CD56(+) DC2 acute leukemia using conventional and fluorescence in situ hybridization/24-color karyotyping. Clonal, mostly complex chromosome aberrations were found in 14 patients (66%). Six major recurrent chromosomal targets were defined. These were 5q, 12p, 13q, 6q, 15q, and 9, which were involved in 72% (5q), 64% (12p and 13q), 50% (6q), 43% (15q), and 28% (monosomy 9) of cases, respectively. Cytogenetic features can be summarized as follows: (1) gross genomic imbalances (mostly losses) predominate, (2) no single anomaly can be considered as specific, whereas their combination/accumulation is, and (3) both lymphoid and myeloid lineage-associated rearrangements are observed in unusual combinations in the same cell. This is suggestive of complex multistep tumorigenic mechanisms and is supportive of the hypothesis that CD4(+), CD56(+) DC2 acute leukemia may arise from an undifferentiated nonmyeloid nonlymphoid progenitor cell. In conclusion, the present study documents for the first time the existence of a characteristic cytogenetic profile for this novel disease entity.

Clinical significance of HOX11L2 expression linked to t(5;14)(q35;q32), of HOX11 expression, and of SIL-TAL fusion in childhood T-cell malignancies: results of EORTC studies 58881 and 58951.

In a series of 153 children with T-cell malignancies enrolled in 2 consecutive European Organization for Research and Treatment of Cancer (EORTC) trials, we assessed the HOX11L2 expression and/or the presence of a t(5;14)(q35;q32). Additionally, in 138 of these patients, HOX11 expression and SIL-TAL rearrangement were also assessed. These alterations were mutually exclusive, and their frequency was 23% (n = 35), 7% (n = 10), and 12% (n = 17), respectively. HOX11L2/t(5;14) positivity was more frequent in acute lymphoblastic leukemia (ALL) with cortical T immunophenotype and in children aged between 6 and 9 years. In contrast with previously reported data, patients positive and negative for HOX11L2/t(5;14) were comparable with regard to clinical outcome as well as to the response to a 7-day prephase treatment or to residual disease at completion of induction therapy. The 3-year event-free survival (EFS) rate (+/- SE percentage) for patients positive and negative for HOX11L2/t(5;14) was 75.5% (+/- 8.1%) and 68.3% (+/- 5.0%), respectively; the hazard ratio was 0.84 (95% confidence interval, 0.40-1.80). Patients with HOX11-high expression and those with SIL-TAL fusion had low levels of residual disease at the end of induction and a favorable prognosis: the 3-year EFS rate was 83.3% (+/- 8.5%) and 75.3% (+/- 12.6%), respectively. The results obtained in HOX11L2/t(5;14) patients in this study do not confirm the unfavorable prognosis reported in previous studies.