José Sánchez de Toledo

Relationship between minimal residual disease measured by multiparametric flow cytometry prior to allogeneic hematopoietic stem cell transplantation and outcome in children with acute lymphoblastic leukemia

Background The presence of minimal residual disease detected by polymerase chain reaction techniques prior to allogeneic hematopoietic stem cell transplantation has proven to be an independent prognostic factor for poor outcome in children with acute lymphoblastic leukemia. Design and Methods The aim of this study was to ascertain whether the presence of minimal residual disease detected by multiparametric flow cytometry prior to allogeneic hematopoietic stem cell transplantation is related to outcome in children acute lymphoblastic leukemia. Minimal residual disease was quantified by multiparametric flow cytometry at a median of 10 days prior to hematopoietic stem cell transplantation in 31 children (age range, 10 months to 16 years) with acute lymphoblastic leukemia. Thirteen patients were transplanted in first remission. Stem cell donors were HLA-identical siblings in 8 cases and matched unrelated donors in 23. Twenty-six children received a total body irradiation-containing conditioning regimen. According to the level of minimal residual disease, patients were divided into two groups: minimal residual disease-positive (≥0.01%) (n=10) and minimal residual disease-negative (<0.01%) (n=21). Results Estimated event-free survival rates at 2 years for the minimal residual disease-negative and -positive subgroups were 74% and 20%, respectively (P=0.004) and overall survival rates were 80% and 20%, respectively (P=0.005). Bivariate analysis identified pre-transplant minimal residual disease as the only significant factor for relapse and also for death (P<0.01). Conclusions The presence of minimal residual disease measured by multiparametric flow cytometry identified a group of patients with a 9.5-fold higher risk of relapse and a 3.2-fold higher risk of death than those without minimal residual disease. This study supports the strong relationship between pre-transplantation minimal residual disease measured by multiparametric flow cytometry and outcome following allogeneic hematopoietic stem cell transplantation and concur with the results of previous studies using polymerase chain reaction techniques.

Chromosome fragility in patients with Fanconi anaemia: diagnostic implications and clinical impact

Background Fanconi anaemia (FA) is a rare syndrome characterized by bone marrow failure, malformations and cancer predisposition. Chromosome fragility induced by DNA interstrand crosslink (ICL)-inducing agents such as diepoxybutane (DEB) or mitomycin C (MMC) is the ‘gold standard’ test for the diagnosis of FA. Objective To study the variability, the diagnostic implications and the clinical impact of chromosome fragility in FA. Methods Data are presented from 198 DEB-induced chromosome fragility tests in patients with and without FA where information on genetic subtype, cell sensitivity to MMC and clinical data were available. Results This large series allowed quantification of the variability and the level of overlap in ICL sensitivity among patients with FA and the normal population. A new chromosome fragility index is proposed that provides a cut-off diagnostic level to unambiguously distinguish patients with FA, including mosaics, from non-FA individuals. Spontaneous chromosome fragility and its correlation with DEB-induced fragility was also analysed, indicating that although both variables are correlated, 54% of patients with FA do not have spontaneous fragility. The data reveal a correlation between malformations and sensitivity to ICL-inducing agents. This correlation was also statistically significant when the analysis was restricted to patients from the FA-A complementation group. Finally, chromosome fragility does not correlate with the age of onset of haematological disease. Conclusions This study proposes a new chromosome fragility index and suggests that genome instability during embryo development may be related to malformations in FA, while DEB-induced chromosome breaks in T cells have no prognostic value for the haematological disease.

A novel G6PC3 homozygous 1-bp deletion as a cause of severe congenital neutropenia

To the editor: Hereditary severe congenital neutropenia (SCN) represents a heterogeneous group of diseases characterized by early-onset life-threatening bacterial infections associated with absolute neutrophil counts (ANC) below 500/μL.[1][1],[2][2] In recent years, different studies have

Anesthetic Efficacy of Eutectic Prilocalne-Lidocaine Cream in Pediatric Oncology Patients Undergoing Lumbar Puncture

OBJECTIVE: To evaluate the efficacy of eutectic mixture of local anesthetics 5% (Emla) in reducing pain associated with lumbar punctures in children. DESIGN: Prospective, double-blind, randomized, placebo-controlled trial. SETTING: University pediatric hospital. PATIENTS: Eleven pediatric oncology patients (mean age 6.6 y, range 4–16) who underwent 31 lumbar punctures. MAIN OUTCOME MEASURES: The analgesic effect was measured by using two methods. The first was a 10-point visual analog scale reported by the patient and the second was an 8-point behavioral pain scale assessed by the nurse who applied the cream. RESULTS: Emla cream was associated with significantly lower pain scores than those with placebo as measured by the patient when the puncture was successful on the first attempt (2.0 +1.6 Emla group, 3.8 +1.9 placebo group; p < 0.05). CONCLUSIONS: The use of Emla cream may reduce pain substantially only in patients who undergo a successful lumbar puncture on the first attempt.

Myeloproliferative disorder in Noonan syndrome.

Children with Noonan syndrome (NS) are at increased risk of developing juvenile myelomonocytic leukemia (JMML) or a myeloproliferative disorder associated with NS (MPD/NS) resembling JMML in the first weeks of life; whereas JMML is an aggressive disorder requiring hematopoietic stem cell transplantation, MPD/NS may resolve without treatment and cases with spontaneous remission have also been reported. Two cases of NS with hematologic disorders are described. Diagnosis of the syndrome was confirmed by the identification of earlier reported germline missense mutations in the PTPN11 gene. Splenomegaly in 1 patient and leukocytosis, monocytosis and “in vitro” culture assays consistent with JMML in both were the most salient hematologic features. After a 24-month follow-up, these 2 infants continue to improve and JMML has been ruled out. Splenomegaly persists in 1 patient and monocytosis in both, but without signs of malignancy, thereby suggesting abnormal hematopoiesis or MPD/NS, as described in NS.

New splicing variants for human Tyrosine Hydroxylase gene with possible implications for the detection of minimal residual disease in patients with neuroblastoma

Expression of Tyrosine Hydroxylase (TH) is frequently seen in neuroblastomas, the most common extracranial tumor in children, and TH mRNA detection is used for the analysis of microcirculating or micrometastatic disease in this neoplasia. TH is known to have at least seven isoforms produced by alternative splicing of the N-terminal region (exons 1-4), although no other splicing variants have been described downstream. TH expression was analyzed in six samples of neuroblastoma by RT-PCR using highly restrictive conditions and primers between exons 5 and 12, a region of the gene previously considered to be constant. In the analyzed samples we found two novel TH mRNAs, one lacking exon 8, and another lacking exons 8+9. These new splicing variants are described in a region of TH previously reported to be conserved, and that has been used for the design of reverse transcriptase-polymerase chain-reaction assays for the detection of minimal residual disease [Eur. J. Cancer, 27 (1991) 762]. The splicing pattern characteristic of every tumor could allow the monitoring of the minimal residual disease in a tumor-specific manner.

Non-Hodgkin's lymphoma after liver transplantation: Response to chemotherapy

An increased incidence of lymphoproliferative disorders in immunosuppressed organ transplant recipients has long been recognised. Lymphoproliferative disorders occur in 2% of orthotopic liver transplant patients. Different therapies have been used, but the optimal treatment remains unknown. Relatively little information is available on experience with cytotoxic chemotherapy. Three children who developed Burkitt-like, non-Hodgkins lymphomas after liver transplantation are described. The disease failed to regress after initial management, which included a reduction in immunosuppression. With cytotoxic chemotherapy all three achieved complete remission, which continued 36+, 35+, and 16+ months after diagnosis. Results suggest that in selected cases chemotherapy can be safe in late-onset lymphomas appearing after solid organ transplantation.

Genetic changes including gene copy number alterations and their relation to prognosis in childhood acute myeloid leukemia

We studied a series of 68 subjects diagnosed with childhood acute myeloid leukemia (AML) using conventional cytogenetics and fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR) to analyze mutations in FLT3 and NPM1 genes, and/or array comparative genomic hybridization (CGH). Cytogenetic/FISH abnormalities were observed in 71% of subjects, FLT3-ITD mutations in 15%, and NPM1 mutations in 13%. The array CGH alterations (average 3.6 per case) were observed in 96% of the tested subjects. The most frequent alterations were gains of 8q24.3 and 11p15.5-p15.4 in 16% of the samples. Six genes (AKT1, RUNX1, LTB, SDC1, RUNX1T1, and JAK2) from the imbalanced regions have been reported to be involved in AML, whereas other 30 cancer genes, not previously reported in an AML context, were identified as imbalanced. They probably correspond to non passenger alterations that cooperate with the recurrent translocations. The clinical data and genetic changes were tested to find out the possible association with prognosis. Genomic instability (four or more genomic imbalances) was correlated with poor patient outcome (p = 0.029).

Calidad de vida en adolescentes supervivientes de cáncer infantojuvenil

BACKGROUND AND OBJECTIVE To assess health-related quality of life of adolescent survivors of childhood cancer, compared to adolescents health-related quality of life who had no history of cancer. PATIENTS AND METHOD A total of 372 adolescents aged between 14 and 19 years, 34 cancer survivors and a comparison group of 338 peers without a history of cancer, were assessed. All of them filled in the SF-12v(2) in a cross-sectional study. RESULTS Survivors revealed significantly higher mean values compared to the normative group for the Mental Component Scale (MCS) from the SF-12v(2) (52,60 vs. 47,85; p=0,004; IC 95%, -7,9--1,6). No significant differences between groups were found for the Physical Component Scale (PCS), even though adolescent survivors of childhood cancer showed higher mean scores (54,03 vs. 52,72). CONCLUSIONS Adolescent cancer survivors showed a satisfactory quality of life (mean scores around the normative values), and, specifically, they reported greater perception of psychological wellbeing compared to peers.

MicroRNA-497 impairs the growth of chemoresistant neuroblastoma cells by targeting cell cycle, survival and vascular permeability genes.

Despite multimodal therapies, a high percentage of high-risk neuroblastoma (NB) become refractory to current treatments, most of which interfere with cell cycle and DNA synthesis or function, activating the DNA damage response (DDR). In cancer, this process is frequently altered by deregulated expression or function of several genes which contribute to multidrug resistance (MDR). MicroRNAs are outstanding candidates for therapy since a single microRNA can modulate the expression of multiple genes of the same or different pathways, thus hindering the development of resistance mechanisms by the tumor. We found several genes implicated in the MDR to be overexpressed in high-risk NB which could be targeted by microRNAs simultaneously. Our functional screening identified several of those microRNAs that reduced proliferation of chemoresistant NB cell lines, the best of which was miR-497. Low expression of miR-497 correlated with poor patient outcome. The overexpression of miR-497 reduced the proliferation of multiple chemoresistant NB cell lines and induced apoptosis in MYCN-amplified cell lines. Moreover, the conditional expression of miR-497 in NB xenografts reduced tumor growth and inhibited vascular permeabilization. MiR-497 targets multiple genes related to the DDR, cell cycle, survival and angiogenesis, which renders this molecule a promising candidate for NB therapy.