Acute chest syndrome in children with sickle cell disease: Data from a national AIEOP cohort identify priority areas of intervention in a hub-and-spoke system.

Acute chest syndrome (ACS) is a frequent cause of hospitalization in sickle cell disease (SCD). Despite advances in acute care, many settings still lack knowledge about ACS best practices. After the AIEOP Guidelines were published in 2012, suggesting standardized management in Italy, a retrospective study was performed to assess the diagnostic and therapeutic pathways of ACS in children. From 2013 to 2018, 208 ACS episodes were presented by 122/583 kids in 11 centres. 73 were male, mean age 10.9 years, 85% African, 92% HbSS or Sß°. In our hub-and-spoke system, a good adherence to Guidelines was documented, but discrepancies between reference centres and general hospitals were noted. Improvement is needed for timely transfer to reference centres, use of incentive spirometry, oxygen therapy and pain management.

p53 gene inactivation in acute lymphoblastic leukemia of B cell lineage associates with chromosomal breakpoints at 11q23 and 8q24.

The clinical heterogeneity of acute lymphoblastic leukemia (ALL) of B cell lineage reflects the presence of distinct molecular pathways leading to well-defined ALL molecular subtypes. These molecular pathways include the formation of the fusion transcripts BCR/ABL and E2A/PBX1, due to t(9;22) and t(1;19), respectively, as well as rearrangements of the MLL gene at 11q23 and of c-MYC at 8q24. Hyperdiploid ALL in the absence of chromosomal structural abnormalities is an additional ALL molecular subtype. Mutations of the RAS family genes and of the p53 tumor suppressor gene represent additional genetic lesions detected in a fraction (10-20%) of ALL cases. RAS activation in ALL may be detected in all molecular subtypes of ALL and denotes poor prognosis. Conversely, little is known regarding the clinical and biological features of ALL cases carrying p53 mutations. In order to help clarify the role of p53 inactivation in ALL development, we have determined the frequency of p53 mutations throughout the molecular spectrum of B cell lineage ALL. We report that p53 inactivation in ALL of B cell lineage is restricted to cases carrying a rearrangement of MLL or c-MYC, whereas it is consistently negative in other molecular subgroups. These data underline the molecular heterogeneity of ALL of B cell lineage and indicate that at least some of the molecular pathways involved in ALL pathogenesis require more than one genetic lesion.

Deletion of parental GST genes as a possible susceptibility factor in the etiology of infant leukemia.

Infant leukemia below the age of 12 months is a rare disease that exhibits a high frequency of 11q23 rearrangements. We assessed the presence of polymorphisms in several metabolic genes in 23 families of infants diagnosed with leukemia under 12 months of age in Italy. When polymorphism frequencies were calculated within families, frequencies of GST gene deletions were significantly higher than expected only among the parents of infants without the 11q23 rearrangement. These data suggest that the deletion of GST genes in parents may affect the risk of infant leukemia through a pathway independent of the MLL gene.

Evidence of involvement of the PLAG1 gene in lipoblastomas.

Previous cytogenetic studies have demonstrated that the majority of lipoblastomas show rearrangements, in particular translocations and insertions, with breakpoints in 8q11-13. Here we present evidence for involvement of the developmentally regulated zink finger gene PLAG1 in these rearrangements. Northern blot and RT-PCR analyses revealed overexpression of PLAG1 in two lipoblastomas. Using immunohistochemistry, expression of the PLAG1 protein was also demonstrated in tissue sections from two lipoblastomas, one of which had a t(3;8)(q13.1;q12) translocation and the other a t(1;6)(q42;p22) translocation. Since no aberrant PLAG1 transcripts could be detected, it is likely that the gene may be activated by promoter swapping/substitution or alternatively by an as yet unknown mechanism. Our findings indicate that PLAG1 activation is a recurrent event in lipoblastomas and that PLAG1 is likely to be the target gene on chromosome 8 in these tumors.

Successful treatment of secondary acute myeloid leukemia relapsing after allogeneic bone marrow transplantation with donor lymphocyte infusion failed to prevent recurrence of primary disease: a case report.

We report a case of therapy-related secondary acute myeloid leukemia occurring in a patient during treatment for anaplastic large cell lymphoma. In spite of response to induction chemotherapy and prompt bone marrow transplantation from his matched sister, the patient experienced an early leukemia relapse within 3 months of the transplant. Treatment with oral etoposide for 3 weeks followed by donor lymphocyte infusion achieved a 7-month remission from leukemia without any further treatment. Unfortunately, the patient suffered a recurrence of the primary anaplastic large cell lymphoma that was treated by resuming chemotherapy and local radiotherapy. The patient died 20 months after DLI, still in CR for his leukemia, due to ALCL progression.

Fluorescence in situ hybridization improves cytogenetic results in the analysis of hepatoblastoma.

Hepatoblastoma (HB) is the most frequent malignant liver tumor in children. Cytogenetic data indicate the presence of recurring trisomies of the chromosomes 2, 8, and 20, but more work is needed to clarify their incidence and prognostic significance. Cytogenetic analysis is limited by the requirement of suitable cells in metaphase. A different method that increases analysis sensitivity is fluorescence in situ hybridization (FISH). We studied 20 cases of hepatoblastoma; FISH analysis obtained results in 10 cases of HB with no informative karyotype. In 5 of 10 of these cases at least one trisomic clone was detected, which always coexisted with a population of diploid cells. These results confirm that trisomy 20 and/or 2 and 8 coexisting with diploid cells is a frequent finding in hepatoblastoma and provide further support to the clonal evolution theory: indeed, trisomy 20 was the most frequently detected abnormality, followed by trisomy of chromosomes 2 and 8. In view of the high incidence of recurrent trisomies, FISH analysis should be recommended in all the cases of HB with no informative karyotype.

A mesenchymal chondrosarcoma of a child with the reciprocal translocation (11;22)(q24;q12).

The reciprocal translocation (11;22)(q24;q12) was observed in a seven day culture from a mesenchymal chondrosarcoma of the bone, a tumor not characterized cytogenetically so far. We suggest that because of the presence of a similar cytogenetic abnormality, mesenchymal chondrosarcoma may belong to the wide group of "t(11;22)-small round cell tumors".

Cytogenetics of pediatric central nervous system tumors.

A cytogenetic analysis was performed on short-term cultures of 43 previously untreated childhood central nervous system neoplasms of various histology. The cells were obtained from pediatric patients, none of whom had received therapy before karyotypic evaluation. Successful chromosome studies were performed on 24 tumors. The most commonly detected structural abnormalities involved chromosomes 1 and 17. Other structural chromosome abnormalities involved chromosomes 3, 6, 8, 9, 11, 12, and 20.

Cytogenetic t(11;17)(q13;q21) in a pediatric ependymoma. Is 11q13 a recurring breakpoint in ependymomas?

Cytogenetic studies on a supratentorial ependymoma from a 1-year-old boy showed a t(11;17)(q13;q21). This is the second ependymoma reported with a rearrangement at 11q13; to our knowledge the 11q13 is the first recurring breakpoint reported in ependymoma.

Cytogenetic analysis of hepatoblastoma: hypothesis of cytogenetic evolution in such tumors and results of a multicentric study.

Hepatoblastoma is a rare pediatric malignant tumor of the liver. Previous cytogenetic reports are sporadic. We karyotyped nine consecutive hepatoblastomas from the Italian centers participating in a multicentric study on hepatic tumors (SIOPEL 1). Six cases showed abnormal karyotypes. The most common abnormalities were trisomies of chromosomes 2 and 20. Four cases showed abnormalities of chromosome 1. On the basis of findings, we speculate the possibility of a cytogenetic evolutive pattern of hepatoblastomas.

Undifferentiated (embryonal) sarcoma of the liver in childhood: results of a retrospective Italian study.

The clinical features and the treatment of undifferentiated (embryonal) sarcoma of the liver in 8 patients younger than 19 years old were analyzed. All these cases were registered in the retrospective multicentric study on childhood malignant tumors of the liver, conducted between 1983 and 1985 by the Italian Association of Pediatric Hematology Oncology. The age of the patients ranged from 94 to 190 months (median = 113.5 months); all children were males. An abdominal mass was the common presenting features. Abnormalities in hemogram and common liver tests were rarely reported. Angiography revealed various degrees of vascularization in these tumors. Two patients achieved a surgical complete remission (CR) at diagnosis; one patient achieved surgical CR after primary chemotherapy with vincristine, adriamycin, cyclophosphamide and 5-fluorouracil, which reduced the tumor volume and permitted surgical resection. Two of these patients are still in CR at 14 and 60 months after diagnosis; the third patient died of liver failure without evidence of recurrence 6 months after diagnosis. All of the other patients, who never achieved CR, died of disease. One was lost to follow-up, and one surgical death occurred. Reports of childhood undifferentiated sarcoma are reviewed.

Mesenchymal stem cells from Shwachman-Diamond syndrome patients display normal functions and do not contribute to hematological defects.

Shwachman-Diamond syndrome (SDS) is a rare inherited disorder characterized by bone marrow (BM) dysfunction and exocrine pancreatic insufficiency. SDS patients have an increased risk for myelodisplastic syndrome and acute myeloid leukemia. Mesenchymal stem cells (MSCs) are the key component of the hematopoietic microenvironment and are relevant in inducing genetic mutations leading to leukemia. However, their role in SDS is still unexplored. We demonstrated that morphology, growth kinetics and expression of surface markers of MSCs from SDS patients (SDS-MSCs) were similar to normal MSCs. Moreover, SDS-MSCs were able to differentiate into mesengenic lineages and to inhibit the proliferation of mitogen-activated lymphocytes. We demonstrated in an in vitro coculture system that SDS-MSCs, significantly inhibited neutrophil apoptosis probably through interleukin-6 production. In a long-term coculture with CD34(+)-sorted cells, SDS-MSCs were able to sustain CD34(+) cells survival and to preserve their stemness. Finally, SDS-MSCs had normal karyotype and did not show any chromosomal abnormality observed in the hematological components of the BM of SDS patients. Despite their pivotal role in the hematopoietic stem cell niche, our data suggest that MSC themselves do not seem to be responsible for the hematological defects typical of SDS patients.

Shwachman-Diamond syndrome and type 1 diabetes mellitus: more than a chance association?

Shwachman-Diamond syndrome is a rare clinical condition consisting of exocrine pancreatic dysfunction, various degree of pancytopenia, and metaphyseal dysplasia. The majority of Shwachman-Diamond syndrome cases result from mutations in the Shwachman-Bodian-Diamond Syndrome gene. To date, type 1 diabetes mellitus has only been reported in 4 independent cases presenting with Shwachman-Diamond syndrome, 3 of them with molecular confirmation of the diagnosis. We describe 2 unrelated patients with clinical and molecular features typical of Shwachman-Diamond syndrome and type 1 diabetes mellitus. In addition, we report the occurrence rate of type 1 diabetes mellitus in the Italian registry for Shwachman-Diamond syndrome, which is low (3.23%) but increased at least 30-fold over the type 1 diabetes mellitus occurrence rate in the general population. No evidence of a direct correlation between Shwachman-Diamond syndrome and type 1 diabetes mellitus have been reported, therefore the presence of both diseases in the same patient might be a chance association, however we suggest that the defects in immune regulation of Shwachman-Diamond syndrome might play a role in the development of type 1 diabetes mellitus.

The isochromosome i(7)(q10) carrying c.258+2t>c mutation of the SBDS gene does not promote development of myeloid malignancies in patients with Shwachman syndrome.

Shwachman-Diamond syndrome (SDS) is an autosomal recessive disorder, characterized by exocrine pancreatic insufficiency, skeletal abnormalities and bone marrow (BM) dysfunction with an increased risk to develop myelodysplastic syndrome and/or acute myeloid leukaemia (MDS/AML). SDS is caused, in nearly 90% of cases, by two common mutations (that is, c.183_184TA>CT and c.258+2T>C) in exon 2 of the SBDS gene, localized on chromosome 7. Clonal chromosome anomalies are often found in the BM of SDS patients; the most frequent is an isochromosome for long arms of chromosome 7, i(7)(q10). We studied eight patients with SDS carrying the i(7)(q10) who were compound heterozygotes for SBDS mutations. By assessing the parental origin of the i(7)(q10) using microsatellite analysis, we inferred from the results which mutation was present in double dose in the isochromosome. We demonstrate that in all cases the i(7)(q10) carries a double dose of the c.258+2T>C, and we suggest that, as the c.258+2T>C mutation still allows the production of some amount of normal protein, this may contribute to the low incidence of MDS/AML in this subset of SDS patients.

Features of essential thrombocythaemia in childhood: a study of five children.

Essential thrombocythaemia (ET) is usually considered a disease of the middle-aged but, with the advent of automated platelet counting, ET is diagnosed with increasing frequency in young adults and, even more rarely, in children. We report five paediatric patients (four girls and one boy, mean age 89 months) diagnosed with ET in agreement with Polycythaemia Vera Study Group criteria. The patients had a persistent thrombocytosis over 900 x 10(9)/l and, at the time of diagnosis, their platelet count ranged between 1,112 and 3,178 x 10(9)/l. A 9-month-old girl had thrombosis of the inferior cava vein, two children had headaches and two others remained asymptomatic throughout the follow-up period. Megakaryocytes in the bone marrow were increased in number. The chromosomal analysis was normal, and bcr rearrangement was always negative. None of the patients had spontaneous BFU-E or altered levels of serum erythropoietin and thrombopoietin. Two patients showed alteration of platelet aggregation, and all had decreased levels of intraplatelet serotonin. In spite of the diagnosis of ET in our patients, we are not sure that the cases reported here are really myeloproliferative disorders. The features could suggest that the cases observed may be affected by an 'idiopathic thrombocytosis' without myeloproliferation. Possible variants of ET are described in young adults, and the heterogeneous nature of ET is also suggested by our paediatric patients. Only careful long-term follow-up of patients such as these will clarify the natural history of these disorders and suggest therapeutic management.