Key Points• Germline GATA2 mutations account for 15% of advanced and 7% of all primary pediatric MDS and do not influence overall survival. • The majority (72%) of adolescents with MDS and monosomy 7 carry an underlying GATA2 deficiency.Germline GATA2 mutations cause cellular deficiencies with high propensity for myeloid disease. We investigated 426 children and adolescents with primary myelodysplastic syndrome (MDS) and 82 cases with secondary MDS enrolled in 2 consecutive prospective studies of the European Working Group of MDS in Childhood (EWOG-MDS) conducted in Germany over a period of 15 years. Germline GATA2 mutations accounted for 15% of advanced and 7% of all primary MDS cases, but were absent in children with MDS secondary to therapy or acquired aplastic anemia. Mutation carriers were older at diagnosis and more likely to present with monosomy 7 and advanced disease compared with wild-type cases. For stratified analysis according to karyotype, 108 additional primary MDS patients registered with EWOG-MDS were studied. Overall, we identified 57 MDS patients with germline GATA2 mutations. GATA2 mutations were highly prevalent among patients with monosomy 7 (37%, all ages) reaching its peak in adolescence (72% of adolescents with monosomy 7). Unexpectedly, monocytosis was more frequent in GATA2-mutated patients. However, when adjusted for the selection bias from monosomy 7, mutational status had no effect on the hematologic phenotype. Finally, overall survival and outcome of hematopoietic stem cell transplantation (HSCT) were not influenced by mutational status. This study identifies GATA2 mutations as the most common germline defect predisposing to pediatric MDS with a very high prevalence in adolescents with monosomy 7. GATA2 mutations do not confer poor prognosis in childhood MDS. However, the high risk for progression to advanced disease must guide decision-making toward timely

Context Hematopoietic stem cell transplantation (HSCT) requires significant infrastructure. Little is known on its use and the factors associated with it on a global level. Objective To determine current use of HSCT, to assess differences in its application and to explore associations of macroeconomic factors with transplant rates on a global level. Design Structured worldwide collection of numbers of allogeneic and autologous HSCT by main indication, donor type and stem cell source for the year 2006. Setting Worldwide Network for Blood and Marrow Transplantation (WBMT), a global non-profit umbrella organization for clinical HSCT. Patients All patients with an allogeneic or autologous HSCT for any indication transplanted in 2006 within any of the participating countries. Interventions none Main Outcome measures Transplant rates (number of HSCT per 10 million inhabitants) by indication, donor type and country; description of main differences in HSCT use; macroeconomic factors of reporting countries associated with transplant rates. Results There were 50’417 first HSCT, 21’516 allogeneic (43%), 28’901 autologous (57%) reported from 1’327 centers in 71 countries for leukemia (17’049 (34%; 89% allogeneic)), lymphoma (27’492 (54%; 87% autologous)), solid tumors (2’925 (6%, 95% autologous)), non-malignant disorder (2’593 (5%; 92% allogeneic)) or, “others” 358 (1%). Use of allogeneic or autologous HSCT, use of unrelated or family donors for allogeneic HSCT and proportions of disease indications varied significantly between countries and continental regions. In linear regression analyses, Government Health Care Expenditures (r2 = 77.33), team density (r2 =76.28), Human Development Index (r2 = 74.36) and Gross National Income /Capita (r2 = 74.04) showed the highest association with transplant rates. Conclusions HSCT is an accepted therapy today with different use and needs worldwide. Availability of resources, Governmental support and, access for patients to a team were identified as key factors for higher transplant rates.

There are 4 registries of hematopoietic cell transplantation in Japan; the Japan Society for Hematopoietic Cell Transplantation (JSHCT), Japanese Society of Pediatric Hematology, Japan Marrow Donor Program, and Japan Cord Blood Bank Network; each play an important role in society by reporting the number and outcomes of transplantations and contributing new findings obtained from studies on individual topics. However, there have been a number of issues with the difficulty of analyzing data in overlapping registries and multiple databases at centers affiliated with each of the 4 registry organizations. JSHCT was pivotal in orchestrating the computerization and unification of hematopoietic stem cell transplantation registries for the purpose of resolving these issues and providing a more accurate awareness of hematopoietic stem cell transplantations being performed in Japan. JSHCT played a central role in developing the "Transplant Registry Unified Management Program (TRUMP)" to enable transplantation institutes to manage patient information with emphases on convenience to institutes, safety of patient information, and quality of data management. While enhancing domestic registries, the program seeks to coordinate with other hematopoietic cell transplantation registries around the world to contribute to the development of registries throughout Asia.

The classification of myelodysplastic syndromes is based on the morphological criteria proposed by the French-American-British (FAB) and World Health Organization (WHO) groups. Accurate enumeration of blast cells, although essential for diagnosis of myelodysplastic syndrome and for assignment to prognostic groups, is often difficult, due to imprecise criteria for the morphological definition of blasts and promyelocytes. An International Working Group on Morphology of Myelodysplastic Syndrome (IWGM-MDS) of hematopathologists and hematologists expert in the field of myelodysplastic syndrome reviewed the morphological features of bone marrows from all subtypes of myelodysplastic syndrome and agreed on a set of recommendations, including recommendations for the definition and enumeration of blast cells and ring sideroblasts. It is recommended that (1) agranular or granular blast cells be defined (replacing the previous type I, II and III blasts), (2) dysplastic promyelocytes be distinguished from cytologically normal promyelocytes and from granular blast cells, (3) sufficient cells be counted to give a precise blast percentage, particularly at thresholds that are important for diagnosis or prognosis and (4) ring sideroblasts be defined as erythroblasts in which there are a minimum of 5 siderotic granules covering at least a third of the nuclear circumference. Clear definitions and a differential count of a sufficient number of cells is likely to improve precision in the diagnosis and classification of myelodysplastic syndrome. Recommendations should be applied in the context of the WHO classification.

Griscelli syndrome (GS) was diagnosed in a 2-year-old patient with oculocutaneous albinism and immunodeficiency, but sequencing of RAB27a revealed only a heterozygous mutation. Due to impaired natural killer (NK) and T-cell cytotoxicity implying a high risk of developing hemophagocytic lymphohistiocytosis (HLH), he was prepared for hematopoietic stem cell transplantation (HSCT). Unexpectedly, a severe bleeding episode occurred that led to the demonstration of disturbed platelet aggregation, reduced plateletdense granules, and impaired platelet degranulation. In combination with neutropenia, this suggested the diagnosis of Hermansky-Pudlak syndrome type II (HPSII) and a novel homozygous mutation in AP3B1 was detected. None of the 3 reported HPSII patients had developed HLH, and our patient seroconverted to Epstein-Barr virus (EBV) without clinical symptoms. HSCT was therefore withheld, and granulocyte-colony-stimulating factor (G-CSF) therapy was initiated and prevented further bacterial infections. At 3 years of age, however, the patient developed, without an obvious trigger, fulminant HLH that was resistant to therapy. This patient shows that careful clinical and molecular diagnosis is essential to differentiate the complex disorders of ly- IntroductionSecretory lysosomes are cellular organelles involved in trafficking and exocytosis of intracellular proteins. 1 They have important functions in several cell types including melanocytes, neuronal cells, platelets, granulocytes, mast cells, natural killer (NK) cells, and T cells. 2 The protein machinery required for adequate biogenesis, transport, and delivery of secretory lysosomes has a variable composition in each cell type. Therefore, the clinical phenotype of diseases due to genetic defects in proteins involved in lysosomal trafficking varies widely despite the similar cell-biologic basis. This has led to their classification as predominantly dermatologic, hematologic, hemostaseologic, or immunologic disorders. While the 7 genetically defined Hermansky-Pudlak syndromes (HPSs) predominantly present as bleeding disorders, 3 the most important clinical problem of patients with Chédiak-Higashi syndrome (CHS) and Griscelli syndrome type II (GSII) is immunodeficiency. 4 Neurologic defects characterize GSI and CHS, 5 while patients with GSIII show only oculocutaneous albinism. 6 This latter feature links all of these syndromes. However, studies showing that also some forms of familial hemophagocytic lymphohistiocytosis (FHL) represent lysosomal trafficking disorders 7,8 revealed that albinism is not a constant feature in this heterogenous family of diseases.Lysosomal trafficking disorders associated with immunodeficiency are life-threatening conditions due to the high risk of developing hemophagocytic lymphohistiocytosis (HLH). 4 HLH is a systemic inflammatory disorder characterized by uncontrolled CD8 ϩ T-cell and macrophage activation with infiltration of multiple tissues. 9 The common defect in most genetic diseases predisposing to HLH is disturbed secretion of ...

A novel real-time PCR assay system was developed to quantify the cytomegalovirus (CMV) genome load. The real-time PCR assay could detect from 6 to over 10(6) copies of CMV-DNA with a wide linear range. The virus load of immunocompromised patients with symptomatic CMV infections was quantified and compared to that of asymptomatic ones. In symptomatic patients, all 17 peripheral blood leukocytes were positive for CMV DNA, and its mean value was 10(3.3) copies/10(6) cells. On the other hand, only 9 of 38 samples (24%) were positive in the asymptomatic patients, and its mean titer was lower (10(2.0) copies/10(6) cells) than that of the symptomatic group (P = 0.002). In plasma, the virus genome was detected in 13 out of 17 samples from symptomatic patients (76%), and its mean value was 10(4.0) copies/ml. In contrast, for the asymptomatic group, only one out of 36 samples were positive (3%). Finally, this system was used to monitor two patients with CMV infections serially. The CMV DNA copy number changed with their clinical symptoms and anti-CMV therapy, and virtually paralleled the result of the pp65 antigenemia assay in both cases. In one patient with the cord blood transplantation, however, the CMV DNA became positive faster than the antigenemia assay. These results indicate that this assay is sensitive and useful for estimating the CMV genome load not only in peripheral blood leukocytes but also in plasma. It can be very helpful for diagnosing CMV-related diseases and monitoring the virus load in patients with CMV infections.

SummaryTo characterize childhood acute megakaryoblastic leukaemia (AMKL), we reviewed 45 children with AMKL diagnosed between 1986 and 2005 at Nagoya University Hospital and Japanese Red Cross Nagoya First Hospital. Twenty-four patients (53%) had AMKL associated with Down syndrome (DS-AMKL) and 21 (47%) had non-DS-AMKL. The median age of the DS-AMKL patients was 21 months (range, 8-38 months) and that of non-DS-AMKL patients was 15 months (range, 2-185 months). The morphology of blast cells was categorized into three groups according to the stage of megakaryocyte maturation. The blast cells were more immature in DS-AMKL than in non-DS-AMKL in terms of morphology and immunophenotyping. Cytogenetic abnormalities of leukaemic cells were classified into seven categories: normal karyotype including constitutional trisomy 21 in DS-AMKL; numerical abnormalities only; t(1;22)(p13;q13); 3q21q26 abnormalities; t(16;21)(p11;q22); )5/del(5q) and/or )7/del(7q); and other structural changes. The outcome of children with either DS-AMKL or non-DS-AMKL is excellent. The 10-year overall survival estimate was 79% [95% confidence interval (CI): 54-90] for DS-AMKL and 76% (95% CI: 58-91) for non-DS-AMKL (P = 0AE81) with a median follow-up of 78 months (range, 20-243 months). Our study shows the diverse heterogeneity of childhood AMKL and the need for subclassification according to cytogenetic and morphological features.

Mutations in RAS, neurofibromatosis type 1 (NF1), and PTPN11, constituents of the granulocyte-macrophage colonystimulating factor signaling pathway, have been recognized in patients with juvenile myelomonocytic leukemia (JMML). We assessed 71 children with JMML for NRAS, KRAS, and PTPN11 mutations and evaluated their clinical significance. Of the 71 patients, three had been clinically diagnosed with neurofibromatosis type 1, and PTPN11 and NRAS/KRAS mutations were found in 32 (45%) and 13 (18%) patients, respectively. No simultaneous aberrations were found. Compared with patients with RAS mutation or without any aberrations, patients with PTPN11 mutation were significantly older at diagnosis and had higher fetal Hb levels, both of which have been recognized as poor prognostic factors. As was expected, overall survival was lower for patients with the PTPN11 mutation than for those without (25 versus 64%; p ϭ 0.0029). In an analysis of 48 patients who received hematopoietic stem cell transplantation, PTPN11 mutations were also associated with poor prognosis for survival. Mutation in PTPN11 was the only unfavorable factor for relapse after hematopoietic stem cell transplantation (p ϭ 0.001). All patients who died after relapse had PTPN11 mutation. These results suggest that JMML with PTPN11 mutation might be a distinct subgroup with specific clinical characteristics and poor outcome.