[Germline mutations in children with cancer - leopoldina meeting report, september 26, 2014, jesuit monastery merzhausen]. / Keimbahnmutationen bei krebskranken Kindern - Symposium der Leopoldina am 26.09.2014 im Jesuitenkloster Merzhausen bei Freiburg.

Under the umbrella of the Leopoldina, National Academy of Science Germany, a one-day workshop took place with experts from Pediatric Oncology, Human Genetics, Jurisprudence and Science Ethics. Professor Dr. Matthias Brandis, former head of the Clinic of Pediatrics and Adolescent Medicine, Albert-Ludwigs-University Freiburg, encouraged the authors to organize this workshop near Freiburg and provided professional and logistic support. Professor Dr. Matthias Brandis serves as the chairmen of our pediatric-gynecological section within the Leopoldina.

Histone deacetylase inhibitors induce apoptosis in myeloid leukemia by suppressing autophagy.

Histone deacetylase (HDAC) inhibitors (HDACis) are well-characterized anti-cancer agents with promising results in clinical trials. However, mechanistically little is known regarding their selectivity in killing malignant cells while sparing normal cells. Gene expression-based chemical genomics identified HDACis as being particularly potent against Down syndrome-associated myeloid leukemia (DS-AMKL) blasts. Investigating the antileukemic function of HDACis revealed their transcriptional and post-translational regulation of key autophagic proteins, including ATG7. This leads to suppression of autophagy, a lysosomal degradation process that can protect cells against damaged or unnecessary organelles and protein aggregates. DS-AMKL cells exhibit low baseline autophagy due to mammalian target of rapamycin (mTOR) activation. Consequently, HDAC inhibition repressed autophagy below a critical threshold, which resulted in accumulation of mitochondria, production of reactive oxygen species, DNA damage and apoptosis. Those HDACi-mediated effects could be reverted upon autophagy activation or aggravated upon further pharmacological or genetic inhibition. Our findings were further extended to other major acute myeloid leukemia subgroups with low basal level autophagy. The constitutive suppression of autophagy due to mTOR activation represents an inherent difference between cancer and normal cells. Thus, via autophagy suppression, HDACis deprive cells of an essential pro-survival mechanism, which translates into an attractive strategy to specifically target cancer cells.

[The West-Berlin therapy study of acute lymphoblastic leukemia in childhood--report after 6 years]. / Die West-Berliner Studie zur Behandlung der akuten lymphoblastischen Leukämie des Kindes--Erfahrungsbericht nach 6 Jahren.

During the last 6 years 73 previously untreated children and adolescents with acute lymphoblastic leukemia were enrolled on a non-randomized therapy protocol. In this longitudinal study the specific accent was put on the intensified induction treatment of 8 weeks' duration which was thought to achieve a higher remission quality. In this phase 8 effective drugs were applied up to the patient's tolerance limits; in addition prophylactic irradiation to the central nervous system was given in two modifications. After 4 weeks all patients were in complete remission. During the first 4 months 6 children died due to complications for which therapy must be at least partially responsible. 17 out of 67 patients relapsed between 4 and 59 months after diagnosis, which corresponds to a remission rate according to the life table analysis of 62% (50 out of 67 patients in first remission). The majority of patients with relapse is characterized at diagnosis by a specific pattern of clinical findings. 2 therapy groups, differently treated in respect to central nervous system irradiation and duration of continuation therapy, do not at present statistically differ from each other. According to statistics 8 more children may be expected to suffer from relapse. The improved results are due to a lower incidence of bone marrow relapses; it seems that there is a direct relation between intensity of treatment during the induction phase and the occurrence of bone marrow relapses. The specific problems of the presented study take place during the induction phase, which, due to toxicity, regularly results in a number of side effects and severe complications. In order to realize the induction therapy, the use of prophylactic and supportive procedures is of utmost importance. Profound knowledge of possible side effects and complications is most essential as well as the knowledge of how to cope with these problems. It is the authors' opinion that the induction phase can only be performed in specialized institutions, because only at these places enough information may be obtained from an adequate number of patients and only there pediatric oncologists may share in the decisions and responsibilities. Only by using every kind of medical service this method of therapy may be justified at present, according to the results of this study, for the benefit of children with leukemia.

[Research in pediatric hematology [Germany, 1970-2000]]. / Forschung in der Pädiatrischen Hämatologie [Deutschland, 1970-2000].

Professor Riehm was not only an excellent pediatric oncologist, but also an excellent hematologist. He was a mentor also for young scientists who were interested in hematological research as his/her main focus. In the 1970s he has promoted research in coagulation disorders, during 1980s he supported the investigation on hematopoetic growth factors. During the 1990 s he was one of the first in Europe who have used hematopoietic growth factors as a supportive therapy in the protocol ALL-BFM and has also helped to set up the International Registry for Severe Chronic Neutropenias [SCNIR] in his Department. The sense of the top research directions of the time distinguishes him not only as a pioneer of the leukaemia therapy studies, but also as a pioneer in hematology. He created the environment in which research could blossom.

Key treatment questions in childhood acute lymphoblastic leukemia: results in 5 consecutive trials performed by the ALL-BFM study group from 1981 to 2000.

Between 1981 and 2000, 6 609 children (<18 years of age) were treated in 5 consecutive trials of the Berlin-Frankfurt-Münster (BFM) study group for childhood acute lymphoblastic leukemia (ALL). Patients were treated in up to 82 centers in Germany, Austria, and Switzerland. Probability of 10-year event-free survival (survival) improved from 65% (77%) in study ALL-BFM 81-78% (85%) in ALL-BFM 95. In parallel to relapse reduction, major efforts focused on reducing acute and late toxicity through advanced risk adaptation of treatment. The major findings derived from these ALL-BFM trials were as follows: 1) preventive cranial radiotherapy could be safely reduced to 12 Gy in T-ALL and high-risk ALL patients and eliminated in non-high-risk non-T-ALL patients, if it was replaced by high-dose and intrathecal methotrexate; 2) omission of delayed reintensification severely impaired outcome of low-risk patients; 3) 6 months less maintenance therapy caused an increase in systemic relapses; 4) slow response to an initial 7-day prednisone window was identified as adverse prognostic factor; 5) condensed induction therapy resulted in a significant improvement of outcome; 6) the daunorubicin dose in induction could be safely reduced in low-risk patients; 7) intensification of consolidation/reintensification treatment led to considerable improvement of outcome in high-risk patients.

International exchange of cord blood units: the registry aspects.

The international exchange of cord blood units (CBUs) for transplantation has brought new challenges to the stem cell donor registries involved in the exchange of BM and PBSCs. The unique properties of cord blood cells and differences in the search processes between CBUs and adult unrelated donors has required registries responsible for cord blood bank (CBB) networks to review their current practices and to develop new processes to accommodate for the provision of CBUs. This paper describes the aims and activities of the World Marrow Donor Association (WMDA) Cord Blood Working Group (CBWG) which was established in 2007 to gather and exchange information about cord blood registry needs and activities, and to develop guidelines to support and promote safe effective international exchange of unrelated CBUs for transplantation.

Long-term results of five consecutive trials in childhood acute lymphoblastic leukemia performed by the ALL-BFM study group from 1981 to 2000.

Between 1981 and 2000, 6609 children (<18 years of age) were treated in five consecutive trials of the Berlin-Frankfurt-Münster (BFM) study group for childhood acute lymphoblastic leukemia (ALL). Patients were treated in up to 82 centers in Germany, Austria and Switzerland. Probability of 10-year event-free survival (EFS) (survival) improved from 65% (77%) in study ALL-BFM 81 to 78% (85%) in ALL-BFM 95. In parallel to relapse reduction, major efforts focused on reducing acute and late toxicity through advanced risk adaptation of treatment. The major findings derived from these ALL-BFM trials were as follows: (1) preventive cranial radiotherapy could be safely reduced to 12 Gy in T-ALL and high-risk (HR) ALL patients, and eliminated in non- HR non-T-ALL patients, if it was replaced by high-dose and intrathecal (IT) MTX; (2) omission of delayed re-intensification severely impaired outcome of low-risk patients; (3) 6-month-less maintenance therapy caused an increase in systemic relapses; (4) slow response to an initial 7-day prednisone window was identified as adverse prognostic factor; (5) condensed induction therapy resulted in significant improvement of outcome; (6) the daunorubicin dose in induction could be safely reduced in low-risk patients and (7) intensification of consolidation/re-intensification treatment led to considerable improvement of outcome in HR patients.

Allogeneic blood SCT for children with Hurler's syndrome: results from the German multicenter approach MPS-HCT 2005.

Hurler's syndrome is an inborn error of mucopolysaccharide metabolism leading to premature death in childhood. Allogeneic hematopoietic SCT can achieve long-term survival by correcting the enzymatic deficiency. In an attempt to improve long-term engraftment and to reduce regimen-related toxicity (RRT), a prospective multicenter approach was initiated in Germany using a fludarabine-based radiation-free preparative regimen. Between 2001 and 2008, 12 children were enrolled. Median age at SCT was 14 months (range, 4-31 months). The conditioning regimen contained fludarabine, BU, melphalan and antithymocyte globulin. CD34 positively selected PBSC were used in 10 children with a matched unrelated donor. Median cell dose was 24.6 x 10(6) CD34+ cells per kg (range 10.0-54.8). Two children with a matched sibling donor received non-manipulated BM. Donor lymphocyte infusions were given in 6/12 children for mixed hematopoietic chimerism. At a median follow-up of 29 months (range 2-85 months), all children engrafted and have either stabilized or improved neurological function. In total, 12/12 patients showed donor-derived engraftment with 9/12 having full and 3/12 having mixed hematopoiesis. One developed acute GVHD >or=grade II. RRT >or=grade II was observed in two patients.

Pharmacokinetic monitoring of intravenous cyclosporine A in pediatric stem-cell transplant recipients. The trough level is not enough.

In order to monitor CsA serum levels after SCT, trough levels (C0) are widely used. The aim of this study was to estimate the population and individual PK parameters for patients receiving intravenous CsA after SCT. In 27 pediatric patients after SCT receiving CsA (3 mg/kg/day) every 12 h, a total of 289 CsA concentrations was obtained. To describe the PK parameters of CsA, a two-compartment model with first order elimination was used. Covariate analysis identified body weight, age, and the co-administration with itraconazole and tobramycine as factors influencing the Cl. The statistical comparison of AUC, trough level, and C2 indicates a correlation between AUC and C2, but no correlation between the AUC and C0, r = 0.24 (p = 0.146) vs. r = 0.526 (p = 0.000692), respectively. Our results underscore the fact that CsA trough levels do not reflect the drug exposure in patients receiving intravenous CsA after SCT. By contrast, CsA blood levels measured 2-6 h after CsA infusion showed a better correlation with the AUC. Our data provide new information to optimize the balancing act between GvHD-prophylaxis, graft vs. leukemia effect, and CsA side-effects after SCT.

Inhibitor-Immunology-Study. Different HLA-types seem to be involved in the inhibitor development in haemophilia A.

UNLABELLED: The development of inhibitors is one of the most important complications of replacement therapy in haemophilia, affecting mortality and morbidity. Inhibitor development is based on complex immunological factors. Cytokines and their receptors, T-cell receptors, and the Major Histocompatibility Complex may play important roles in the development of inhibitors. Earlier studies showed non significant associations between HLA class and inhibitor development. Later studies found an increased risk of inhibitor development if there was a combination between certain factor VIII mutations and HLA antigens. We performed HLA typing in 50 patients with haemophilia A in an effort to find associations with inhibitor development. RESULTS: 25 patients had developed an inhibitor (11 low titre, 14 high titre), and 25 never had. In logistic regression analysis, HLA-A 34, DRB1 0405, DRB1 1301 seemed to be involved in inhibitor development and HLA-A 30, B 13, B15, B 57, Cw 12, DQB1 0303, DPB1 0201 protection against inhibitor development. In our patients, the HLA-associations with inhibitor development were different from those in previous publications.

Multiple independent second-site mutations in two siblings with somatic mosaicism for Wiskott-Aldrich syndrome.

Wiskott-Aldrich syndrome (WAS) is an X-linked primary immunodeficiency disorder associated with microthrombocytopenia, eczema, autoimmunity and predisposition to malignant lymphoma. Although rare, few cases of somatic mosaicism have been published in WAS patients to date. We here report on two Ukrainian siblings who were referred to us at the age of 3 and 4 years, respectively. Both patients suffered from severe WAS caused by a nonsense mutation in exon 1 of the WAS gene. In both siblings, flow cytometric analysis revealed the presence of Wiskott-Aldrich syndrome protein (WASp)-positive and WASp-negative cell populations among T and B lymphocytes as well as natural killer (NK) cells. In contrast to previously described cases of revertant mosaicism in WAS, molecular analyses in both children showed that the WASp-positive T cells, B cells, and NK cells carried multiple different second-site mutations, resulting in different missense mutations. To our knowledge, this is the first report describing somatic mosaicism in WAS patients caused by several independent second-site mutations in the WAS gene.

[Congenital bone marrow failure syndromes. The last 20 years by the example of congenital neutropenia]. / Angeborene Störungen der Blutbildung. Die Entwicklung der letzten 20 Jahre am Beispiel der kongenitalen Neutropenie.

Congenital bone marrow failure syndromes are rare diseases characterised by a reduction of mature blood cells (erythrocytes, platelets, neutrophils). Examples of such disorders include congenital aplastic anemia (Fanconi anemia), congenital hypoplastic anemia (Diamond-Blackfan anemia), congenital neutropenias (Kostmann syndrome, cyclic neutropenia, Shwachman-Diamond syndrome and others), and congenital thrombocytopenias (TAR syndrome, amegacaryocytic thrombocytopenia). In Germany the prevalence of congenital bone marrow failure syndromes can be estimated to be 10/1,000,000 children and adolescents. Although rare, these diseases contributed significantly to the current knowledge on normal haematopoiesis. The documentation of rare diseases by patient registries and the cooperation of clinical centres within networks are most important for the resolution of such disorders. In the following, congenital neutropenia will be presented as an example: Until the 1980s congenital neutropenia could only be classified clinically. Few cases had been reported in the literature. All subtypes were therefore collected under the general term "congenital neutropenia". The establishment of an international network of experts and the long-term documentation of the courses of disease in a common database allowed for statistically workable data in response to therapy, secondary diagnoses and the long-term prognosis. A close cooperation with scientists finally led to the characterisation of genetically different disorders with common pathomechanisms.

Relapse, not regimen-related toxicity, was the major cause of treatment failure in 11 children with Down syndrome undergoing haematopoietic stem cell transplantation for acute leukaemia.

We report a retrospective analysis of 11 children with Down syndrome (DS) treated by SCT in eight German/Austrian SCT centres. Indications for transplantation were acute lymphoblastic leukaemia (N=8) and acute myeloid leukaemia (N=3). A reduced intensity conditioning (RIC) containing 2 Gy TBI was given to two patients, another five received a myeloablative regimen with 12 Gy TBI. Treosulphan or busulphan was used in the remaining four children. Four of eleven (36%) patients are alive. All of them were treated with a myeloablative regimen. One of the four surviving children relapsed 9 months after SCT and is currently receiving palliative outpatient treatment. The main cause of death was relapse (5/11). Two children died of regimen-related toxicity (RRT), one from severe exfoliative dermatitis and multiorgan failure after a treosulphan-containing regimen, the other from GvHD-related infections after RIC. Acute GvHD of the skin was observed in 10 of 10 evaluable patients, and chronic GvHD in 4 of 8. Our data show that DS patients can tolerate commonly used, fully myeloablative preparative regimens. The major cause of death is relapse rather than RRT resulting in an event-free survival of 18% and over all survival of 36%.

Chromosomal aberrations in congenital bone marrow failure disorders--an early indicator for leukemogenesis?

As chromosomal instability may contribute to leukemogenesis in patients with congenital bone marrow failure (CBMF) disorders, it was the aim of this study to characterize chromosomally aberrant clones that arise during the clinical course of disease by means of R-banding and fluorescence in situ hybridization (FISH) analyses. In addition, multicolor-FISH and array-comparative genomic hybridization (CGH) were applied to characterize clonal chromosome aberrations in more detail. Between January 2004 and December 2005, we prospectively analyzed 90 samples of 73 patients with proven or suspected CBMF disorders enrolled in a German Study Network of CBMF diseases. Clonal aberrations could be identified in four of 73 patients examined. In one child with congenital thrombocytopenia, Jacobsen syndrome [del(11)(q24)c] was diagnosed, and thus a CBMF could be excluded. In a girl with Shwachman-Diamond syndrome, two independent clones, one with an isochromosome i(7)(q10), another with a complex aberrant karyotype, were identified. Simultaneously, transition into a myelodysplastic syndrome (MDS) occurred. The brother, who was also afflicted with Shwachman-Diamond syndrome, showed an isochromosome i(7q) as a single aberration. In the fourth patient with severe congenital neutropenia, an add(21)(q22) marker containing a low-level amplification of the AML1 gene was identified at the time point of transition into acute myelogenous leukemia (AML). In summary, we suggest that follow-up of patients with CBMF using chromosome and FISH analyses will be helpful for the early detection of transition into MDS or AML and thus should be an integral part of the clinical management of these patients.

Intravenous and oral sequential itraconazole antifungal prophylaxis in paediatric stem cell transplantation recipients: a pilot study for evaluation of safety and efficacy.

This single-centre, retrospective, observational pilot study was performed to evaluate the safety and efficacy of intravenous and oral itraconazole prophylaxis in paediatric haematopoietic stem cell transplantation (HCT). Study end-points were proven invasive fungal infection (IFI), survival, adverse reactions and graft-vs.-host disease (GVHD); 53 children and one young adult (median age 8.6 yr; range 0.4-18.3) transplanted between November 2001 and August 2004 were included in this study. Itraconazole was given intravenously from day +3 after HCT until oral medication became possible and continued until day +100 after HCT. Two proven new IFI in the itraconazole group (candidiasis, n = 1; aspergillosis, n = 1) were observed. After a median follow-up of 1.6 yr (0.3-6.1), six deaths (8%) were seen; 24 patients (45%) developed GVHD degree I-II, three children (6%) had GVHD degree III-IV. In 11 of 53 patients (21%), itraconazole prophylaxis was discontinued prematurely, mostly because of fever of unknown origin (n = 7). In total, 21 of 53 (40%) of the children had abnormal results of laboratory investigations during the prophylaxis. The results of this pilot study indicate that itraconazole prophylaxis during HCT in children is feasible and safe, despite abnormal laboratory results. The efficacy in terms of prevention of IFI, however, has to be addressed in a prospective large-scale study.