Treatment and outcome of 2904 CML patients from the EUTOS population-based registry.

The European Treatment and Outcome Study (EUTOS) population-based registry includes data of all adult patients newly diagnosed with Philadelphia chromosome-positive and/or BCR-ABL1+ chronic myeloid leukemia (CML) in 20 predefined countries and regions of Europe. Registration time ranged from 12 to 60 months between January 2008 and December 2013. Median age was 55 years and median observation time was 29 months. Eighty percent of patients were treated first line with imatinib, and 17% with a second-generation tyrosine kinase inhibitor, mostly according to European LeukemiaNet recommendations. After 12 months, complete cytogenetic remission (CCyR) and major molecular response (MMR) were achieved in 57% and 41% of patients, respectively. Patients with high EUTOS risk scores achieved CCyR and MMR significantly later than patients with low EUTOS risk. Probabilities of overall survival (OS) and progression-free survival for all patients at 12, 24 and 30 months was 97%, 94% and 92%, and 95%, 92% and 90%, respectively. The new EUTOS long-term survival score was validated: the OS of patients differed significantly between the three risk groups. The probability of dying in remission was 1% after 24 months. The current management of patients with tyrosine kinase inhibitors resulted in responses and outcomes in the range reported from clinical trials. These data from a large population-based, patient sample provide a solid benchmark for the evaluation of new treatment policies.

Eye on the B-ALL: B-cell receptor repertoires reveal persistence of numerous B-lymphoblastic leukemia subclones from diagnosis to relapse.

The strongest predictor of relapse in B-cell acute lymphoblastic leukemia (B-ALL) is the level of persistence of tumor cells after initial therapy. The high mutation rate of the B-cell receptor (BCR) locus allows high-resolution tracking of the architecture, evolution and clonal dynamics of B-ALL. Using longitudinal BCR repertoire sequencing, we find that the BCR undergoes an unexpectedly high level of clonal diversification in B-ALL cells through both somatic hypermutation and secondary rearrangements, which can be used for tracking the subclonal composition of the disease and detect minimal residual disease with unprecedented sensitivity. We go on to investigate clonal dynamics of B-ALL using BCR phylogenetic analyses of paired diagnosis-relapse samples and find that large numbers of small leukemic subclones present at diagnosis re-emerge at relapse alongside a dominant clone. Our findings suggest that in all informative relapsed patients, the survival of large numbers of clonogenic cells beyond initial chemotherapy is a surrogate for inherent partial chemoresistance or inadequate therapy, providing an increased opportunity for subsequent emergence of fully resistant clones. These results frame early cytoreduction as an important determinant of long-term outcome.

HLA-G 14-bp polymorphism affects the age of onset in Type I Diabetes Mellitus.

Type I diabetes mellitus (T1DM) is an organ-specific autoimmune disorder affecting the insulin-producing pancreatic cells. T1DM genetic association studies have so far revealed the involvement of more than 40 loci, with particularly strong associations for the human leucocyte antigens (HLA). Further to the well-established HLA class II associations, the immunomodulatory elements in the telomeric major histocompatibility complex locus, specifically nonclassical HLA class I, were also associated with T1DM, either in conferring susceptibility or by contributing to the overall pathogenesis. This study investigates the involvement of a 14-bp deletion polymorphism (rs371194629) at the 3' untranslated region of HLA-G in the context of T1DM and age of onset. The frequency of the polymorphism was determined in unrelated T1DM Cypriot patients and findings that emerge from this study show a strong association between the HLA-G 14-bp polymorphism and T1DM with respect to the age of onset. Specifically, the deletion/deletion (DEL/DEL) genotype was found to be associated with an early age of onset (P = 0.001), while the presence of the insertion allele (INS) was associated to a later age of onset (P = 0.0001), portraying a possible dominant effect over the deletion allele, a role in delaying disease onset and an overall involvement of HLA-G in the pathogenesis of type I diabetes mellitus.

The EUTOS population-based registry: incidence and clinical characteristics of 2904 CML patients in 20 European Countries.

This population-based registry was designed to provide robust and updated information on the characteristics and the epidemiology of chronic myeloid leukemia (CML). All cases of newly diagnosed Philadelphia positive, BCR-ABL1+ CML that occurred in a sample of 92.5 million adults living in 20 European countries, were registered over a median period of 39 months. 94.3% of the 2904 CML patients were diagnosed in chronic phase (CP). Median age was 56 years. 55.5% of patients had comorbidities, mainly cardiovascular (41.9%). High-risk patients were 24.7% by Sokal, 10.8% by EURO, and 11.8% by EUTOS risk scores. The raw incidence increased with age from 0.39/100,000/year in people 20-29 years old to 1.52 in those >70 years old, and showed a maximum of 1.39 in Italy and a minimum of 0.69 in Poland (all countries together: 0.99). The proportion of Sokal and Euro score high-risk patients seen in many countries indicates that trial patients were not a positive selection. Thus from a clinical point of view the results of most trials can be generalized to most countries. The incidences observed among European countries did not differ substantially. The estimated number of new CML cases per year in Europe is about 6370.

Gene expression changes in HLA mismatched mixed lymphocyte cultures reveal genes associated with allorecognition.

Human leucocyte antigen (HLA) compatibility is the main factor determining the occurrence of graft-vs-host disease (GVHD) in patients. It has also been shown that minor histocompatibility antigen differences as well as genetic polymorphisms that are not sequenced by standard methodology for HLA typing can play a role. We used mixed lymphocyte cultures (MLCs) as a functional cellular test and investigated gene expression changes driven by HLA incompatibility in an effort to better understand the mechanisms involved in the disease. Gene expression profile of HLA matched and HLA mismatched MLC identified differentially regulated genes and pathways. We found that a great number of genes related to immune function were differentially regulated; these genes were also found to be associated with GVHD and graft rejection. The majority of differentially regulated genes were interferon-gamma (IFNγ)-inducible genes and IFNγ neutralisation in MLCs abrogated their induction. The microRNA-155, a recently identified target for acute GVHD (aGVHD), was also found to be significantly induced in HLA mismatched MLC but not in the matched setting and its induction was not diminished by blocking IFNγ. In this proof-of-principle study we show gene expression changes in mismatched MLC that represent alloreactive responses, correlate with markers involved in GVHD and can potentially be useful in the study of the biological processes involved in this disease.

Detailed molecular characterisation of acute myeloid leukaemia with a normal karyotype using targeted DNA capture.

Advances in sequencing technologies are giving unprecedented insights into the spectrum of somatic mutations underlying acute myeloid leukaemia with a normal karyotype (AML-NK). It is clear that the prognosis of individual patients is strongly influenced by the combination of mutations in their leukaemia and that many leukaemias are composed of multiple subclones, with differential susceptibilities to treatment. Here, we describe a method, employing targeted capture coupled with next-generation sequencing and tailored bioinformatic analysis, for the simultaneous study of 24 genes recurrently mutated in AML-NK. Mutational analysis was performed using open source software and an in-house script (Mutation Identification and Analysis Software), which identified dominant clone mutations with 100% specificity. In each of seven cases of AML-NK studied, we identified and verified mutations in 2-4 genes in the main leukaemic clone. Additionally, high sequencing depth enabled us to identify putative subclonal mutations and detect leukaemia-specific mutations in DNA from remission marrow. Finally, we used normalised read depths to detect copy number changes and identified and subsequently verified a tandem duplication of exons 2-9 of MLL and at least one deletion involving PTEN. This methodology reliably detects sequence and copy number mutations, and can thus greatly facilitate the classification, clinical research, diagnosis and management of AML-NK.

Unrelated hematopoietic stem cell donors as research subjects.

Requests for participation of unrelated stem cell donors in research transplant protocols are becoming more frequent. World Marrow Donor Association calls on donor registries to participate in research activities. Here, we discuss various implications of research participation and make some recommendations as how to make this possible.

Haematopoietic stem cell donor registries: World Marrow Donor Association recommendations for evaluation of donor health.

The ability to identify unrelated haematopoietic stem cell donors in one country for recipients in another country requires cooperation and standardization in many areas. The donor assessment and testing are very important issues affecting quality and safety of donation. This special report details the World Marrow Donor Association's recommended procedures regarding the medical evaluation of donors, with the intent to protect the volunteer from the risk to damage his health and to offer the recipient the appropriate quality of stem cells. This document describes criteria for permanent or temporary deferral, guidelines for risk evaluation of infectious disease, examples of conditions requiring assessment and questionnaires designed to elicit relevant information about a donor's medical history and general health.

Cytokine polymorphism frequencies in the Greek Cypriot population.

There is considerable evidence to suggest that several cytokine genes are polymorphic, resulting in differential transcription and protein expression levels among individuals. It has also been demonstrated that ethnicity can be a determinant for distinctive cytokine polymorphism frequencies. In this study, we evaluated the distribution of cytokine gene polymorphisms in 100 healthy Greek Cypriot subjects, using polymerase chain reaction-sequence-specific primers (PCR-SSP) typing analysis. Cytokine gene polymorphisms were determined for transforming growth factor (TGF) beta1 codon 10 (TGFbetac10; C to T), TGFbeta1 codon 25 (TGFbetac25; G to C), tumour necrosis factor alpha (TNFalpha) promoter -308 (G to A), interleukin (IL)-6 promoter -174 (G to C), IL-10 promoter -1082 (G to A), IL-10 promoter -819 (C to T), IL-10 promoter -592 (C to A) and interferon gamma (IFNgamma) intron 1 +874 (A to T). Frequencies for the above cytokine genotypes were calculated for the Greek Cypriot population.

Acidification and glucocorticoids independently regulate branched-chain alpha-ketoacid dehydrogenase subunit genes.

Acidification or glucocorticoids increase the maximal activity and subunit mRNA levels of branched chain alpha-ketoacid dehydrogenase (BCKAD) in various cell types. We examined whether these stimuli increase transcription of BCKAD subunit genes by transfecting BCKAD subunit promoter-luciferase plasmids containing the mouse E2 or human E1alpha-subunit promoter into LLC-PK(1) cells, which do not express glucocorticoid receptors, or LLC-PK(1)-GR101 cells, which we have engineered to constitutively express the glucocorticoid receptor gene. Dexamethasone or acidification increased luciferase activity in LLC-PK(1)-GR101 cells transfected with the E2 or E1alpha-minigenes; acidification augmented luciferase activity in LLC-PK(1) cells transfected with these minigenes but dexamethasone did not. A pH-responsive element in the E2 subunit promoter was mapped to a region >4.0 kb upstream of the transcription start site. Dexamethasone concurrently stimulated E2 subunit promoter activity and reduced the binding of nuclear factor-kappaB (NF-kappaB) to a site in the E2 promoter. Thus acidification and glucocorticoids independently enhance BCKAD subunit gene expression, and the glucocorticoid response in the E2 subunit involves interference with NF-kappaB, which may act as a transrepressor.

Regulation of expression of branched-chain alpha-keto acid dehydrogenase subunits in permanent cell lines.

The rat hepatoma cell line H4IIEC3 has demonstrated a response to both insulin and glucocorticoids in its accumulation of BCKAD subunit RNAs. It is amenable to BCKAD promoter minigene transfection analyses, demonstrating positive (glucocorticoids) and negative (insulin) regulatory effects. These cells can therefore be used as a model to identify cis-acting sites responsible for regulation of BCKAD subunit promoter activity.

Glucocorticoid regulation of branched-chain alpha-ketoacid dehydrogenase E2 subunit gene expression.

Regulation of the mammalian branched-chain alpha-ketoacid dehydrogenase complex (BCKAD) occurs under a variety of stressful conditions associated with changes in circulating glucocorticoids. Multiple levels of regulation in hepatocytes, including alteration of the levels of the structural subunits available for assembly (E1, alpha-ketoacid decarboxylase; E2, dihydrolipoamide acyltransferase; and E3, dihydrolipoamide dehydrogenase), as well as BCKAD kinase, which serves to phosphorylate the E1alpha subunit and inactivate complex activity, have been proposed. The direct role of glucocorticoids in regulating the expression of the murine gene encoding the major BCKAD subunit E2, upon which the other BCKAD subunits assemble, was therefore examined. Deletion analysis of the 5' proximal 7.0 kb of the murine E2 promoter sequence, using E2 promoter/luciferase expression minigene plasmids introduced into the hepatic H4IIEC3 cell line, suggested a promoter proximal region responsive to glucocorticoid regulation. Linker-scanning mutagenesis combined with deletion analysis established this functional glucocorticoid-responsive unit (GRU) to be located near the murine E2 proximal promoter site at -140 to -70 bp upstream from the transcription initiation site. The presence of this region in plasmid minigenes, containing varying amounts of the murine genomic sequence 5' upstream from proximal E2 promoter sequences, conferred 2-10 fold increases in luciferase reporter gene expression in H4IIEC3 cells, whether introduced by transient transfection or following co-selection for stable transfectants. The GRU region itself appeared to contain multiple interacting elements that combine to regulate overall E2 promoter activity in response to changing physiological conditions associated with varying concentrations of glucocorticoids and likely other hormonal effectors.

Molecular characterization of a unique patient with epimerase-deficiency galactosaemia.

Inherited deficiencies of UDP-galactose 4-epimerase (GALE) have been associated with two distinct phenotypes. The vast majority of North American patients are clinically asymptomatic, are identified through newborn screening programmes for classical galactosaemia, and are of African-American descent. At least two symptomatic patients have been reported, one Pakistani and the other Asian Muslim, both with severe complications in the neonatal period and subsequent mental retardation. Through newborn screening, we have identified a GALE-deficient patient who is of mixed Pakistani/caucasian ancestry. He was clinically well in the neonatal period on a lactose-containing diet, and biochemical studies, including urine reducing sugars and galactitol, were consistent with a diagnosis of peripheral GALE deficiency. Although early developmental milestones were met normally, he now shows significant developmental delays in both motor and language skills. Mutational analysis revealed this patient to be a compound heterozygote at the GALE locus, with mutations N34S and L183P identified in the patient and confirmed in the parents. This report represents the first characterization of specific mutations in a GALE-deficient patient in conjunction with biochemical and clinical phenotype, and facilitates further studies of the GALE enzyme and its role in the different clinical forms of epimerase-deficiency galactosaemia.

Isolation of the murine branched-chain alpha-ketoacid dehydrogenase E2 subunit promoter region.

The promoter region of the murine branched-chain alpha-ketoacid dehydrogenase E2 subunit (dihydrolipoyl transacylase) gene was isolated and characterized. Sequence analysis of the promoter-regulatory region showed the presence of two inverted 'CAAT box' sequences, the most proximal being -42 to -48 bp upstream from the determined transcription initiation site, but no TATA-box sequences, similar to the human BCKAD E2 gene. The boundary of the minimum promoter sequence appeared to reside just inclusive of this first inverted CAAT sequence, but minigene transfer analysis demonstrated that the promoter proximal between -65 and -140 bp is likely to be extremely important for controlling regulated changes in E2 RNA expression. The regulatory effect of this region may be modulated by a number of other upstream regions which were identified within the 7.0 kb sequence examined.

A nonsense mutation (R242X) in the branched-chain alpha-keto acid dehydrogenase E1alpha subunit gene (BCKDHA) as a cause of maple syrup urine disease. Mutations in brief no. 160. Online.

Mutation analysis of DNA from cultured amniocytes with absent branched-chain alpha-ketoacid dehydrogenase activity revealed a C to T transition producing a nonsense mutation (R242X) in exon 7 of the gene encoding the E1a subunit of this multienzme complex (BCKDHA). This pregnancy occured in a large consanguinous pedigree with mutiple individuals with maple syrup urine disease (MSUD). PCR amplification of the region surrounding exon 7 allowed the identification of this mutation as well as two other previously identified mutations which cause MSUD.

Effects of insulin on the regulation of branched-chain alpha-keto acid dehydrogenase E1 alpha subunit gene expression.

Alterations in dietary intake, especially of protein, may produce changes in the hepatic levels of the branched-chain alpha-keto acid dehydrogenase (BCKAD) complex. The possible role of insulin in the regulation of these observed changes in hepatic capacity for BCKAD expression was therefore examined. Steady-state RNA levels encoding three of the subunits, E1 alpha, E1 beta and E2, increased by 2-4-fold in the livers of mice starved for 3 days, a known hypoinsulinaemic state. In contrast, the levels of E1 beta and E2, but not E1 alpha, RNA were decreased when mice were fed 0% protein diets compared with the levels observed in mice fed standard (23%) or higher protein isocaloric diets. BCKAD subunit protein levels under these conditions changed co-ordinately even though the changes in RNA were not co-ordinate. The effects of hormonal changes that might be associated with these dietary changes were examined, using the rodent hepatoma cell line H4IIEC3. In these cells, the levels of E1 alpha protein and mRNA were significantly depressed in the presence of insulin. In contrast, the levels of E1 beta and E2 RNAs were not decreased by insulin. The half-lives of the E1 alpha and E2 RNAs were determined to be quite long, from 13 to 18 h, with insulin having no dramatic overall effect on the half-lives determined over 24 h. Therefore, it is likely that insulin directly affects the transcription of the E1 alpha gene rather than RNA stability in exerting its negative regulatory effect. This effect is specific to the E1 alpha subunit. The differences in BCKAD subunit RNA levels observed under various nutritional and developmental conditions may therefore be the result of the differential effects of insulin and other hormones on the multiple regulatory mechanisms modulating BCKAD subunit expression.

Molecular cloning of the murine branched chain alpha-ketoacid dehydrogenase E2 subunit: presence of 3' B1 repeat elements.

The cDNA sequence encoding the murine E2 subunit (dihydrolipoyl transacylase) of the branched-chain alpha-ketoacid dehydrogenase (BCKAD) complex was determined. In the region encoding the mature E2 subunit protein, both the nucleotide composition and predicted amino acid sequence are highly conserved between murine, human, and bovine species. In contrast, the 5' sequence encoding the amino-terminal preprotein sequence and 3' untranslated region are less well conserved. The 3'-noncoding region contains sequences highly homologous to the rodent B1 repeat elements, which are related to human Alu repeat sequences. This finding is similar to the presence of three Alu repeat sequences in the 3'-noncoding region of human E2 cDNA.

Noncoordinated responses of branched-chain alpha-ketoacid dehydrogenase subunit genes to dietary protein.

The response of the murine genes encoding the subunits of branched-chain alpha-ketoacid dehydrogenase complex (BCKAD) to changes in dietary protein was determined. Steady-state RNA levels for two of the subunits, E1 beta and E2, decreased by two- to four-fold in the livers of mice fed 0% protein isocaloric diets compared to the levels observed in mice fed standard (23%) or high (50%) protein isocaloric diets. In contrast, the levels of RNA encoding the E1 alpha subunit did not change significantly in response to these dietary protein changes. The hepatic decreases in E1 beta and E2 RNA associated with 0% protein isocaloric diets were reversible, with prompt return to baseline levels following 48 hours of 50% protein isocaloric diets ad libitum. In kidney, no significant changes in the RNAs encoding any of the three BCKAD subunits were observed in response to changes in dietary protein. Studies of RNA variations associated with growth and development in several murine tissues, including liver and kidney, demonstrated coordinated changes between all subunits. Similar coordinated changes were observed during 3T3-L1 adipocyte differentiation. These studies suggest that the responses of the BCKAD subunit genes to alterations in dietary protein are noncoordinated and tissue-specific, in contrast to the coordinated changes observed during growth and/or differentiation. The differences in BCKAD subunit RNA levels observed under varying nutritional and developmental conditions suggest that multiple regulatory mechanisms modulate BCKAD subunit expression.