Shwachman-Diamond syndrome with late-onset neutropenia and fatal acute myeloid leukaemia without maturation: a case report

We report on a male patient affected by Shwachman Diamond syndrome (SDS) who presented an unusual delayed neutropenia and then developed a poorly differentiated acute myeloid leukaemia (M0-AML) with trilineage myelodysplasia in adulthood. Conventional cytogenetics revealed complex karyotypic changes (monosomies 20, 21, 22, additional 15p). The patient was treated with conventional chemotherapy but never reached complete remission of leukaemia and died 18 months after diagnosis. SDS is an inherited bone marrow failure syndrome with a high propensity to leukaemic transformation. Since neutropenia may be intermittent or with delayed onset, and leukaemic transformation may not occur until adulthood, full blood count should be regularly monitored in such patients.     

Cancer in relatives of children with myelodysplastic syndrome, acute and chronic myeloid leukaemia

Familial myelodysplastic syndrome (MDS) has been claimed to account for as many as one third of children with MDS, especially among those showing monosomy 7. The present study is the first to provide population-based estimates of the risk of haematological and other malignancies in relatives of children with MDS. The study was extended to include children with acute myeloid leukaemia (AML) and chronic myeloid leukaemia (CML). The index group consisted of 46 children with MDS, 62 with AML, and eight with CML, which is thought to represent all myeloid leukaemias in Danish children, 1980–91. By linkage to the Central Population Register we identified parents (230), siblings (231), grandparents (151), aunts and uncles (132) and cousins (140). Information on the cancer incidence was obtained from the Danish Cancer Registry. 27 cancers were observed versus 26.7 expected (relative risk 1.0). Leukaemia in relatives was observed in only one family. None of 11 children with MDS and monosomy 7 had family members affected by leukaemia. We found no evidence of an increased overall risk of cancer in the relatives. The risk of familial MDS may be considerably lower than previously estimated.     

Mutation screening of the c-MYB negative regulatory domain in acute and chronic myeloid leukaemia

Over-expression of the c-myb gene and expression of activated forms of myb are known to transform haemopoietic cells, particularly cells of the myeloid lineage. Truncations or mutations that disrupt the negative regulatory domain (NRD) of the Myb protein confer an increased ability to transform cells. Although it has proved difficult to link mutations in c-MYB to human leukaemia, no studies investigating the presence of mutations within the c-MYB NRD have been reported. Therefore, we have performed mutational analysis of this region, using polymerase chain reaction-single-stranded conformation polymorphism and sequence analysis, in 26 patients with acute or chronic myeloid leukaemia. No mutations were detected, indicating that mutation of this region of the Myb protein is not common in the pathogenesis or progression of these diseases.     

Childhood acute myeloid leukaemia

Although acute myeloid leukaemia (AML) has long been recognized for its morphological and cytogenetic heterogeneity, recent high-resolution genomic profiling has demonstrated a complexity even greater than previously imagined. This complexity can be seen in the number and diversity of genetic alterations, epigenetic modifications, and characteristics of the leukaemic stem cells. The broad range of abnormalities across different AML subtypes suggests that improvements in clinical outcome will require the development of targeted therapies for each subtype of disease and the design of novel clinical trials to test these strategies. It is highly unlikely that further gains in long-term survival rates will be possible by mere intensification of conventional chemotherapy. In this review, we summarize recent studies that provide new insight into the genetics and biology of AML, discuss risk stratification and therapy for this disease, and profile some of the therapeutic agents currently under investigation.     

Minor breakpoint cluster region (m-BCR) positive chronic myeloid leukaemia with an acute lymphoblastic leukaemia onset: a case report

Summary. m-BCR chronic myeloid leukaemia (CML) is a rare entity. We report a patient presenting with Philadelphia (Ph)-positive, m-BCR-positive acute lymphoblastic leukaemia (ALL) who achieved complete remission after induction chemotherapy, but showed a majority of Ph-positive mitoses during this remission. A diagnosis of m-BCR CML was established and the patient was given interferon a therapy. This is the first m-BCR CML presenting as ab initio ALL. This report emphasizes the importance of karyotyping Ph-positive ALL during remission so as not to misdiagnose CML patients who can benefit from Interferon therapy.     

Aberrant Fanconi anaemia protein profiles in acute myeloid leukaemia cells

Fanconi anaemia (FA) is an autosomal recessive disease strongly predisposing to bone marrow failure and acute myeloid leukaemia (AML). Four FA genes, corresponding to complementation groups A, C, F and G, have been cloned, but the molecular functions of the corresponding proteins are unknown. The high risk of AML in FA patients suggests that the 'FA pathway' helps to prevent AML in non-FA individuals. We examined 10 AML cell lines, as well as primary cells from 15 AML patients representing the French-American-British subclasses M1-M5a, for possible deficiencies in the 'FA pathway'. Cellular lysates were analysed for the presence of the FA proteins FANCA, FANCC, FANCF and FANCG, as well as the complexes reported to be formed between these proteins, using immunoprecipitation and Western blot analysis. Aberrant protein profiles were observed in five of the 10 cell lines and in 11 of the 15 primary AML samples. Aberrations, that included absence or reduced presence of FA proteins and/or their complexes, were noted in the subclasses M1-M4, but not in M5a (n = 3). Our results suggest that a significant proportion of general AML is characterized by a disturbance of the 'FA pathway' that may represent an early event in the development of this type of leukaemia.     

Successful treatment of chronic idiopathic neutropenia using recombinant granulocyte colony-stimulating factor

Summary A patient with chronic idiopathic neutropenia, who had been suffering from repeated infections, was successfully treated with recombinant granulocyte stimulating factor (rhG-CSF). Subcutaneous injection of 30g/m² rhG-CSF every two days was sufficient to maintain the neutrophil count at approximately 1,000/l. The patient has lived without any evidence of infection for the last 10 months using that treatment. There were no side effect caused by rhG-CSF and antibodies against G-CSF were not detected in the patient's plasma.     

Low expression of the putative tumour suppressor gene gravin in chronic myeloid leukaemia, myelodysplastic syndromes and acute myeloid leukaemia

The putative tumour suppressor gene gravin is down-regulated in several solid tumours and is implicated in tumorigenesis. We have evaluated the expression levels of the gravin gene in the CD34(+)/blast cells of a range of myeloid malignancies as compared with controls using real-time quantitative polymerase chain reaction (PCR). Gravin was markedly down-regulated in 41 of 41 patients with acute myeloid leukaemia (AML), nine of 10 patients with myelodysplastic syndromes (MDS) and 33 of 33 patients with chronic myeloid leukaemia (CML), of whom 24 were in blast crisis (BC). We have shown that gravin is consistently down-regulated in the CD34(+)/blast cells of myeloid malignancies and may play a role in the molecular pathogenesis of these disorders.     

Secondary T-acute lymphoblastic leukaemia mimicking blast crisis in chronic myeloid leukaemia

A 34-year-old man with chronic myeloid leukaemia (CML) firstly developed a lymphoid blast crisis of B-cell type. After a second chronic phase which lasted for > 4 years with maintenance chemotherapy of hydroxyurea, 6-mercaptopurine and methotrexate, he developed a T-cell acute lymphoblastic leukaemia of TcR-gammadelta+ type. Cytogenetic analysis revealed disappearance of the t(9;22) translocation and appearance of new abnormalities consistent with the diagnosis secondary acute leukaemia. To our knowledge, secondary leukaemia in CML has not previously been reported.     

Spontaneous remission in acute myeloid leukaemia

A summary of the literature of adult patients with acute myeloid leukaemia (AML) who have undergone spontaneous remission (SR) is presented together with a report of a patient whose SR was accompanied by cytogenetic remission. There are less than 20 reports of SR since the 1980s. SR is by no means synonymous with cure, since the average duration of the remission is only 7·1±9·2 months. Neither infections nor transfusions are absolute requirements of SR.     

Stable long‐term risk of leukaemia in patients with severe congenital neutropenia maintained on G‐CSF therapy

In severe congenital neutropenia (SCN), long‐term therapy with granulocyte colony‐stimulating factor (G‐CSF) has reduced mortality from sepsis, revealing an underlying predisposition to myelodysplastic syndrome and acute myeloid leukaemia (MDS/AML). We have reported the early pattern of evolution to MDS/AML, but the long‐term risk remains uncertain. We updated a prospective study of 374 SCN patients on long‐term G‐CSF enrolled in the Severe Chronic Neutropenia International Registry. Long‐term, the annual risk of MDS/AML attained a plateau (2·3%/year after 10 years). This risk now appears similar to, rather than higher than, the risk of AML in Fanconi anaemia and dyskeratosis congenita.     

Quantitative expression of thrombopoietin receptor on leukaemia cells from patients with acute myeloid leukaemia and acute lymphoblastic leukaemia

Using a non-isotopic ligand binding assay, we quantitatively examined the amount of human thrombopoietin (TPO) receptor (TPO-R) on leukaemia cells from 128 patients with acute myeloid leukaemia (AML) or acute lymphoblastic leukaemia (ALL). The TPO-R was expressed in 53 (47%) of 114 AML cases, and an in vitro treatment with TPO led to proliferation (stimulation index >1.5) of leukaemia cells in 13 (20%) of 66 AML cases examined. The TPO levels had no relation to the FAB classification except for FAB-M7 AML. All five FAB-M7 cases expressed TPO-R, and one of three FAB-M7 examined showed in vitro proliferative response to TPO. Although there was no significant correlation ( r  = 0.3125) between the amount of TPO-R and the proliferative response, all of the AML cases which showed the in vitro response had TPO-R expression. There was no relationship between TPO-R amount and CD phenotypes, or the amount of granulocyte-colony stimulating factor (G-CSF) receptor. TPO-R was also expressed in two (14%) of 14 cases of ALL, and only these two cases had in vitro proliferative response to TPO. One had only lymphoid antigens, and the other had both lymphoid and myeloid antigens. Our results suggest that some leukaemia cells express functionally active TPO-R.     

Single agent thalidomide in patients with relapsed or refractory acute myeloid leukaemia

Thalidomide is a putative anti-angiogenesis agent that has significant anti-tumour activity in haematological malignancies with increased bone marrow angiogenesis, including multiple myeloma (MM) and myelodysplastic syndromes (MDS). Increased levels of the mitogen for angiogenesis, vascular endothelial growth factor (VEGF), correlate with worse survival in acute myeloid leukaemia (AML). A phase II trial of thalidomide was conducted in patients with relapsed- or refractory-AML previously treated with cytarabine-containing regimens. A total of 16 patients with refractory- or relapsed-AML were treated with thalidomide 200-800 mg orally daily (median dose 400 mg daily) for a median of 27 d (range, 3-94 d). Overall, one patient (6%) achieved complete remission (CR) lasting for 36 months, and two patients had a transient reduction in marrow blasts from 8% and 7% to less than 5% in both cases. There was no correlation between reduction in levels of angiogenesis markers and response. Toxicities related to thalidomide were significant, and precluded dose escalation beyond 400 mg orally daily in most patients. Although there appears to be some evidence of biological activity, single agent thalidomide is not an optimal choice of therapy for salvaging patients with relapsed- or refractory-AML. Thalidomide analogues with more potent immunomodulatory activities and more favourable toxicity profiles may offer more promise as anti-AML therapy.     

Isolated gingival relapse in acute myeloid leukaemia

A 47-yr-old man with acute myeloid leukaemia had been in complete remission for 18 months when he developed a gingival tumour. Histological examination revealed leukaemic infiltrate and, at this stage, no other signs of relapse could be demonstrated. Chemotherapy and local radiotherapy resulted in the disappearance of the mass; however, histological abnormalities persisted. First relapse of acute myeloid leukaemia presenting as a gingival tumour has not been previously reported.     

Antibody therapy for acute myeloid leukaemia

Novel therapies with increased efficacy and decreased toxicity are desperately needed for the treatment of acute myeloid leukaemia (AML). The anti CD33 immunoconjugate, gemtuzumab ozogamicin (GO), was withdrawn with concerns over induction mortality and lack of efficacy. However a number of recent trials suggest that, particularly in AML with favourable cytogenetics, GO may improve overall survival. This data and the development of alternative novel monoclonal antibodies (mAb) have renewed interest in the area. Leukaemic stem cells (LSC) are identified as the subset of AML blasts that reproduces the leukaemic phenotype upon transplantation into immunosuppressed mice. AML relapse may be caused by chemoresistant LSC and this has refocused interest on identifying and targeting antigens specific for LSC. Several mAb have been developed that target LSC effectively in xenogeneic models but only a few have begun clinical evaluation. Antibody engineering may improve the activity of potential new therapeutics for AML. The encouraging results seen with bispecific T cell‐engaging mAb‐based molecules against CD19 in the treatment of B‐cell acute lymphobalstic leukaemia, highlight the potential efficacy of engineered antibodies in the treatment of acute leukaemia. Potent engineered mAb, possibly targeting novel LSC antigens, offer hope for improving the current poor prognosis for AML.     

Epigenetics of paediatric acute myeloid leukaemia

Comprehensive cataloguing of the acute myeloid leukaemia (AML) genome has revealed a high frequency of mutations and deletions in epigenetic factors that are frequently linked to treatment resistance and poor patient outcome. In this review, we discuss how the epigenetic mechanisms that underpin normal haematopoiesis are subverted in AML, and in particular how these processes are altered in childhood and adolescent leukaemias. We also provide a brief summary of the burgeoning field of epigenetic-based therapies, and how AML treatment might be improved through provision of better conceptual frameworks for understanding the pleiotropic molecular effects of epigenetic disruption.     

Rapid isolation of translocation breakpoints in chronic myeloid and acute promyelocytic leukaemia

Isolation and sequencing of the translocation breakpoint in chronic myeloid leukaemia‐(CML) and acute promyelocytic leukaemia (APML) may help to elucidate the mechanism of translocation and provide a molecular marker for monitoring of minimal residual disease. Amplification across the translocation breakpoint was performed in samples from 91 patients with CML and 15 patients with APML using single‐tube multiplex polymerase chain reaction (PCR) involving 308 primers for CML and 40 primers for APML. Nonspecific amplification was removed by a modification of PCR, termed sequential hybrid primer PCR (SHP‐PCR), which involved two sequential rounds of PCR, each of which used a low concentration of a specially designed hybrid primer. The resultant amplified material was sequenced. The method as finally developed was simple quick and robust. The translocation breakpoint was successfully isolated and sequenced in all 106 samples. The strategy of highly multiplexed PCR followed by SHP‐PCR is thus an effective method for isolating the translocation breakpoint in CML and APML. It may also be applicable to other haematological disorders characterised by translocation, deletion or inversion.