GATA1-mutant clones are frequent and often unsuspected in babies with Down syndrome: identification of a population at risk of leukemia.

Transient abnormal myelopoiesis (TAM), a preleukemic disorder unique to neonates with Down syndrome (DS), may transform to childhood acute myeloid leukemia (ML-DS). Acquired GATA1 mutations are present in both TAM and ML-DS. Current definitions of TAM specify neither the percentage of blasts nor the role of GATA1 mutation analysis. To define TAM, we prospectively analyzed clinical findings, blood counts and smears, and GATA1 mutation status in 200 DS neonates. All DS neonates had multiple blood count and smear abnormalities. Surprisingly, 195 of 200 (97.5%) had circulating blasts. GATA1 mutations were detected by Sanger sequencing/denaturing high performance liquid chromatography (Ss/DHPLC) in 17 of 200 (8.5%), all with blasts >10%. Furthermore low-abundance GATA1 mutant clones were detected by targeted next-generation resequencing (NGS) in 18 of 88 (20.4%; sensitivity ∼0.3%) DS neonates without Ss/DHPLC-detectable GATA1 mutations. No clinical or hematologic features distinguished these 18 neonates. We suggest the term "silent TAM" for neonates with DS with GATA1 mutations detectable only by NGS. To identify all babies at risk of ML-DS, we suggest GATA1 mutation and blood count and smear analyses should be performed in DS neonates. Ss/DPHLC can be used for initial screening, but where GATA1 mutations are undetectable by Ss/DHPLC, NGS-based methods can identify neonates with small GATA1 mutant clones.

Leukemic presentation of ALK-negative anaplastic large cell lymphoma in a patient with myelodysplastic syndrome.

A 50-year-old woman with a history of aplastic anemia developed cervical lymphadenopathy and atypical lymphocytosis. Atypical cells of lymph nodes were positive for CD3 and CD30 but negative for anaplastic lymphoma kinase (ALK). Bone marrow examination showed trilineage myelodysplasia. She was diagnosed with ALK-negative anaplastic large cell lymphoma (ALCL) with leukemic transformation and myelodysplastic syndrome (MDS) which presumably developed from aplastic anemia. The lymphoma was resistant to intensive chemotherapies, ultimately leading to death. Leukemic presentation of ALK-negative ALCL as an initial manifestation is extremely rare, and the progression of the disease may be influenced by MDS through alteration of immune functions.

Fever of unknown origin due to preleukemia/myelodysplastic syndrome: the diagnostic importance of monocytosis with elevated serum ferritin levels.

Fever of unknown origin (FUO) is a common clinical diagnostic dilemma. In the elderly, causes of FUO most commonly include malignancy or infection, and less commonly include collagen vascular diseases. Among the collagen vascular diseases causing FUO in the elderly, polymyalgia rheumatica/temporal arteritis, and adult Still's disease (adult juvenile rheumatoid arthritis) are difficult diagnoses to prove. Among the infectious causes of FUO in the elderly are subacute bacterial endocarditis, intra-abdominal abscesses, and extrapulmonary tuberculosis. In the elderly, neoplastic causes of FUO include lymphomas, hepatomas, renal cell carcinomas, and hepatic or central nervous system metastases. Acute leukemias, particularly during "blast" transformation, may present as acute fevers in the absence of infection, but are rare causes of FUO. Preleukemia/myelodysplastic syndromes are exceedingly rare causes of FUO. We present a case of an elderly man who presented with findings that initially suggested adult Still's disease. Prolonged and profound monocytosis provided the key clue to his subsequent diagnosis of preleukemia/myelodysplastic syndrome. In this patient, a positive Naprosyn test result also suggested a neoplastic cause for his FUO. After months of prolonged fevers, myelocytes/metamyelocytes were eventually demonstrated in his peripheral smear during hospital evaluation. These findings, in concert with the persistent monocytosis, highly elevated ferritin levels, polyclonal gammopathy on serum protein electrophoresis, and eventual presence of myelocytes/metamyelocytes on peripheral smear, prompted a bone marrow test that demonstrated blast cells confirming the diagnosis of preleukemia myelodysplastic syndrome as the cause of this patient's FUO.

In utero origins of childhood leukaemia.

Chimaeric fusion genes derived by chromosome translocation are common molecular abnormalities in paediatric leukaemia and provide unique markers for the malignant clone. They have been especially informative in studies with twins concordant for leukaemia and in retrospective scrutiny of archived neonatal blood spots. These data have indicated that, in paediatric leukaemia, the majority of chromosome translocations arise in utero during foetal haemopoiesis. Chromosomal translocations and preleukaemic clones arise at a substantially higher frequency ( approximately 100x) before birth than the cumulative incidence or risk of disease, reflecting the requirement for complementary and secondary genetic events that occur postnatally. A consequence of the latter is a very variable and occasionally protracted postnatal latency of disease (1-15 years). These natural histories provide an important framework for consideration of key aetiological events in paediatric leukaemia.

Lack of circulating megakaryoblasts in newborn peripheral blood: development and validation of a sensitive flow cytometric detection method.

It is currently thought that approximately 1% of children with Down syndrome will develop a "premalignant" syndrome known as transient myeloproliferative disorder (TMD). Prospective, population-based studies of the incidence of TMD in Down syndrome infants is lacking. Although most cases of TMD resolve by 1 year of age, data suggest that 10% to 20% of Down syndrome patients with TMD develop AML-M7 (megakaryoblastic leukemia). To identify the true incidence of TMD in the Down syndrome population, a sensitive, rapid, and cost-effective method of quantifying circulating megakaryoblasts in large numbers of patients was needed. In this pilot study, the authors tested the hypothesis that there are fewer than 1% megakaryoblasts of nucleated cells circulating in the blood of normosomic infants. Four-antigen flow cytometry was used to establish the percentage of megakaryoblasts present in each of 100 cord blood samples collected blindly from "normosomic" live births. There was a mean percentage of 0.017% megakaryoblasts in 100 cord blood samples from normosomic infants. Flow cytometry proved to be a sensitive, rapid, and reproducible method for the quantification of megakaryoblasts. Less than 1% of circulating nucleated cells in the blood of newborn infants are megakaryoblasts, providing a comparison population for the authors' larger proposed incidence study.

Elevated plasma level of differentiation inhibitory factor nm23-H1 protein correlates with risk factors for myelodysplastic syndrome.

We measured plasma nm23-H1 level (nm23-H1), a differentiation inhibitory factor, by an enzyme-linked immunosorbent assay (ELISA) in patients with aplastic anemia (AA) and myelodysplastic syndrome (MDS). The nm23-H1 in AA was not significantly elevated when compared to normal subjects (6.66 +/- 1.20 ng/ml vs 5.13 +/- 0.81 ng/ml; P = 0.274). In contrast, MDS patients had significantly high levels of nm23-H1 compared not only to normal subjects (11.16 +/- 1.42 vs 5.13 +/- 0.81 ng/ml; P = 0.0004) but also to those of the AA group (11.16 +/- 1.42 ng/ml vs 6.66 +/- 1.20 ng/ml; P = 0.018). In the MDS group of patients, no significant difference was observed in the nm23-H1 levels between patients with refractory anemia (RA) and RA with excess blasts (RAEB)/RAEB in transformation (10.71 +/- 1.61 ng/ml vs 9.24 +/- 2.66 ng/ml; P = 0.672). Of the patients with RA, patients with low risk according to the International Prognostic Scoring System (IPSS) had significantly low levels of nm23-H1 compared to those of IPSS INT-1 level cases (6.40 +/- 1.36 ng/ml vs 13.05 +/- 2.50 ng/ml; P = 0.0028), suggesting that nm23-H1 may be useful as a prognostic marker for MDS, especially in low risk patients.

[Refractory anemia and preleukemia: an analysis of 92 cases].

OBJECTIVE: To investigate the relationship between MDS-RA (refractory anemia subtype of myelodysplastic syndromes) and preleukemia (PL). METHODS: Hematological parameters of 86 RA and 6 PL patients were retrospectively analyzed. RESULTS: Thirty-four RA cases (39.53%) transformed into acute leukemia (AL), RA with excess blasts (RAEB), or RAEB in transformation (RAEB-t). As compared with 52 non-transformed RA cases, the transformed cases showed the following hematological features: 1. higher frequencies of immature granulocytes (P < 0.005), erythroblasts (P < 0.05) and megaloerythrocytes (P < 0.05), and higher granulocyte nuclear lobulation (P < 0.001) in peripheral blood; 2. higher percentages of early erythroid and granulocytic lineages (P < 0.05), and higher frequencies of erythroblasts with multiple nuclei (P < 0.05), pseudo Pelger-Huet abnormality (P < 0.05), and micromegakaryocytes (P < 0.005) in bone marrow. CONCLUSION: There is a higher overlap between RA and PL; the above hematological features may be useful for predicting the transformation of RA patients. Based on those findings, a score system for predicting the transformation of RA was proposed.

Preleukemia in long-term plasmacytoma-regressor mice.

Our previous results have indicated that mice whose plasmacytoma regressed following curative melphalan chemotherapy manifested various persistent immunohematological abnormalities including immunosuppression, myeloproliferation, as well as excessive production of and response to growth factors. Mice not bearing plasmacytoma treated with an identical dose of melphalan chemotherapy did not exhibit such abnormalities. In the present study we show that plasmacytoma-regressor mice (PRM) contain preleukemic cells which do not progress to leukemia in these mice. However, adoptive transfer of splenocytes originating in PRM to preirradiated but otherwise untreated syngeneic recipients resulted in the development of overt leukemia in these recipients. The presence of leukemia in the primary recipient mice was ascertained by blood counts as well as by spleen histology. Furthermore, splenocytes from the irradiated primary recipients adoptively transferred to non-irradiated secondary recipients caused leukemia formation in 100% of the secondary recipients. Sex chromosome analysis of the leukemic cells in the irradiated primary recipients clearly showed that they originated in the PRM donors. Two leukemic lines were established from leukemias developing in the secondary recipients and both expressed surface markers of hematopoietic progenitor cells as well as markers of T cells. We suggest that PRM could serve as an animal model to investigate development of chemotherapy-related leukemia in humans.

Secondary leukaemias. Clinical and cytobiological aspects.

Patients treated with radiation and cytotoxic agents for a variety of neoplastic conditions develop with increased frequency a secondary leukaemia, usually a form of acute myeloblastic leukaemia. The authors illustrate and discuss the various morphological and cytobiological which characterize the "preleukaemic phase", and which comprise myelodysplastic alterations, cytochemical abnormalities, concerning the presence of glycogen and free iron in the red cell series, as well as a number of changes in enzymatic activities in the myeloid series, cytokinetic changes, indicative of accumulation of cells in G0 and G1, cytogenetic non-random abnormalities, involving specific chromosomes, and finally in vitro cultures which show a reduction in colony formation. The authors underline the differences between primary and secondary preleukaemic myelodysplastic states, consisting in the presence in the latter of frequent hypocellularity, fibrosis and almost invariability a clear involvement of multiple cell lines.

Arylsulfatase B in Kurloff cells: increased activity of anionic isoforms in guinea pig acute lymphoblastic leukemia.

We examined the in vivo role of Kurloff cells (KC), guinea pig natural killer cells, during the development of L2C leukemia, by analysing changes in the arylsulfatases (Asases) in the lysosomal Kurloff body. The Kurloff body is rich in acid phosphatase, esterase and proteoglycans, as are large granular lymphocyte granules. Moreover, the Kurloff body contains lysosomal Asase B, with unusual anionic isoforms. Injection of L2C cells elicited a three-fold increase in KC Asase activity on day 6. The increase in KC Asase activity was correlated with the number of circulating L2C cells. The basic Asase form (pl 8) was lost, and a concomitant increase in anionic isoforms (pl 5-6) was observed on day 6. The role of the latter in cytolysis was investigated by examining their capacity to lyse L2C target cells. We conclude that Asase participates in cytolysis when lysis is mediated by the complete assembly of cytolytic proteins. Changing and increasing KC Asase activity during leukemia development may be a marker for activated KC in vivo. These findings suggest that the cytolytic activation of KC occurs during the preleukemic period.

Increased plasma M-CSF concentration in patients with adult T cell leukemia: clinical correlation.

Plasma concentration of M-CSF was measured in 35 patients with adult T cell leukemia (ATL), using a radioimmunoassay (RIA). ATL patients showed elevated levels of plasma M-CSF concentration when compared with healthy adult volunteers. Higher M-CSF levels were observed in acute ATL patients than in patients with chronic or smouldering ATL (P < 0.0001). There was a significant positive correlation of M-CSF concentration with serum lactic dehydrogenase (LDL) level, a reliable marker for assessing the grade of malignancy in ATL (P = 0.0003). There was, however, no correlation of M-CSF concentration with total counts of peripheral blood ATL cells, neutrophils or monocytes, or with serum calcium levels. Although there was a significant positive correlation of M-CSF concentration with body temperature (P = 0.003), there was not a significant correlation of M-CSF concentration with C-reactive protein (CRP), a protein indicative of the severity of inflammation (P = 0.063). These results indicate that plasma M-CSF concentration reflects the disease activity of ATL, and can thus serve as a marker in the clinical subclassification of ATL patients.

Transient aplasia preceding adult acute lymphoblastic leukemia.

A 62-year-old woman developed common acute lymphoblastic leukemia (ALL) after spontaneous recovery from transient marrow aplasia. Although the mechanisms underlying bone marrow suppression in acute leukemia are obscure, it is important to know that transient aplasia may be observed as a prodromal feature in ALL in adult patients as well as in children.

Involvement of the spleen in preleukemic development of a murine retrovirus-induced promonocytic leukemia.

An acute myeloid leukemia can result from the inoculation of Moloney murine leukemia virus into BALB/c mice undergoing a 2,6,10,14-tetramethylpentadecane-induced chronic inflammatory response in the peritoneal cavity. This leukemia is ultimately observed in the peritoneal cavity as an ascites with cells infiltrating the granulomatous tissue. It has been proposed, however, that hematopoietic organs such as the spleen and bone marrow are involved in preleukemic development of Moloney murine leukemia. Therefore, to determine if the spleen plays a role in this development, mice were splenectomized at various times relative to virus inoculation. When splenectomies were performed 3 days before and 2, 4, 6, and 8 weeks after virus inoculation there was, in all cases, a decreased death rate compared to sham-splenectomized controls. The greatest difference in death rate due to promonocytic leukemia was observed when mice were splenectomized at 4 weeks after virus inoculation. The decrease in disease incidence observed as a result of splenectomy was not caused by decreased virus spread in hematopoietic organs or an alteration in the profile of the cellular infiltrate in the granuloma. It was found, however, that the spleens of 2,6,10,14-tetramethylpentadecane-treated mice, relative to those of normal mice, have a significantly increased number of granulocyte-macrophage colony-forming cells and a slightly increased number of multipotential colony-forming cells. These observations suggest that a population of target cells for transformation, consisting of granulocyte-macrophage precursor cells, may reside in the spleen. Alternatively, partially transformed cells may reside temporarily in the spleen during the developmental stages of the disease process.

[The significance of beta 2-microglobulin for the diagnosis of preleukemic states in workers of the chemical industry]. / Znachenie beta 2-mikroglobulina dlia diagnostiki predleikoznykh sostoianii u rabochikh khimicheskoi promyshlennosti.

A study is presented of 89 workers contacting with benzene and its derivatives and 98 workers without contacts with chemical substances. Radioimmunological assay of peripheral blood B2-microglobulin was carried out. Persons with a length of work over 10 years contacting with anilin and its derivatives showed a marked increase of B2-microglobulin in the blood serum as well a marked reduction of leucocyte number. It is considered that leucopenia with granulocytopenia and marked increase of B2-microglobulin is regarded as a preleucosis state.