The role of eosinophil morphology in distinguishing between reactive eosinophilia and eosinophilia as a feature of a myeloid neoplasm.

Morphological features of eosinophils in patients with reactive eosinophilia (28 patients) and clonal eosinophilia (26 patients) have been compared with each other and with the eosinophil characteristics of healthy volunteers (three subjects) and of patients with the idiopathic hypereosinophilic syndrome (three patients). Morphological features, assessed in isolation from other haematological abnormalities, were found to have poor specificity for a myeloid neoplasm. The most useful feature was the presence of basophilic granules in mature eosinophils, which was associated particularly with acute myeloid leukaemia with inv(16). Marked reduction in granules occurred more often in some subsets of the myeloid neoplasm group but nevertheless was lacking in specificity since it was not infrequently seen in reactive eosinophilia. Although experienced morphologists more often considered that a myeloid neoplasm was likely in patients in whom this was the diagnosis (69%), myeloid neoplasia was also considered likely in a considerable proportion (39%) of patients with reactive eosinophilia. Morphological abnormalities of eosinophils therefore cannot be assessed in isolation in seeking to make a diagnosis of a myeloid neoplasm. Morphology is, however, needed and should be integrated with the results of other investigations.

Tooth enamel ESR doses and cytogenetic doses of Nagasaki atomic-bomb survivors in comparison with DS02R1 doses.

PURPOSE: Cancer risks for Nagasaki survivors once appeared to be lower than for Hiroshima survivors. The possibility that this was due to overestimation of the doses for the Nagasaki survivors was tested by measuring biological doses of Nagasaki survivors and comparing them with DS02R1 individual doses as previously done for Hiroshima survivors. MATERIALS AND METHODS: The electron spin resonance (ESR) method and cytogenetic method were used to estimate radiation doses for 24 Nagasaki survivors, and the results were compared to calculated DS02R1 doses. RESULTS: Six factory workers and 10 other survivors showed ESR or cytogenetically estimated doses that were in reasonably good agreement with their DS02R1 doses, while one factory worker was found to have an ESR dose estimate of nearly one half of the DS02R1 dose to the eye lens (a proxy organ for teeth). A few outliers were also observed. CONCLUSIONS: Although apparently lower cancer risks were observed in the past for Nagasaki survivors when compared to Hiroshima survivors, the present results do not indicate the existence of a trend that DS02R1 doses are overestimated when compared with biologically estimated tooth or cytogenetic doses. This observation is in line with the recent disappearance of the city difference in cancer risks.

Dyserythropoiesis in the diagnosis of the myelodysplastic syndromes and other myeloid neoplasms: problem areas.

An evaluation of the significance of specified dyserythropoietic features in suspected myelodysplastic syndrome (MDS) and acute myeloid leukaemia with erythroid dysplasia was made by means of evaluation of 100 electronic images of bone marrow erythroblasts from each of 20 subjects: 11 with a myeloid neoplasm, six with another condition that could cause erythroid dysplasia and three healthy controls. The evaluation was carried out independently by seven experienced haematologists/haematopathologists who were blinded to the diagnosis. The majority of the dyserythropoietic features listed in the World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues were validated, although karyorrhexis was found to be infrequent and lacking in specificity; multinuclearity and megaloblastosis were more often observed but also lacked specificity. Good majority agreement on the identification of dysplastic features was obtained. Despite this, it was demonstrated that a reliable diagnosis of MDS can often not be made on the basis of erythroid morphology alone. Interpretation of dyserythropoiesis must be carried out with full knowledge of other clinicopathological features and with a constant awareness of the other conditions that can be confused with MDS. An iron stain is essential, as cases with ring sideroblasts may otherwise not be recognised as having MDS.

Internal exposure to neutron-activated 56Mn dioxide powder in Wistar rats-Part 2: pathological effects.

To fully understand the radiation effects of the atomic bombing of Hiroshima and Nagasaki among the survivors, radiation from neutron-induced radioisotopes in soil and other materials should be considered in addition to the initial radiation directly received from the bombs. This might be important for evaluating the radiation risks to the people who moved to these cities soon after the detonations and probably inhaled activated radioactive "dust." Manganese-56 is known to be one of the dominant radioisotopes produced in soil by neutrons. Due to its short physical half-life, 56Mn emits residual radiation during the first hours after explosion. Hence, the biological effects of internal exposure of Wistar rats to 56Mn were investigated in the present study. MnO2 powder was activated by a neutron beam to produce radioactive 56Mn. Rats were divided into four groups: those exposed to 56Mn, to non-radioactive Mn, to 60Co γ rays (2 Gy, whole body), and those not exposed to any additional radiation (control). On days 3, 14, and 60 after exposure, the animals were killed and major organs were dissected and subjected to histopathological analysis. As described in more detail by an accompanying publication, the highest internal radiation dose was observed in the digestive system of the rats, followed by the lungs. It was found that the number of mitotic cells increased in the small intestine on day 3 after 56Mn and 60Co exposure, and this change persisted only in 56Mn-exposed animals. Lung tissue was severely damaged only by exposure to 56Mn, despite a rather low radiation dose (less than 0.1 Gy). These data suggest that internal exposure to 56Mn has a significant biological impact on the lungs and small intestine.

Quality control initiative on the evaluation of the dysmegakaryopoiesis in myeloid neoplasms: Difficulties in the assessment of dysplasia.

Evaluation of megakaryocyte morphology is difficult but can be essential for the diagnosis of myelodysplastic syndromes (MDS) and other myeloid neoplasms. We agreed upon descriptions and provided images of megakaryoblasts and of normal and dysplastic megakaryocytes, which were used as a basis for assessing the concordance of expert morphologists in their recognition. We showed a high rate of concordance for the recognition of micromegakaryocytes and confirmed their strong association with hematologic neoplasia, including MDS. Concordance was also found to be good for the recognition of multinucleated megakaryocytes, which showed a significant association with MDS. However cytoplasmic abnormalities were found not to be useful in MDS recognition. The occurrence of appreciable numbers of nonlobulated and hypolobulated megakaryocytes in individuals without a myeloid neoplasm was confirmed. We demonstrated that subjects without a myeloid neoplasm can have some megakaryocytes that are assessed as 'dysplastic' or 'possibly dysplastic' and that to avoid over diagnosis of dysplasia, 'possibly dysplastic' forms should be excluded from the count of dysplastic cells. Our results demonstrate that the nature as well as the presence of megakaryocyte dysplasia is important in the diagnosis of MDS; although evaluation of 30 megakaryocytes is strongly recommended, it may be possible to recognize diagnostically important dysplasia when fewer megakaryocytes are present but highly diagnostic forms are seen.

Proposal of criteria for dyserythropoiesis in the diagnosis of myelodysplastic syndromes.

The percentage manifesting dysplasia in bone marrow needed to qualify as significant is ≥10 % in each lineage. However, detailed analyses of this threshold have not been reported. Here, we analyzed dyserythropoiesis (dysE) in 109 myelodysplastic syndromes (MDS) patients with 21 immune thrombocytopenia (ITP)/12 hemolytic anemia (HA) patients as a control. In present study, mild megaloblastic erythroblasts were specifically named 'red cell with abnormal chromatin clumping (RCACC)'. RCACC ≥10 % in erythroblasts was observed in 29 % of ITP patients and 58 % of HA patients. The numbers of MDS patients with RCACC in erythroblasts <10, 10-19 and ≥20 % were 1, 3, and 105, respectively. We analyzed dysE criteria according to the WHO classification (original WHO dysE). Most of our MDS patients (98 %) had original WHO dysE ≥20 %. The ITP patients with original WHO dysE ≥10 % was 48 %, and there were no ITP patients had original WHO dysE ≥20 %. Sixty-seven percent of HA patients had original WHO dysE ≥10 %, and three patients (25 %) had original WHO dysE ≥20 %. Raising the threshold of the original WHO dysE from 10 to 20 or 30 % may provide more suitable criteria. If RCACC is not included in dysE criteria, we think that '10 %' is a suitable threshold for the determination of dyserythropoiesis.

The level of bone marrow WT1 message is a useful marker to differentiate myelodysplastic syndromes with low blast percentage from cytopenia due to other reasons.

OBJECTIVE: Myelodysplastic syndromes (MDS) are a group of hematological neoplasms associated with ineffective hematopoiesis and that transform to acute leukemia. Distinguishing MDS from other cytopenias is sometimes difficult even for trained hematologists. WT1, the gene mutated in Wilms' tumor, was found expressed in acute myeloid leukemia and MDS. The amount of WT1 in peripheral blood and bone marrow (BM) is low in low-risk MDS subtypes, and is high in high-risk MDS subtypes. However, the role of WT1 in the differential diagnosis between MDS and other diseases showing cytopenia has not been fully addressed. The present study evaluated whether WT1 expression level can assist in the differential diagnosis of MDS from other cytopenias. METHODS: The amount of WT1 message was evaluated among 56 MDS patients and 47 patients with cytopenia for various other reasons (cytopenia VR) at the Nagasaki University Hospital. RESULTS: The level of WT1 was significantly related to the percentage of blasts in BM among MDS cases, and the type of French-American-British classification of MDS; refractory anemia (RA) cases showed significantly lower WT1 level than patients with RA with excess blasts. WT1 level was significantly related to the prognostic risk categories of MDS by the International Prognostic Scoring System (IPSS) and the revised IPSS. Although the blast percentage in the BM of RA and cytopenia VR were both less than 5%, there was a significant difference in the level of WT1 between MDS and cytopenia VR. CONCLUSION: WT1 might be a good marker to differentiate low blast percentage MDS and cytopenia VR.

Dose-intensified chemotherapy alone or in combination with mogamulizumab in newly diagnosed aggressive adult T-cell leukaemia-lymphoma: a randomized phase II study.

This multicentre, randomized, phase II study was conducted to examine whether the addition of mogamulizumab, a humanized anti-CC chemokine receptor 4 antibody, to mLSG15, a dose-intensified chemotherapy, further increases efficacy without compromising safety of patients with newly diagnosed aggressive adult T-cell leukaemia-lymphoma (ATL). Patients were assigned 1:1 to receive mLSG15 plus mogamulizumab or mLSG15 alone. The primary endpoint was the complete response rate (%CR); secondary endpoints included the overall response rate (ORR) and safety. The %CR and ORR in the mLSG15-plus-mogamulizumab arm (n = 29) were 52% [95% confidence interval (CI), 33-71%] and 86%, respectively; the corresponding values in the mLSG15 arm (n = 24) were 33% (95% CI, 16-55%) and 75%, respectively. Grade ≥ 3 treatment-emergent adverse events, including anaemia, thrombocytopenia, lymphopenia, leucopenia and decreased appetite, were observed more frequently (≥10% difference) in the mLSG15-plus-mogamulizumab arm. Several adverse events, including skin disorders, cytomegalovirus infection, pyrexia, hyperglycaemia and interstitial lung disease, were observed only in the mLSG15-plus-mogamulizumab arm. Although the combination strategy showed a potentially less favourable safety profile, a higher %CR was achieved, providing the basis for further investigation of this novel treatment for newly diagnosed aggressive ATL. This study was registered at ClinicalTrials.gov, identifier: NCT01173887.

Multicenter phase II study of mogamulizumab (KW-0761), a defucosylated anti-cc chemokine receptor 4 antibody, in patients with relapsed peripheral T-cell lymphoma and cutaneous T-cell lymphoma.

PURPOSE: CC chemokine receptor 4 (CCR4) is expressed by peripheral T-cell lymphomas (PTCLs) and is associated with poor outcomes. Mogamulizumab (KW-0761) is a defucosylated humanized anti-CCR4 antibody engineered to exert potent antibody-dependent cellular cytotoxicity. This multicenter phase II study evaluated the efficacy and safety of mogamulizumab in patients with relapsed PTCL and cutaneous T-cell lymphoma (CTCL). PATIENTS AND METHODS: Mogamulizumab (1.0 mg/kg) was administered intravenously once per week for 8 weeks to patients with relapsed CCR4-positive PTCL or CTCL. The primary end point was the overall response rate, and the secondary end points included safety, progression-free survival (PFS), and overall survival (OS). RESULTS: A total of 38 patients were enrolled, and 37 patients received mogamulizumab. Objective responses were noted for 13 of 37 patients (35%; 95% CI, 20% to 53%), including five patients (14%) with complete response. The median PFS was 3.0 months (95% CI, 1.6 to 4.9 months), and the median OS was not calculated. The mean maximum and trough mogamulizumab concentrations (± standard deviation) after the eighth infusion were 45.9 ± 9.3 and 29.0 ± 13.3 µg/mL, respectively. The most common adverse events were hematologic events, pyrexia, and skin disorders, all of which were reversible and manageable. CONCLUSION: Mogamulizumab exhibited clinically meaningful antitumor activity in patients with relapsed PTCL and CTCL, with an acceptable toxicity profile. Further investigation of mogamulizumab for treatment of T-cell lymphoma is warranted.

Proposal for refining the definition of dysgranulopoiesis in acute myeloid leukemia and myelodysplastic syndromes.

Studies of morphology of myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) refer to the definitions produced by the French-American-British (FAB) group and by the World Health Organization expert group. To clarify some points regarding the dysgranulopoiesis that are still unclear we analyzed a series of 98 neutrophils from MDS patients with regard to granularity, nuclear segmentation, the appearance of the chromatin, the presence of giant neutrophils, and the presence of nuclear chromatin extensions. We found that cells with at least 2/3 reduction of the content of granules, Pelger-like neutrophils, dysplastic non-Pelger cells, neutrophils with abnormal clumping of the chromatin, and macropolycytes could be recognized as dysplastic and included in the 10% count recommended by these two classifications. In addition, we suggest that neutrophils with more than 4 nuclear projections could be recognized as a relevant dysplastic feature.

Prevalence of monoclonal gammopathy of undetermined significance in Asia: a viewpoint from nagasaki atomic bomb survivors.

Exposure to ionizing radiation is a known environmental risk factor for a variety of cancers including hematological malignancies, such as leukemia, myelodysplastic syndromes, and multiple myeloma. Therefore, for Hiroshima and Nagasaki atomic bomb survivors (surviving victims who were exposed to ionizing radiation emitted from the nuclear weapons), several cancer-screening tests have been provided annually, with government support, to detect the early stage of malignancies. An M-protein screening test has been used to detect multiple myeloma at an early stage among atomic bomb survivors. In the screening process, a number of patients with monoclonal gammopathy of undetermined significance (MGUS), in addition to multiple myeloma, have been identified. In 2009 and 2011, we reported the age- and sex-specific prevalence of MGUS between 1988 and 2004 and the possible role of radiation exposure in the development of MGUS using the screening data of more than 1000 patients with MGUS among approximately 52,000 Nagasaki atomic bomb survivors. The findings included: (1) a significant lower overall prevalence (2.1%) than that observed in Caucasian or African-origin populations; (2) a significantly higher prevalence in men than in women; (3) an age-related increase in the prevalence; (4) a significantly higher prevalence in people exposed to higher radiation doses only among those exposed at age 20 years or younger; and (5) a lower frequency of immunoglobulin M MGUS in Japanese patients than in patients in Western countries. The large study of MGUS among Nagasaki atomic bomb survivors has provided important findings for the etiology of MGUS, including a possible role of radiation exposure on the cause of MGUS and an ethnicity-related difference in the characteristics of MGUS.

Molecular analysis of the BCR-ABL1 kinase domain in chronic-phase chronic myelogenous leukemia treated with tyrosine kinase inhibitors in practice: study by the Nagasaki CML Study Group.

An appropriate trigger for BCR-ABL1 mutation analysis has not yet been established in unselected cohorts of chronic-phase chronic myelogenous leukemia patients. We examined 92 patients after 12 months of tyrosine kinase inhibitor (TKI) treatment in Nagasaki Prefecture, Japan. Univariate analysis revealed that significant factors associated with not attaining a major molecular response (MMR) were the presence of the minor BCR-ABL1 fusion gene, a low daily dose of TKI, and the emergence of BCR-ABL1 kinase domain mutations conferring resistance to imatinib. Factors associated with the loss of sustained MMR were a low daily dose of TKI and the emergence of alternatively spliced BCR-ABL1 mRNA with a 35-nucleotide insertion. Taken together, our results suggest that the search for BCR-ABL1 mutations should be initiated if patients have not achieved MMR following 12 months of TKI treatment.

Long-term outcome of immunosuppressive therapy for Japanese patients with lower-risk myelodysplastic syndromes.

To investigate the long-term usefulness of immunosuppressive therapy (IST) for Japanese patients with lower-risk myelodysplastic syndromes, we retrospectively analyzed 29 MDS patients who were treated with cyclosporine A alone or with anti-thymocyte globulin at a single institute in Japan. A total of 58.6 % of patients showed hematological response to IST. Overall survival of all patients was 74.5 % at 5 years and 48.3 % at 10 years. The major adverse event was the elevation of creatinine level (grade 1 and 2). Eleven patients were still on IST at the time of analysis with, at least, some clinical benefits. Pneumonia was the most frequent cause of death (eight of 12 deaths), followed by bleeding (three of 12); most of the patients who died were non-responders. The presence of paroxysmal nocturnal hemoglobinuria-type cells was significantly associated with both response to IST and long-term survival by univariate analysis. The 10-year overall survival of responders (72.2 %) was significantly superior to that of non-responders (15.6 %, P < 0.0001). These results suggest that IST using cyclosporine A provides long-term benefit for Japanese patients with lower-risk MDS.

Correlation between dysplastic lineage and type of cytopenia in myelodysplastic syndromes patients with refractory anemia according to the FAB classification.

OBJECTIVES: To analyze the correlation between dysplastic lineage and type of cytopenia in myelodysplastic syndromes. METHODS: We analyzed the correlation between dysplasia and cell count using the data set of our previous morphologic study. RESULTS: There were no correlations between dysgranulopoiesis of 10% or more and absolute neutrophil count (ANC). Similarly, hyposegmented mature neutrophils (Pelger) of 10% or more were not related to ANC. Interestingly, the platelet count of patients with dysmegakaryopoiesis (dys Mgk) was higher than that of patients without dys Mgk (dys Mgk ≥10% vs <10%, P = .08; dys Mgk ≥40% vs <40%, P = .02; micromegakaryocytes ≥10% vs <10%, P = .004). CONCLUSIONS: Since low cell counts did not correlate with the presence of dysplastic features, we suggest that dysplastic features do not directly relate to apoptosis.

Clinicopathological features of acute megakaryoblastic leukaemia: Relationship between fibrosis and platelet-derived growth factor.

Acute megakaryoblastic leukaemia (AMGL) is an uncommon disease with poor prognosis. Histopathologically, AMGL cases show variable degree of fibrosis and the presence of uniform blasts or mature dysplastic megakaryocytes. Here we examined 18 cases of AMGL, including idiopathic (n = 9) and secondary (n = 9) cases. Fourteen cases were males and four were females, ranging in age from 14 to 87 years (median, 58). All cases had anaemia, but leukocyte and platelet counts varied. Blast cells were detected in the peripheral blood of 14 cases. Fourteen of 16 cases showed chromosomal abnormalities. The median survival was 6 months (range, 1-48 months). Survival rates did not correlate with the severity of fibrosis, proportion of blast cells and cause of AMGL. Nine of the 11 cases examined immunohistochemically were positive for platelet-derived growth factor (PDGF)(-BB), especially megakaryoblasts and a few fibroblasts. The PDGF-positive cases showed various degrees of fibrosis, while the negative cases showed no evidence of fibrosis. Our results confirmed the poor prognosis of patients with AMGL, irrespective of the degrees of fibrosis, and demonstrated that PDGF could play an important role in the pathogenesis of marrow fibrosis.

The incidence of leukemia, lymphoma and multiple myeloma among atomic bomb survivors: 1950-2001.

A marked increase in leukemia risks was the first and most striking late effect of radiation exposure seen among the Hiroshima and Nagasaki atomic bomb survivors. This article presents analyses of radiation effects on leukemia, lymphoma and multiple myeloma incidence in the Life Span Study cohort of atomic bomb survivors updated 14 years since the last comprehensive report on these malignancies. These analyses make use of tumor- and leukemia-registry based incidence data on 113,011 cohort members with 3.6 million person-years of follow-up from late 1950 through the end of 2001. In addition to a detailed analysis of the excess risk for all leukemias other than chronic lymphocytic leukemia or adult T-cell leukemia (neither of which appear to be radiation-related), we present results for the major hematopoietic malignancy types: acute lymphoblastic leukemia, chronic lymphocytic leukemia, acute myeloid leukemia, chronic myeloid leukemia, adult T-cell leukemia, Hodgkin and non-Hodgkin lymphoma and multiple myeloma. Poisson regression methods were used to characterize the shape of the radiation dose-response relationship and, to the extent the data allowed, to investigate variation in the excess risks with gender, attained age, exposure age and time since exposure. In contrast to the previous report that focused on describing excess absolute rates, we considered both excess absolute rate (EAR) and excess relative risk (ERR) models and found that ERR models can often provide equivalent and sometimes more parsimonious descriptions of the excess risk than EAR models. The leukemia results indicated that there was a nonlinear dose response for leukemias other than chronic lymphocytic leukemia or adult T-cell leukemia, which varied markedly with time and age at exposure, with much of the evidence for this nonlinearity arising from the acute myeloid leukemia risks. Although the leukemia excess risks generally declined with attained age or time since exposure, there was evidence that the radiation-associated excess leukemia risks, especially for acute myeloid leukemia, had persisted throughout the follow-up period out to 55 years after the bombings. As in earlier analyses, there was a weak suggestion of a radiation dose response for non-Hodgkin lymphoma among men, with no indication of such an effect among women. There was no evidence of radiation-associated excess risks for either Hodgkin lymphoma or multiple myeloma.

Mutations in the nucleolar phosphoprotein, nucleophosmin, promote the expression of the oncogenic transcription factor MEF/ELF4 in leukemia cells and potentiates transformation.

Myeloid ELF1-like factor (MEF/ELF4), a member of the ETS transcription factors, can function as an oncogene in murine cancer models and is overexpressed in various human cancers. Here, we report a mechanism by which MEF/ELF4 may be activated by a common leukemia-associated mutation in the nucleophosmin gene. By using a tandem affinity purification assay, we found that MEF/ELF4 interacts with multifactorial protein nucleophosmin (NPM1). Coimmunoprecipitation and GST pull-down experiments demonstrated that MEF/ELF4 directly forms a complex with NPM1 and also identified the region of NPM1 that is responsible for this interaction. Functional analyses showed that wild-type NPM1 inhibited the DNA binding and transcriptional activity of MEF/ELF4 on the HDM2 promoter, whereas NPM1 mutant protein (Mt-NPM1) enhanced these activities of MEF/ELF4. Induction of Mt-NPM1 into MEF/ELF4-overexpressing NIH3T3 cells facilitated malignant transformation. In addition, clinical leukemia samples with NPM1 mutations had higher human MDM2 (HDM2) mRNA expression. Our data suggest that enhanced HDM2 expression induced by mutant NPM1 may have a role in MEF/ELF4-dependent leukemogenesis.