Nahoko Shoji

Clinico-hematologic features of myelodysplastic syndrome presenting as isolated thrombocytopenia: An entity with a relatively favorable prognosis

The existence of isolated cytopenia in myelodysplastic syndrome (MDS) has been described, however, the exact clinico-hematologic features of such MDS patients are still obscure. The aim of this study was to provide additive clinico-hematologic information on MDS patients with isolated thrombocytopenia in comparison with idiopathic thrombocytopenic purpura (ITP). We searched for MDS with isolated thrombocytopenia in 146 sequential patients with MDS and evaluated their clinical features at the time of MDS diagnosis. We found 13/146 (8.9%) patients with MDS showing isolated thrombocytopenia. These patients were male predominant (10:3) and were all diagnosed as refractory anemia after reassessment of marrow findings, however, two of them had an initial diagnosis of ITP. Leukemic transformation was rarely noted (1/13 patients), but 1 patient developed myelofibrosis. Cytogenetic study demonstrated that 3 patients had del(20q), 2 had t(1;7)(q10;p10), and 5 showed normal karyotypes. The most prominent morphologic feature in the megakaryocytes was the presence of micromegakaryocytes (5/13) and 8/13 had hypogranulated neutrophils, whereas pseudo-Pelger nuclear anomaly was rarely detectable. Of note is that 7/13 patients had an increased number of megakaryocytes in the marrow. Most patients survived for more than 2 years. Approximately 9% of MDS patients showed isolated thrombocytopenia and most of them had a favorable prognosis. Some MDS patients with isolated thrombocytopenia have been mistakenly diagnosed as having ITP, since approximately 50% of our MDS patients with isolated thrombocytopenia had an increased number of megakaryocytes with low grade dysplasia. Therefore, careful attention to differential diagnosis is recommended for these patients.

Comparative multi-color flow cytometric analysis of cell surface antigens in bone marrow hematopoietic progenitors between refractory anemia and aplastic anemia.

Refractory anemia (RA) in myelodysplastic syndrome (MDS) without prominent dysplasia closely resemble the mild type of aplastic anemia (AA) in their hematological features. This sometimes makes it difficult to distinguish clearly between the two diseases. Using the multi-color flow cytometric technique, we compared cell surface antigen expression patterns on bone marrow hematopoietic progenitor cells which were isolated as a CD34 positive- CD45 dull positive with low side scatter intensity (CD34(+)CD45(dull+)SSC(low)) population in flow cytogram between RA (n=12) and AA (n=11). The antigens analyzed in CD34(+)CD45(dull+)SSC(low) mononuclear cells were: CD38 and CD71 for cell growth-related antigens, CD 33 and CD13 for myeloid and monocytoid lineage-associated antigens, CD7 and CD19 for lymphoid lineage, and CD14 for a monocytic lineage specific antigen. The percentages of CD34(+)CD45(dull+)SSC(low) cells in bone marrow non-erythroid mononuclear cells, and the expression frequencies of CD38, CD71, CD33 and CD13 antigens in CD34(+)CD45(dull+)SSC(low) progenitors were all significantly decreased in AA compared to normal bone marrows (n=7) (P<0.005). In contrast, in RA bone marrows the percentages of CD34(+)CD45(dull+)SSC(low) cells showed wide distribution and the cell surface antigen expression patterns varied among each case: some cases showed low frequencies of CD38 and CD71 expression as well as AA, whereas the others showed high expression frequency of specific antigen(s) which may reflect the clonal expansion of an abnormal clone in bone marrow. An MDS patient who had progressed from RA to RAEB showed further projecting pattern of expression of CD38 and CD33 in CD34(+)CD45(dull+)SSC(low) population in accordance with the disease progression. These data suggest that analysis of cell surface antigen expression patterns of CD34(+)CD45(dull+)SSC(low) progenitor cells by multi-color flow cytometry appears to be a useful method for qualitative and quantitative assessment of marrow progenitor states in AA and RA, therefore this method could be helpful for early detection of clonal evolution in MDS.

Pulmonary alveolar proteinosis as a terminal complication in myelodysplastic syndromes: a report of four cases detected on autopsy.

Secondary pulmonary alveolar proteinosis (PAP) is one of the complications of hematologic malignancy and immunosuppressive diseases. We encountered four cases of myelodysplastic syndrome (MDS) associated with PAP detected on autopsy. They consisted of two refractory anemia (RA) and two patients with refractory anemia with excess blasts in transformation (RAEBt) at the time of MDS diagnosis, but all of them developed leukemic phase and were resistant to chemotherapy at the time of pulmonary episodes. Of the four MDS patients, two also had pulmonary aspergillosis. Previously, 69 patients with PAP associated with hematologic disorders have been reported, but there have been only seven cases with MDS, including our four patients. Of the 69 reported cases of PAP in hematologic malignancies, 24/63 (38%) informative patients with infection had fungal infections of the lung; 2/7 (29%) MDS cases had fungal infection. We should, therefore, pay careful attention to this possibility in cases of MDS with lung complications, including PAP, especially in patients in the leukemic phase of MDS.

Hepatosplenic αβ T-cell lymphoma with myelodysplastic syndrome

We describe a patient with hepatosplenic 33 T-cell lymphoma who showed pancytopenia and myelodysplasia. A 35-year-old man was admitted with fever, pancytopenia, and hepatosplenomegaly but with no lymphadenopathy. We also found trilineage myelodysplasia in the bone marrow on his first admission. The patient had high fever and anemia but no evidence of infection and was tentatively treated with prednisolone. This treatment resulted in a transient improvement of the cytopenia and a reduction of spleen size. However, 10 months after the first manifestation, progression of the splenomegaly and fever became apparent, and a splenectomy was performed. The pathologic findings for the spleen showed diffuse and disseminated infiltration of medium- to large-sized T-lymphocytes in the splenic red pulp. These cells were immunohistochemically positive for CD3, CD5, CD7, CD8, CD16, CD56,T-cell receptor 33 (TCR33),T-cell intracellular antigen 1, and granzyme B but were negative for CD4, CD30, CD57, and TCR33. These data suggested a diagnosis of hepatosplenic 33 T-cell lymphoma. A Southern blot analysis revealed gene rearrangement of the TCR 3-chain gene but not the immunoglobulin heavy chain gene in the spleen cells. An in situ hybridization analysis for the Epstein-Barr virus revealed negative results. The patient received 8 courses of combination chemotherapy and achieved a partial remission; however, the dysplastic features of the marrow cells persisted after the partial remission was obtained. Additional treatment with allogeneic bone marrow transplantation resulted in a transient complete remission; however, the patient relapsed 11 months later. Because he had experienced no lymphadenopathy and showed dysplastic features in the bone marrow, the diagnosis was highly dependent on the pathologic findings for the resected spleen.

Thrombocytopenia induced by imatinib mesylate (Glivec) in patients with chronic myelogenous leukemia: is 400 mg daily of imatinib mesylate an optimal starting dose for Japanese patients?

Imatinib mesylate (Glivec) is a potent and selective inhibitor of the tyrosine kinase activity of BCR-ABL. Because the mechanism of action of imatinib mesylate is inhibition of BCR-ABL tyrosine kinase, it seems likely that to achieve maximum therapeutic benefit for chronic myelogenous leukemia (CML), imatinib mesylate must be administered at a dose that maximally inhibits BCR-ABL kinase activity or, alternatively, that inhibits sufficient BCR-ABL kinase activity to induce apoptosis. According to in vitro study results, 1 M levels of imatinib mesylate are optimal for inducing cell death, and 1 M trough levels are achieved in patients using imatinib mesylate at a daily dose of more than 300 mg [1]. In a phase I/II study in which the dose-response curve in chronic-phase CML patients was examined, the therapeutic effect was reported to plateau at a dose at or slightly above 300 mg. In addition, there was no convincing evidence of dose-limiting toxicity in patients receiving a maximum dose of 1000 mg [2]. These data were used to set the standard therapeutic dose of imatinib mesylate for chronicphase patients at 400 mg daily, and thereafter, the therapeutic benefits for CML patients of imatinib mesylate at this dose were demonstrated in clinical trials [2,3]. This standard therapeutic dose has been used in administering imatinib mesylate to Japanese patients as well as patients in the United States and Europe. At our institute, however, a series of CML patients treated with 400 mg of imatinib mesylate showed thrombocytopenia, and imatinib mesylate adminisThrombocytopenia Induced by Imatinib Mesylate (Glivec) in Patients with Chronic Myelogenous Leukemia: Is 400 mg Daily of Imatinib Mesylate an Optimal Starting Dose for Japanese Patients?

Decline in Antibiotic Enzyme Activity of Neutrophils Is a Prognostic Factor for Infections in Patients with Myelodysplastic Syndrome

We used flow cytometry to measure the activities of cathepsin G and elastase. The activity of elastase in neutrophils from patients with myelodysplastic syndrome (MDS) was significantly lower than that in neutrophils from the control group (P<.001). Patients with low elastase activity were significantly susceptible to infection (P<. 05). Our study suggests that analyzing antibacterial enzymes is useful in evaluating the prognosis of patients with MDS.

Granulocyte colony-stimulating factor (G-CSF) could enhance Fcγ receptor expression in neutrophils of patients with B-cell lymphoma treated with rituximab

In the past few years, chimeric monoclonal antiCD20 antibody (IDEC-C2B8, rituximab) has been commonly used in the treatment of patients with CD20-positive B-cell lymphoma. Several studies in mice and humans suggest that rituximab can induce complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC) mediated by neutrophils as effector cells after rituximab ligation to CD20. It has been demonstrated that the activation of ADCC in vivo requires an Fcg receptor-dependent mechanism in rituximab treatment [1]. Because granulocyte colony-stimulating factor (G-CSF) can enhance the cytotoxicity and quantity of granulocytes in the activation of ADCC, it has been attempted to clarify how G-CSF administration enhances the efficacy of rituximab in the treatment of non-Hodgkin lymphoma (NHL) [2]. We therefore evaluated the efficacy of the combination of rituximab and G-CSF and measured Fcg receptor type I (CD64) and Fcg receptor type III (CD16) expression of neutrophils obtained from peripheral blood. We enrolled 6 patients with CD20-positive NHL (4 diffuse large and 2 follicular lymphoma patients) after obtaining informed consent. The patients received 6 cycles of rituximab combined with CHOP (cyclophospamide 750 mg/m on day 1, doxorubicin 50 mg/m on day 1, vincristine 1.4 mg/m on day 1, predonisolone 100 mg on days 1 through 5) during the period February 2003 to December 2003. The patients had not received any cytotoxic agents and glucocorticoids. Rituximab (375 mg/m) was given 2 days before each administration of CHOP (RCHOP). No G-CSF was administered during the first cycle of R-CHOP, but G-CSF (lenograstim, 2 mg/kg/day) was given for 3 days starting 2 days before the second infusion of rituximab (Figure 1). We measured the percentages and mean fluorescence intensity (MFI) of CD64 and CD16 on neutrophils by flow cytometry before and after each rituximab injection (on days – 3, – 1, + 17, and +19), and after the first R-CHOP (on day +5). The results of 6 patients are summarized in Figure 1. The time points of measurements were not different between each patient. Percentages of CD16-positive neutrophils did not differ during the first CHOP treatment, while the percentage of CD64-positive neutrophils before rituximab (second day of G-CSF administration) significantly increased after the first CHOP therapy (83.2% vs. 98.5%: P=0.0363). The CD16 MFI deceased after the first rituximab administration (243.3+ 151.4 vs. 164.9+ 123.9: P=0.349). However, the CD16 MFI did not change significantly during the CHOP/R-CHOP therapy. In contrast, the CD64 MFI significantly increased during the second cycle with G-CSF, more than with the first cycle without G-CSF, either before the first rituximab administration (142.6+ 38.8 vs. 77.5+ 41.4: P=0.0185) or after the first CHOP therapy (142.6+ 38.8 vs. 70.2+ 54.2: P=0.0296). The