Takao Sekine

Diagnostic and clinical importance of interleukin-2 receptor alpha chain expression on non-T-cell acute leukaemia cells

The expression of interleukin‐2 receptors (IL‐2R) was examined in 328 adult patients with non‐T‐cell (non‐T) acute leukaemia and blast crisis of chronic myelocytic leukaemia (CML.BC) using two monoclonal antibodies, anti‐Tac for IL‐2R α chain (IL‐2Rα) and Mikβ1 for IL‐2R β chain (IL‐2Rβ). Leukaemic cells in the following cases were positive for anti‐Tac; 28/192 of acute myelocytic leukaemia (AML), 24/44 CML‐BC, 4/28 CD19(+)CD10(‐) acute lympho‐blastic leukaemia (ALL), and 20/64 common ALL (c‐ALL). IL‐2Rβ was not detected on leukaemic cells of any case examined. Eleven of IL‐2Rα(+) AML were derived from myelodysplastic syndrome. None of the IL‐2Rα positive leukaemic cells responded to exogenous recombinant human IL‐2 (rhIL‐2) in culture. In addition, IL‐2Rα expression on non‐T leukaemic cells was closely correlated with coexpressing different lineage markers and the presence of the Philadelphia abnormality. Marked increase of serum soluble IL‐2Rα was demonstrated in the IL‐2Rα(+) patients examined. Clinically, the IL‐2Rα(+) patients showed significantly lower response to chemotherapy and poorer prognosis than IL‐2Rα(‐) patients. Our results clearly indicate the diagnostic importance of IL‐2Rα expression in non‐T acute leukaemia with a close relation to the particular cellular characteristics and the prognosis.

Breakthrough disseminated zygomycosis induced massive gastrointestinal bleeding in a patient with acute myeloid leukemia receiving micafungin.

A 69-year-old man, who had been receiving prednisolone for 11 months for treatment of interstitial pneumonia, was diagnosed with acute myeloid leukemia. During induction therapy, he developed severe pneumonia. Although meropenem and micafungin were started, he died of circulatory failure owing to massive gastrointestinal bleeding. Autopsy specimens obtained from the stomach revealed fungal hyphae, which had invaded diffusely into submucosal vessels and caused the massive gastric bleeding. The same hyphae were also observed in both lungs. A diagnosis of disseminated zygomycosis was confirmed by its characteristic histopathological findings. Because zygomycetes are spontaneously resistant to the newer antifungal agents, such as voriconazole or micafungin, it seems likely that the prevalence of zygomycosis as a breakthrough infection may increase in the future. Zygomycosis is a rare, but life-threatening, deep fungal infection that appears in immunologically or metabolically compromised hosts. Its manifestations are clinically similar to those of invasive aspergillosis. In addition to the well-established epidemiology of zygomycosis, this case suggests the following new characteristics. (1) Although the gastrointestinal manifestation of zygomycosis is relatively rare, it is observed more frequently than invasive aspergillosis. (2) Gastrointestinal zygomycosis occasionally leads to the development of necrotic ulcers and may induce hemorrhagic shock.(3) We should be cautious of an occurrence of breakthrough zygomycosis when we use echinocandins for patients with known risk factors, especially steroid use and neutropenia. (4) For patients who are receiving broad-spectrum antibiotics and echinocandins, who are negative for culture studies and aspergillus antigen, and who present with unresolved fever, it is important to make a prompt clinical diagnosis of zygomycosis.

A potential activity of valproic acid in the stimulation of interleukin-3 mediated megakaryopoiesis and erythropoiesis

OBJECTIVE Although the anticancer activities of histone deacetylase (HDAC) inhibitors have been studied, a role for HDAC in normal hematopoiesis has not been clearly defined. Previous studies have shown that the potent HDAC inhibitor FK228 stimulates interleukin (IL)-3-mediated erythropoiesis. Here, we examined whether the widely used valproic acid (VPA) affects megakaryopoiesis as well as erythropoiesis. MATERIALS AND METHODS CD34(+) cells were incubated in serum-free or serum-containing cultures with cytokines, with or without VPA. RESULTS In the serum-free cultures containing IL-3+stem cell factor (SCF), VPA significantly increased generation of CD61(+)GPA(-) megakaryocytic and a CD61(+)GPA(+) mixture of megakaryocytic and erythroid precursors from CD34(+) hematopoietic precursors at a pharmacological concentration (100 microg/mL). The increase in generation of megakaryocytic and erythroid precursors by VPA was confirmed by replating cultured cells with thrombopoietin+SCF and erythropoietin+SCF, respectively. VPA was as potent as FK228. In cultures with granulocyte-macrophage colony-stimulating factor+SCF, where CD61(-)GPA(+) erythroid precursors were mostly developed, VPA mainly enhanced the generation of CD61(-)GPA(+) erythroid precursors. In serum-containing cultures, only low numbers of CD61(+) or GPA(+) cells were developed with IL-3+SCF. Nevertheless, a substantial number of these cells were generated with VPA. Furthermore, these stimulating effects of VPA were observed by incubating CD34(+) cells from patients with myelodysplastic syndrome. Quantitative reverse transcription polymerase chain reaction showed that VPA enhanced GATA-2, but not GATA-1, messenger RNA expression with IL-3+SCF. CONCLUSIONS These results indicate a novel role for VPA in enhancing the potential of IL-3 to stimulate megakaryopoiesis as well as erythropoiesis and suggest a new therapeutic approach of epigenetic therapy for hematological disease.

Low BCL-2 expression in acute leukemia with t(8;21) chromosomal abnormality

In de novo t(8;21) AML which shows terminal neutrophilic differentiation, the BCL-2 expression was found to be significantly lower than that in types of other AML regardless of the phenotypic differentiation status. An inverse correlation between BCL-2 expression and the S/G2/M population cells was observed in AML. The S/G2/M population in t(8;21)AML was larger than in the other types of AML. In t(8;21)AML, spontaneous apoptosis after a 12-h liquid culture was prominent, and the autonomous DNA synthesis after a 72-h liquid culture was low. G-CSF and IL-5 promoted the colony formation of t(8;21)AML cells. The data suggest that, in vivo, the low BCL-2 in t(8;21)AML induced entry of cells from the G0/G1 phase to S phase, but the cells easily die by apoptosis, in vitro. The low BCL-2 expression and the supportive effects of G-CSF and IL-5 in t(8;21)AML is thought to be a key phenomenon which might be related to the formation of the in vivo blood picture, such as prominent neutrophilic differentiation and eosinophilia. Cellular extracts from t(8;21)AML cell line Kasumi-1 bound to both the AML1 and CRE binding sites in the bcl-2 promoter, but none of the cellular extracts from de novo t(8;21)AML bound to either of these sites. The DNA binding activity of transactivators in de novo t(8;21)AML is different from that in Kasumi-1 cells probably due to the phosphorylation status.

Breakthrough cryptococcosis in a patient with systemic lupus erythematosus (SLE) receiving micafungin

A 67-year-old woman with systemic lupus erythematosus (SLE) was admitted to our hospital because of lupus nephritis. Methylprednisolone minipulse therapy dramatically reduced her proteinuria; however; she then complained of general fatigue with low-grade fever. Radiological and culture studies revealed no infectious focus, but she was treated with meropenem and micafungin, considering her immunosuppressive state. Cytomegalovirus antigenemia was later determined and ganciclovir was added. She became afebrile, but complained of nausea and headache, and disorientation, without meningeal signs. Because a brain computed tomography (CT) scan showed no abnormality, we initially suspected some kind of drug interaction. Despite the discontinuation of all drugs, however, she still suffered from disturbance of consciousness. A lumbar puncture revealed yeast cells stained by India ink. A diagnosis of cryptococcal meningitis was confirmed. Though fluconazole and meropenem were administered, the patient died. Autopsy findings revealed disseminated cryptococcosis concomitant with pulmonary aspergillosis. Micafungin is a recently approved echinocandin-class antifungal agent that is now widely used in Japan because of its minimal toxicity and broadspectrum activity. However, such echinocandins have limited activity against a number of fungi. Indeed, breakthrough trichosporonosis is becoming a significant problem in patients with hematological malignancies who are receiving echinocandins. To the best of our knowledge, breakthrough cryptococcosis, as seen in our patient, has not been reported previously in patients who were receiving micafungin as an empiric antifungal therapy. This case highlights that cryptococcosis should be kept in mind as a possible breakthrough infection during the administration of echinocandins, especially in patients with cellular immunodeficiency.

Molecular analysis of PDGFRα/β genes in core binding factor leukemia with eosinophilia

Abstract:  Eosinophilia sometimes occurs in acute myeloid leukemia (AML), especially in core binding factor (CBF) leukemia. However, the pathogenesis of the differentiation from leukemic progenitors to eosinophils is not well understood in this type of leukemia. Recent reports showed that a novel fusion tyrosine kinase, Fip1‐like1 (FIP1L1) platelet‐derived growth factor receptor alpha (PDGFRα), is found in idiopathic hypereosinophilic syndrome. The involvement of another chimeric gene, PDGFRβ, was also reported in myeloproliferative disorder with eosinophilia. These chimeric genes cause constitutive activation of PDGFR tyrosine kinases. On the other hand, a two‐hit model for the pathogenesis of AML, which seems to be caused by inactivating mutations in transcription factors and genetic lesions in tyrosine kinase resulting in constitutive activation, has been proposed. On the basis of these findings, we screened for the expression of the FIP1L1‐PDGFRα fusion gene and for mutations in the juxtamembrane and tyrosine kinase domains of PDGFRα/β genes in 22 cases of CBF leukemia with eosinophilia. Among these cases, no FIP1L1‐PDGFRα fusion gene was found. Although cDNA sequencing also detected three types of single‐nucleotide alterations at kinase domains in PDGFRα/β genes, all of them were silent changes and polymorphisms. Therefore, PDGFRα/β genes do not appear to play a significant pathogenetic role in eosinophilia or leukemogenesis of CBF leukemia.

Colonic and peritoneal tuberculosis associated with coloduodenal fistula

We report a very rare case of tuberculous colitis that showed relatively long-segment involvement of the colon near the hepatic flexure with coloduodenal fistula that caused severe malnutrition. The formation of fistula in abdominal tuberculosis is very rare. This is the eighth reported case of abdominal tuberculosis with fistula and the first reported case with a coloduodenal fistula.

A role for protein kinase C in the growth of human erythroid progenitor cells

We searched for a possible role for protein kinase C in the growth of human erythroid progenitor cells, using pharmacologic approaches. Two protein kinase C inhibitors, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7) and staurosporine, dose-dependently inhibited the growth of immature erythroid progenitor cells (BFU-E) induced by interleukin 3 (IL-3) plus erythropoietin (Ep) or granulocyte macrophage colony-stimulating factor (GM-CSF) plus Ep whereas a weaker analog of H-7, N-(2-guanidinoethyl)-5-isoquinoline sulfonamide (HA-1004), had no effect on the number of BFU-E. These three compounds had no effect on the growth of mature erythroid progenitor cells (CFU-E) stimulated by Ep. The culture of accessory cell-depleted bone marrow demonstrated that the effects of these compounds on colony formation do not appear to be mediated by accessory cells. The potential of these compounds to inhibit the GM-CSF-dependent growth of KG-1 cells correlated well with the extent of their inhibitor of protein kinase C activities from KG-1 cells. Thus, the protein kinase C system is apparently involved in the growth of BFU-E, supported by IL-3 or GM-CSF. The growth signal for CFU-E transduced by Ep may be achieved through other systems.

Selective Blast Cell Reduction in Elderly Patients with Acute Myeloid Leukemia Secondary to Myelodysplastic Syndrome Treated with Methylprednisolone

The management of elderly patients with acute myeloid leukemia (AML) and a poor performance status is challenging. An 89-year-old man with AML secondary to myelodysplastic syndrome (MDS) and a poor performance status (4) underwent treatment with methylprednisolone (mPSL) (125 mg/body), which resulted in a remarkable reduction of blast cells in the peripheral blood. Neutrophil counts were maintained or increased. Although the suppression was of short duration, mPSL was useful for disease control because it selectively reduced blast counts while maintaining the patient’s performance status. In vivo and in vitro findings suggested that mPSL had direct inhibitory actions on the survival of blast cells. On the basis of this experience, we gave the same mPSL dose to other elderly patients with MDS/AML (n = 5) or AML-M4 (n = 1) who had a poor performance status (3 or higher) and appeared unable to tolerate standard cytotoxic chemotherapies. Selective and significant blast cell reduction was observed in 4 of the 5 patients with MDS/AML, whereas no effects were seen in the AML patient. Although our experience is limited, these findings may provide a clue to understanding the mechanisms regulating the survival of blast cells of MDS/AML and indicate that mPSL may provide a benefit to a subset of these patients.

[Relapse in the nasal cavity of a patient with extranodal NK/T-cell lymphoma initially presenting as plantar subcutaneous tumor].

A 36-year-old woman complained of a mass on the sole of her foot in February 200X. She was diagnosed with extranodal NK/T-cell lymphoma, nasal type (ENKL) by skin biopsy. Because the lesion was localized on the subcutaneous tissue of the sole, she was treated with RT/2/3DeVIC, resulting in a complete response (CR). In March of the following year, PET/CT showed significant uptake and mucosal thickening in the right nasal cavity, and a mucosal biopsy confirmed ENKL infiltration. Because the lesion was localized in the nasal cavity, she was re-treated with RT/2/3DeVIC, with a focus on local control, and she achieved a second CR. She subsequently received allogeneic hematopoietic stem cell transplantation in the hope of preventing systemic relapse. She has remained in CR for four years since the transplantation. Our case suggests that allogeneic hematopoietic stem cell transplantation to be a potentially promising approach to curative treatment for recurrent ENKL in younger patients. As nasal lesions may subsequently appear during the course of primary non-nasal ENKL, ongoing meticulous evaluation for nasal lesions is important.