[Acquired hemophilia A requiring plasma exchange and mechanical ventilation].

A 56-year-old man who sustained a right waist injury 1 month ago, reported to our department complaining of pain in the right waist and femur for 1 day. In a computed tomography examination, hematoma of the right iliopsoas muscle was revealed, and arterial embolization was immediately performed but was not effective. Laboratory findings showed hemoglobin levels as 5.4 g/dl, platelet of 20.2×104/µl, prothrombine time of 13.1 s, partial thromboplastin time (APTT) of 81.1 s, and a convex upward curve of the APTT cross-mixing test. The activity of the coagulation factor VIII was <1.0%, but its amount was 120%, and the level of factor VIII inhibitor was 130 Bethesda Unit/ml. Disseminated intravascular coagulation was not noted. Under the diagnosis of acquired hemophilia A, treatment with prednisolone and recombinant activated factor VII was initiated. However, APTT remained prolonged, and intubation and mechanical ventilation were required because of right hemothorax. After steroid pulse therapy and plasma exchange, APTT returned to its normal range, and the inhibitor disappeared. Thus, we finally succeeded in extubation. This case indicated that intensive care may be necessary in the early phase treatment for acquired hemophilia A.

Prednisone versus high-dose dexamethasone for untreated primary immune thrombocytopenia. A retrospective study of the Japan Hematology & Oncology Clinical Study Group.

High-dose dexamethasone (HDD) has been shown to be an effective initial treatment for immune thrombocytopenia (ITP), but it is not clear whether HDD offers any advantages over conventional-dose prednisone (PSL). We retrospectively compared the efficacy and toxicity of HDD and PSL for newly diagnosed ITP. The response was evaluated according to the International Working Group (IWG) criteria. We analyzed data from 31 and 69 patients in the HDD and PSL groups, respectively. There were no significant differences in patient characteristics between the two groups except for the incidence of the eradication of Helicobacter pylori. The response rate was better in the HDD group (42.7 vs. 28.4 %), and this difference was statistically significant when adjusted for other factors including the eradication of H. pylori. In the HDD group, a response was achieved earlier (28 vs. 152 days in median) and steroids were more frequently discontinued at 6 months (64.5 vs. 37.7 %). Among patients who achieved a response, there was no significant difference in the incidence of loss of response. There were no significant differences in the rate of adverse events, transition to chronic ITP, and splenectomy. In conclusion, HDD might enable the early cessation of steroids without a loss of response.

[Detection of BCR-ABL1 chimeric gene-positive neutrophils in a patient with mixed phenotype acute leukemia].

We experienced two patients with mixed phenotype acute leukemia with t(9;22)(q34;q11.2); BCR-ABL1 according to the WHO classification 2008. The type of BCR/ABL1 was major in both patients, and the chimeric gene was also detected in neutrophils from peripheral blood by the fluorescence in situ hybridization technique. Patient 1 was a 59-year-old Japanese woman, and patient 2 a 45-year-old Japanese man. They had both developed leukemia suddenly. Their leukemic blasts expressed B cell and myeloid cell antigens, but concomitantly in patient 1 (biphenotypic) and separately in patient 2 (biclonal). Percentages of BCR-ABL1-positive neutrophils were 98% and 89%, respectively. Both patients received an imatinib (600 mg/day)-combined Hyper-CVAD regimen as induction therapy, followed by treatment with dasatinib (140 mg/day). MEC therapy was also applied between these two treatments in patient 2. At present, patient 1 has obtained complete molecular remission quantitatively and qualitatively, and patient 2 only quantitatively. Considering their acute onsets with no prior history of chronic myelocytic leukemia (CML), they were both diagnosed as having acute leukemia with Ph1, but not blastic crisis of CML. In this tyrosine kinase inhibitor era, it has become more difficult to differentiate these two types of Ph1-positive leukemia development.

[CD20-positive peripheral T-cell lymphoma, not otherwise specified].

We report a 69-year-old male with CD3-positive peripheral T-cell lymphoma, not otherwise specified (PTCL-nos). Interestingly, tumor cells slightly expressed CD20 as well. Southern analyses of the tumor cells showed rearrangement for only the T cell receptor gene but not the immunoglobulin genes. This patient achieved partial remission with a treatment regimen of THP-COP excluding prednisolone, but died of pneumonia. Although CD20-positive PTCL is rare, a review of the reported cases suggests that CD20-positive PTCL has a poor prognosis and that bone marrow infiltration of tumor cells results in a poorer prognosis in CD20-positive PTCL than in usual PTCL. By accumulating cases of this rare entity of lymphoma, we need to clarify the biological nature of the tumor cells and usefulness of rituximab combined with standard chemotherapy.

[CAG-GO therapy for patients with relapsed or primary refractory CD33-positive acute myelogenous leukemia].

We previously tested a less toxic CAG regimen consisting of low-dose cytarabine, aclarubicin and granulocyte-colony stimulating factor for the treatment of patients with relapsed or refractory myeloid malignancies or elderly patients with untreated ones, obtaining a satisfactory complete remission rate of 62%. Gemtuzumab ozogamicin, an anti-CD33 monoclonal antibody conjugated to calicheamicin, has recently been approved as a single agent in Japan for the treatment of relapsed/refractory CD33-positive acute myelogenous leukemia (9 mg/m(2) on days1 and 15). Complete remission rate was reported as 30% in a phase 2 trial in Japan. In this study, effectiveness and safety of combining dose-attenuated gemtuzumab ozogamicin (3 mg/m(2) on day5) and original CAG regimen were assessed in nine patients with relapsed/refractory CD33-positive acute myelogenous leukemia and a median age of 70 years. Rate of complete remission with or without platelet recovery was 44% (4/9). The median duration of complete remission and overall survival were 5.5 and 16 months, respectively. Reversible myelosuppression and liver toxicity were the main adverse events, but no regimen-related death was recorded. Although only a small number of cases were included in this preliminary study, this CAG-GO regimen was found to be feasible and useful even in high-risk relapsed or refractory patients.

[Small lymphocytic lymphoma during the course of pure red cell aplasia].

A 29-year-old woman was diagnosed as having pure red cell aplasia (PRCA) in 1983. Her serum and IgG inhibited erythroid colony formation of bone marrow cells from a normal individual, suggesting antibody-mediated suppression of erythropoiesis. She was first successfully treated with corticosteroids, azathiopurine and cyclophosphamide. However, she relapsed in 1995 and her anemia became refractory to immunosuppressive therapy. In 1998, she developed systemic lymph node enlargement and was diagnosed as having B-cell small lymphocytic lymphoma. Combination chemotherapy resulted in regression of the lesion, but failed to improve the anemia. In this patient's case, we can speculate that B cells producing autoantibodies against erythroid cells have undergone transformation, or alternatively that the immunosuppressive state caused by the PRCA therapy promoted generation of a neoplastic B cell clone.

N-ras and p53 gene mutations in Japanese patients with myeloproliferative disorders.

Alterations of the N-ras oncogene and p53 tumor suppressor gene have been demonstrated to play an important role in pathogenesis of hematological malignancies. We simultaneously investigated genetic lesions of both genes in bone marrow cells from 64 Japanese patients with myeloproliferative disorders (MPD), including polycythemia vera (PV), essential thrombocythemia (ET), and idiopathic myelofibrosis (MF), by direct sequencing analysis. No mutations of the N-ras gene were detected in any cases. Two patients, one with chronic neutrophilic leukemia derived from PV and one with acute mylogenous leukemia derived from ET, exhibited three mutations of the p53 gene. Among them, two were missense mutations in exon 5 or 7 and one was a deletion in exon 5. All samples in chronic phase or from MF were devoid of mutations in both genes. These data suggested that disruptions of both genes are extremely rare in MPD in chronic phase and that loss of functions in the p53 gene could be involved in progression of MPD such as PV and ET.