Naohito Fujishima

Acquired pure red cell aplasia: updated review of treatment.

Pure red cell aplasia (PRCA) is a syndrome characterized by a severe normocytic anaemia, reticulocytopenia, and absence of erythroblasts from an otherwise normal bone marrow. Primary PRCA, or secondary PRCA which has not responded to treatment of the underlying disease, is treated as an immunologically‐mediated disease. Although vigorous immunosuppressive treatments induce and maintain remissions in a majority of patients, they carry an increased risk of serious complications. Corticosteroids were used in the treatment of PRCA and this has been considered the treatment of first choice although relapse is not uncommon. Cyclosporine A (CsA) has become established as one of the leading drugs for treatment of PRCA. However, common concerns have been the number of patients treated with CsA who achieve sustained remissions and the number that relapse. This article reviews the current status of CsA therapy and compares it to other treatments for diverse PRCAs.

Influence of CYP3A5 and drug transporter polymorphisms on imatinib trough concentration and clinical response among patients with chronic phase chronic myeloid leukemia

Imatinib mesylate (IM) trough concentration varies among IM-treated chronic myeloid leukemia (CML) patients. Although IM pharmacokinetics is influenced by several enzymes and transporters, little is known about the role of pharmacogenetic variation in IM metabolism. In this study, associations between IM trough concentration, clinical response and 11 single-nucleotide polymorphisms in genes involved in IM pharmacokinetics (ABCB1, ABCC2, ABCG2 CYP3A5, SLC22A1 and SLCO1B3) were investigated among 67 Japanese chronic phase CML patients. IM trough concentration was significantly higher in patients with a major molecular response than in those without one (P=0.010). No significant correlations between IM trough concentration and age, weight, body mass index or biochemical data were observed. However, the dose-adjusted IM trough concentration was significantly higher in patients with ABCG2 421A than in those with 421C/C (P=0.015). By multivariate regression analysis, only ABCG2 421A was independently predictive of a higher dose-adjusted IM trough concentration (P=0.015). Moreover, previous studies have shown that the ABCG2 421C>A (p.Q141K) variant is prevalent among Japanese and Han Chinese individuals and less common among Africans and Caucasians. Together, these data indicate that plasma IM concentration monitoring and prospective ABCG2 421C>A genotyping may improve the efficacy of IM therapy, particularly among Asian CML patients.

Prognostic factors and outcomes of adult patients with acute myeloid leukemia after first relapse

Background Patients with acute myeloid leukemia who are treated with conventional chemotherapy still have a substantial risk of relapse; the prognostic factors and optimal treatments after relapse have not been fully established. We, therefore, retrospectively analyzed data from patients with acute myeloid leukemia who had achieved first complete remission to assess their prognosis after first relapse. Design and Methods Clinical data were collected from 70 institutions across the country on adult patients who were diagnosed with acute myeloid leukemia and who had achieved a first complete remission after one or two courses of induction chemotherapy. Results Among the 1,535 patients who were treated with chemotherapy alone, 1,015 relapsed. Half of them subsequently achieved a second complete remission. The overall survival was 30% at 3 years after relapse. Multivariate analysis showed that achievement of second complete remission, salvage allogeneic hematopoietic cell transplantation, and a relapse-free interval of 1 year or longer were independent prognostic factors. The outcome after allogeneic transplantation in second complete remission was comparable to that after transplantation in first complete remission. Patients with acute myeloid leukemia and cytogenetic risk factors other than inv(16) or t(8;21) had a significantly worse outcome when they did not undergo salvage transplantation even when they achieved second complete remission. Conclusions We found that both the achievement of second complete remission and the application of salvage transplantation were crucial for improving the prognosis of patients with acute myeloid leukemia in first relapse. Our results indicate that the optimal treatment strategy after first relapse may differ according to the cytogenetic risk.

Long-term responses and outcomes following immunosuppressive therapy in large granular lymphocyte leukemia-associated pure red cell aplasia: a Nationwide Cohort Study in Japan for the PRCA Collaborative Study Group

This report describes long-term responses following immunosuppressive therapy in large granular lymphocyte leukemia-associated pure red cell aplasia. Large granular lymphocyte leukemia-associated pure red cell aplasia accounts for a significant portion of secondary pure red cell aplasia cases. However, because of its rarity, long-term responses and relapse rates after immunosuppressive therapy are largely unknown. We conducted a nationwide survey in Japan and collected 185 evaluable patients. Fourteen patients with large granular lymphocyte leukemia-associated pure red cell aplasia were evaluated. Cyclophosphamide, cyclosporine A and prednisolone produced remissions in 6/8, 1/4 and 0/2 patients respectively. Seven and 5 patients were maintained on cyclophosphamide or cyclosporine A respectively. Two patients relapsed after stopping cyclophosphamide, and 2 patients relapsed during maintenance therapy with cyclosporine A. The median relapse-free survival in the cyclophosphamide - and the cyclosporine A groups was 53 and 123 months respectively. Large granular lymphocyte leukemia-associated pure red cell aplasia showed a good response to either cyclophosphamide or cyclosporine A. Most patients continued to receive maintenance therapy and it remains uncertain whether cyclophosphamide or cyclosporine A can induce a maintenance-free hematologic response in large granular lymphocyte leukemia-associated pure red cell aplasia.

Long-term response and outcome following immunosuppressive therapy in thymoma-associated pure red cell aplasia: a nationwide cohort study in Japan by the PRCA collaborative study group

This nationwide survey in Japan indicates that thymoma-associated pure red cell aplasia responds in most instances to cyclosporine A, and that this treatment is also effective in preventing relapse of anemia. Background Thymoma-associated pure red cell aplasia (PRCA) accounts for a significant proportion of cases of secondary PRCA and immunosuppressive therapy has been reported to be useful in this condition. However, because of its rarity, the long-term response and relapse rates after immunosuppressive therapy are largely unknown, and optimal management of this disorder remains unclear. The aim of this study was to collect more information on the outcome of patients with thymoma-associated PRCA. Design and Methods We conducted a nationwide survey in Japan. From a total of 185 patients, comprising 73 with idiopathic and 112 with secondary PRCA, 41 patients with thymoma were evaluated for this report. End-points of this study were the response rate, duration of the response after immunosuppressive therapy and overall survival. Results Surgical removal of thymoma was reported in 36 patients, 16 of whom developed PRCA at a median of 80 months post-thymectomy. First remission induction therapy was effective in 19 of 20 patients treated with cyclosporine, 6 of 13 patients treated with corticosteroids and 1 of 1 treated with cyclophosphamide. No cyclosporine-responders relapsed within a median observation period of 18 months (range; 1 to 118 months). Relapse of anemia was observed in three corticosteroid-responders who did not receive additional cyclosporine. Only two patients were in remission after stopping therapy for 19 and 67 months. The estimated median overall survival time of all patients was 142 months. Conclusions Thymoma-associated PRCA showed an excellent response to cyclosporine and cyclosporine-containing regimens were effective in preventing relapse of anemia. It does, however, remain uncertain whether cyclosporine can induce a maintenance-free hematologic response.

Diagnosis and Management of Acquired Pure Red Cell Aplasia

Pure red cell aplasia is a syndrome characterized by a severe normocytic anemia, reticulocytopenia, and absence of erythroblasts from an otherwise normal bone marrow. Although the causes and natural course of this syndrome are variable and although the anemia in some patients can be managed by treatment of an underlying inflammatory or neoplastic disease, the pathogenesis of a large number of cases is autoimmune, including those associated with thymoma, and are best managed with immunosuppressive therapy.

Acquired pure red cell aplasia associated with malignant lymphomas: a nationwide cohort study in Japan for the PRCA Collaborative Study Group.

Pure red cell aplasia (PRCA) has been reported in association with lymphoma as one of the autoimmune diseases seen during the course of lymphoid malignancies. However, the relation of PRCA with the underlying lymphomas remains unclear. The aim of this study was to clarify the histologic subtypes of lymphomas, the chronological sequence of anemia and lymphoma, and the response to treatment. We conducted a nationwide survey in Japan. From a cohort of 185 PRCA patients, 8 patients with lymphoma were evaluated. Histologic subtypes varied and the lymphoma was of the B‐cell type in four cases and of the T‐cell type in four. Four patients simultaneously developed PRCA and lymphoma. Three patients developed PRCA following lymphoma, two of whom developed anemia during remission of lymphoma. PRCA preceded lymphoma in one patient. Effective chemotherapy was associated with remission of anemia in concurrent lymphoma and PRCA. Overall, anemia responded to chemotherapy and/or immunosuppressive therapy in seven patients. In four responding patients, PRCA remained in durable remission without maintenance immunosuppressive therapy, which is different from a recurrent feature of idiopathic PRCA. We suggest that the mechanism of lymphoma‐associated PRCA is heterogeneous and that durable maintenance‐free remission of anemia can be obtained in some patients. Am. J. Hematol., 2009.

Hepatic adverse event profile of inotuzumab ozogamicin in adult patients with relapsed or refractory acute lymphoblastic leukaemia: results from the open-label, randomised, phase 3 INO-VATE study

BACKGROUND The INO-VATE study demonstrated efficacy and safety of inotuzumab ozogamicin versus standard care in adults with relapsed or refractory B-cell acute lymphoblastic leukaemia. Here, we report the frequency of, and potential risk factors for, hepatotoxicity in patients in this trial and after treatment and subsequent haemopoietic stem-cell transplantation (HSCT). METHODS In this open-label, phase 3, multicentre, international study, adults with relapsed or refractory, CD22-positive, Philadelphia chromosome (Ph)-positive or Ph-negative B-cell acute lymphoblastic leukaemia who were due to receive first or second salvage treatment were randomly assigned (1:1) via an interactive voice response system to receive inotuzumab ozogamicin (starting dose 1·8 mg/m2 per cycle [0·8 mg/m2 on day 1; 0·5 mg/m2 on days 8 and 15 of a 21-28 day cycle for ≤6 cycles]) or standard care (either fludarabine plus cytarabine plus granulocyte colony-stimulating factor, mitoxantrone plus cytarabine, or high-dose cytarabine). Stratification factors at randomisation were duration of first remission (<12 months vs ≥12 months), salvage treatment phase (first vs second), and age (<55 years vs ≥55 years). We present data up to March 8, 2016. At this cutoff date, all patients had been discontinued from treatment but 54 patients were continuing in long-term follow-up. Long-term follow-up has now been completed, with the final patients last visit on Jan 4, 2017. This prespecified safety analysis describes investigator-assessed treatment-emergent hepatotoxicity, including sinusoidal obstruction syndrome (also known as veno-occlusive disease) in patients during study treatment or thereafter (without follow-up HSCT) and after study treatment and subsequent HSCT, for all patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, number NCT01564784. FINDINGS Between Aug 27, 2012, and and the data cutoff of March 8, 2016, 326 patients were randomly assigned to receive inotuzumab ozogamicin (n=164) or standard care (n=162). 164 patients in the inotuzumab ozogamicin group and 143 in the standard care group received at least one dose of study treatment and were included in the safety population. At data cutoff, median duration of treatment (induction) was 8·9 weeks (IQR 4·1-13·1) in the inotuzumab ozogamicin group and 0·9 weeks (0·9-1·1) in the standard care group. Treatment-emergent hepatotoxicities (of all grades) were more frequent in the inotuzumab ozogamicin group (83 [51%] of 164 patients) than in the standard care group (49 [34%] of 143 patients). The frequency of sinusoidal obstruction syndrome-comprising events occurring during treatment (or follow-up without HSCT) and after treatment and subsequent HSCT-was higher in the inotuzumab ozogamicin group (22 [13%]; 18 [82%] of which were grade 3 or worse) than in the standard care group (one [<1%]). During study therapy or follow-up without HSCT, five (3%) patients in the inotuzumab ozogamicin group developed sinusoidal obstruction syndrome compared with no patients in the standard care group. Of the 77 patients who received inotuzumab ozogamicin and proceeded to HSCT, 17 (22%) had sinusoidal obstruction syndrome; five events after follow-up HSCT were fatal. Of 32 patients who received standard care and proceeded to HSCT, one (3%) had (non-fatal) sinusoidal obstruction syndrome that was ongoing at the time of death due to septic shock. In multivariate analysis, conditioning with two alkylating agents (p=0·015 vs one alkylating agent) and last available pre-HSCT bilirubin concentration of greater than or equal to the upper limit of normal (ULN; p=0·009 vs <ULN) were associated with increased risk of sinusoidal obstruction syndrome in patients who received inotuzumab ozogamicin. The estimated hazard ratio for overall survival in patients with follow-up HSCT (inotuzumab ozogamicin vs standard care) was 1·227 (97·5% CI 0·656-2·292; one-sided stratified log-rank p=0·77); at 24 months, the estimated probability of survival was 38·9% (95% CI 27·6-50·0) in the inotuzumab ozogamicin group versus 28·7% (11·2-49·1) in the standard care group. INTERPRETATION Treatment with inotuzumab ozogamicin is associated with increased hepatotoxicity, especially after follow-up HSCT, compared with standard care. FUNDING Pfizer.

Age-associated alteration of γδ T-cell repertoire and different profiles of activation-induced death of Vδ1 and Vδ2 T cells

It has been suggested that γδ T cells are involved in certain autoimmune disorders. To establish reference data for clinical studies to explore the role of γδ T cells in autoimmune bone marrow failure syndrome, we examined the γδ T-cell repertoire in 120 healthy Japanese individuals by flow cytometry. The average numbers of T lymphocytes in blood were as follows: 1,084 ± 369 (SD) αβ T cells, 68 ± 44 γδ T cells, 16 ± 12 Vδ1 T cells, and 43 ± 36 Vδ2 T cells (/μl). Absolute numbers of γδ T cells decreased with aging (R = −0.378, P < 0.001). The decrease of γδ T cells was the result of reduction of Vδ2, but not of Vδ1, T cells. Numbers of Vδ2 T cells were significantly higher in male than in female donors (P = 0.007). The Vδ2 T cells but not Vδ1 T cells showed a rapid reduction in cell numbers on mitogen stimulation, which was accompanied by modest down-regulation of Bcl-2 protein expression. These results indicate that age and gender have a major impact on γδ T-cell repertoire in Japanese donors, as well as European and American donors. The age-related decrease of Vδ2 T cells may be explained by their susceptibility to activation-induced cell death.

A synthetic double-stranded RNA, poly I:C, induces a rapid apoptosis of human CD34+ cells

Toll-like receptor 3 (TLR3), retinoic acid-inducible gene I, and melanoma differentiation-associated antigen 5 (RIG-I/MDA-5) helicases are known to sense double-stranded RNA (dsRNA) virus and initiate antiviral responses, such as production of type-I interferons (IFNs). Recognition of dsRNA by TLR3 or RIG-I/MDA-5 is cell-type-dependent and recent studies have shown a direct link between TLRs and hematopoiesis. We hypothesized that viral dsRNA recognized by either TLR3 or RIG-I/MDA-5, affects the growth of human hematopoietic stem/progenitor cells. Here we show that polyinosinic polycytidylic acid (poly I:C)-mediated very rapid apoptosis occurs within 1 hour in CD34(+) cells in a dose-dependent manner. Polyadenylic-polyuridylic acid, another synthetic dsRNA that signals only through TLR3, had no effect. Poly I:C-LMW/LyoVec, a complex between low molecular-weight poly I:C and the transfection reagent LyoVec, which signals only through RIG-I/MDA-5, induces apoptosis of CD34(+) cells. A strong and sustained upregulation of messenger RNA and protein levels of Noxa, a proapoptotic BH3-only protein that can be induced by RIG-I/MDA-5 pathway, is found in CD34(+) cells treated by poly I:C. Although poly I:C upregulates type-I IFNs in CD34(+) cells, neither exogenous IFN-α nor IFN-β induces rapid apoptosis in CD34(+) cells and neutralization or blocking of type-I IFN receptor does not rescue CD34(+) cells, whereas Z-VAD, a pan-caspase inhibitor, rescues the cells from apoptosis. These results suggest that RIG-I/MDA-5, but not TLR3, signaling triggers poly I:C-induced rapid apoptosis of human CD34(+) cells, which will provide an insight into the mechanisms of dsRNA virus-mediated hematopoietic disorders.