Search

This study aimed to evaluate the sequential changes in the proportion of anemia among young women over eight years after the Great East Japan Earthquake in 2011 using a prospective study of the Fukushima Health Management Survey. This study focused on the women aged between 20 and 44 who lived in the evacuation area of the nuclear power plant accident. The yearly age-adjusted proportion of anemia was accessed with data between July 2011 and March 2019. A total of 9,198 women participated in the health checkup in 2011, albeit the participation was decreased to 1,241 in 2018. The age-adjusted proportion of anemia was 16.7% in 2012 and then declined after 2013 (p with Cochran-Armitage trend test = 0.03). The multivariate regression analysis identified 2 of body mass index (BMI), no history of smoking, and no habitual alcohol use as independent baseline characteristics predictive of temporality anemic condition after the disaster (Adjusted odds ratios [95% confidence interval]; 1.98 [1.43–2.74], 1.85 [1.21–2.83], and 1.42 [1.07–1.90], respectively). Thus, women with low BMI and healthier habits might risk temporarily anemic status after the disaster. Our findings signal the importance of preventing anemia in young women after the disaster.

The similarities between multiple sclerosis and idiopathic central nervous system (CNS) dysfunction after bone marrow transplantation were studied. Three patients who developed CNS dysfunction without an identified cause after bone marrow transplantation were assessed for the levels of various cytokines, evidence of viral infection, and their human leukocyte antigen status. Tumor necrosis factor-α and interferon-γ levels were increased in all three patients when their CNS symptoms occurred. In addition, reactivation of human herpesvirus-6 occurred in all three patients before the onset of CNS symptoms. Furthermore, they all had at least one of the following human leukocyte antigens: A3, B7, DR2, and DRB1: 1501. These findings suggest that the mechanism of CNS dysfunction after bone marrow transplantation has some similarities to that causing multiple sclerosis.

Cytomegalovirus (CMV) disease (interstitial pneumonia and encephalitis) is an important complication of bone marrow transplantation. We monitored cytokine, adhesion molecule, and chemokine levels from before conditioning until the early stage after allogeneic bone marrow transplantation in 15 procedures where recipients or donors were seropositive for CMV. Results were compared between the patients with symptomatic, asymptomatic CMV, and no CMV. All four patients with CMV disease had fever during the aplastic phase after bone marrow transplantation and all of them showed a marked increase of tumor necrosis factor-α, interferon-γ, and interleukin-8 at the time of leukocyte recovery (p

The efficacy and safety of high-dose chemotherapy with tandem autologous peripheral blood stem cell transplantation (auto-PBSCT) were evaluated in a multicenter clinical study of patients with advanced multiple myeloma. Eligible patients (n = 40) were consecutively enrolled in the phase I/II study and received 2-4 cycles of vincristine-adriamycin-dexamethasone regimen. The responding patients underwent PBSC harvesting following high-dose cyclophosphamide and filgrastim administration. The first auto-PBSCT (n = 32) following high-dose melphalan (200 mg/m(2)) was performed within 2 months of PBSC harvesting; the second auto-PBSCT (n = 28) was scheduled 3-6 months later. Treatment-related mortality was 2.5% (n = 1) throughout the protocol. Grade 4 nonhematologic toxicity occurred in 12.5 and 14.3% of the first and second auto-PBSCT patients, respectively. All but one patient (who died) achieved hematopoietic recovery. For the 28 patients completing the second auto-PBSCT, the results were favorable with a response rate of 65% (complete response rate = 27.5%, n = 11); the five-year progression-free survival and overall survival were 20.3 and 66.5%, respectively. In conclusion, high-dose chemotherapy with tandem auto-PBSCT is feasible and safe with a favorable response rate in treating advanced multiple myeloma in Japan.

This prospective trial assessed the safety and efficacy of allogeneic hematopoietic stem cell transplantation from a HLA-matched donor with a reduced-intensity regimen (RIST) consisting of iv fludarabine 30 mg/m(2) for 6 days and oral busulfan 4 mg/kg/day for 2 days in patients older than 50 years with hematological malignancies. Cyclosporine alone or cyclosporine with short-term methotrexate was randomized for graft-versus-host disease prophylaxis. After 30 patients had been enrolled, an interim analysis was performed, and this report focuses on a precise evaluation of the toxicity profile and chimerism kinetics. Sustained engraftment in all patients, no severe regimen-related toxicity (RRT) within 20 days, and no transplant-related mortality through Day 100 were observed. T-cell (CD3+) full-donor (over 90%) chimerism was observed in 22 of the 30 patients, while the remaining eight had mixed-donor chimerism over 77% on Day 90. Thereafter, five subsequently converted to full-donor chimerism without donor lymphocyte infusion by day 120 (n = 4) or Day 180 (n = 1). Two showed persistent mixed chimerism without relapse through Day 180. Grade III-IV acute graft-versus-host disease and extensive chronic graft-versus-host disease occurred in 10% and 73%, respectively. With a median follow-up of 1.5 years, overall survival and disease-free survival at 1 year was 83% and 62%, respectively. Seven patients hematologically relapsed overall, and five of them had myelodysplastic syndrome with poor prognostic factors. In older patients, RIST with fludarabine and busulfan was associated with acceptable toxicities and a satisfactory antileukemia effect, regardless of the early chimerism status.

The present case involves unique enteritis forming multiple ulcers associated with Epstein-Barr virus (EBV). A 57-year-old man had undergone a reduced intensity allogeneic stem cell transplantation for a relapse of multiple myeloma following sequential autologous peripheral blood stem cell transplantation. The ileum, resected for massive melena, showed multiple irregular ulcers with occasional cobblestone-like appearance. There was inflammation including numerous plasma cells in the ulcer bases and surrounding areas, where many EBV-infected plasma cells were detected by double staining with EBV-encoded small RNA-1 (EBER-1) in situ hybridization and CD79a, while EBV-infected epithelial cells were not noted. The number of EBER-1-positive cells in the ileum (mucosa, 1451 cells/mm(2); submucosa, 465 cells/mm(2)) was much larger than in control samples (malignant lymphoma or leukemia after allogeneic stem cell transplantation, n = 4, range 0-113 cells/mm(2); malignant lymphoma after chemotherapy, n = 14, range 0-0.89 cells/mm(2); colon cancer, n = 12, range 0-3.5 cells/mm(2)). In the mucosa near the ulcers, EBER-1-positive cells often surrounded and involved the glandular epithelium, forming lymphoepithelial-like lesions. The histological findings differ from post-transplant lymphoproliferative disorders or intestinal thrombotic microangiopathy, and this is the first case of EBV-associated enteritis with ulcers characterized by numerous plasma cells and lymphoepithelial-like lesions after stem cell transplantation.

The impact of human leucocyte antigen (HLA) incompatibility between donor and recipient on graft-versus-host disease (GVHD) and graft failure after reduced-intensity conditioning stem cell transplantation (RICT) remains to be elucidated. We retrospectively analysed outcome in 341 patients who underwent RICT from related donors for haematological malignancies. The overall cumulative incidence of grade II-IV acute GVHD (aGVHD) was 40% for all subjects; 39% in recipients with HLA-matched donors, 44% in those with one-locus-mismatched donors, and 50% in those with two- to three-loci-mismatched donors. In a Cox regression model adjusted for potential confounders, the tendency for grade II-IV aGVHD (P=0.01), chronic GVHD (cGVHD) (P=0.05) and graft failure (P=0.033) increased with HLA disparity. Use of peripheral blood grafts instead of marrow was a risk factor for cGVHD. Use of antithymocyte globulin was associated with reduced aGVHD and cGVHD. Overall survival (OS) in recipients of two- to three-loci-mismatched RICT at 2 years (18%) was significantly worse than that in patients who received one-locus-mismatched RICT (51%) and HLA-matched RICT (48%) (P

Infection with cytomegalovirus (CMV) or human herpesvirus-6 (HHV-6) may have a role in vascular endothelial damage after bone marrow transplantation (BMT). In total, 41 patients who underwent BMT were classified into four groups (12, 10, 7, and 12 patients who were infected with both CMV and HHV-6, CMV alone, HHV-6, and neither virus, respectively). Levels of thrombomodulin, plasminogen activator inhibitor-1, and cyclic GMP were 7.5+/-1.7 FU/ml, 76.4+/-24.1 ng/ml, and 9.51+/-1.1 pmol/ml, respectively, in the patients with both viruses, while the respective values were 2.9+/-0.67 FU/ml, 33.8+/-8.09 ng/ml, and 2.90+/-1.4 pmol/ml in patients infected with CMV alone, 4.8+/-0.96 FU/ml, 47.7+/-9.21 ng/ml, and 5.48+/-0.55 pmol/ml in patients with HHV-6 alone, and 1.6+/-0.39, 17.5+/-7.88 ng/ml, and 0.45+/-0.3 in those with neither virus. All three markers were significantly higher in the three groups with at least one virus than in the uninfected patients (P

Study objective Respiratory disturbance caused by ARDS has been reported during administration of granulocyte-colony stimulating factor. The clinical features of such respiratory distress were investigated in this study. Design Retrospective case review. Setting A 1,100-bed university teaching hospital. Patients Five patients who had dyspnea caused by ARDS develop after chemotherapy or bone marrow transplantation (BMT) at our hospital. Interventions None. Measurement and results Levels of cytokines, human leukocyte antigen (HLA) typing, and the clinical course were analyzed to clarify common features. All five patients possessed HLA-B51 or HLA-B52, and all had fever and an enhanced inflammatory response at the time of the WBC nadir. The tumor necrosis factor (TNF)-α and interleukin (IL)-8 levels increased when respiratory distress syndrome occurred. Conclusions If patients with HLA-B51 or HLA-B52 have infection develop at the time of WBC nadir after chemotherapy or BMT, ARDS may occur in association with elevation of TNF-α and IL-8 during WBC recovery.;1720>

Loss of the inhibition of apoptosis is important in leukemogenesis and may influence the prognosis. Survivin is an inhibitor of apoptosis that shows selective expression during fetal development and in human malignancies. Survivin expression was examined in human leukemias using the reverse transcriptase-polymerase chain reaction. Survivin gene expression was detected in 17 of 31 patients with acute myelocytic leukemia and 11 of 16 patients with acute lymphocytic leukemia but was not identified in normal bone marrow cells. Survivin expression was lower in patients with M3 acute myelocytic leukemia than in patients with other types of acute leukemia. Survivin was not detected in the chronic phase of chronic myelocytic leukemia but was observed in 5 of 7 patients with chronic myelocytic leukemia in blastic crisis. These findings suggest a relationship between survivin gene expression and hematopoietic cell differentiation. In fact, survivin gene expression was down-regulated during the differentiation of HL-60 cells after treatment with dimethyl sulfoxide or all-trans-retinoic acid. Moreover, the disease-free survival rates of patients with survivin expression were lower than in patients without survivin expression. Accordingly, survivin may have a role in leukemogenesis as well as in other malignancies. Detecting survivin may also provide prognostic information.

We report the case of a 42-year-old male who underwent allogeneic bone marrow transplantation (BMT) for acute myelogenous leukemia, and then developed pneumonitis with a bronchiolitis obliterans organizing pneumonia (BOOP)-like shadow. When he came with exertional dyspnea four months after BMT, the chest X-ray and CT findings disclosed bilateral infiltration, and remarkable elevation of his serum KL-6 level, a monitoring marker for disease activity in interstitial lung disease. Although organizing pneumonia (OP) was revealed by a transbronchial lung biopsy, no pathogen was detected in bacterial, fungal and routine viral cultures or by direct cytological examinations using bronchoalveolar lavage (BAL) specimens. Since human herpes virus-6 (HHV-6) was detected in BAL specimens by the polymerase chain reaction (PCR), a diagnosis of a pneumonitis-like BOOP shadow related to HHV-6 was made, and he was treated with methylprednisolone and ganciclovir (GCV). Although there was a relapse of his OP 1.5 months later, with re-elevation of his serum KL-6 level, continuous administration of GCV led to disappearance of HHV-6 in BAL specimens assayed by PCR, in association with normalization of the serum KL-6 level. HHV-6 should be considered as a cause of unexplained pneumonitis in BMT recipients, and KL-6 is useful for monitoring the pneumonitis status in these patients.

Aspergillosis is known for the variety of unusual presentations in immuno-suppressed patients. We report a patient in whom aspergillosis caused the superior vena cava (SVC) syndrome. A 37-year-old woman became febrile soon after bone marrow transplantation (BMT). Chest radiography demonstrated a 5-cm mass extending from the right lung apex to the right supraclavicular fossa beside her Hickman catheter. She then developed SVC syndrome, which progressed despite treatment. Despite recovery of the white blood cell count, the patient continued to deteriorate, became comatose, suffered a cardiac arrest and died 31 days after BMT. Autopsy revealed Aspergillus infection at the apex of the right lung associated with innominate artery thrombosis.

Viral infections are an important cause of death following bone marrow transplantation. We investigated the clinical significance of herpesvirus infection. The nine subjects consisted of five patients with CML, two with ALL, and one each with AML and the myelodysplastic syndrome. Viral markers were investigated in bronchoalveolar lavage fluid and peripheral blood lymphocytes before and 35 days after bone marrow transplantation, as well as in peripheral blood lymphocytes at 100 days afterwards. Cytomegalovirus DNA became positive in four patients after bone marrow transplantation. Human herpesvirus-6 DNA became positive in two patients and human herpesvirus 7 DNA became negative in the same two patients. Two of the nine patients died of disease recurrence. Two other patients died of complications, and both of them became positive human herpesvirus-6 after the procedure. These results suggested the possibility that infection with not only cytomegalovirus but also other human herpesvirus can influence the prognosis and complications of bone marrow tansplantation.

Colonic graft-versus-host disease (GVHD) occurring after allogeneic bone marrow transplantation (BMT) resembles ulcerative colitis (UC) with respect to pathological features. In addition, therapy for UC has been reported to be effective for the treatment of refractory GVHD. The relationship of these two conditions with respect to cytokines was investigated in the present study. Among 27 patients who underwent allogeneic BMT during the previous two years, six developed GVHD of grade 3 or higher, and these six patients were compared with the other 21 patients. In six patients, the levels of the following cytokines were significantly elevated at the onset of GVHD: tumor necrosis factor-α (p

Bone marrow transplantation has been established as a useful treatment for various hematological disorders and is now performed widely, but the mortality rate is still high due to various complications. A clear therapeutic policy for such complications has not yet been established because of their complex nature. We investigated whether the major complications occurring after bone marrow transplantation could be classified as aspects of the systemic inflammatory response syndrome. Subjects were 10 patients who developed severe complications after bone marrow transplantation (graft-versus-host disease, thrombotic microangiopathy, respiratory disorders, and cytomegalovirus interstitial pneumonitis) and 16 patients without complications. Their symptoms, serum cytokines, and factors related to vascular endothelial damage were compared before and after transplantation. Whereas all 10 patients who developed complications had fever in the aplastic phase after transplantation, 15 of the 16 patients without complications remained afebrile (P < 0.001, t-test). When compared with the patients who did not develop complications, the patients with complications also showed significantly higher cytokine levels during the recovery phase after transplantation (P < 0.0001, t-test). Thus, the patients with complications developed fever in the aplastic phase and showed an increase of cytokines during the recovery phase, which triggered the occurrence of vascular endothelial damage shown by factors such as the thrombomodulin and plasminogen activator inhibitor type 1. This sequence of events corresponds with that occurring during systemic inflammatory response syndrome, so many of the complications of bone marrow transplantation can be considered as manifestations of this syndrome.

Acute graft-versus-host disease (aGVHD) after allogeneic bone marrow transplantation (BMT) is mediated by grafted T lymphocytes after their polarization into type 1 T cells. Interleukin (IL)-18, a novel immunoregulatory cytokine, strongly stimulates type 1 T cells, therefore we postulated that IL-18 may be involved in the pathogenesis of aGVHD. Using an enzyme-linked immunosorbent assay (ELISA), we serially measured serum levels of IL-18 in 37 patients with haematological malignancy before and after allogeneic BMT. Patients with aGVHD had high levels of IL-18 that strongly correlated with the severity of aGVHD. We also found that they showed reduced serum levels of IL-18 after appropriate treatment or at a state of resolution. IL-18 levels were not affected by the pretransplant regimen, engraftment or bacterial infection. Compared with circulating interferon (IFN)-γ or IL-12 levels, serum levels of IL-18 showed a more sensitive and specific correlation with the disease status of aGVHD. These findings suggest that IL-18 may play important roles in the pathogenesis of aGVHD and that measurement of serum IL-18 levels can be useful indicator of aGVHD.

Up-regulation of Fas/APO-1 (CD95) on haematopoietic progenitors and Fas-mediated apoptosis have been suggested to occur in a possible pathological mechanism in some bone marrow failure syndromes. We examined the expression of Fas antigen and susceptibility to Fas-mediated suppression of donor-derived haematopoietic cells of allogeneic bone marrow transplantation (BMT) recipients. Cytofluorometric analysis revealed low expression of Fas on CD34+ bone marrow cells from marrow donors or healthy controls. However, significantly higher expression of Fas antigen was observed on CD34+ bone marrow cells of BMT recipients, in whom engraftment of donor bone marrow (BM) cells was confirmed. The addition of an agonistic anti-Fas antibody (Ab) (CH-11) to haematopoietic stem cell culture of BM cells more strongly suppressed colony formation from granulocyte–macrophage colony-forming units (GM-CFU) and erythroid burst-forming units (BFU-E) after BMT. Pretreatment by blocking anti-Fas Ab (ZB4) abrogated the Fas-mediated GM-CFU and BFU-E suppression. Purified marrow CD34+ cells from BMT recipients were also susceptible to the Fas-mediated colony suppression. Thus, donor-derived CD34+ haematopoietic cells increased their expression of Fas antigen and were susceptible to Fas-mediated haematopoietic suppression. These findings provide new insight for understanding the haematological condition after BMT.

Although the occurrence of marrow fibrosis in acute myeloid leukemia has been described, there have been no reports of acute promyelocytic leukemia (APL) associated with marrow fibrosis. Here we describe an APL patient with severe marrow fibrosis at initial presentation. He had the typical manifestations of APL, except for marrow fibrosis. Complete remission was achieved by treatment with all-trans retinoic acid plus chemotherapy, and his marrow fibrosis gradually improved concomitantly with the decrease in leukemic cells. To clarify the mechanism of marrow fibrosis in this patient, we investigated the expression of genes for several cytokines promoting fibrosis by the reverse transcriptase polymerase chain reaction methods. An overexpression of transforming growth factor-β1 was noted in his leukemic cells at initial presentation, whereas no increase in expression was observed at the time of relapse when he no longer had marrow fibrosis. These findings suggest that overexpression of transforming growth factor-β1 was involved in the development of marrow fibrosis in this APL patient.

Background. Adult respiratory distress syndromelike respiratory disorders are a serious, but uncommon, complication of bone marrow transplantation. Methods. We measured various cytokines in 2 patients with respiratory disorders and 11 patients without respiratory problems after allogeneic bone marrow transplantation. Results. The patients with respiratory disorders had elevated levels of interferon-g and interleukin-2 in the aplastic phase, and elevation of tumor necrosis factor-a, intercellular adhesion molecule-1, and interleukin-8 at the time of leukocyte recovery. Both patients with respiratory disorders developed fever during the aplastic phase, whereas none of the patients without fever had respiratory disorders. Among patients who had fever during the aplastic phase but no respiratory disorders, there was no elevation of cytokines from the aplastic phase to the recovery phase. Conclusions. Respiratory disorders may occur after bone marrow transplantation when an inflammatory response during the aplastic phase stimulates cytokines that cause vascular endothelial damage and increases the levels of chemokines and adhesive molecules along with elevation of the leukocyte count. There have been a few reports of a relationship between granulocyte colony-stimulating factor (G-CSF*) therapy and pulmonary toxicity (1‐ 6), but the relationship has never been proven unequivocally. We have previously reported a possible correlation between neurotoxicity and rapid elevation of the leukocyte count at the time of engraftment after bone marrow transplantation (BMT) in patients treated with GCSF (7). In one of our two patients who developed neurotoxicity, pulmonary toxicity occurred at the same time. We therefore hypothesized that vascular endothelial damage caused by G-CSF or by inflammation may lead to pulmonary toxicity at the time of recovery of the leukocyte count after BMT. Various cytokines, adhesion molecules, and chemokines may be involved in this process (8 ‐29). The purpose of the present study was to investigate the mechanism of adult respiratory distress syndrome (ARDS)-like disorders that occur when the leukocyte count recovers during administration of G-CSF after BMT.

von Willebrand factor (vWF) is synthesized exclusively by endothelial cells and megakaryocytes, and stored in the intracellular granules or constitutively secreted into plasma. ABO blood group antigens are covalently associated with asparagine-linked sugar chains of plasma vWF. The effect of ABO-mismatched bone marrow transplantation (BMT) or blood stem cell transplantation (BSCT) on the expression of ABO blood group antigens on the vWF was examined to obtain information on the origin of these antigens. In ABO-mismatched (HLA-matched) groups, 8 cases of BMT and 4 cases of BSCT were examined. In all cases, the ABO blood groups on red blood cells were gradually converted to the donor’s type within 80 to 90 days after the transplantation. The blood group antigens on the vWF were consistent with the recipient’s blood group for the period monitored by enzyme-linked immunosorbent assay (ELISA). When vWF was isolated from normal platelets and examined for the blood group antigens using ELISA or immunoblotting, it showed few antigens. However, vWF extracted from veins expressed blood group antigens. These findings indicate that platelet (megakaryocyte)-derived vWF does not contain blood group antigens and that these antigens may be specifically associated with vWF synthesized in endothelial cells and secreted into plasma. Furthermore, it is possible that the persistence of the recipient’s blood group antigens on plasma glycoproteins such as vWF, independent of the donor-derived erythrocytes, after ABO-mismatched stem cell transplantation, may influence the immunological system in the production of anti-blood group antibodies resulting in the establishment of immunological tolerance in the recipient plasma.

Thrombotic microangiopathy is one of the complications of bone marrow transplantation and is related to other complications such as graft-versus-host disease, veno-occlusive disease, diffuse alveolar hemorrhage, and cytomegalovirus infection. Thrombotic microangiopathy occurred in three out of 12 patients who underwent allogeneic bone marrow transplantation over the past 1 year at our department. We compared the changes in cytokines and other molecules between patients with and without microangiopathy from before conditioning to the early post-transplantation period. All three patients with microangiopathy showed a significant increase of interleukin-12 at the time of leukocyte recovery after transplantation (two-way layout analysis of variance; P < 0.05), while none of the patients without microangiopathy showed an increase of interleukin-12. No significant differences were found between the two groups with respect to the other cytokines and molecules that were tested. These findings suggested that thrombotic microangiopathy might be predicted at an early stage after bone marrow transplantation by detecting an increase of interleukin-12 at the time of leukocyte recovery. The possibility that thrombotic microangiopathy is related to inflammation or autoimmunity was also suggested.

The incidence of patients with aplastic anaemia (AA) who show a deficiency of glycosylphosphatidylinositol (GPI)-anchored proteins on their peripheral blood (PB) or bone marrow (BM) cells is higher than that previously reported. We analysed the expression of CD55 or CD59 on PB and BM cells and those of colonies and bursts formed in cultures with marrow cells from AA patients. 4/21 (19%) AA cases later developed paroxysmal nocturnal haemoglobinuria (PNH). 7/17 (41. 2%) AA cases showed a subpopulation without GPI-anchored proteins. The defect characteristic for PNH was observed only on the colonies/bursts but not on the PB or BM cells in three cases. We found the affected colonies/bursts in cultures using thawed marrow cells which had been cryopreserved at the diagnosis of aplasia in one patient who developed PNH 3 years later. Two different mutations of the PIG-A gene were found in the colonies/bursts at the time of AA. The nucleotide sequences were identical between the colonies/bursts at the time of AA and those after the transition to PNH. However, one of the mutations was detected only at the haemopoietic progenitor level but not in PB granulocytes. There may be latent subclones with PNH abnormalities which could expand to the level of clinical detection, or which do not progress and remain indolent for a relatively long time, implying the different extents of clonal expansion among the affected progenitors.

To investigate the pathogenesis of immunological abnormalities (IA) in myelodysplastic syndrome (MDS), we examined B cells for their ability to produce cytokine and their X chromosome inactivation pattern (XCIP). An IA was defined as being positive for at least one autoimmune laboratory test (e.g. antinuclear antibody, rheumatoid factor). Seventy-three MDS patients [65 with refractory anemia (RA), 3 with RA with excess blasts (RAEB), and 5 with RAEB in transformation] were examined; 47 had IA and 26 had no IA. To examine the function of B cells in MDS, the production of interleukin (IL)-6 and IL-10 was measured in cultures of purified B cells with or without stimulators. Both IL-6 and IL-10 production rates in patients with IA were significantly higher than in patients without IA and normal controls. The skewing of XCIP of B cells was analyzed by using the polymerase chain reaction, and the skewing rate of B cell XCIP was quantitatively assayed by compared to control T lymphocytes. The skewing rate of B cells was higher in patients with IA than in those without IA and normal controls. Therefore, a small population of B cells in patients with IA might be derived from MDS clones, and be associated with the induction of IA.

Patients with trilineage myelodysplasia (TMDS) in de novo acute myeloid leukaemia (AML) at diagnosis and remission were clinically evaluated between 1983 and 1996. AML with TMDS (AML/TMDS) was observed in 20 (12%) of 162 patients with de novo AML at diagnosis. Complete remission (CR) was achieved with combination chemotherapy in 12 (67%) of 18 AML/TMDS cases. This CR rate was relatively worse than the rate of 78% (106/136 cases) of AML without TMDS, but this difference was not significant. Disease-free survival curves also showed no difference between AML/TMDS and AML without TMDS. During remission, eight (67%) of 12 AML/TMDS cases had myelodysplastic remission marrow (AML/MRM). AML/MRM was also seen in seven (7%) of 106 AML cases without TMDS. The actuarial disease-free survival was significantly lower in AML/MRM than in AML without MRM (P = 0.0003). All of the AML/MRM cases exhibited early leukaemic relapse; median remission duration was only 9 months. Clonal changes occurred in two cases of AML/TMDS and five cases of AML/MRM at the time of relapse. These findings suggest that TMDS during remission predicts a poorer prognosis and early leukaemic relapse when compared with the absence of TMDS.

We encountered two patients with uncommon neurological manifestations after allogeneic bone marrow transplantation (BMT), which occurred with rapid elevation of the leukocyte count at engraftment. Both patients then developed severe acute graft-versus-host disease (GVHD). To investigate the pathogenesis, we measured the levels of soluble P-selectin, von Willebrand factor (vWF) and thrombomodulin (TM), which reflect endothelial damage. The P-selectin, vWF and TM levels in the patients with (n=2) and without (n=5) neurotoxicity were, respectively, 168.5+/-52.5 ng/ml vs 27.7+/-3.9 ng/ml, 6.7+/-0.15 FU/ml vs 3.42+/-0.41 FU/ml and 459+/-37% vs 189.4+/-32.4% (mean+/-s.d.). All three parameters were much higher in the patients with neurological complications. These results suggest that neurotoxicity after BMT may be related to endothelial damage.

We conducted a multicenter trial of treatment with all-trans retinoic acid (ATRA) for newly diagnosed acute promyelocytic leukemia (APL) in the AML-92 study and compared it with our previous study with standard intensive chemotherapy, the AML-89 study, in the view of complete remission (CR) rate, incidence of early death, and event-free survival (EFS). Patients were scheduled to receive oral ATRA 45 mg/m2 daily until CR. If patients had leukocyte counts above 3 x 10(9)/L at the start of therapy, they received daunorubicine (DNR) 40 mg/m2 for 3 days and behenoyl cytosine arabinoside (BHAC) 200 mg/m2 for 5 days in addition to ATRA. During the ATRA therapy, if patients showed myeloblast plus promyelocyte counts higher than 1 x 10(9)/L in the peripheral blood, they received additional DNR and BHAC in the same schedule, as well. A total of 110 patients were entered into the study. Median age was 43 years (range, 16 to 74). Twenty-eight (26%) of 109 patients (one died before the start of therapy) received ATRA alone. Ninety-seven patients (89%) achieved CR; 48 of 49 (98%) aged less than 40 years, 44 of 52 (84%) aged between 40 and 69, and 5 of 8 (63%) aged above 70 achieved CR, respectively; 25 of 28 (89%) with ATRA alone, 46 of 51 (90%) with ATRA plus initial chemotherapy and 26 of 30 (87%) with ATRA plus later chemotherapy attained CR, respectively. Nine (8%) patients died within 28 days after the start of therapy. In contrast, 44 of 62 patients (71%) attained CR, and 13 (21%) died within 28 days in the AML-89 study with the combination of DNR, BHAC, 6-mercaptopurine and prednisolone. Seven developed retinoic acid syndrome and one died of it in the present study. Other toxicities associated with this drug included cheilitis, desquamation, muscle pain, and hypertriglyceridemia. Predicted 23 months EFS for all ATRA-treated patients and disease-free survival (DFS) in the CR cases were 75% and 81%, respectively, in a median follow-up period of 21 months. Compared to the AML-89 study, there was a highly significant difference in remission rate (P = .004), EFS (P = .0007), and also early mortality rate (P = .02). Present results demonstrated that ATRA with or without chemotherapy gives a statistical improvement in CR rate and early mortality rate, as well as superior survival in newly diagnosed APL.

Summary. We previously established a long-term bone marrow culture (LTBMC) system in which novel abnormal karyotypes could emerge in vitro prior to the appearance of the same karyotypes in vivo in patients with myelodysplastic syndrome (MDS). We extended our study to examine whether acute myeloid leukaemia (AML) transformed from MDS (MDS/AML) and de novo AML with trilineage myelodysplasia (AML/TMDS) show clonal evolution in LTBMC similar to that of typical AML or MDS. We also analysed the cytogenetic changes in cultures with bone marrows from AML with myelodysplastic remission marrow (AML/MRM) as well as chronic myeloid leukaemia (CML) to compare them with typical AML with respect to the liability of clonal evolution. Among the 34 AML cases, abnormal karyotypes were newly detected in four of seven MDS/AML, three of six AML/TMDS and three of three AML/MRM. Novel abnormal karyotypes were also observed in nine out of 13 CML cases after culture. In contrast, no other abnormal karyotypes were found after culture in 18 typical AML without myelodysplasia. These findings suggest that AML/TMDS and AML/MRM are different from typical AML and are similar to MDS/AML and CML in view of their potential for disease progression from latent multiple clones. Typical AML may develop from a single abnormal clone without any subclones.

The authors conducted a comparative study on the rapid diagnosis of cytomegalovirus (CMV) interstitial pneumonitis by 4 different methods. Among them, the polymerase chain reaction (PCR) method was found to achieve the most rapid diagnosis of CMV infection. The clinical usefulness of making a diagnosis from the serum antibody titer and viral isolation was questionable as compared with the PCR method. Therefore, early diagnosis of CMV infection by PCR may be promising especially for the compromised patients with hematological diseases.

Intestinal graft-versus-host disease (GVHD) can readily easily induce generalized metabolic disturbance that influences morbidity and mortality after allogeneic bone marrow transplantation. Although adding a new drug or increasing the doses of immunosuppressive agents will probably be effective for controlling intestinal GVHD, the systemic side effects of such therapy cannot be ignored. In this study, we used betamethasone retention enemas as a local treatment for eight patients with refractory and/or severe intestinal GVHD. Six of the eight patients showed improvement of diarrhea and/or abdominal pain, with a reduction in the stage of GVHD. When treatment with betamethasone enemas was continued for 10 to 27 days in the 6 responding patients, no severe toxicity was observed. One patient failed to respond to treatment and another could not tolerate the enemas. Despite some uncertainty regarding the indications and duration of treatment, betamethasone enemas seem to be a potential alternative method for the management of intestinal GVHD.

The outcome of sixty-four patients with acute leukemia in first remission who had been treated with either bone marrow transplantation (BMT) or conventional chemotherapy was retrospectively evaluated (a median follow-up of 37 months). Among them, 26 patients (age range; 14-42 years) received allogeneic BMT from HLA-identical siblings and 38 patients (age range; 13-43 years) who had no HLA-identical donors undertook the continued combination chemotherapy. Kaplan-Meier product-limit estimate of actuarial survival of acute myelogenous leukemia (AML) patients was 48.9% for the BMT group and 15.7% for the chemotherapy group (p = not significant, NS). For acute lymphoblastic leukemia (ALL) patients, the survival following BMT was 80.2% and was significantly higher than that of the chemotherapy group of 33.3% (p0.05). The disease-free survival of AML and ALL for the BMT group was 34.3% and 36.5%, respectively, which was higher than that of the chemotherapy group (16.7% and 23.4%, respectively (p = NS)). These findings in our Japanese single institution study suggested that BMT may be the treatment of choice for adult patients with acute leukemia in first remission if they had suitable donors and that more effective therapeutic regimens were necessary for patients without compatible donors in order to obtain the longer remission duration.

Allogeneic bone marrow transplantation was performed in a 24-year-old woman with acute myelogenous leukemia in the first remission (FAB classification: M4). Graft-versus-host disease occurred from around day 150 after bone marrow transplantation. The levels of tumour necrosis factor-alpha, interleukin 12, and intercellular adhesion molecule-1 were elevated in the early stage of graft-versus-host disease, followed by elevation of interleukin 10 and interleukin 8. Her symptoms subsequently improved and all of these parameters became normal. The levels of thrombomodulin and plasminogen activator inhibitor type 1 showed changes that were in parallel with the clinical course. Interleukin 1beta, interleukin 6, interleukin 2, and interferon-gamma showed no changes throughout the course of her graft-versus-host disease. These findings suggested the possibility that release of inflammatory molecules occurred at the onset of graft-versus-host disease and caused vascular endothelial damage, which led to the exacerbation of her disease.

Central nervous system disorders are an important complication of bone marrow transplantation (BMT). We have recently performed cerebral angiography to examine central nervous system dysfunction in a 22-year-old woman with acute lymphoblastic leukaemia who had undergone BMT. Angiography demonstrated multiple stenoses and occlusions in the peripheral branches of the anterior and middle cerebral arteries, a pattern similar to that seen in vasculitis. She was thought to most likely have cytomegalovirus (CMV) vasculitis, but other forms of vasculitis, such as angiitis-like-syndrome-associated graft-versus-host disease could not be excluded. This case suggests that CMV vasculitis may cause central nervous system dysfunction after BMT and that imaging studies may provide useful information about central nervous system disorders in these patients.

Acute graft-versus-host disease (GVHD) is the most important complication of allogeneic bone marrow transplantation. We investigated the possibility of predicting severe acute GVHD using plasma interleukin-10 levels in 31 patients who underwent allogeneic bone marrow transplantation. In patients with acute GVHD, the interleukin-10 (IL-10) level increased significantly from the aplastic phase through the leukocyte recovery phase after transplantation (P

A 43-year-old man with chronic myeloid leukaemia underwent a second transplant with CD34 + bone marrow cells selected from his two-loci HLA-mismatched sibling after rejection of the first graft from an HLA-matched unrelated donor. By immunomagnetic positive selection, CD34 + marrow cells at 0.95 x 10 6 /kg with 97% purity and CD3 + T lymphocytes at 1.3 x 10 4 /kg were collected and transplanted. Engraftment was confirmed to be of CD34 + cell-donor origin. The patient developed only grade I acute graft-versus-host disease (GVHD) and no chronic GVHD to date. These observations suggest that allogeneic CD34 + bone marrow cells are capable of reconstituting haemopoiesis and that CD34 + selection could be applicable to T-cell depletion.

Cutaneous GVHD is histologically similar to eruptions induced by drugs containing a sulfhydryl group. The levels of interleukin-2 and interleukin-2 receptor were determined in a group of patients undergoing bone marrow transplantation (BMT) without graft-versus-host disease or any other complications and in a group with cutaneous graft-versus-host disease (GVHD) alone. In patients who only developed cutaneous GVHD, both interleukin-2 and inter-leukin-2 receptor levels were elevated when the disease was evident. As the elevation of these parameters became more marked, the grade of cutaneous graft versus-host disease also increased. In some patients, only one of the two parameters was elevated and the grade of graft-versus-host disease was low or no skin manifestations were seen. These findings suggest that interleukin-2 and interleukin-2 receptor act together in the development of cutaneous GVHD. This study also showed that the mechanism of cutaneous GVHD resembles that involved in the induction of eruptions by sulfhydryl-containing drugs.

We performed a retrospective survey in 62 hematopoietic cell transplantation (HCT) centers in Japan in which all HCTs performed between 1986 and 1998 were reviewed, and those involving hepatitis B virus surface antigen (HBsAg)-positive donors were identified. One hundred and thirty-five patients who underwent allogeneic HCT (alloHCT) were studied for complications related to hepatitis B virus (HBV) or hepatitis C virus (HCV). The median follow-up period was 24 months. Positivity for HBsAg was observed in 32 patients (24%) throughout the study. Twenty-six of the 32 patients were HBsAg carriers before alloHCT, whereas the remaining 6 became HBsAg(+) after alloHCT. Forty-two recipients were anti-HBs antibody (HBsAb)-positive, and 58 recipients (43%) were HCV Ab(+). Eleven of 26 (42%) HBsAg(+) recipients survived between >4 and >119 months. Six of 26 cases received transplants from HBsAg(+) donors, and, although they had not developed acute graft-versus-host disease, 4 of 6 died of hepatic and renal failure within 10 months after HCT. After transplantation, 5 patients showed serologic evidence of HBV reactivation, whereas 4 patients showed evidence of an immune response to HBV. Viral reactivation occurred during the tapering of the immunosuppressive agent. However, 3 of 5 were alive at the time of this report, suggesting that reactivation is not directly correlated with severe liver dysfunction. Seventeen patients (13%) of 135 recipients developed hepatic failure. Eight (47%) of 17 were diagnosed with fulminant hepatitis and 5 (29%) with veno-occlusive disease (VOD). VOD was observed in 12% of both HBsAg(+) and HCVAb(+) patients. In this study, the relatively high incidence of HBV events occurred after alloHCT, and, therefore, we should consider a protocol for active immunization of donors and recipients against HBV. Moreover, although the presence of HBV or HCV is not a contraindication for alloHCT, we recommend a careful follow-up of recipients after transplantation, especially during immunosuppression tapering.

Urinary trypsin inhibitor has attracted attention as an index of the systemic inflammatory response syndrome. In this study, the urine concentration of trypsin inhibitor was measured to compare the immunological insult of conventional chemotherapy and conditioning chemotherapy for bone marrow transplantation. We also investigated whether urinary trypsin inhibitor was a useful index of the complications and outcome of bone marrow transplantation. Urinary trypsin inhibitor concentration was determined before chemotherapy, on the day after finishing chemotherapy (day 0 of transplant- ation), and during recovery of the white cell count, in 17 patients (seven receiving conventional chemotherapy and 10 receiving conditioning for bone marrow transplantation). Urinary trypsin inhibitor concentrations were significantly higher after conditioning for bone marrow transplantation than after conventional chemotherapy (P < 0.001), indicating that conditioning was more invasive. After bone marrow transplantation, the incidence of severe complications and the mortality rate were higher in patients whose urinary trypsin inhibitor concentrations rose during recovery of the white cell count. Comparison of urinary trypsin inhibitor concentrations suggested that conditioning for bone marrow transplantation was more invasive than conventional chemotherapy. This study also suggested that the urine concentration of trypsin inhibitor could be useful for predicting the risk of complications and outcome of bone marrow transplantation. Bone Marrow Transplantation (2001) 27, 195–199.

The ‘systemic inflammatory response syndrome’ (SIRS) may represent the underlying cause of complications after bone marrow transplantation (BMT). This study was conducted to determine whether blocking the etiologic factors of SIRS could improve the complications of BMT. Sixteen consecutive patients with unrelated donors were allocated alternately to two groups. Seven patients received 1.8 g/day of eicosapentaenoic acid (EPA) orally from 3 weeks before to about 180 days after transplantation, while nine patients did not. These two groups were compared with respect to complications, survival, and various cytokines and factors causing vascular endothelial damage. All seven patients receiving EPA survived and only two had grade III graft-versus-host disease (GVHD). Among the nine patients not receiving EPA, three had grade III or IV GVHD. In addition, thrombotic microangiopathy developed in four patients and cytomegalovirus disease occurred in four. Five patients died in this group. The levels of leukotriene B4, thromboxane A2, and prostaglandin I2 were significantly lower in patients receiving EPA than in those not receiving it (all P

In order to detect chimerism, fluorescence in situ hybridization (FISH) and cytogenetic analyses were performed on bone marrow cells from 47 patients with hematological malignancies following allogeneic hematopoietic cell transplant (HCT). The dual-color XY, major Bcr-Abl (M-Bcr-Abl), and specific alpha-satellite probes were used for sex-mismatched HCT, chronic myeloid leukemia (CML), and myelodysplastic syndrome (MDS) cases with karyotypic abnormalities before HCT, respectively. Donor cells were found using FISH analysis in all 32 cases examined within 2 months following HCT, confirming engraftment. In six cases, however, cytogenetic analysis failed to detect donor cells due to lack of metaphases. Relapse occurred in four of the six cases in which mixed chimerism was detected using FISH analysis after 6 months of HCT. In contrast, after 12 months of HCT, no relapse was found in 24 patients without host cells. For two patients with mixed chimerism, gradual reduction of immunosuppressants or donor lymphocyte infusion resulted in the disappearance of host cells as analyzed using FISH analysis. In three extramedullary relapse cases, however, cytogenetic relapse preceded morphological and FISH relapse. These findings suggest that FISH analysis is more useful for detecting residual host cells after HCT, and the combination of FISH and cytogenetic analyses provide a more detailed evaluation for HCT patients. The results also indicate that monitoring of mixed chimerism using FISH analysis after 6 months of HCT is important for allowing the early detection of hematological relapse.

We evaluated the relationship between CMV and human herpes virus-6 (HHV-6) reactivation and the incidence of grades 2 to 4 acute GVHD post BMT. Bronchoalveolar lavage fluid (BALF) samples extracted from 54 BMT recipients on post-BMT day 35 were analyzed by PCR for detection of CMV DNA, HHV-6 DNA and CMV plus HHV-6 DNA. CMV DNA was detected in 26 patients and 13 (50%) developed grades 2 to 4 acute GVHD. Of the 28 who were CMV negative, only six (21.4%) developed grades 2 to 4 acute GVHD. HHV-6 was detected in 18 patients, and 11 (61.1%) developed grades 2 to 4 acute GVHD. Of the 36 who were HHV-6 negative, only eight (22.2%) developed grades 2 to 4 acute GVHD. CMV and HHV-6 were detected in 13 patients, and eight (61.5%) developed grades 2 to 4 acute GVHD. Of the 23 who were negative for both CMV and HHV-6, only three (13%) developed grades 2 to 4 acute GVHD. In all experiments, the difference between the groups was significant (P

Certain human leukocyte antigens may increase the risk of cytomegalovirus interstitial pneumonitis, an important complication of bone marrow transplantation. The prevalence of this pneumonitis was compared between patients possessing either HLA-B51 or HLA-B52 and patients without either antigen. The role of tumor necrosis factor-α in cytomegalovirus interstitial pneumonitis was also studied. Among 72 patients undergoing allogeneic bone marrow transplantation at our institution during the past 5 years, HLA-B51 or -B52 was detected in 29. Among these 29 patients, 13 (45%) developed cytomegalovirus interstitial pneumonitis, a significantly higher rate (P

Good response to cyclosporine therapy in patients with myelodysplastic syndrromes having the HLA-DRB1*1501 allele

Expression of erythropoietin (EPO) receptor (EPO-R) was analysed in leukaemia cells from 150 patients with acute myeloid leukaemia (AML) or acute lymphoblastic leukaemia (ALL). EPO-R was expressed in 81 (60%) out of 136 AML, and in vitro treatment with EPO led to proliferation of leukaemia cells in 13 (16%) out of 81 AML examined. EPO-R expression and in vitro response to EPO were observed in all subtypes of AML according to the French-American-British (FAB) classification. All eight patients with FAB-M6 expressed EPO-R, and one out of four showed an in vitro response to EPO. Although there was no significant correlation (r = 0.2522) between the amount of EPO-R and the in vitro response to EPO, all of the AML patients who showed in vitro response expressed EPO-R. Stem cell factor significantly enhanced both EPO-R expression and in vitro response to EPO. Interleukin-3 tended to increase in vitro response to EPO. CD phenotypes, the amount of granulocyte colony-stimulating factor (G-CSF) receptors and the amount of TPO receptors had no significant relationship with the amount of EPO-R. Patients with both EPO-R expression and in vitro response to EPO had shorter duration of complete remission than those without EPO-R (P = 0.0053). EPO-R was expressed in four (29%) out of 14 ALL, and none out of five ALL showed in vitro response to EPO.

The effect of interferon-alpha (IFN) for chronic myeloid leukemia (CML) in the chronic phase (CP) was retrospectively evaluated in comparison with that of busulfan (BU) or hydroxyurea (HU) given alone. Among 107 patients diagnosed with CML between 1982 and 1997, 72 CP cases evaluable for long-term follow-up included 13 patients treated with BU alone, 18 with HU alone, and 41 with IFN-based therapy. Complete cytogenetic response (CCR) was achieved in 4/41 IFN cases (10%), and partial or minimal cytogenetic response occurred in 18/41 IFN cases (44%). In contrast, no cytogenetic response (NCR) was achieved in any BU or HU case. IFN treatment for 6 to 60 months was needed to achieve CCR. Overall survival curves revealed that the IFN group had significantly better survival than BU and HU groups (p=0.008 and 0.04, respectively). A significant correlation was found between karyotypic findings and fluorescence in situ hybridization (FISH) analyses in IFN-treated cases (r=0.739, p=0.0001). In some cases, however, the two methods showed discrepancy; BCR/ABL-positive cells represented only 20-75% of interphase bone marrow cells in NCR cases, although all metaphases examined were positive for the Philadelphia chromosome (Ph). A discrepancy was also seen in CCR cases; up to 22% of cells assessed were BCR/ABL-positive. These findings suggest that IFN is a useful therapy for CML in CP, and may have a suppressive effect on the CML clone even in NCR cases. The results also indicate that a combination of FISH and cytogenetic analyses may provide more detailed information for evaluating the efficacy of IFN than conventional cytogenetics alone.

The acute graft-versus-host disease (GVHD) generated in BDF1 mice by the injection of spleen cells from the C57BL/6 parental strain induces a direct cell-mediated attack on host lymphohematopoietic populations, resulting in the reconstitution of the host with donor hematopoietic stem cells. We examined the effect of GVHD on the donor and host hematopoiesis in parental-induced acute GVHD. The bone marrow was hypoplastic and the number of hematopoietic progenitor cells significantly decreased at 4 weeks after GVHD induction. However, extramedullary splenic hematopoiesis was present and the number of hematopoietic progenitor cells in the spleen significantly increased at this time. Fas expression on the host spleen cells and bone marrow cells significantly increased during weeks 2 to 8 of GVHD. Host cell incubation with anti-Fas Ab induced apoptosis, and the number of hematopoietic progenitor cells decreased during these weeks. A significant correlation between the augmented Fas expression on host bone marrow cells and the decreased number of host bone marrow cells by acute GVHD was observed. Furthermore, the injection of Fas ligand (FasL)-deficient B6/gld spleen cells failed to affect host bone marrow cells. Although Fas expression on repopulating donor cells also increased, Fas-induced apoptosis by the repopulating donor cells was not remarkable until 12 weeks, when more than 90% of the cells were donor cells. The number of hematopoietic progenitor cells in the bone marrow and the spleen by the repopulating donor cells, however, decreased over an extended time during acute GVHD. This suggests that Fas–FasL interactions may regulate suppression of host hematopoietic cells but not of donor hematopoietic cells. Hematopoietic dysfunctions caused by the reconstituted donor cells are independent to Fas–FasL interactions and persisted for a long time during parental-induced acute GVHD.

The expression of leukocyte alkaline phosphatase (LAP) in neutrophils is reduced in some patients with myelodysplastic syndrome (MDS). We quantitatively assayed for LAP in MDS leukocytes by a flow cytometry based method using a monoclonal antibody raised against human bone alkaline phosphatase. The LAP expression was assayed in blood samples from a group of 46 MDS patients, consisting of 39 patients with refractory anemia (RA), 3 with RA with excess blasts (RAEB), and 4 patients with RAEB in transformation. The percentage of LAP-positive cells was significantly higher in the MDS patients than in the normal subjects and also higher in RA than in RAEB and RAEB in transformation. To investigate the cause of the elevated LAP expression, we measured the serum concentrations of several cytokines. The granulocyte colony-stimulating factor (G-CSF) level was significantly elevated in MDS patients, and the serum G-CSF concentration clearly correlated with the percentage of LAP-positive cells. Thus, the LAP activity in RA is higher than in normal subjects, and G-CSF is thought to be one of the causes stimulating LAP expression in MDS neutrophils.

We analyzed the efficacy of all-trans retinoic acid (ATRA) as an early treatment for four acute promyelocytic leukemia (APL) patients in remission who were PML/RARalpha-positive by reverse transcription-polymerase chain reaction or fluorescence in situ hybridization. ATRA 45 mg/m2 was administered orally. All became negative for PML/RARalpha transcripts after 3 to 6 months of ATRA treatment. However, the PML/RARalpha transcripts subsequently reverted to positive in three cases. Although retreatment with ATRA failed to prevent hematological relapse in two patients, one case remains in hematological remission. No serious side effects were encountered during ATRA treatment. These findings suggest that early treatment of ATRA for PML/RARalpha-positive APL patients in remission may have a therapeutic benefit and prolong the duration of hematological remission without chemotherapy.