Myelodysplastic Syndrome Refractory Anemia Research Articles

Total hearing loss and blindness caused by relapsing polychondritis and myelodysplastic syndrome

Relapsing polychondritis is an autoimmune disease that primarily manifests as cartilaginous tissue destruction. However, the immune impairment may also involve noncartilaginous tissues such as kidneys, blood vessels, etc. The disease may occur as a primary disorder or in association with other diseases. The case of a female patient with concurrent manifestation of myelodysplastic syndrome-refractory anemia with excess blasts, and relapsing polychondritis, is presented. The diagnosis of relapsing polychondritis was established ten months after the diagnosis of myelodysplastic syndrome, when the criteria for the former were met. Total hearing loss and blindness developed soon thereafter.

A comparative study of molecular mutations in 381 patients with myelodysplastic syndrome and in 4130 patients with acute myeloid leukemia

The precise relationship between myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) is unclear and the role of molecular mutations in leukemic transformation in MDS is controversial. The aim of this study was to clarify the relationship between AML and MDS by comparing the frequency of molecular mutations in the two conditions. We compared the frequency of FLT3-length mutations (FLT3-LM), FLT3-TKD, MLL-partial tandem duplications (MLL-PTD), NRAS, and KITD816 in 381 patients with MDS refractory anemia with excess blasts [RAEB] n=49; with ringed sideroblasts [RARS] n=310; chronic monomyelocytic leukemia [CMML] n=22) and in 4130 patients with AML (de novo: n=3139; secondary AML [s-AML] following MDS: n=397; therapy-related [t-AML]: n=233; relapsed: n=361). All mutations were more frequent in s-AML than in MDS and all but the FLT3-TKD were more frequent in RAEB than in RA/RARS. The higher incidences in s-AML were significant for FLT3-TKD (p=0.032), MLL-PTD (p=0.034), and FLT3-LM (RA/RARS: 0/45; RAEB: 8/293; 2.7%; s-AML: 45/389; 11.6%; p<0.0001). The incidence of NRAS-mutations increased from 17/272 (6.3%) in MDS to 41/343 in s-AML (12.0%) and that of KITD816-mutations from 2/290 (0.7%) to 5/341 (1.5%) (p=n.s.). FLT3-LM-acquisition occurred in 3/22 cases (13.6%) during MDS transformation; NRAS-acquisition occurred in 1/24 (4.2%). FLT3-LM and MLL-PTD were more frequent in AML relapse than in de novo AML or s-AML (p<0.0001). The increase of molecular mutations from low- to high-risk MDS, to s-AML, and to relapsed AML emphasizes the value of these mutations as markers of progressing disease. Finally, we found a low rate of 5q- in the molecularly mutated cases in MDS which might explain the stability of this subtype.

Clinical Efficacy and Feasibility of an Intensive Preparative Regimen with Busulfan, Cyclophosphamide, and Total Body Irradiation Followed by Allogeneic Stem Cell Transplantation for Patients with Myeloid Malignancies.

Purpose: High-intensity conditioning regimens before allogeneic stem cell transplantation (all-SCT) could reduce relapse but may increase nonrelapse mortality. We have investigated the efficacy and feasibility of an intensive preparative regimen of busulfan (BU), cyclophosphamide (CY), and total body irradiation (TBI) for patients with myeloid malignancies.Patients and methods: From November 1990 to February 2005, 80 patients (acute myeloid leukemia (AML) 33, chronic myeloid leukemia (CML) 29, myelodysplastic syndrome (MDS) 18) treated with BU (8 mg/kg), CY (120 mg/kg), and TBI (10 Gy) followed by related (n=46) or unrelated (n=34) allo-SCT. Thirty-eight consecutive patients with AML in 1st remission, CML in chronic phase, and MDS (refractory anemia) defined as a standard risk group, and 42 patients with advanced AML, CML, and MDS (more than 5% marrow blasts) defined as a poor risk group.RESULTS: With a median follow-up was 6.9 years, the 7-year actuarial overall survival (OS) rate was 58% (standard risk 70% vs poor risk 47%, p=0.0076), and the probability of 7-year relapse rate was 18% (standard risk 17% vs poor risk 18%, p=0.4777). Nonrelapse mortality was 29% (standard risk 26%, poor risk 31%). Multivariate analysis indicated that age older than 40 years (p=0.018) and received allo-SCT before 1998 (p=0.006) had independent predictive value for nonrelapse mortality.CONCLUSION: The BU- CY- TBI regimen resulted in decreased relapse, especially in poor risk patients. The results of this study suggested that the BU- CY- TBI is an effective and feasible preparative regimen for allo-SCT in patients with myeloid malignancies.

Danazol Stimulates Proplatelet Formation of Megakaryocytes Via Rac Activation Pathway.

Danazol (C 22 H 27NO2; 17a-2,4-pregnadien-20-yno[2,3-d]isoxazol-17-ol) have been widely used for patients with endometriosis. Recently, many reports showed that danazol was effective especially in thrombopoietic action in patients with refractory chronic idiopathic thrombocytopenic purpura, apalstic anemia or myelodysplastic syndrome-refractory anemia (MDS/RA). The thrombopoietic mechanism of danazol has been unknown. In this study, we investigated the thrombopoietic effects of danazol on megakaryocytes, especially proplatelet formation (PPF).Murine megakaryocytes were isolated from bone marrow cells by Percoll®‚ density centrifugation and BSA gradient method. Isolated megakaryocytes (300/well) were cultured for 24 hrs in serum free condition with danazol and several kinase specific inhibitors including PPI (Src family kinase inhibitor), SU6695 (Src family kinase inhibitor), or LY294002 (PI3K inhibitor). PPF stimulation index (%) by danazol was calculated as (PPF with danazol)/(PPF without danazol). It was stimulated by danazol in a dose dependent manner(0μM: 100%, 0.2μM: 118±14.29%, 2μM: 136±10.3% (p<0.05), 12μM:176.7±17.4%(p<0.001), mean±SD, n=5).The inhibitiory index(%) by kinase specific inhibitor was calculated as (PPF with danazole and each kinase specific inhibitor)/(PPF without them). Src family kinase inhibitor including PPI or SU6656 did not affect the PPF of murine megakaryocytes at 0, 0.2, 2.4, and 12 μM concentrations of danazol. While, LY294002 inhibited PPF of murine megakaryocytes at 0μM of danazol (LY294002; 0μM: 100%, 10μM: 75.33±4.5% (p<0.01), 100μM: 61.3±9.4% (p<0.01) (n=4)), as shown in Figure 1. PPF with danazole 0.2μM/ LY294002 100μM was 86% of that with danazol 0.2μM/ LY294002 0μM, that with danazol 2.4μM/ LY294002 100μM was 78%(p<0.05) of PPF with danazol 2.4μM/ LY294002 0μM, and that with danazol 12μM/ LY294002 100μM was 60%(p<0.01) of PPF with danazol 12μM/ LY294002 0μM (Figure 1). As a result, the similar inhibitory effects of LY294002 on PPF of murine megakaryocytes at 0, 0.2, 2.4 and 12.0μM of danazol were also observed.These results strongly suggest that danazol is a powerful stimulating agent for PPF and that PI3K activation, followed by Rac activation might be the signal transduction pathway in PPF of megakaryocytes, based on that PI3K and Src family kinase stimulate Rac activation. [Display omitted]

Improved Outcome for Peripheral Blood Stem Cell Transplantation for Advanced Primary Myelodysplastic Syndrome

Stem cell transplantation for myelodysplastic syndrome (MDS) is characterized by high transplant-related mortality (TRM), especially in older patients and those with more advanced disease. Outcome after peripheral blood stem cell transplantation (PBSCT) may be superior to earlier results with bone marrow transplantation. Forty-three patients (aged 12-73 years; median, 49 years) received an HLA-identical sibling donor PBSCT. Twenty three patients aged ≤55 years without prohibitive comorbidity received myeloablative total body irradiation–based conditioning, followed by a T cell–depleted PBSCT and delayed add-back of donor lymphocytes. Older patients or those with comorbidities (n = 20) received reduced-intensity conditioning and an unmanipulated PBSCT. Thirty-seven (86%) had advanced disease (refractory anemia with excess blasts [n = 9], refractory anemia with excess blasts in transformation [n = 6], acute myelogenous leukemia [n = 13], or treatment-related MDS [n = 9]); 6 had low-risk MDS (refractory anemia or refractory anemia with ringed sideroblasts). The median follow-up was 18 months (range, 5-89 months). Actuarial probabilities of 3-year overall survival (OS), disease-free survival, relapse, and TRM were 64%, 59%, 26%, and 23%, respectively, for 34 primary MDS patients. The best results were in 19 patients younger than 50 years of age undergoing myeloablative PBSCT (actuarial probabilities of OS, disease-free survival, relapse, and TRM were 81%, 72%, 22%, and 7%, respectively). Although outcomes for all stages of primary MDS were improved, that for therapy-related MDS remained dismal, with 11% OS, because of a high relapse rate (89%).

Unrelated Cord Blood Transplantation after Myeloablative Conditioning for Adult Patients with Refractory Anemia

We report the results of unrelated cord blood transplantation (CBT) after myeloablative conditioning in 3 patients with myelodysplastic syndrome-refractory anemia (MDS-RA). All patients were treated with total body irradiation, cytosine arabinoside (Ara-C), and cyclophosphamide, followed by unrelated HLA-mismatched CBT. Granulocyte colony-stimulating factor was infused continuously, starting 12 hours before Ara-C therapy and continuing until the end of Ara-C therapy. All patients received standard cyclosporine and methotrexate therapy as graft-versus-host disease prophylaxis. All patients had myeloid reconstitution, and the times to reach an absolute neutrophil count >0.5 x 10(9)/L were 23, 20, and 26 days. All patients showed full donor chimerism at the time of the first bone marrow examination (on day +42, +43, and +62) after CBT. All patients are alive and free of disease at between 17 and 39 months after CBT. These results suggest that adult MDS-RA patients without suitable related or unrelated bone marrow donors should be considered as candidates for CBT.

Reduced-Intensity Hematopoietic Stem Cell Transplantation for a Patient with Myelodysplastic Syndrome and Chronic Obstructive Pulmonary Disease

Allogeneic hematopoietic stem cell transplantation (SCT) following high-dose chemotherapy and total body irradiation (TBI) has improved the prognosis of advanced hematological diseases. In order to assess a patient’s suitability for SCT, a thorough pretransplantation survey is performed. However, patient eligibility has expanded because of the progress of supportive care, so it is difficult to define SCT eligibility limitations due to organ dysfunction. Moreover, recent progress in reduced-intensity stem cell transplantation (RIST) has facilitated the use of SCT in older patients and patients with various underlying diseases [1,2]. This article describes the case of a 65-year-old man with myelodysplastic syndrome (MDS), refractory anemia, and chronic obstructive pulmonary disease (COPD) (emphysema) who underwent SCT. The patient had a history of smoking for more than 40 years and had suffered from Burger’s disease since the age of 40 years. He occasionally complained of lower limb pain and was treated with prostaglandin. In 1998, he presented with anemia, and MDS (refractory anemia) was diagnosed. Two years prior to this report he required frequent red cell transfusions, the frequency of which gradually increased. In June 2004, he was admitted to our hospital for allogeneic hematopoietic SCT. Laboratory examinations confirmed bicytopenia: hemoglobin concentration, 5.7 g/dL; red blood cell count, 2010 109/L; white blood cell count, 3.3 109/L; platelet count, 183 109/L. The bone marrow survey demonstrated normocellular bone marrow with mild dysplasia and a small amount of blasts (<5%). The karyotype analysis showed 3 populations; 4 of 20 analyzed cells were 46XY, del(7)(q20); 3 of 20 analyzed cells were 46XY, +13; the remaining cells were 46XY. Prior to SCT the patient had received a total of 46 transfusions of 2 units of red cells. The pretransplantation Reduced-Intensity Hematopoietic Stem Cell Transplantation for a Patient with Myelodysplastic Syndrome and Chronic Obstructive Pulmonary Disease

Allogeneic hematopoietic cell transplantation from alternative donors in children with myelodysplastic syndrome: is that an alternative?

Allogeneic hematopoietic cell transplantation (HCT) in children with myelodysplastic syndrome (MDS) remains a challenge due to the toxic conditioning regimens administered to minimize the risk of relapse in the HLA-matched or of graft rejection in the HLA-mismatched settings. In the absence of matched sibling donors, alternative donors such as unrelated and/or partially matched family sources remain risky, yet the only available, options. Herein we report the results of HCT from alternative donors in 14 children with different subtypes of MDS (juvenile myelomonocytic leukemia [JMML] n = 9; myelodysplastic syndrome [MDS] refractory anemia n = 3; MDS refractory anemia with excess of blasts in transformation n = 2) transplanted at our institution. The median time from diagnosis to HCT was 9 months (range 4 to 90 months). The variety of HCT types included: unrelated peripheral blood progenitor cell transplantation (PBPCT) ( n = 2), partially matched family donor T-cell–repleted BMT/ PBPCT ( n = 6), and haploidentical T-cell–depleted PBPCT ( n = 6). Five of 14 patients remain alive at 7 to 37 months posttransplant (including two patients after partially matched family donor BMT, two patients after haploidentical T-cell–depleted- PBPCT, and one after unrelated- PBPCT, respectively). The major complications were: primary graft failure in the haploidentical T-cell–depleted-setting or graft-versus-host disease (GvHD) in T-cell–repleted partially matched family or unrelated settings, respectively. Despite the high transplant-related mortality rate in this series, allogeneic HCT from alternative donors remains an interesting solution for children with MDS who lack matched sibling donors. Due to improved immune reconstitution, despite an increased risk of GvHD, T-cell–repleted transplants from single HLA-mismatched family donors remain a valuable option for children without matched donors. Splenectomy prior to HCT may positively affect the posttransplant course in patients with overt splenomegaly for example those afflicted with JMML.

High expression of YB-1 gene in erythroid cells in patients with refractory anemia.

It has been shown that aberrant expression of a transcription factor, GATA-1, leads to maturation arrest and transformation of erythroid cells. We previously reported that a multifunctional protein, YB-1, was expressed strongly in the spleen of a GATA-1 mutant mouse, which was filled with transformed erythroblasts. This finding suggested that YB-1 has roles in erythropoiesis. In this study, we examined in vivo expression of YB-1 messenger RNA (mRNA) in bone marrow erythroid cells and erythroid leukemic cell lines. During erythroid differentiation of erythroid leukemic cell lines, the expression level of YB-1 mRNA was highest at the early phase of differentiation and then decreased. In human bone marrow cells, the in vivo expression level of YB-1 mRNA was higher in glycophorin A-positive cells than in glycophorin A-negative cells. An interesting finding was that expression of YB-1 was higher in erythroblasts in myelodysplastic syndrome-refractory anemia (MDS-RA) than in normal cells. The findings suggested that YB-1 functions in the early stage of erythropoiesis and that aberrant expression of this protein may induce hematological diseases such as MDS.

Expression and functional analysis of granulocyte colony-stimulating factor receptors on CD34++ cells in patients with myelodysplastic syndrome (MDS) and MDS-acute myeloid leukaemia.

CD34++ cells from 45 patients with myelodysplastic syndrome (MDS) and MDS-acute myeloid leukaemia (MDS-AML) were observed by flow cytometry for the expression of granulocyte colony-stimulating factor receptor (G-CSFR). Ten patients had a significantly reduced expression of G-CSFR. Late stages of disease showed a higher proportion of either high or low G-CSFR expression than earlier stages. In MDS refractory anaemia (RA), G-CSFR was inversely related to CD33 expression. Most patients (9/10) with low G-CSFR expression had neutropenia of the peripheral blood. Neutropenia was less common in the normal group, but also occurred in the high expression group. No neutrophil response was observed following G-CSF administration to MDS-AML patients (6/6) with low G-CSFR expression. In the high expression group, patients (3/3) showed a response to G-CSF while, in the normal group (1/2), the response was minor. In the normal- or high-receptor-expressing groups, the receptors were functionally active in terms of apoptosis but not proliferation and clonogenic growth, although no clear correlation to receptor expression was observed. The G-CSFR signal transduction pathway in the normal and high group was not deficient of messenger RNA for either janus kinases (Jaks) or signal transducers and activators of transcription (Stats). These findings suggest that the lowered expression of G-CSFR may cause neutropenia in MDS and MDS-AML patients and, therefore, may partially explain the neutropenia in myelodysplastic patients.

HLA-DR15 (DR2) is overrepresented in myelodysplastic syndrome and aplastic anemia and predicts a response to immunosuppression in myelodysplastic syndrome

The extent and importance of autoimmune mechanisms in myelodysplastic syndrome (MDS) and the role of immunosuppression in the treatment of this disease are not well defined. We report overrepresentation of HLA-DR2 and its serologic split HLA-DR15 in both MDS and aplastic anemia (AA). Four clinically and ethnically defined patient groups were analyzed. The HLA-DR15 antigen frequencies among North American white MDS patients (n = 72) and AA patients (n = 59), who received immunosuppressive treatment at the National Institutes of Health (NIH), were 36% and 42%, respectively. These antigen frequencies were significantly higher than that of the control population of 240 North American white NIH blood donors typed for HLA antigens by the same molecular technique (HLA-DR15, 21.3%, P =.01 for MDS, P <.001 for AA). Among North American white patients reported in the International Bone Marrow Transplant Registry (IBMTR), 30% of 341 MDS patients and 33% of 364 AA patients were positive for HLA-DR2. These antigen frequencies were higher than those reported for the general North American white population (HLA-DR2, 25.3%, P =.089 for MDS, P =.01 for AA). The DR15 and DR2 frequencies were significantly increased in MDS refractory anemia (RA) (P =.036 and P =.01, respectively) but not MDS refractory anemia with excess blasts. In the NIH MDS patients, HLA-DR15 was significantly associated with a clinically relevant response to antithymocyte globulin (ATG) or cyclosporine immunosuppression (multivariate analysis, P =.008). In MDS with RA, DR15 may be useful as a guide to pathophysiology, prognosis, and treatment.

Leukaemia cutis and leukaemic vasculitis.

Leukaemia cutis (LC) and leukaemic vasculitis (LV) are uncommon but important features of haematological malignancy. We aimed to evaluate clinicopathological features of a series of such cases. Thirty-four patients with LC were studied. Nineteen had acute myeloblastic leukaemia, six had acute lymphoblastic leukaemia, three had myelodysplastic syndrome-refractory anaemia with excess blast in transformation, three had non-Hodgkin's lymphoma in leukaemic phase, two had chronic lymphocytic leukaemia and one had multiple myeloma. Cutaneous lesions were widely dispersed in 15 patients, but were restricted to the extremities in eight patients. In other patients lesions were localized on the face, hands and feet. Cutaneous lesions were generally erythematous, maculopapular, squamous, nodular, haemorrhagic or necrotic. Two localizations were very interesting: in one case, lesions were confined to the site of previous varicella zoster virus infection; in the other case, leukaemic infiltration occurred within a lesion of cutaneous leishmaniasis. All of the patients had high white blood cell count and/or other findings of high tumour burden. Vasculitis with leukaemic cell infiltration (LV) was detected in 24 patients, and was high-grade LV in 16 patients. Patients with high-grade LV tended to have a higher white blood cell count and other findings associated with an aggressive clinical course compared with patients not having LV. Thirteen patients with LV died within 1 month but five patients lived more than 1 year. LC, and especially LV, is generally an indicator of poor prognosis. Its pathogenesis must be evaluated further with additional studies, including adhesion molecules, angiogenic factors and other biological parameters.

Induction of apoptotic change of hematopoietic cells by cloned stromal cells from mds patient via direct cellular interactions

We previously reported on the heterogeneity of bone marrow stromal cell function in supporting hematopoietic cell proliferation and differentiation in vitro among refractory anemia (RA) of myelodysplastic syndrome (MDS) patients. Interestingly, stromal cells from same MDS RA patients induced an apoptotic change in CD34-positive hematopoietic cells (CD34+). To clarify the mechanism of this action of stromal cells, a cloned stromal cell line (LS801) from MDS patient was established. In a coculture system with LS801, proliferation and differentiation of CD34+ cells was inhibited. Assay for the expression of 7A6 antigen on CD34+ cells, for monitoring the cells undergoing apoptosis, showed that LS801 induced an apoptotic change in CD34+ cells. When CD34+ cells were cocultured but kept separate fom LS801 by a 0.45-mm millipore membrane to prevent their attachment, the action of LS801 for inducing apoptosis of CD34+ cells was inhibited. The expression of CD95 on CD34+ cells was induce by LS801, however, no production of fas ligand, TNF-α or IFN-γ in LS801 was observed. In light of these observations, direct contact between LS801 and CD34+ cells might be essential for maximum induction of CD34+ cells undergoing apoptosis.

Monosomy 16 as the Sole Abnormality in Myeloid Malignancies

The majority of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) patients reported with chromosome 16 abnormalities had the inv(16)(p13q22) or t(16;16)(p13;q22) rearrangements, which were associated with a favorable prognosis. In contrast, del(16)(q22) was reported less commonly but was associated with a less favorable prognosis. We describe an 80-year-old woman who presented with MDS (refractory anemia). Chromosome analysis from bone marrow aspirate cultures showed monosomy 16 as the sole cytogenetic abnormality. Comparison of this patient with previously reported cases of monosomy 16 showed that this uncommon abnormality was associated with myeloid disorders. Monosomy 16 patients, similar to del(16)(q22) patients, tended to be elderly, presented with MDS or AML, and had a poor prognosis. The similarity in clinical course for del(16)(q22) and monosomy 16 patients suggests that the phenotype in both groups resulted from loss of important gene(s) on 16q, as distinct from the fusion gene product identified in the inv(16) and t(16;16) rearrangements.

Establishment of stromal cell line from an MDS RA patient which induced an apoptopic change in hematopoietic and leukemic cells in vitro

Objective We previously reported on the heterogeneity of bone marrow stromal cell function in supporting hematopoietic cell proliferation and differentiation in vitro among refractory anemia (RA) of myelodysplastic syndrome (MDS) patients. Interestingly, stromal cells from some MDS RA patients induced an apoptotic change in CD34 + hematopoietic cells. However, the mechanism responsible for this action was unclear. Materials and Methods In the present study, we established a cloned stromal cell line (LS801) from an MDS RA patient by introducing recombinant SV40-adenovirus vector containing the SV40 early gene. Results LS801 induced an apoptotic change in CD34 + cells from normal subjects and cloned leukemic cells in a coculture system. When hematopoietic cells were cocultured but kept separate from LS801 by a 0.45-μm Millipore membrane to prevent their attachment, the action of LS801 in inducing apoptosis of hematopoietic cells was inhibited. Additionally, no production of fas ligand, tumor necrosis factor α or interferon γ in LS801 was observed. Conclusion These findings suggest that the novel stromal cell line LS801 will shed light on research into the mechanism underlying the apoptotic changes induced by stromal cells in hematopoietic cells.

Incidence of nucleoli in erythroblasts in patients suffering from refractory anemia of myelodysplastic syndrome.

Nucleoli of erythroblasts have been studied in patients suffering from refractory anemia (RA) of myelodysplastic syndrome (MDS) and in control patients without a disturbed erythropoiesis in order to provide information on the incidence of nucleoli and micronucleoli in these cells. Nucleoli in erythroblasts were visualized by a simple cytochemical procedure for the demonstration of RNA which facilitated the visualization not only large nucleoli but also micronucleoli in advanced stages of the erythroblastic maturation. In control patients nucleoli were detected in all stages of erythroblastic development. In patients suffering from RA of MDS, a relatively large population of polychromatic and orthochromatic erythroblasts was characterized by a loss of nucleoli accompanied by the decreased incidence of micronucleoli characteristic of these cells. In contrast to control patients, in patients suffering from RA of MDS the number of nucleoli expressed by the values of the nucleolar coefficient of erythroblasts was smaller, particularly in both the early and terminal stages of erythroblastic development. Thus in patients with RA of MDS both the abnormal loss of nucleoli and decreased number of nucleoli in erythroblasts apparently represent and reflect a further abnormality of disturbed erythropoiesis.

Bone marrow stroma from refractory anemia of myelodysplastic syndrome is defective in its ability to support normal CD34-positive cell proliferation and differentiation in vitro

We examined the supportive function of stromal cells from patients with refractory anemia (RA) of myelodysplastic syndrome (MDS) on CD34-positive hematopoietic cell proliferation and differentiation using a long-term bone marrow culture (LTMC) system. Primary marrow stromal cells were obtained from 11 MDS RA patients and 12 healthy volunteers, and freshly prepared CD34-positive bone marrow cells from a normal subject were inoculated onto the stroma. There seems to be three broad patterns of hematopoietic cell growth in the LTMCs. In one group, hematopoietic cells were maintained at near normal levels (type A). In the second group, the number of hematopoietic cells increased within the first 5–10 days of culture, but declined to low levels at 15–20 days of culture as compared with normal control (type B). In the third group, the incidence of hematopoietic cells steadily declined from the beginning of the culture (type C). Furthermore, apoptotic change of hematopoietic cells was very frequently observed in cultures with the type C stroma, which were especially defective for supporting CD34+cell proliferation and differentiation. The expression of CD95 on hematopoietic cells was induced by the type C stroma, however, production of fas ligand by the stromal cells was not observed. These findings suggest a lack of hematopoietic supportive function in some cases of MDS RA and also indicate that there is heterogeneity of stromal function among MDS RA patients.

Double Minute Chromosomes in a Patient with Myelodysplastic Syndrome Transforming into Acute Myeloid Leukemia

Presence of double minute chromosomes (dmin) is rare in bone marrow cells in patients with preleukemia and leukemia. We describe a case of myelodysplastic syndrome-refractory anemia with excess of blasts (MDS-RAEB) associated with two unrelated pathological chromosomal clones that developed during the progression of the disease. The patient was followed cytogenetically for a period of 4 years. At the time of transition into RAEB-T and later to acute myeloid leukemia (AML), dmin were associated with resistance to chemotherapy. Fluorescence in situ hybridization study proved that the dmin in this case were c-MYC amplicons. At the terminal stage of the disease, dmins were present in all 50 analyzed cells.

Elliptocytosis in Myelodysplastic Syndrome Associated with Translocation (1;5)(p10;q10) and Deletion of 20q

Acquired elliptocytosis is a red blood cell abnormality occasionally associated with myelodysplastic syndrome (MDS). A Japanese male with MDS who presented with elliptocytosis had mild anemia and hypercellular bone marrow with three lineage-dysplasia. He was diagnosed with refractory anemia of MDS. Cytogenetic analysis of bone marrow cells showed 47,XY,+1,der(1;5)(q10;p10),t(1;5)(p10;q10),del(20)(q11) in 70% of the analyzed cells. Analysis of red blood cell membrane proteins by sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed normal electrophoretic patterns with no quantitative abnormalities of each protein. Del(20q) and/or t(1;5)(p10;q10) might be associated with elliptocytosis in this patient.

Pharmacokinetic studies of intravenous glycosylated recombinant human granulocyte colony-stimulating factor in various hematological disorders: inverse correlation between the half-life and bone marrow myeloid cell pool.

The pharmacokinetics of an intravenous bolus dose of glycosylated recombinant human G-CSF (rhG-CSF) was examined in 15 patients with various hematological disorders and 3 normal volunteers. The elimination half-life of rhG-CSF varied with the disorder. The half-life of an initial dose of rhG-CSF (2 micrograms/weight kg) was significantly prolonged in patients with aplastic anemia (2.7 +/- 0.3 h, n = 3) and myelodysplastic syndrome-refractory anemia (2.0 +/- 0.3 h, n = 3) when compared with those in normal controls (0.9 +/- 0.5 h, n = 3). In contrast, in patients with acute myelogenous leukemia which was overt leukemia from myelodysplastic syndrome-refractory anemia with excess of blasts in transformation, the half-life was shortened after chemotherapy (0.2 +/- 0.1 h, n = 3). The half-life of rhG-CSF in 2 patients with acute lymphoblastic leukemia in complete remission was prolonged (2.0 and 2.7 h) at the time of marrow-suppression after chemotherapy and then shortened (0.5, 1.0 h, respectively) in the recovery phase. The half-life of rhG-CSF was very weakly, inversely correlated with absolute neutrophil count in blood (n = 24, r2 = 0.32, P < 0.01), and was inversely correlated with the absolute count of bone-marrow myeloid cells (nucleated cell count in bone-marrow aspirates x the percentage of myeloid cells/100) of patients with aplastic anemia and myelodysplastic syndrome-refractory anemia (n = 12, r2 = 0.63, P = 0.002). These results suggest that the half-life of intravenously administered rhG-CSF (2 micrograms/kg) reflects the size of the myeloid cell compartment in vivo, and support the hypothesis that receptor-mediated consumption mainly accounts for the clearance of exogenous G-CSF.