Naomi Sugimori

Origin and fate of blood cells deficient in glycosylphosphatidylinositol‐anchored protein among patients with bone marrow failure

Peripheral blood from 489 recently diagnosed patients with aplastic anaemia (AA) and 316 with refractory anaemia (RA) of myelodysplastic syndrome was evaluated to characterize CD55−CD59− [paroxysmal nocturnal haemoglobinuria (PNH)]‐type blood cells associated with bone marrow (BM) failure. PNH‐type cells were detected in 57% and 20% of patients with AA and RA, respectively. The percentages of PNH‐type granulocytes ranged from 0·003% to 94·2% and the distribution was log‐normal with a median of 0·178%. Serial analyses of 75 patients with PNH‐type cells over 5 years revealed that the percentage of PNH‐type cells constantly increased in 13 (17%), persisted in 44 (59%), disappeared in the remaining 18 (24%) although even in the ‘Disappearance’ group, PNH‐type granulocytes persisted for at least 6 months. A scattergram profile of PNH‐type cells unique to each patient persisted regardless of the response to immunosuppressive therapy and only single PIGA mutations were detected in PNH‐type granulocytes sorted from four patients. These findings suggest that the PNH‐type cells in patients with BM failure are derived from single PIGA mutant haematopoietic stem cells even when their percentages are <1% and their fate depends on the proliferation and self‐maintenance properties of the individual PIGA mutants.

Successful treatment of Epstein-Barr virus-associated natural killer cell large granular lymphocytic leukaemia using allogeneic peripheral blood stem cell transplantation

We report a case of natural killer cell large granular lymphocytic (NK-LGL) leukaemia successfully treated with allogeneic peripheral blood stem cell transplantation (allo-PBSCT). The peripheral blood (PB) revealed an abnormal expansion of LGL that were CD3−, CD16− and CD56+, and had natural killer activity. In situ EBER-1 hybridization of the PB mononuclear cells showed the presence of Epstein–Barr virus (EBV) in the LGL as well as in lymphocytes infiltrating the tonsils and colon. Southern blotting with an EBV-terminal repetitive sequence probe demonstrated clonal proliferation of EBV+ cells. The patient received allo-PBSCT from his HLA-matched sister with a conditioning regimen involving the use of cyclophosphamide and fractionated total body irradiation. The patient promptly recovered trilineage haematopoiesis without graft-versus-host disease, and has been in complete remission without therapy for 10 months since allo-PBSCT, suggesting that allo-PBSCT could eradicate the NK-LGL leukaemic cells.

Favorable outcome of patients who have 13q deletion: a suggestion for revision of the WHO 'MDS-U' designation.

To characterize bone marrow failure with del(13q), we reviewed clinical records of 22 bone marrow failure patients possessing del(13q) alone or del(13q) plus other abnormalities. All del(13q) patients were diagnosed with myelodysplastic syndrome-unclassified due to the absence of apparent dysplasia. Elevated glycosylphosphatidylinositol-anchored protein-deficient blood cell percentages were detected in all 16 with del(13q) alone and 3 of 6 (50%) patients with del(13q) plus other abnormalities. All 14 patients with del(13q) alone and 2 of 5 (40%) patients with del(13q) plus other abnormalities responded to immunosuppressive therapy with 10-year overall survival rates of 83% and 67%, respectively. Only 2 patients who had abnormalities in addition to the del(13q) abnormality developed acute myeloid leukemia. Given that myelodysplastic syndrome-unclassified with del(13q) is a benign bone marrow failure subset characterized by good response to immunosuppressive therapy and a high prevalence of increased glycosylphosphatidylinositol-anchored protein-deficient cells, del(13q) should not be considered an intermediate-risk chromosomal abnormality.

Prospective Trial of High-Dose Chemotherapy Followed by Infusions of Peripheral Blood Stem Cells and Dose-Escalated Donor Lymphocytes for Relapsed Leukemia after Allogeneic Stem Cell Transplantation

To determine whether induction of graft-versus-host disease (GVHD) improves the outcome of acute relapsed leukemia after stem cell transplantation (SCT), we used high-dose cytarabine (ara-C) followed by infusions of donor-derived buffy coats containing peripheral blood stem cells to treat 12 patients with relapsed leukemia. Donor lymphocyte infusion (DLI) was repeated at least twice over a 5-week interval for patients in whom grade II to IV acute GVHD did not develop after the first DLI. Grade II to IV acute GVHD developed in 4 (33%) of the patients. Chronic GVHD developed in 3 patients, 2 of whom had not experienced acute GVHD. Four (67%) of the 6 patients who developed grade II to IV acute and/or chronic GVHD after DLI responded, but none of the other 6 patients responded. Four (33%) of the patients (2 with acute myelogenous leukemia [AML]and 2 with acute lymphoblastic leukemia [ALL]) achieved complete remission lasting longer than 4 months after the first DLI, but 3 of them had relapses in bone sites. Of these 4 patients, 1 patient with AML and 2 with ALL were alive 8 to 27 months after DLI. These findings indicate that high-dose ara-C combined with megadose DLI may produce durable remission of acute leukemia that has relapsed after SCT when GVHD is induced. The low induction rate of GVHD and extramedullary relapse after remission is achieved with DLI are problems yet to be solved.

Administration of G-CSF to normal individuals diminishes L-selectin + T cells in the peripheral blood that respond better to alloantigen stimulation than L-selectin - T cells

To determine whether administration of G-CSF induces phenotypic or functional changes in T cells, we examined peripheral blood T cells from normal individuals receiving G-CSF for activation antigen and adhesion molecule expression before and after G-CSF administration. G-CSF (10 μg/kg/day) was administered subcutaneously to 14 normal individuals for 3–5 days and their PBMC were serially analyzed with monoclonal Ab (mAb) directed to HLA-DR, CD45RO, CD45RA, CD25, CD122, CD95, CD11a, CD49d, CD44 and CD62L (L-selectin) coupled with anti-CD3 mAb. Among T cells positive for these antigens, only the proportion of T cells expressing L-selectin significantly decreased from 68% to 37% after 3-day G-CSF administration. When peripheral blood CD3+ T cells obtained before and after G-CSF administration were sorted into two populations depending on the expression of L-selectin and tested for their proliferative response to allogeneic B cells, the reactivity of L-selectin− cells to alloantigen stimulation was consistently lower than that of L-selectin+ cells regardless of the exposure to G-CSF. The decrease in the relative number of L-selectin+ cells induced by G-CSF administration may contribute to the unexpectedly low incidence of severe acute GVHD after allogeneic PBSC transplantation.

Response to immunosuppressive therapy and an HLA‐DRB1 allele in patients with aplastic anaemia: HLA‐DRB1*1501 does not predict response to antithymocyte globulin

HLA‐DRB1*1501, a subtype of HLA‐DR2, has been shown to be closely associated with a good response to cyclosporine (CyA) therapy in patients with aplastic anaemia (AA). To determine whether this DRB1 allele can also predict a response to antithymocyte globulin (ATG) therapy in AA patients, we analysed the results of HLA‐DRB1 typing in 59 Japanese patients who received ATG within 2 years after diagnosis of AA and also in 52 patients treated with CyA. All patients were divided into three groups: those with DRB1*1501, those with DRB1*1502, and those without either of these two alleles (DR2–). The response rate to ATG in DRB1*1501+ patients (56%) was not significantly higher than that in DRB1*1502+ patients (47%) and in the other DR2– patients (54%). In contrast, the response rate to CyA therapy in DRB1*1501+ patients (92%) was significantly higher than that in the DRB1*1502+ (41%) and in DR2– patients (57%). Multivariate analysis revealed that possessing DRB1*1501 was an independent factor significantly predictive of a good response to CyA. These results indicate that although identifying the DRB1*1501 allele in AA patients prior to therapy is predictive of a good response to CyA therapy, it does not have a predictive value for ATG therapy.

Autoantibodies specific to hnRNP K: a new diagnostic marker for immune pathophysiology in aplastic anemia

To identify a new diagnostic marker for the immune pathophysiology of aplastic anemia (AA), we screened sera of immune-mediated AA patients for the presence of antibodies (Abs) specific to proteins derived from a leukemia cell line UT-7 using two-dimensional electrophoresis followed by immunoblotting. The target proteins were identified by peptide mass fingerprinting. Heterogeneous nuclear ribonucleoprotein (hnRNP) K was identified as a novel autoantigen. An enzyme-linked immunosorbent assay revealed high titers of anti-hnRNP K Abs in 85 (31%) of 273 patients with AA. Sixty-four patients received antithymocyte globulin and cyclosporine after undergoing screening for anti-hnRNP K Ab, anti-DRS-1 Ab, anti-moesin Ab, and paroxysmal nocturnal hemoglobinuria (PNH)-type cells. Twenty (87%) of 23 patients with the presence of anti-hnRNP K Abs responded to the immunosuppressive therapy (IST), while 19 (46%) of 41 patients without the presence of anti-hnRNP K Abs responded. A multivariate analysis showed only PNH-type cells and anti-hnRNP K Abs to be significant factors for the prediction of a good response to IST. The detection of anti-hnRNP K Abs as well as PNH-type cells may therefore be useful for diagnosing the immune pathophysiology of AA.

Aberrant increase in the immature platelet fraction in patients with myelodysplastic syndrome: a marker of karyotypic abnormalities associated with poor prognosis

Objectives:  Some patients with myelodysplastic syndrome (MDS) show a marked increase in the percentage of immature platelet fraction (IPF%) despite the absence of severe thrombocytopenia. To determine the significance of such an unbalanced increase in the IPF%, we investigated the IPF% and other laboratory findings of 51 patients recently diagnosed with MDS.

Increased plasma thrombopoietin levels in patients with myelodysplastic syndrome: a reliable marker for a benign subset of bone marrow failure

Although myelodysplastic syndromes are heterogeneous disorders comprising a benign subset of bone marrow failure similar to aplastic anemia, no laboratory test has been established to distinguish it from bone marrow failures that can evolve into acute myeloid leukemia. Plasma thrombopoietin levels were measured in 120 patients who had myelodysplastic syndrome with thrombocytopenia (< 100 × 109/L) to determine any correlation to markers associated with immune pathophysiology and outcome. Thrombopoietin levels were consistently low for patients with refractory anemia with excess of blasts, while patients with other myelodysplatic syndrome subsets had more variable results. Patients with thrombopoietin levels of 320 pg/mL and over had increased glycosylphosphatidylinositol-anchored protein-deficient blood cells (49.1% vs. 0%), were more likely to have a low International Prognostic Scoring System (IPSS) score (≤1.0, 100% vs. 65.5%), a higher response rate to immunosuppressive therapy (84.2% vs. 14.3%), and a better 5-year progression-free survival rate (94.1% vs. 63.6% for refractory cytopenia with unilineage dysplasia; 100.0% vs. 44.4% for refractory cytopenia with multilineage dysplasia). In conclusion, increased plasma thrombopoietin levels were associated with a favorable prognosis of bone marrow failure and could, therefore, represent a reliable marker for a benign subset of myelodysplastic syndrome.

Successful treatment of Trichosporon fungemia in a patient with refractory acute myeloid leukemia using voriconazole combined with liposomal amphotericin B

Trichosporon fungemia is a rare and fatal fungal infection that occurs in patients with prolonged neutropenia associated with hematologic malignancies. A 21‐year‐old male developed Trichosporon fungemia during remission induction therapy for acute myeloid leukemia (AML). Although two courses of induction therapy failed to induce a remission of AML, combination therapy with voriconazole and liposomal amphotericin B (L‐AmB) followed by monocyte colony‐stimulating factor ameliorated the Trichosporon fungemia and enabled the patient to receive reduced‐intensity bone marrow transplantation (BMT) from his human leukocyte antigen‐A one‐locus mismatched mother. The patient achieved a durable remission after BMT without exacerbation of Trichosporon fungemia. The combination therapy with voriconazole and L‐AmB may therefore be useful in controlling Trichosporon fungemia associated with prolonged neutropenia after remission induction therapy for AML.