Reference guide for the diagnosis of adult primary immune thrombocytopenia, 2023 edition.

Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by isolated thrombocytopenia due to accelerated platelet destruction and impaired platelet production. Diagnosis of ITP is still challenging because ITP has been diagnosed by exclusion. Exclusion of thrombocytopenia due to bone marrow failure is especially important in Japan because of high prevalence of aplastic anemia compared to Western countries. Hence, we propose a new diagnostic criteria involving the measurement of plasma thrombopoietin (TPO) levels and percentage of immature platelet fraction (RP% or IPF%); 1) isolated thrombocytopenia with no morphological evidence of dysplasia in any blood cell type in a blood smear, 2) normal or slightly increased plasma TPO level (< cutoff), 3) elevated RP% or IPF% (> upper limit of normal), and 4) absence of other conditions that potentially cause thrombocytopenia including secondary ITP. A diagnosis of ITP is made if conditions 1-4 are all met. Cases in which criterion 2 or 3 is not met or unavailable are defined as "possible ITP," and diagnosis of ITP can be made mainly by typical clinical course. These new criteria enable us to clearly differentiate ITP from aplastic anemia and other forms of hypoplastic thrombocytopenia and can be highly useful in clinical practice for avoiding unnecessary bone marrow examination as well as for appropriate selection of treatments.

Safe childbirth for a type 1 antithrombin-deficient woman with novel mutation in the SERPINC1 gene undergoing antithrombin concentrate therapy.

: Inherited antithrombin (AT) deficiency is an autosomal dominant thrombotic disorder. We encountered a case of inherited type I AT deficiency and identified the causative mutation; a novel c.7430A>G missense mutation in the SERPINC1 gene in which tyrosine was substituted for cysteine at the 292nd amino acid. A recombinant AT protein with the 7430A>G mutation was not detected in cell lysates or culture supernatants. And then, our patient without personal or family history of thrombosis was pregnant woman with asymptomatic AT deficiency. Our patient treated with only AT concentrate therapy during pregnancy and she was able to safely give birth naturally and avoid thrombosis. We believe that this therapy for pregnant woman with asymptomatic AT deficiency is effective and safety as anticoagulant therapy during pregnancy.

Usefulness of Low-Dose Splenic Irradiation prior to Reduced-Intensity Conditioning Regimen for Hematopoietic Stem Cell Transplantation in Elderly Patients with Myelofibrosis.

The Janus kinase (JAK) 1 and 2 inhibitor, ruxolitinib, was recently approved in Japan and has been effective in many patients with myelofibrosis (MF). Although the inhibitor decreases splenomegaly and relieves MF-related symptoms, allogeneic hematopoietic cell transplantation (HCT) remains as the only curative therapy for MF. The presence of splenomegaly has been reported as a risk factor for graft failure, delayed engraftment, and poor survival. Here, we report two elderly MF patients with massive splenomegaly and a JAK2 V617F mutation. These patients underwent splenic irradiation to decrease splenomegaly prior to HCT with a reduced-intensity conditioning (RIC) regimen. Massive splenomegaly gradually decreased by 4 Gy splenic irradiation. The subsequent RIC regimen involved 4 Gy total body irradiation and fludarabine and intravenous busulfan. In both patients, engraftment failure did not occur, and complete remission was achieved. The splenomegaly decreased, and MF-related symptoms were resolved. Furthermore, the JAK2 V617F mutation disappeared, and fibrosis in the bone marrow regressed. We suggest that splenic irradiation prior to the RIC regimen for HCT in elderly MF patients with massive splenomegaly is safe. Furthermore, the HCT protocols with splenic irradiation should be considered for patients who have not shown clinical benefits to optimal medical management such as treatment with ruxolitinib.

Successful rituximab treatment in an elderly patient with recurrent thrombotic thrombocytopenic purpura.

An 81-year-old man presenting with fever, neurological symptoms, thrombocytopenia, and hemolytic anemia was diagnosed with acquired idiopathic thrombotic thrombocytopenic purpura (TTP). His disintegrin-like and metalloproteinase with thrombospondin type 1 motifs 13 (ADAMTS13) activity was <1% and the ADAMTS13 inhibitor titer was 3.2 BU/ml. He received plasma exchange and steroid administration until remission was achieved. Seven months later, he suffered from paralysis of the right hand, hemolytic anemia, and thrombocytopenia. We confirmed TTP recurrence based on ADAMTS13 activity <1% and an ADAMTS13 inhibitor titer of 19.4 BU/ml. Four infusions of rituximab were administered in addition to plasma exchange and steroid pulse therapy. Platelet count recovery was observed within 5 days. No severe side effects related to rituximab occurred. Although rituximab has not been approved for TTP in Japan, we report the efficacy and safety of rituximab in an elderly patient with recurrent TTP. We suggest that rituximab therapy should be started as soon as possible for recurrent TTP in patients with high titers of ADAMTS13 inhibitor.

Role of activation-induced cytidine deaminase in the progression of follicular lymphoma.

Activation-induced cytidine deaminase (AID/AICDA) is required for somatic hypermutation and class-switch recombination of the immunoglobulin gene, and for c-myc translocation of germinal center-derived B-cell lymphoma. In the present study, we attempted to clarify the significance of AID associated with c-myc in the progression of follicular lymphoma (FL) using RT-PCR and quantitative real-time PCR. Tissues from the patients with grade 3 FL expressed relatively higher levels of c-myc and AID. The samples taken from a patient with FL who died within 2 years after the start of treatment showed either no or low expression of AID, despite expressing high levels of c-myc. In order to examine the role of AID expression in rapidly progressive FL, the full-length AID transcript was transfected into AID-negative cell lines established from different patients with rapidly progressive FL. This led to the establishment of AID-expressing transfectants with a low proliferation rate and a significantly increased incidence of G(0)/G(1) arrest compared with controls. Our results indicate that AID may act as a negative regulator of cell survival in FL when sufficient c-myc is expressed. Switch-off or low expression of AID after c-myc amplification may correlate with the clinical outcomes of FL.

A new four-way variant t(5;17;15;20)(q33;q12;q22;q11.2) in acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is characterized by t(15;17)(q22;q21), which results in the fusion of the promyelocytic leukemia (PML) gene at 15q22 with the retinoic acid alpha-receptor (RARA) at 17q21. We report a patient with APL carrying a new complex variant translocation (5;17;15;20). Spectral karyotyping analysis of bone marrow cells revealed t(5;17;15;20)(q33;q12;q22;q11.2). Fluorescence in situ hybridization with a PML/RARA dual-color DNA probe showed a single fusion signal, and RT-PCR analysis showed PML/RARA fusion transcripts. Complete remission was attained with a course of conventional chemotherapy with all-trans retinoic acid (ATRA). To our knowledge, this is the first report of a four-way translocation of 5q33 and 20q11 involvement in APL.

Usage of granulocyte colony-stimulating factor every 2 days is clinically useful and cost-effective for febrile neutropenia during early courses of chemotherapy.

BACKGROUND: In order to analyze the clinical activity and cost-effectiveness of granulocyte colony-stimulating factors (G-CSF), the prophylactic usage of G-CSF in patients treated with a single chemotherapy regimen during early courses was prospectively evaluated. METHODS: Thirty patients with newly diagnosed non-Hodgkin lymphoma (NHL) treated with the first course of an R-CHOP regimen were enrolled randomly. After treatment with the first course of chemotherapy, a daily dose of G-CSF (lenograstim, 100 µg) was administered to half (15 cases) of the patients, and a dose of G-CSF (100 µg) was administered every other day to the other half of the patients when leukocytopenia (<1.5 × 10(9)/L) and/or neutropenia (<0.5 × 10(9)/L) occurred. Changes in leukocyte and neutrophil counts, prophylaxis, febrile neutropenia (FN) events, and cost performance between the two groups were analyzed. RESULTS: No significant difference between the two groups was observed in recoveries of leukocyte and neutrophil counts and evidence of FN. The only difference was the total cost of G-CSF. CONCLUSION: We concluded that every-other-day use of G-CSF was as clinically effective for the prophylaxis of FN as the daily use of G-CSF, and economically speaking, the administration of G-CSF every other day should be more beneficial for patients with NHL during early courses of R-CHOP chemotherapy.

Derivative (1;18)(q10;q10) in essential thrombocythemia.

This study reports the association of the chromosomal abnormality derivative (1;18)(q10;q10) with essential thrombocythemia (ET) occurring in a 75-year-old woman. Allele-specific polymerase chain reaction also revealed a V617F mutation in the Janus Kinase 2 gene (JAK2) in the platelet compartment in this patient. The der(1;18)(q10;q10) abnormality has previously been reported in two cases of myeloid disorders. The etiological implications for ET of this combination of chromosomal abnormality and JAK2 mutation still remain elusive. This is a novel report of derivative (1;18)(q10;q10) abnormality in ET.

Germ cell tumor concomitant with acquired immune deficiency syndrome.

Patients with acquired immune deficiency syndrome (AIDS) are susceptible to secondary malignant tumors. Among those malignancies, the increased incidence of germ cell tumor (GCT) in patients with AIDS has recently been documented in Western countries, while that is still rare in Japan. Here, we report a man patient with advanced GCT (seminoma) complicated with AIDS who was continuously treated with highly active antiretroviral therapy (HAART). A partial response was obtained after resection of the primary left testis and three courses of chemotherapy. During the clinical course, he contracted unexpected gastric bleeding that made it impossible to take HAART agents and prophylactic agents for opportunistic infection. Thereafter, he suffered from a severe pulmonary infection and consequently died of severe respiratory failure. The lymphopenia related to both chemotherapy and AIDS synergistically rendered this patient immunoincompetent and thus he suffered from this fatal pulmonary infection. The recent progress in AIDS treatment has been reported to prolong the survival of tumor-bearing AIDS patients, especially GCT-bearing AIDS patients. Because of the current increase in the number of AIDS patients in Japan, it is important to report the present case which indicated that careful chemotherapy against GCT with strict management of the immunoincompetence can provide a good prognosis for GCT-bearing AIDS patients.

[Acquired hemophilia complicated with multiple muscle abscess by Nocardia].

An 82-year-old man was referred to our hospital because of bilateral leg swelling and ecchymosis. A hemostatic study showed prolonged aPTT, <1% factor VIII coagulant activity, and a high titer (30.4 Bethesda Units/ml) of factor VIII inhibitor. The diagnosis of acquired hemophilia A (AHA) was made, and treatment with prednisolone (PSL) was started. Within one month of treatment, the hemorrhagic symptom disappeared, aPTT levels returned to normal, and his factor VIII inhibitor was eradicated; however, factor VIII inhibitor was detected again when PSL was decreased to 10 mg/day. We then added cyclosporine A (CyA) to PSL as a second line salvage therapy. CyA therapy resulted in the resolution of AHA with marked and prolonged efficacy; however, hot, red tumors appeared in his right arm and left thigh. Needle aspiration of the tumors revealed muscle abscess, and Nocardia brasiliensis was isolated. We started treatment with sulfamethoxazole-trimethoprim, and the abscess healed promptly without recurrence.

Clinical significance of co-expression of CD21 and LFA-1 in B-cell lymphoma.

We previously reported that the prognosis of CD21-positive diffuse large B-cell lymphoma (DLBCL) is significantly favorable to that of CD21-negative DLBCL (Otsuka et al. in Br J Haematol 127:416-424, 2004). In this study, we attempted to clarify the biological significance of CD21 expression in B-cell lymphoma (BCL) by performing in vitro experiments using CD21 transfection into a CD21-negative lymphoma cell line and analyzing clinical data from lymphoma samples. Established clones of CD21 transfectants showed homotypic aggregation in suspension culture. Analysis of integrin expression revealed that LFA-1 appeared to be expressed on CD21 transfectants, and the cell aggregation was abrogated by anti-LFA-1 antibody. The CD21 transfectants could adhere to plastic plates coated with ICAM-1. Moreover, flow cytometry and/or immunohistochemical analyses of clinical BCL samples (n = 29) revealed positive for CD21 in all cases; LFA-1 was also expressed without exception. All BCL cells isolated from cavity fluids (n = 10) failed to express both CD21 and LFA-1. These data suggest that CD21 is tightly related to LFA-1 expression in BCL and the absence of CD21/LFA-1 expression is associated with pleural/peritoneal fluid involvement by BCL, a potential indicator of disease progression of BCL.

[Primary osseous lymphoma with pathological fracture during therapy].

A 66-year-old woman was aware of a cervical tumor in May 2007. She was hospitalized in June 2007 because her cervical tumor had increased. A biopsy was performed and a diagnosis of CD20-positive diffuse large B-cell lymphoma was obtained. Ga-67 scintigraphy showed abnormal accumulation in the right clavicle, right femur, right knee joint, right ankle joint, and the left tibia and fibula; however, no abnormality was detected on plain radiography and CT scan, whereas MRI showed that the right femur had a low signal on the T1-weighted image, and high and low signals on the T2-weighted image. CHOP therapy was begun, and the right cervical tumor promptly reduced. She was administered rituximab seven days after initiation of the treatment. When standing up from the toilet at midnight, she suffered fractures of the left tibia and fibula, and the right neck of the femur. These regions were identical to the sites with abnormal accumulation on Ga-67 scintigraphy, so we supposed them to be chemotherapy-associated pathologic fractures. This case is reported because primary bone lymphoma is rare and followed an unusual course of pathologic fracture under treatment.

Aurora-A kinase: a novel target of cellular immunotherapy for leukemia.

Aurora-A kinase (Aur-A) is a member of the serine/threonine kinase family that regulates the cell division process, and has recently been implicated in tumorigenesis. In this study, we identified an antigenic 9-amino-acid epitope (Aur-A(207-215): YLILEYAPL) derived from Aur-A capable of generating leukemia-reactive cytotoxic T lymphocytes (CTLs) in the context of HLA-A*0201. The synthetic peptide of this epitope appeared to be capable of binding to HLA-A*2402 as well as HLA-A*0201 molecules. Leukemia cell lines and freshly isolated leukemia cells, particularly chronic myelogenous leukemia (CML) cells, appeared to express Aur-A abundantly. Aur-A-specific CTLs were able to lyse human leukemia cell lines and freshly isolated leukemia cells, but not normal cells, in an HLA-A*0201-restricted manner. Importantly, Aur-A-specific CTLs were able to lyse CD34+ CML progenitor cells but did not show any cytotoxicity against normal CD34+ hematopoietic stem cells. The tetramer assay revealed that the Aur-A(207-215) epitope-specific CTL precursors are present in peripheral blood of HLA-A*0201-positive and HLA-A*2402-positive patients with leukemia, but not in healthy individuals. Our results indicate that cellular immunotherapy targeting Aur-A is a promising strategy for treatment of leukemia.

The role of zinc finger protein 521/early hematopoietic zinc finger protein in erythroid cell differentiation.

ZNF521 (zinc finger protein 521) is a transcription factor with an N-terminal transcriptional repressor motif and 30 zinc finger domains. Although a high expression level of ZNF521 in human CD34+ progenitors and hematopoietic malignancies has been demonstrated, the functional role of ZNF521 in hematopoietic cell differentiation has not been clarified. In this study, we analyzed the role of ZNF521 in erythroid cell differentiation using the short hairpin RNA (shRNA)-mediated gene silencing method. Down-regulation of ZNF521 mediated by transient expression of shRNA for ZNF521 resulted in increased synthesis of hemoglobin in K562 and HEL cell lines as compared with control cells. K562-derived clones in which ZNF521 was constitutively silenced by shRNA also showed marked synthesis of hemoglobin and an increased expression level of glycophorin A. Since GATA-1 is the key regulator of erythroid differentiation, the effect of ZNF521 on transcription activity of GATA-1 was analyzed using a luciferase assay. GATA-1 activity was markedly inhibited by ZNF521 in a dose-dependent manner. Deletion analysis of ZNF521 showed that the repressive effect requires an N-terminal repression motif. Furthermore, the direct interaction of ZNF521 with GATA-1 was demonstrated. These results indicate that ZNF521 modulates erythroid cell differentiation through direct binding with GATA-1.

Identification of an epitope derived from CML66, a novel tumor-associated antigen expressed broadly in human leukemia, recognized by human leukocyte antigen-A*2402-restricted cytotoxic T lymphocytes.

CML66 is a newly identified differentiation antigen that is expressed broadly in human leukemia and solid tumors, but its physiological function remains unknown. In the present study, to clarify the feasibility of CML66-targeted cancer immunotherapy, we attempted to identify cytotoxic T lymphocyte (CTL) epitopes derived from CML66. An immunogenic CML66-derived epitope (amino acid residues 76-84; YYIDTLGRI) capable of inducing human leukocyte antigen (HLA)-A*2402-restricted CTL specific for this peptide was identified. CML66-derived peptide-specific CTL efficiently lysed human leukemia cells, but not normal cells, in a HLA-A*2402-restricted fashion. Quantitative real-time polymerase chain reaction revealed that CML66 mRNA is expressed abundantly in primary acute myeloid leukemia cells, acute lymphoid leukemia cells, and chronic myelogenous leukemia cells in advanced phase, and that the expression level of CML66 mRNA in normal cells is low compared with that in leukemia cells. CML66-specific CTL precursors were detected in the peripheral blood of patients with acute leukemia. These data indicate that the CML66-derived epitope identified in the present study is a new target antigen for cellular immunotherapy of human leukemia.