[Rinsho ketsueki] The Japanese journal of clinical hematology最新文献

A 53-year-old man was presented with fever, eyelid edema, and thrombocytopenia. Based on examination outcomes, he was diagnosed with immune thrombocytopenia. He was prescribed prednisolone (PSL) at 0.5 mg/kg/day; subsequently, his platelet count improved and fever improved. PSL dose was tapered and stopped without relapse. However, 1 month later, the patient presented to our hospital with fever, generalized edema, thrombocytopenia, and acute renal failure. Computed tomography revealed multiple lymphadenopathies, hepatomegaly, pleural effusion, and ascites. Bone marrow biopsy indicated reticulin fibrosis, and lymph node biopsy revealed mixed-type Castleman disease. Based on these findings, he was diagnosed with grade 5 TAFRO syndrome (very severe). Steroid pulse therapy and tocilizumab were ineffective in improving his condition. Therefore, rituximab was administered instead of tocilizumab, and his condition eventually improved. The optimal treatment for TAFRO syndrome is yet to be established. If tocilizumab is ineffective as the second-line treatment, then rituximab might be effective.

The patient is a 45-year-old man who was diagnosed with severe hemophilia A during childhood and received FVIII replacement therapy, which became ineffective due to inhibitor production (5-225 BU/ml). After initiating emicizumab therapy, bleeding symptoms markedly improved, but he developed an intramuscular hematoma at the right thigh due to a fall. He was hospitalized and maintained on bed rest; however, the size of the hematoma increased, and anemia developed. Since the inhibitor level was markedly decreased at 0.6 BU/ml, a recombinant FVIII preparation was administered, and the size of the hematoma decreased along with an increase in FVIII activity. Levels of the inhibitor increased to 54.2 BU/ml, but tended to decrease during continued emicizumab treatment. Emicizumab therapy seems useful in hemophilia A patients with inhibitor production.

Aortic regurgitation, a thoracoabdominal aortic aneurysm, chronic myeloid leukemia, and chronic kidney disease were all being treated at two hospitals for an 83-year-old man. He was admitted to the Department of Orthopedics at our hospital with a lumbar compression fracture. Later, he experienced melena, for which the Department of Internal Medicine was consulted. Due to the aberrant results of PT-INR (7.1) and a PTT > 200 seconds on a coagulation test, we suspected the presence of an autoimmune coagulation factor deficiency, and prednisolone immunosuppressive therapy medication was started right away. Due to a sharp decline in FV/5 activity, the presence of FV/5 inhibitors, and the presence of anti-FV/5 autoantibodies, a final diagnosis of autoimmune coagulation factor V (FV/5) deficiency was made. After the start of immunosuppressive therapy, the FV/5 inhibitor and anti-FV/5 autoantibodies disappeared, and the FV/5 activity progressively returned to normal. Disseminated intravascular coagulation-which may have been caused by a known aortic aneurysm-worsened while tapering off prednisolone. Due to the patient's advanced age and other problems, the aneurysm was extensive and inappropriate for surgical repair. The coagulation test findings improved gradually upon initiation of warfarin therapy. Herein, the patient had autoimmune FV/5 deficiency, a rare disorder that made diagnosis and therapy difficult because of the patient's several coexisting conditions.

Aplastic anemia (AA) is a non-neoplastic bone marrow failure syndrome caused by the destruction of hematopoietic stem and progenitor cells by the immune system. However, in some cases of AA, a small number of specific clones with gene mutations are observed without clinical manifestations. Cases with mutated PIG-A, BCOR/BCORL1, or HLA class I allele clones respond better to immunosuppressive therapies (ISTs). Cases with MDS-related clones, such as DNMT3A or ASXL1 mutations, are at a higher risk for secondary MDS. In this review, I will focus on the clonal hematopoiesis (CH) in AA and discuss its clinical significance, including its impact on disease boundaries and transition. I will also discuss the pathophysiology and diagnosis of hypoplastic MDS, a type of MDS that responds to ISTs.

Coagulation factor V (FV) is both procoagulant and anticoagulant functions. Congenital FV abnormality, which are caused by mutations in the FV gene, are characterized by a tendency to bleed. However, FV-R506Q (FV_Leiden) is the most common FV abnormality that eliminates an activated protein C (APC) cleavage site, resulting in the occurrence of deep venous thrombosis (DVT). In Japan, the thrombotic predisposition caused by FV_Leiden and FV molecular abnormalities was believed to be nonexistent. We did, however, report the first case in Japan of a young patient with FV abnormality-related thrombosis. The recurrent DVT in this case was caused by a novel mutation of FV-W1920R (FV_Nara), located in the C1 domain and far from the APC cleavage sites. We considered the possibility that there were cases of FV-related thrombotic predisposition that had gone undetected in Japan. We thoroughly examined FV-related anticoagulant function to understand the pathogenesis of thrombosis caused by FV abnormality. Furthermore, using recombinant thrombomodulin, we successfully developed a novel assay with clot waveform analysis for the rapid detection of FV deficiency with APC resistance. Other FV abnormality-related thrombosis has been reported in Japan in recent years, and we hope to further clarify the FV-related thrombotic predisposition in the future.

The frequency of the manufacturing failure of chimeric antigen receptor (CAR)-T cell therapy in clinical practice is unknown. To clarify the current state of how likely CAR-T cell production is to succeed or fail for B-cell acute lymphoblastic leukemia (B-ALL), we analyzed cases in which the production of tisagenlecleucel was performed for patients with B-ALL at 15 facilities in Japan from October 2019 to March 2022. Total 81 patients (47 males and 34 females) were analyzed. The median age at apheresis was 13 years (1-25) with a median number of prior treatments of 4 (1-9). The numbers of patients with histories of allogeneic transplantation, inotuzumab ozogamicin, or blinatumomab treatments were 51 (63.0%), 26 (32.1%), and 37 (45.7%), respectively. The median blast percentage and CD3⁺ cell counts in peripheral blood were 0% (0-91.5), and 611/µl (35-4,210) at apheresis, and the median number of CD3⁺ cells shipped was 2.2×10⁹ (0.5-8.3). While cases with a history of heavy prior treatment before apheresis were included, no manufacturing failures were observed. Continuing to monitor the status of manufacturing failures is necessary as the number of B-ALL cases treated with CAR-T cell therapy increases.

By carrying a systemic circulation, hematopoietic and vascular systems coordinately govern the functional organ connections in the body. Blood vessels play an important role in the development, regeneration, and maintenance of organs by acting as conduits for environmental factors in the blood to tissues and secreting organ-specific cytokines as angiocrine signals. Recently, it has become clear that vascular endothelial cells, which are the main constituent cells of the blood vessels and play a role in homeostasis, are diverse. It has also been established that the cells of stem cell fraction exist in endothelial cells. The vascular endothelial cells in various organs are functionally different. For example, it has been discovered that sinusoidal blood vessels in the liver produce coagulation factor VIII as an organ-specific vascular function. Determining how such tissue-/organ-specific function of the endothelial cells is induced is a topic of interest in the vascular field of study.