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

Thrombotic thrombocytopenic purpura (TTP) is a fatal thrombotic disease caused by a marked decrease in the activity of ADAMTS13, a von Willebrand factor cleaving protease. In congenital TTP, ADAMTS13 activity is decreased by an abnormality in ADAMTS13, and in acquired TTP, by anti-ADAMTS13 autoantibody. Death from thrombosis in the acute phase has been an issue with conventional treatment of acquired TTP by plasma exchange or immunosuppressive therapy. However, the advent of caplacizumab, an anti-VWF nanobody, has made it possible to suppress thrombus formation and is expected to improve survival rates. In addition, some case series have shown the efficacy of caplacizumab without plasma exchange for acquired TTP, and this approach is being investigated in clinical trials. Fresh-frozen plasma is transfused to supply ADAMTS13 for congenital TTP, but frequent transfusions over a long period of time can lead to problems such as infection and allergic reactions. Novel therapies such as recombinant ADAMTS13 products and gene therapy are now under development, and show promise for future clinical use.

An 80-year-old man with FLT3-TKD mutation-positive acute myeloid leukemia (AML) relapsed during consolidation therapy with venetoclax/azacitidine and was started on gilteritinib as salvage therapy. On the day after treatment initiation, febrile neutropenia was observed, but the fever resolved promptly after initiation of antimicrobial therapy. On the fifth day after completion of antimicrobial therapy, the patient experienced fever and watery diarrhea over 10 times a day, and a diagnosis of Clostridioides difficile infection (CDI) was made based on stool examination. The patient was treated with intravenous metronidazole, but renal dysfunction, hypotension, and hypoxemia developed, and a CT scan showed pleural and intraperitoneal effusion, significant intestinal wall thickening, and intestinal dilatation. Fidaxomicin was started under general monitoring in the intensive care unit and response was achieved. The patient was discharged from the intensive care unit on the 18th day after the onset of CDI. We report this case not only due to the rarity of fulminant CDI during AML treatment, but also because it is a valuable example of effective treatment of fulminant CDI with fidaxomicin.

The proportion of female doctors among younger generations has increased in recent years, and support for reemployment after childbirth and childcare leave is important for maintaining stability of local healthcare. We conducted a questionnaire with doctors in the Department of Pediatrics at Ehime University School of Medicine and it's affiliated hospitals to identify issues in the career development of female doctors. Although many female physicians want to pursue career development by obtaining subspecialty qualifications and PhD degrees, a high percentage have not actually obtained them. This is not only due to interruptions in work caused by childbirth and childcare but also because they are busy with housework, childcare, and daily work, and lack sufficient information about career development. In this regard, it appears that beyond improving work-life balance, female doctors must always keep in mind their career design and future goals, as well as their social mission as a physician. For administrators of these departments, acceptance of diversity, providing adequate support for female physicians to return to work after maternity/childcare leave, and balancing childcare and work are important for expanding female doctors' opportunities and career development.

Atypical chronic myeloid leukemia (aCML) is a rare disease classified as a myelodysplastic/myeloproliferative neoplasm (MDS/MPN). Recent advances in gene mutational profiling have clarified the characteristics of aCML as a disease entity relative to other MDS/MPNs. Although some studies suggest the efficacy of DNA demethylating agents and tyrosine kinase inhibitors, data about these agents are limited due to the small number of patients. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is only therapeutic option that can provide durable remission for aCML and other MDS/MPNs. Retrospective studies from Europe and Japan revealed the clinical results of allo-HSCT for aCML. This review summarizes the pathogenesis of aCML and the development of allo-HSCT and other therapeutic options.

FLT3 mutations are the most frequently identified genetic abnormalities in adult acute myeloid leukemia (AML) patients, accounting for approximately 30%. FLT3-ITD mutation specifically is considered as a poor prognostic factor in AML, and allogeneic hematopoietic cell transplantation in first remission is recommended for younger patients. The recent clinical introduction of FLT3 inhibitors has been reported to improve the prognosis of patients with FLT3 mutation-positive AML. In Japan, alongside monotherapy with gilteritinib or quizartinib for relapsed/refractory patients, combination of quizartinib with intensive chemotherapy was approved in 2023 for untreated FLT3-ITD mutation-positive AML. Studies to date have demonstrated the utility of measurable/minimal residual disease evaluation targeting FLT3 mutations and the efficacy of maintenance therapy after allogeneic transplantation. However, emergence of additional genetic mutations associated with treatment resistance has been observed. Thus, FLT3 mutations are utilized not only as a prognostic factor in AML but also as a target for treatment and for response assessment. Furthermore, the development of new treatment strategies involving FLT3 inhibitors is highly anticipated to improve clinical outcomes for patients with FLT3 mutation-positive AML.

Unlike for anticoagulants, no good monitoring methods exist for antiplatelet agents, and their monitoring is considered unnecessary. In the platelet aggregation test, which is the standard test for platelet function, aggregation is evaluated by adding a platelet activator to platelets in a cuvette. Therefore, it provides information on the maximum potential of platelets to induce aggregation, but not the actual in vivo degree of platelet activation. In vivo platelet activation markers are not widely used because they require a special blood collection method, although some tests are covered by insurance. My colleagues and I identified the platelet activation receptor C-type lectin-like receptor 2 (CLEC-2) and found that CLEC-2 is cleaved and released during platelet activation. We established a plasma-soluble CLEC-2 (sCLEC-2) assay system with the aim of using it as a marker of in vivo platelet activation. Elevation of sCLEC-2 has been reported in various thrombotic diseases. The multi-center prospective cohort study CLECSTRO is now underway to investigate the usefulness of sCLEC-2 for diagnosis, typing, and prognostic estimation in acute ischemic stroke.

For nearly 40 years, combination therapy with cytarabine and anthracycline has been the standard of care for acute myeloid leukemia (AML). The cytogenetics and molecular biology of AML are now understood, and the treatment of AML has undergone dramatic changes in Japan with the launch of drugs such as FLT3 inhibitors, Bcl2 inhibitors, and hypomethylating agents since 2018. However, AML remains very difficult to cure, with a high relapse rate. Here, we review novel agents that have not yet been approved in Japan (CPX-351, IDH inhibitors, menin inhibitors, and oral azacitidine) as potential treatments for AML, as well as therapeutic antibodies (BiTEs, DARTs, immune checkpoint inhibitors) currently under investigation in clinical trials or in development. These novel agents are being investigated not only as monotherapy but also as combination therapy with intensive chemotherapy or azacitidine/venetoclax. The new era of AML treatment is expected to support a variety of goals, including leukemic cell elimination, long-term remission, and improved quality of life.