Production and nonclinical evaluation of an autologous iPSC-derived platelet product for the iPLAT1 clinical trial.

Donor-derived platelets are used to treat or prevent hemorrhage in patients with thrombocytopenia. However, ∼5% or more of these patients are complicated with alloimmune platelet transfusion refractoriness (allo-PTR) due to alloantibodies against HLA-I or human platelet antigens (HPA). In these cases, platelets from compatible donors are necessary, but it is difficult to find such donors for patients with rare HLA-I or HPA. To produce platelet products for patients with aplastic anemia with allo-PTR due to rare HPA-1 mismatch in Japan, we developed an ex vivo good manufacturing process (GMP)-based production system for an induced pluripotent stem cell-derived platelet product (iPSC-PLTs). Immortalized megakaryocyte progenitor cell lines (imMKCLs) were established from patient iPSCs, and a competent imMKCL clone was selected for the master cell bank (MCB) and confirmed for safety, including negativity of pathogens. From this MCB, iPSC-PLTs were produced using turbulent flow bioreactors and new drugs. In extensive nonclinical studies, iPSC-PLTs were confirmed for quality, safety, and efficacy, including hemostasis in a rabbit model. This report presents a complete system for the GMP-based production of iPSC-PLTs and the required nonclinical studies and thus supports the iPLAT1 study, the first-in-human clinical trial of iPSC-PLTs in a patient with allo-PTR and no compatible donor using the autologous product. It also serves as a comprehensive reference for the development of widely applicable allogeneic iPSC-PLTs and other cell products that use iPSC-derived progenitor cells as MCB.

[Bacteremia Due to Edwardsiella tarda Emerging after Chemotherapy for Recurrent Ph-Positive Acute Lymphoblastic Leukemia].

We report the case ofa 76-year-old man who had bacteremia due to Edwardsiella tarda during the course ofchemotherapy, including ponatinib, for the treatment of recurrent Philadelphia-positive acute lymphoblastic leukemia. Treatment with cefepime improved his general condition. The number ofreported cases ofbacteremia due to Edwardsiella tarda is limited. Further accumulation ofcases is necessary to obtain accurate data such as the risk factors of Edwardsiella tarda bacteremia.

An isolated der(1;21)(q10;q10) translocation in a patient with myelodysplastic syndrome: a case report.

Whole-arm translocations are relatively rare among hematological malignancies. There are a few reports on myeloid malignancies harboring der(1;21)(q10;q10). A 65-year-old male was referred to our hospital due to squamous cell carcinoma of the lung. Pembrolizumab monotherapy resulted in progression, and so chemotherapy involving nab-paclitaxel and carboplatin was administered thereafter. The patient developed cytopenia, and his bone marrow exhibited dysplasia. Chromosomal analysis revealed a whole-arm translocation, der(1;21)(q10;q10). Thus, the patient was diagnosed with myelodysplastic syndrome. The der(1;21)(q10;q10) translocation is a rare variant of the der(1;7)(q10;p10) translocation, which is an adverse prognostic factor for myeloid neoplasms. Clarifying the clinical features of myeloid neoplasms in patients with der(1;21)(q10;q10) would facilitate the elucidation of their tumorigenic mechanisms.

[Septic shock due to Citrobacter braakii following high-dose cytosine arabinoside therapy in a patient with acute myeloid leukemia].

Here, we report a case of a 67-year-old man who had septic shock due to Citrobacter braakii infection during the course of chemotherapy with high-dose cytosine arabinoside for acute myeloid leukemia. Treatment with cefepime rapidly improved his condition. The number of reported cases of sepsis due to Citrobacter braakii is limited. Further accumulation of cases is necessary to obtain accurate data such as the risk factors for Citrobacter braakii infections.

Trisomy 6 as the sole stemline abnormality in a patient with acute monocytic leukemia: a case report.

It is rare for trisomy 6 to occur as the sole autosomal anomaly in hematological malignancies, but this finding has been reported to be associated with a hypoplastic bone marrow. We report the case of a 75-year-old male with acute monocytic leukemia, in which trisomy 6 was detected as the sole stemline abnormality. We also summarize the 26 published cases of acute myeloid leukemia involving isolated trisomy 6.

A Rare t(5;11)(q35;q13) Translocation in an Elderly Patient With Acute Myeloid Leukemia With Maturation: A Case Report.

The t(5;11)(q35;q13) reciprocal translocation is a rare chromosomal abnormality that can arise in myeloid neoplasms, mainly in children and younger adults. Here, we report a case of acute myeloid leukemia with maturation, involving an 85-year-old, in which the tumor cells harbored the t(5;11)(q35;q13) chromosomal abnormality. We also address the diagnostic and immunophenotypic characteristics of acute myeloid leukemia involving t(5;11)(q35;q13), along with a review of the literature.

Dasatinib and Prednisolone Induction Therapy for a Case of Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia with Dilated Cardiomyopathy Accompanied by Life-Threatening Ventricular Tachycardia.

A 56-year-old man being treated for dilated cardiomyopathy presented with epigastralgia. He was diagnosed with ventricular tachycardia and Philadelphia chromosome-positive acute lymphoblastic leukemia. After treating incessant ventricular tachycardia, we commenced induction therapy for leukemia with dasatinib and prednisolone to minimize toxicity towards cardiomyocytes and the cardiac conduction system. Although dasatinib was temporarily withheld because of a recurrence of ventricular tachycardia, we rechallenged dasatinib while using bisoprolol and amiodarone and achieved a complete hematological response three weeks later. Although drug interactions between dasatinib and amiodarone were of concern, the blood concentration of each drug remained within the safe range after concomitant use, and there were no adverse cardiac effects such as QT prolongation after rechallenging dasatinib. Induction therapy with dasatinib and prednisolone may be an acceptable therapeutic option for Philadelphia chromosome-positive acute lymphoblastic leukemia with severe cardiac complications.

Total Hip Arthroplasty for Rapidly Destructive Coxarthrosis in a Patient with Severe Platelet Deficiency due to Liver Cirrhosis and Immune Thrombocytopenic Purpura.

Rapidly destructive coxarthrosis (RDC) causes rapid and extreme destruction of the hip joint, which was reported by Postel and Kerboull. RDC is commonly unilateral and occurs mostly in elderly women. Immune thrombocytopenic purpura (ITP) is characterized by a low platelet count that is the result of both immune-mediated platelet destruction and suppression of platelet production. In patients with ITP undergoing surgery, bleeding associated with a low preoperative platelet count can lead to unsuccessful outcomes. To the best of our knowledge, there has been only one report describing total hip arthroplasty (THA) for patients with ITP and there have been no reports of THA for RDC with a very low platelet count due to liver cirrhosis (LC) and ITP. We report the case of a patient who had right RDC and a very low platelet count due to LC and ITP in whom THA was successfully performed. Furthermore, this case was also unique in that her platelet count increased after THA. THA for right RDC might resolve ITP by relieving inflammation of the right hip since her platelet count recovered after THA.

Therapy-related myelodysplastic syndrome: a case study.

We present a case of therapy-related myelodyspastic syndrome in which the t(3;8)(q26;q24) translocation appeared, even though no chromosomal abnormalities were found at the initial diagnosis of acute myeloid leukemia. To the best of our knowledge, there have only been around 20 reported cases of myeloid malignancies involving t(3;8)(q26;q24). We discuss the characteristics of t(3;8)(q26;q24) along with a review of literature.

[Epstein-Barr virus-associated post-transplant lymphoproliferative disorder diagnosed by the episode of intestinal perforation following allogeneic hematopoietic stem cell transplantation].

A 64-year-old man was diagnosed as having acute myeloid leukemia. We performed sequential treatment with chemotherapy and reduced-intensity stem cell transplantation from an unrelated donor while the patient was in partial remission. After engraftment, he developed acute graft-versus-host disease of the gut on day 42 and steroid therapy was started. Despite transient aggravation of diarrhea, his symptoms slowly improved and the dose of steroid was tapered. On day 159, he complained of acute left lower abdominal pain. A CT scan showed perforation of the digestive tract and ileectomy was performed. At surgery, multiple ulcers of the intestine were found and one of the ulcers was perforated. Pathologically, transmural and diffuse proliferation of atypical cells in the ulcer were confirmed. Since these cells were positive for CD20 and Epstein-Barr-virus (EBV) encoded RNA, we made a diagnosis of EBV-associated post-transplant lymphoproliferative disorder (PTLD). Reduction in the dose of immunosuppressive agents and rituximab led to complete remission of PTLD. PTLD after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is relatively rare, and the development of gastrointestinal perforation after allo-HSCT is very rare.