[Congenital thrombotic thrombocytopenic purpura diagnosed in adulthood after repeated thrombocytopenia since neonatal period].

A 27-year-old woman was diagnosed with idiopathic thrombocytopenic purpura in the neonatal period, and was admitted to our hospital after presenting with impaired consciousness, purpura, nausea and vomiting, with a platelet count of 10×109/l. Congenital thrombotic thrombocytopenic purpura (cTTP) was suspected on the basis of recurrent thrombocytopenia and impaired consciousness, so tests for ADAMTS13 activity and inhibitor were performed. ADAMTS13 activity was severely decreased, ADAMTS13 inhibitor was negative, and platelet count increased after transfusion of fresh frozen plasma. These findings and the results of genetic testing done on all family members led to a diagnosis of cTTP. cTTP requires differential diagnosis even in adults. If a patient diagnosed with ITP in childhood has a history or findings that suggest cTTP during follow-up observation, it is necessary to actively consider ADAMTS13 testing.

Outcomes of allogeneic stem cell transplantation for patients with hematologic diseases ≥60 years old.

Hematologic diseases frequently affect people >60 years old, and allogeneic stem cell transplantation (allo-SCT) is a potentially curative treatment for these patients. Although several multicenter studies proposed the risk assessment of allo-SCT for the elderly, they receive different treatments and management at each facility. Therefore, accumulating data from institutions that exhibit relatively the same treatment policy and patient care is important. This retrospective study aimed to clarify the prognostic factors of allo-SCT for the elderly in our institution. Of the 104 patients, 51.0% were 60-64 years old, and 49.0% were ≥65 years old. The 3-year overall survival (OS) was 40.9% and 35.7% for patients 60-64 and ≥65 years old, respectively, which is not significant. While the disease status prior to allo-SCT demonstrated strong effects on the 3-year OS for patients that are 60-64 years old (in remission, 76.9%; non-remission, 15.7%, p<0.001), this effect was smaller for patients ≥65 years old (in remission, 43.1%; non-remission, 30.1%, p=0.048). Multivariate analysis revealed that the performance status (PS), not the disease status prior to allo-SCT, was the prognostic risk factor of OS for patients aged ≥65 years. Our data suggest that PS is a useful predictor of better OS following allo-SCT, especially for patients ≥65 years old.

Successful pseudo-autologous stem cell transplantation for donor-derived Burkitt lymphoma occurring 9 years after allogeneic transplantation.

Donor-derived hematological malignancies have been recognized as rare but serious late complications in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Most cases in the literature were diagnosed as myelodysplastic syndrome or acute leukemia, with very few malignant lymphoma reported. We herein present another case of donor-derived Burkitt lymphoma that occurred 9 years after allo-HSCT under continued administration of immunosuppressants for chronic graft-versus-host disease (GVHD). The patient achieved a partial response after rituximab-combined intensive chemotherapy. To reduce the risk of relapse and to avoid organ toxicities due to repeated chemotherapies, we performed upfront high-dose chemotherapy followed by stem cell rescue using donor-derived CD34+ cells, called pseudo-autologous HSCT (pASCT), and adjusted immunosuppressants appropriately. The patient remained disease-free for 23 months after pASCT without exacerbation of cGVHD. Although the observation period has been relatively short and longer follow-up is needed, pASCT may be a feasible option for donor-derived lymphoma even in patients with active cGVHD.

[Acute myeloid leukemia with type I CBFB::MYH11 fusion gene not detected by screening test for leukemia-related chimeric genes].

A 27-year-old woman with pancytopenia was admitted to our hospital. Bone marrow aspiration revealed 52.2% myeloperoxidase-positive myeloblasts, leading to a diagnosis of acute myeloid leukemia. While a screening test for chimeric genes related to leukemia initially yielded negative results, including for the CBFB::MYH11 fusion gene, G-banded karyotyping uncovered the presence of inv (16)(p13.1q22). Further investigation by fluorescence in situ hybridization (FISH) confirmed the split signals for CBFB. A second screening test for leukemia-related chimeric genes with different PCR primers revealed the elusive CBFB::MYH11 fusion gene. Subsequently, the type I CBFB::MYH11 fusion gene was identified through exhaustive exploration using RNA sequencing for fusion gene discovery. This exceptional case highlights the existence of a distinctive subtype of CBFB::MYH11 that may yield false-negative results in conventional chimeric fusion screening, thus emphasizing the indispensable utility of PCR primer modification, FISH, and RNA sequencing in the investigative process.