Yoshihiro Ohara

T‐cell‐replete haploidentical stem cell transplantation is highly efficacious for relapsed and refractory childhood acute leukaemia

Despite improvements in first‐line therapies, the outcomes of relapsed or refractory childhood acute leukaemia that has not achieved complete remission after relapse, has relapsed after stem cell transplantation (SCT), has primary induction failure and has relapsed with a very unfavourable cytogenetic risk profile, are dismal.

Loss of mismatched HLA in myeloid/NK cell precursor acute leukemia relapse after T cell-replete haploidentical hematopoietic stem cell transplantation.

Myeloid/natural killer cell precursor acute leukemia (MNKL) is an aggressive disease with a high relapse rate even after allogeneic hematopoietic stem cell transplantation (SCT). We report a patient with MNKL who had a donor lymphocyte infusion (DLI) for relapse after T cell‐replete human leukocyte antigen (HLA)‐haploidentical SCT, but relapsed again 20 months later with loss of mismatched HLA. This case suggests that a strong graft‐versus‐leukemia effect of haploidentical SCT can be expected in MNKL patients. In the haploidentical setting, DLI should be considered for patients with relapsed leukemia whose leukemic cells have not lost HLA cell surface expression. Pediatr Blood Cancer 2014; 61:1880–1882.

Comprehensive technical and patient-care optimization in the management of pediatric apheresis for peripheral blood stem cell harvesting

BACKGROUND Pediatric apheresis for peripheral blood stem cell transplantation should be carried out with due concern for low corporeal blood volume and vulnerability to hypocalcemia-related complications, hypovolemic shock, and hypervolemic cardiac overload. STUDY DESIGN AND METHODS We retrospectively investigated a total of 267 apheresis procedures from 1990 to 2013 on 93 children between 0 and 10 years old, including 89 patients and 4 healthy donors, with body weights of 6.3 to 44.0 kg. RESULTS The median CD34+ cell yield per apheresis procedure was 2.3 × 106 CD34+ cells/kg (0.2-77.9 × 106 CD34+ cells/kg). Adverse events occurred in 11.6% of procedures (n = 31), including mild perivascular pain (n = 12), emesis (n = 9), hypotension (n = 3), urticaria (n = 2), numbness (n = 2), chest pain (n = 1), facial flush (n = 1), and abdominal pain (n = 1). Among hypotensive events, shock in a 9.6 kg one-year-old boy required emergency treatment in 1996. Thereafter, we adopted continuous injection of calcium gluconate, ionized calcium monitoring, central venous catheter access and circuit priming with albumin in addition to concentrated red cells. Since then we have had fewer complications: 16.4% per apheresis during 1990-1997 versus 5.8% during 1998-2013. No healthy pediatric donors suffered from any late-onset complications related to apheresis or G-CSF administration. CONCLUSION By employing appropriate measures, peripheral blood stem cell apheresis for small children can have an improved safety profile, even for children weighing <10 kg.

Preemptive therapy with rituximab for Epstein-Barr virus reactivation after haplo-HSCT

Epstein–Barr virus‐related post‐transplantation lymphoproliferative disease (EBV‐PTLD) is a serious complication in hematopoietic stem cell transplantation (HSCT) recipients.

Malignant peritoneal mesothelioma in a child: chemotherapy with gemcitabine and platinum was effective for the disease unresponsive to other treatments

Malignant peritoneal mesothelioma in children is a very rare disease and has a poor prognosis. Unlike malignant mesothelioma in adults, there is no clear causal association between this very rare malignancy in children and asbestos exposure. We report a case of peritoneal mesothelioma in an 11-year-old boy who presented with ascites. He was diagnosed with malignant mesothelioma on the basis of histopathological findings. His disease showed resistance to pemetrexed, but was treated successfully with platinum-based therapy with gemcitabine. He has achieved long-term survival in partial remission with stable disease.

T cell replete–haploidentical second hematopoietic stem cell transplantation for primary graft failure in pediatric patients with hematologic malignancies

GF is one of the fatal complications of allogeneic HSCT. To rescue patients with primary GF, a second HSCT should be conducted as soon as possible, but the optimal donor source and technique have yet to be established. In this study, we retrospectively analyzed six children with hematologic malignancies who received TCR‐haploidentical second HSCT for primary GF. The median interval between the prior HSCT and the second HSCT was 37.5 days. All patients received fludarabine and ATG containing reduced‐intensity re‐conditioning before the second HSCT. All patients, except one who died early, achieved both neutrophil and Plt engraftment at a median time of 15 and 33 days, respectively. Chimerism analysis showed that all engrafted patients achieved complete donor chimerism within 3 weeks. Four patients developed acute GVHD, and three patients developed chronic GVHD. TRM occurred in two patients. Median follow‐up of the four survivors was 6.8 years, and all remained in sustained remission until the last follow‐up. These results suggested that a TCR‐haploidentical second HSCT for pediatric patients is feasible, and this approach may provide a potent option for children with primary GF.

Idiopathic Hyperammonemia That Developed During Initial Treatment With Steroid in a Patient With Newly Diagnosed Leukemia.

Idiopathic hyperammonemia (IHA) has been described as a complication of intensive chemotherapy for the treatment of hematologic malignancy but has subsequently been found in patients undergoing bone marrow transplantation and in those with solid tumors treated with 5-fluorouracil. Although IHA is a rare complication, it is sometimes associated with high mortality in hematologic malignancies. Here we report the case of a 15-year-old boy in whom hyperammonemia developed during the initial treatment with prednisolone for newly diagnosed acute lymphoblastic leukemia and who survived after early detection and oral lactulose therapy. To the best of our knowledge, this is the first report of IHA that was not induced by intensive chemotherapy, stem cell transplantation, or asparaginase therapy in a patient with newly diagnosed leukemia, but developed during an initial treatment with a steroid. Early detection of IHA by measuring the plasma ammonia level in patients with neurological symptoms may improve the outcome.