Vedat Uygun

Idiopathic hyperammonemia after hematopoietic stem cell transplantation: A case report.

IHA is characterized by a sudden increase in plasma ammonia levels in the absence of any identifiable causes, which mostly results in intractable coma and high mortality. It has been reported in some patients after receiving intensive chemotherapy for hematological malignancy or HSCT. We describe a case of a patient with FA that developed acute idiopathic hyperammonemia after the preparative regimen for HSCT.

Haploidentical hematopoietic stem cell transplantation with post‐transplant high‐dose cyclophosphamide in high‐risk children: A single‐center study

Recently, haploidentical transplantations have been performed with unmanipulated BM or PBSC. This approach is becoming more widely adopted with the use of PTCY. However, there is limited evidence about this approach in children. We present 15 children who received 16 haploidentical HSCT with unmanipulated BM or PBSC using PTCY for GVHD prophylaxis. Post‐transplant CY(50 mg/kg IV) was given on the third and fifth day, and CsA or tacrolimus with MMF or MP was also used for GVHD prophylaxis. All patients engrafted at a median of 16 and 18 days for neutrophil and thrombocyte recovery, respectively. Grades II–III acute GVHD developed in seven patients, and mild chronic GVHD was found in two patients. Two patients died within the first 100 days due to sepsis (TRM 12.5%). Eleven patients are currently alive, with a median follow‐up of 12 months (range 6–22 months). The 12‐month OS and DFS were 75 ± 10.8% and 68.8 ± 11.6%, respectively. Our results with these high‐risk patients are encouraging for haploidentical HSCT in pediatric patients. Future studies should continue to assess haploidentical HSCT, including comparison of other modalities, in a primary pediatric population.

A successful unrelated peripheral blood stem cell transplantation with reduced intensity-conditioning regimen in a patient with late-onset purine nucleoside phosphorylase deficiency

PNP deficiency is a rare combined immunodeficiency with autosomal recessive mode of inheritance. The immunodeficiency is progressive with normal immune functions at birth, but then, T‐cell deficiency with variable B‐cell functions usually presents by the age of two yr. The only curative treatment for PNP deficiency is hematopoietic stem cell transplantation. Here, we present a 13‐yr‐old girl with late‐onset PNP deficiency. Despite many complications of infections, she was successfully transplanted with a reduced intensity‐conditioning regimen from an HLA‐identical unrelated donor.

Risk factors predicting the survival of pediatric patients with relapsed/refractory non-Hodgkin lymphoma who underwent hematopoietic stem cell transplantation: a retrospective study from the Turkish pediatric bone marrow transplantation registry

Abstract We examined outcomes of 62 pediatric patients with relapsed or refractory non-Hodgkin lymphoma (rr-NHL) who underwent hematopoietic stem cell transplantation (HSCT). The overall survival (OS) and event-free survival (EFS) rates were 65% and 48%, respectively. Survival rates for patients with chemosensitive disease at the time of HSCT were significantly higher than those of patients with chemoresistant disease (69% vs. 37%, p = .019 for OS; 54% vs. 12%, p < .001 for EFS; respectively). A chemoresistant disease at transplantation was the only factor that predicted a limited OS (hazard ratio = 10.00) and EFS (hazard ratio = 16.39) rates. Intensive chemotherapy followed by HSCT could be an effective strategy for treating children with rr-NHL and may offer improved survival for a significant group of pediatric patients, particularly those with chemosensitive disease at transplantation.

Three relapses after a haploidentical transplantation in a pediatric patient: Cure with no further transplantation.

Isolated extramedullary relapse (EMR) after hematopoietic stem cell transplantation (HSCT) is a highly fatal condition that creates uncertainty regarding treatment options. Although certain approaches such as repeat HSCT and donor lymphocyte infusion are recommended, we report a patient with acute lymphoblastic leukemia who had three isolated EMRs after HSCT at different locations and at different times that were responsive to local and systemic therapies, without the need for a second transplantation.

Extracorporeal photopheresis did not prevent the development of an autoimmune disease: myasthenia gravis.

Myasthenia gravis (MG) is a neuromuscular disorder characterized by an autoimmune defect in the neuromuscular junction. In most patients, the autoimmune attack is mediated by antibodies against the acetylcholine receptor (AChR) on the postsynaptic membrane. Deficient immunoregulation, including regulatory T cells, is consistently observed. Extracorporeal photopheresis (ECP) leads to the induction of regulatory T cells that mediate immunologic tolerance in autoimmune diseases; however, the data regarding MG are very limited.