Gülsün Karasu

The risk of hemophagocytic lymphohistiocytosis in Hermansky-Pudlak syndrome type 2.

Genetic disorders of lymphocyte cytotoxicity predispose patients to hemophagocytic lymphohistiocytosis (HLH). Reduced lymphocyte cytotoxicity has been demonstrated in Hermansky-Pudlak syndrome type 2 (HPS2), but only a single patient was reported who developed HLH. Because that patient also carried a potentially contributing heterozygous RAB27A mutation, the risk for HLH in HPS2 remains unclear. We analyzed susceptibility to HLH in the pearl mouse model of HPS2. After infection with lymphocytic choriomeningitis virus, pearl mice developed all key features of HLH, linked to impaired virus control caused by a moderate defect in CTL cytotoxicity in vivo. However, in contrast to perforin-deficient mice, the disease was transient, and all mice fully recovered and controlled the infection. An additional heterozygous Rab27a mutation did not aggravate the cytotoxicity defect or disease parameters. In the largest survey of 22 HPS2 patients covering 234 patient years, we identified only 1 additional patient with HLH and 2 with incomplete transient HLH-like episodes, although cytotoxicity or degranulation was impaired in all 16 patients tested. HPS2 confers a risk for HLH that is lower than in Griscelli or Chediak-Higashi syndrome, probably because of a milder defect in cytotoxicity. Preemptive hematopoietic stem cell transplantation does not appear justified in HPS2.

Prognostic Factors in Pediatric Cancer Patients Admitted to the Pediatric Intensive Care Unit

Higher mortality and morbidity are well established in children with malignancies in whom intensive care admissions are required. A retrospective cohort study was conducted to assess the risk factors for children with cancer in the pediatric intensive care unit (PICU) for short-term outcome (survival vs. nonsurvival when leaving the PICU). The records of 36 children with a median age of 5 years (range: 0.5 to 21) between August 2004 and August 2007 were reviewed. Mortality rate was 55%, higher than the yearly overall PICU mortality rate of 12% (P<0.0001). The mean Pediatric Risk of Mortality Score (PRISM) III score among survivors was lower than that among nonsurvivors (9.4±5.7 vs. 16.4±5.3, P=0.001). Comparison of observed and predicted mortality derived from the PRISM III score showed that distribution of outcome was not different and the prediction model performed well (goodness of fit test: χ2=3.64, df=6, P=0.725). The mortality rates were 66.6% and 33.3% in patients with high (>10 points) and low (≤10 points) PRISM III score, respectively (P=0.05). Mortality rate was significantly related to presence and number of organ system dysfunction (P=0.031 and P=0.013, respectively), sepsis (P=0.05), mechanical ventilation (P=0.005), and positive inotropic support (P=0.003). By using multiple logistic regressions, the independent risk factor was PRISM III score at the time of admission to PICU (P=0.05). The PRISM III score performed well as a predictor of outcome. For decision to admit such patients to the PICU or to forgo life-sustaining therapies, other factors such as need for mechanical ventilation and positive inotropic support, presence and numbers of organ system dysfunction should be taken into consideration as well.

Piperacillin/tazobactam versus cefepime for the empirical treatment of pediatric cancer patients with neutropenia and fever: A randomized and open‐label study

This is a prospective, randomized, and open‐label clinical trial that examines the efficiency and safety of PIP/TAZO monotherapy in comparison to cefepime (CEF), for the empirical treatment of pediatric cancer patients with neutropenia and fever.

Childhood acute lymphoblastic leukemia in Turkey: factors influencing treatment and outcome: a single center experience.

There is limited data about the long-term treatment outcome and prognosis of childhood acute lymphoblastic leukemia (ALL) in developing countries. Our study was designed to assess survival data and identify risk factors. Data of 142 children with ALL who were treated with a modified BFM 95 protocol between 1997 and 2007 were evaluated. The median age was 4.3 years. Complete remission (CR) rate after induction phase was 93.5%; with 2.1% induction-related mortality and 0.7% having resistance disease. Of complete responders, 67.1% are in continuous CR with a median follow-up of 63 months (range: 24 to 153 mo). Treatment-related mortality was 17.7% and the total rate of treatment abandonment was 3.5%. The probability of event-free survival was 67.3% (95% confidence interval 59.3-75.3) at 4 years and 63.2% (95% confidence interval 54.4-72.0) at 8 years. This report examines children with ALL treated with a modified ALL-BFM 95 protocol in a tertiary care center in Turkey with adequate follow up and demonstrates the need for improvements especially for patients with unfavorable risk group and strategies to reduce deaths from infection in CR to keep pace with cure rates in developed countries.

Safety and Outcomes of Extracorporeal Photopheresis With the Therakos Cellex System for Graft-Versus-Host Disease in Pediatric Patients.

Extracorporeal photopheresis (ECP) is a difficult procedure to perform in the pediatric population. This is a retrospective review of 12 pediatric patients who underwent photopheresis with the Therakos Cellex system for graft-versus-host disease (GVHD). Acute GVHD (aGVHD) occurred in 6 patients, and overlap syndrome and chronic GVHD (cGVHD) occurred in 4 and 2 patients, respectively. The ECP regimen was the same for all aGVHD and cGVHD patients: initially, every week (2 sessions/wk) for 2 months; next, every 2 weeks for 2 months; and finally, every month for at least 1 year. Improvement was observed in 7 of 10 aGVHD patients (70%) and in 4 of 6 cGVHD patients (66%). Eleven patients had skin involvement before ECP; 9 of them responded to treatment (81%). Gastrointestinal involvement occurred in 8 patients; 5 of them experienced improvement during ECP treatment (62%). All 4 patients with liver involvement failed to respond. No serious adverse reactions occurred. In conclusion, our study demonstrates that ECP with the Therakos Cellex system is a safe treatment option for GVHD in children, allowing the tapering of immunosuppressants by at least half.

POSTTRANSPLANT ORAL IRON-CHELATING THERAPY IN PATIENTS WITH β-THALASSEMIA MAJOR

Allogeneic hematopoetic stem cell transplantation (HSCT) is the only radical cure of β-thalassemia. However, iron overload remains a cause of morbidity and mortality in posttransplant period. The authors present 7 patients as a preliminary report who underwent bone marrow transplant (BMT) and received oral chelating therapy (deferasirox) because of poor compliance to phlebotomy and desferrioxamine. The patients investigated mainly for possible side effects of deferasirox. No negative effect was seen in aspartate aminotransferase (AST), alanine aminotransferase (ALT), hemoglobin (Hb), and donor chimerism of the patients while serum ferritin levels significantly reduced (P = .018). Although serum creatinin significantly increased (P = .034), it was in normal limits in all patients. The authors believe that this report shows promising findings to plan further studies to clarify clinical safety and efficacy of deferasirox in posttransplant period.

Successful unrelated bone marrow transplantation in two siblings with alpha-mannosidosis

Yesilipek AM, Akcan M, Karasu G, Uygun V, Kupesiz A, Hazar V. Successful unrelated bone marrow transplantation in two siblings with alpha‐mannosidosis.

The value of donor lymphocyte infusions in thalassemia patients at imminent risk of graft rejection following stem cell transplantation.

The aim was to evaluate the feasibility of donor lymphocyte infusion (DLI) in transplanted patients with thalassemia who were at imminent risk of graft rejection (GR).

Better posttransplant outcome with fludarabine based conditioning in multitransfused fanconi anemia patients who underwent peripheral blood stem cell transplantation.

Several investigators have been looking for less toxic conditioning regimen for stem cell transplantation in Fanconi anemia (FA) patients because of sensitivity to DNA cross-linking agents and tendency to malignancy. We report 16 multitransfused FA patients who underwent peripheral stem cell transplantation from 13 related and 3 unrelated donors. Although the first 6 patients received thoraco-abdominal irradiation + cyclophosphamide + antithymocyte globulin (regimen A) for conditioning, fludarabine (FLU) + cyclophosphamide + antithymocyte globulin (regimen B) were used in the last 10 patients in which 3 of them received unrelated graft. Cyclosporin A was given alone for the related allografts but also included mycophenolate mofetil for the unrelated allograft as graft versus host disease prophylaxis. We observed a lower risk of peritransplant morbidity and mortality with fewer and milder graft versus host disease in FLU based group. We lost 3 patients in regimen A group and 1 of them from secondary acute myeloid leukemia. Three patients are alive with transfusion independent. In regimen B group, 9 of 10 patients are alive with normal hematologic parameters and full donor chimerism. The longest follow-up durations are 90 and 60 months in regimen A and B, respectively. In conclusion, FLU based conditioning is more effective and successful with lower toxicity in multitransfused FA patients. However, it needs more experience and longer follow up duration.

Hematopoietic stem cell transplantation activity and trends at a pediatric transplantation center in Turkey during 1998-2008.

Objective: The aim of this study was to document hematopoietic stem cell transplantation (HSCT) activity and trends at our treatment center. Material and Methods: Data collected over a 10-year period were retrospectively analyzed, concentrating primarily on types of HSCT, transplant-related mortality (TRM), stem cell sources, indications for HSCT, and causes of death following HSCT. Results: In total, 222 allogeneic (allo)-HSCT (87.4%) and 32 autologous (auto)-HSCT (12.6%) procedures were performed between 1998 and 2008. Stem cells obtained from unrelated donors were used in 22.6% (50/222) of the allo- HSCTs. Cord blood was the source of hematopoietic stem cells (HSC) in 12.2% of all transplants. The most common indication for allo-HSCT was hemoglobinopathy (43.2%), versus neuroblastoma (53.1%) for auto-HSCT. The TRM rate 1 year post transplantation was 18.3% ± 2.5% for all transplants, but differed according to transplantation type (23.5% ± 7.9% for auto-HSCT and 17.5% ± 2.6% for allo-HSCT). The most common cause of death 1 year post HSCT was infection (35.9%). Conclusion: The TRM rate in the patients that underwent allo-HSCT was similar to that which has been previously reported; however, the TRM rate in the patients that underwent auto-HSCT was higher than previously reported in developed countries. The selection of these patients to be transplanted must be made attentively.