Alphan Kupesiz

Biallelic loss-of-function mutation in NIK causes a primary immunodeficiency with multifaceted aberrant lymphoid immunity

Primary immunodeficiency disorders enable identification of genes with crucial roles in the human immune system. Here we study patients suffering from recurrent bacterial, viral and Cryptosporidium infections, and identify a biallelic mutation in the MAP3K14 gene encoding NIK (NF-κB-inducing kinase). Loss of kinase activity of mutant NIK, predicted by in silico analysis and confirmed by functional assays, leads to defective activation of both canonical and non-canonical NF-κB signalling. Patients with mutated NIK exhibit B-cell lymphopenia, decreased frequencies of class-switched memory B cells and hypogammaglobulinemia due to impaired B-cell survival, and impaired ICOSL expression. Although overall T-cell numbers are normal, both follicular helper and memory T cells are perturbed. Natural killer (NK) cells are decreased and exhibit defective activation, leading to impaired formation of NK-cell immunological synapses. Collectively, our data illustrate the non-redundant role for NIK in human immune responses, demonstrating that loss-of-function mutations in NIK can cause multiple aberrations of lymphoid immunity.

Tissue plasminogen activator induced fibrinolysis: standardization of method using thromboelastography.

Fibrinolysis is a complex physiological process that involves the interaction of several anticoagulant proteins. Defects of the fibrinolytic system are extremely difficult to diagnose and study because there are no standardized tests available. Thromboelastography is a novel method that allows the study of both coagulation and fibrinolysis using one sample of whole blood, thereby allowing a more physiologic assessment of the coagulation process. Several in-vitro studies have been attempted to determine whether thromboelastography would be a useful assay for the study of fibrinolysis but have reported problems with reproducibility and reliability. Here we report the process involved in developing a thromboelastographic assay in which tissue plasminogen activator (t-PA) is used to induce fibrinolysis. The assay was standardized to ensure that the concentration of the coagulation inducer (tissue factor) and fibrinolytic agent (t-PA) was adequate to induce a clot with lysis parameters that were reproducible and reliable. This method can be used to rapidly assess the intrinsic fibrinolytic potential of whole blood. Our assay showed that it could rapidly predict high levels of plasminogen activator inhibitor, and this information would be beneficial in patients with acute stroke or myocardial infarction.

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.

Peripheral blood stem cell transplantation in children with beta-thalassemia

Fifteen patients with beta-thalassemia received an allogeneic peripheral blood stem cell transplant. Median age was 3.5 years (1–15 years). Six were class I, four class II and five class III according to the Pesaro criteria. All of the donors were HLA-phenotypically identical (13 siblings and two parents). Nine patients were given BU + CY and six BU + CY plus ATG as conditioning. All patients received MTX (+1, +3, +6) and CsA (9–12 months) post transplant for GVHD prophylaxis. The median neutrophil and platelet engraftment times were day 12 and day 16, respectively. cGVHD was observed in three patients. Two patients died. Thirteen patients are well, and transfusion-independent 2–30 months after PSCT. No recurrences of thalassemia have been seen. Overall and event-free survival were 86.6%. In conclusion, we suggest that PSCT can be considered a safe and effective treatment for children with beta- thalassemia.Bone Marrow Transplantation (2001) 28, 1037–1040.

Peripheral stem cell transplantation in a child with amegakaryocytic thrombocytopenia.

Congenital amegakaryocytic thrombocytopenia (CAMT) is an unusual cause of thrombocytopenia without radial or other congenital anomalies in the newborn. Generalized bone marrow dysfunction developing later in life has been reported. We present a 13-month-old girl who was diagnosed as having congenital amegakaryocytic thrombocytopenia and was successfully treated with allogeneic peripheral stem cell transplantation (PSCT) from her fully matched sibling donor. The neutrophil engraftment was on post transplant day 12 and platelet engraftment was on day 14. Her last hemogram revealed platelets of 168 × 109/l 20 months post transplant. Bone Marrow Transplantation (2000) 26, 571–572.

EPISODES OF FEVER AND NEUTROPENIA IN CHILDREN WITH CANCER IN A TERTIARY CARE MEDICAL CENTER IN TURKEY

The aim of this study was to determine the clinical features and microbiological spectrum during episodes of fever and neutropenia (FEN) in children with cancer. Demographics, clinical information, treatment approaches, and outcomes of the patients admitted to Akdeniz University Department of Pediatric Hematology and Oncology from October 1996 to June 2004 were evaluated retrospectively. Of the total 621 episodes, 345 (55.5%) were microbiologically documented (MDI) (36.4%) or clinically suspected (CSI) (19.2%) infections. A total of 425 infections were diagnosed in 345 episodes, in which lower respiratory tract infections were the most common (32.7%). Among the microbiologically documented infections, Staphylococci (both coagulase-negative and coagulase-positive) (38.7%) and Escherichia coli (12.9%) were the most frequently isolated gram-positive and gram-negative organisms, respectively. Monocytopenia less than 100/μL (p = 0.01), duration of neutropenia (p =. 01) and fever (p <. 001) were significantly associated with documented infection by univariate analysis. In addition, presence of previous FEN episode (p =. 001) and hypotension (p =. 029) were also found to be risk factors. However, using the multivariate analyses, only the duration of fever was found to be an independent risk factor for MDI. The rate of mortality was significantly higher among under 1-year-old patients (p =. 039). Hypotension and uncontrolled cancer were the significant determinants of poor prognosis. These results may help to consider a more selective management strategy for children with these problems.

The effect of hemolysis on plasma oxidation and nitration in patients with sickle cell disease.

Abstract This study aimed to determine the effect of haemolysis on plasma oxidation and nitration in sickle cell disease (SCD) patients. Blood was collected from haemoglobin (Hb)A volunteers and homozygous HbSS patients who had not received blood transfusions in the last 3 months. Haemolysis was characterised by low levels of haemoglobin and haptoglobin and high levels of reticulocyte, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), plasma cell-free haemoglobin, bilirubin, total lactate dehydrogenase (LDH) and dominance of LDH-1 isoenzyme. Plasma 8-isoprostane, protein carbonyl and nitrotyrosine levels were measured to evaluate oxidised lipids, oxidised and nitrated proteins, respectively. Plasma nitrite–nitrate levels were also determined to assess nitric oxide (NO) production in both SCD patients and controls. Markers of haemolysis were significantly evident in SCD patients compared to controls. Plasma 8-isoprostane, protein carbonyl and nitrotyrosine levels were markedly elevated in SCD patients compared to controls. Linear regression analysis revealed a significant inverse correlation between haemoglobin and reticulocyte counts and a significant positive correlation of plasma cell-free haemoglobin with protein carbonyl and nitrotyrosine levels. The obtained data shows that increased haemolysis in SCD increases plasma protein oxidation and nitration.

High-dose acyclovir and pre-emptive ganciclovir in prevention of cytomegalovirus disease in pediatric patients following peripheral blood stem cell transplantation.

Summary:Cytomegalovirus (CMV) disease remains an important cause of morbidity and mortality in patients undergoing hematopoietic stem cell transplantation (HSCT). We evaluated high-dose acyclovir (HDACV) and pre-emptive ganciclovir to prevent CMV disease in 76 children who underwent peripheral blood stem cell transplantation (PBSCT) and were at risk for CMV reactivation and disease (both recipient and donor seropositive) from May 1998 to April 2003. All received HDACV from day −9 to 6 months post transplant in conjunction with weekly CMV pp65 antigenemia monitoring. The incidence of antigenemia in this cohort was 19.7%, at a median of 22 days post-PBSCT. The frequencies were 26.4 and 4.4% in allogeneic and autologous groups, respectively (P=0.03). Patients with nonmalignant disease had higher CMV antigenemia than those with malignant disease (30.8 vs 8.1%, P=0.02). Age at PBSCT, sex, graft-versus-host disease (GVHD) prophylaxis regimen and presence of acute GVHD did not affect the risk of CMV antigenemia. None of the patients who had positive pp65 antigenemia developed CMV disease during the study period. We conclude that pp65 antigenemia-guided HDACV and pre-emptive ganciclovir may prevent CMV disease in children undergoing PBSCT.

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.

Unrelated cord blood transplantation in children with severe congenital neutropenia.

Abstract:  SCN is an inherited hematological disorder with severe neutropenia and recurrent infections. Although there are some reports that recombinant rhG‐CSF improves clinical outcome, allogeneic HSCT appears to be the only curative treatment for these patients. We report here two children with SCN successfully treated by CBT from unrelated donors. They were refractory to rhG‐CSF treatment and have no identical family donor. Bu + CY were given as conditioning. Case 1 and Case 2 received 6/6 and 5/6 HLA‐matched unrelated umbilical cord blood, respectively. The number of infused nucleated cells was 6, 18 × 107/kg and CD34+  cell number was 3, 74 × 105/kg in Case 1. Those cell numbers were 8, 8 × 107/kg and 5, 34 × 105/kg for Case 2, respectively. Neutrophil/platelet engraftments were 45/49 days in Case 1 and 24/36 days in Case 2. Grade II cutaneous acute GVHD was seen in Case 2 that was treated successfully with prednisolone. Both patients are well with normal hematological findings and full donor chimerism for post‐transplant 20 and 24 months, respectively. We conclude that UCB can be considered as a safe source of stem cell in patients with SCN who need urgent HSCT.