Gonul Aydogan

Inherited human OX40 deficiency underlying classic Kaposi sarcoma of childhood

Human OX40 is necessary for robust CD4+ T cell memory and confers selective protective immunity against HHV-8 infection in endothelial cells.

Classic Kaposi Sarcoma in 3 Unrelated Turkish Children Born to Consanguineous Kindreds

Infection by human herpesvirus 8 (HHV-8) in childhood is common in the Mediterranean basin; however, classic Kaposi sarcoma (KS) is exceedingly rare in children not infected with HIV and not receiving immunosuppression, with only 30 cases having been reported since 1960. We recently reported 2 children with autosomal and X-linked recessive primary immunodeficiencies underlying KS in a context of multiple clinical manifestations. These reports suggested that classic KS in otherwise healthy children might also result from inborn errors of immunity more specific to HHV-8. In this article, we describe 3 unrelated Turkish children with classic KS born to first-cousin parents. The first patient, a girl, developed KS at 2 years of age with disseminated cutaneous and mucosal lesions. The clinical course progressed rapidly, and the patient died within 3 months despite treatment with vincristine. The other 2 children developed a milder form of KS at the age of 9 years, with multiple cutaneous lesions. A boy treated with interferon α therapy for 12 months is now in full remission at the age of 14, 2 years after treatment. The second girl is currently stabilized with etoposide, which was begun 4 months ago. None of the 3 children had any relevant familial history or other clinical features. The occurrence of classic KS in 3 unrelated Turkish children, each born to consanguineous parents, strongly suggests that autosomal recessive predisposition may drive the rare occurrence of HHV-8–associated classic KS in children.

Deregulated WNT signaling in childhood T-cell acute lymphoblastic leukemia

WNT signaling has been implicated in the regulation of hematopoietic stem cells and plays an important role during T-cell development in thymus. Here we investigated WNT pathway activation in childhood T-cell acute lymphoblastic leukemia (T-ALL) patients. To evaluate the potential role of WNT signaling in T-cell leukomogenesis, we performed expression analysis of key components of WNT pathway. More than 85% of the childhood T-ALL patients showed upregulated β-catenin expression at the protein level compared with normal human thymocytes. The impact of this upregulation was reflected in high expression of known target genes (AXIN2, c-MYC, TCF1 and LEF). Especially AXIN2, the universal target gene of WNT pathway, was upregulated at both mRNA and protein levels in ∼40% of the patients. When β-CATENIN gene was silenced by small interfering RNA, the cancer cells showed higher rates of apoptosis. These results demonstrate that abnormal WNT signaling activation occurs in a significant fraction of human T-ALL cases independent of known T-ALL risk factors. We conclude that deregulated WNT signaling is a novel oncogenic event in childhood T-ALL.

Prognostic significance of NOTCH1 and FBXW7 mutations in pediatric T-ALL.

The NOTCH signaling pathway plays important role in the development of multicellular organisms, as it regulates cell proliferation, survival, and differentiation. In adults, it is essential for the T- or B-lymphocyte lineage commitment. NOTCH1 and FBXW7 mutations both lead the activation of the NOTCH1 pathway and are found in the majority of T-ALL patients. In this study, the mutation analysis of NOTCH1 and FBXW7 genes was performed in 87 pediatric T-ALLs who were treated on the ALL-BFM protocols. In 19 patients (22%), activating NOTCH1 mutations were observed either in the heterodimerization domain or in the PEST domain and 7 cases (10%) demonstrated FBXW7 mutations (2 cases had both NOTCH1 and FBXW7 mutations). We also analyzed the relationship of the mutation data between the clinical and biological data of the patients. NOTCH1 and FBXW7, NOTCH1 alone were found correlated with lower initial leucocyte counts which was independent from the sex and T- cell immunophenotype. However, NOTCH1 and FBXW7 mutations were not predictive of outcome in the overall cohort of pediatric T-ALLs.

Factor VII Deficiency: A Single-Center Experience.

Congenital factor VII deficiency is the most common form of rare coagulation factor deficiencies. This article presents a retrospective evaluation of 73 factor VII deficiency cases that had been followed at our center. The study consisted of 48 males and 25 females (2 months-19 years). Thirty-one (42.5%) of them were asymptomatic. Out of symptomatic patients, 17 had severe clinical symptoms, whereas 8 presented with moderate and 17 with mild symptoms. The symptoms listed in order of frequency were as follows: epistaxis, petechia or ecchymose, easy bruising, and oral cavity bleeding. The genotype was determined in 8 patients. Recombinant activated factor VII (rFVIIa) was used to treat 49 bleeding episodes in 8 patients after 2002. In 2 patients with repeated central nervous system bleeding prophylaxis with rFVIIa was administered. No allergic and thrombotic events were observed during both treatment and prophylaxis courses. Antibody occurrence was not detected in the patients during treatment.

The Value of Echocardiography Versus Cardiac Troponin I levels in the Early Detection of Anthracycline Cardiotoxicity in Childhood Acute Leukemia: Prospective Evaluation of a 7-Year-Long Clinical Follow-up

The present study was designed to evaluate the significance of echocardiography versus cardiac troponin I levels in early detection of anthracycline dependent cardiotoxicity in acute lymphoblastic leukemia (ALL) patients. A total of 276 pediatric ALL patients were included in the study prospectively along 3 phases of data collection lasted from 2002 to 2009; including phase I (March 2002 to February 2003; n = 25; 53.3% females), phase II (September 2003 to April 2004; n = 35; 57.1% females), and phase III (January 2005 to June 2009; n = 216; 52.7% females) with respect to cumulative anthracycline doses applied. Anthracycline was administered in accordance with berlin-Franfurt-Munich (BFM)-2000 protocol in doses of 30 to 350 mg/m2 (in the first phase) and 30 to 240 mg/m2 (in the following phases). Evaluation of cardiotoxicity was performed via echocardiography and measurement of cardiac troponin I levels. Patients in each phase were homogenous in terms of gender and age. Diastolic dysfunction determined via reduction E/A ratio below the cutoff value was demonstrated to deteriorate earlier than systolic functions and alteration in cardiac enzymes. Being similar between dose groups, cTnI levels were shown to rise in the presence of congestive heart failure. In conclusion, anthracycline cardiotoxicity appears to be detected in an earlier stage by using diastolic parameters compared to systolic parameters and cardiac enzymes.

Successful treatment of multiresistant Achromobacter xylosoxidans bacteremia in a child with acute myeloid leukemia.

Achromobacter xylosoxidans is an aerobic gram-negative bacillus and important cause of bacteremia in immunocompromised patients. We describe a leukemia pediatric patient with severe neutropenia who developed bacteremia with A xylosoxidans resistant to multiple antibiotics, and treated the patient with tigecycline and piperacillin-tazobactam in addition to supportive medications.

The Efficacy of Magnetic Resonance Imaging and X-Ray in the Evaluation of Response to Radiosynovectomy in Patients with Hemophilic Arthropathy

Objective: We aimed to assess the role of Magnetic Resonance Imaging (MRI) and X-Ray in the evaluation of response to radiosynovectomy (RS) in patients with hemophilic arthropathy. Material and Methods: Eleven patients who suffered from hemophilic arthropathy with a mean age of 11.7 (range between 7-15) were included in this study. 148-185 MBq Yttrium 90 silicate (Y-90) was administered intraarticularly to ten knee joints and one patient was treated with intraarticular 74 MBq Rhenium 186 (Re-186) injection into his ankle. Before radiosynovectomy, plain anteroposterior and lateral X-rays of the target joints were obtained by standard technique. The follow-up MRI and X-ray studies of the patients were done 6 months after RS. Pettersson hemophilic arthropathy scales were utilized to stage the condition of the joints on plain X-ray and classification of the investigated joints on MRI were done according to Denver score. The clinical assessment of the efficacy of the RS was made with the comparison of the average bleedings before and after the intervention. Results: During the 6-month follow-up period after RS, an improvement in number of hemarthrosis 75% or greater compared with the prior six months occurred in six joints (54.5%). The Pettersson scores worsened in 1/11 (9%), remained unchanged in 9/11 (81.8%), and improved in 1/11 (9%) joints. At the 6-month follow-up, the MRI score worsened in one (9%) and was unchanged in 10/11 joints (90.9%). Conclusion: MRI is a more sensitive tool than plain radiography for evaluating and follow-up of joint disease in persons with hemophilia, but both methods don’t show correlation with the therapeutic response Conflict of interest:None declared.

Assessment of Cardiac Parameters in Evaluation of Cardiac Functions in Patients with Thalassemia Major

The aim of the study was to evaluate cardiac function and early cardiac dysfunction of patients followed as thalassemia major. In this study, the authors compared 100 patients, diagnosed as thalassemia major with mean age 11.84 ± 4.35, with 60 healthy control subjects at the same age between 2008 and 2011. Early diagnosis of iron overload that may occur after repeated transfusions is important in this patient group. To detect early iron accumulation, the authors compared ferritin with the echo findings, the 24-hour Holter, and cardiac magnetic resonance imaging (MRI) T2* values in the patients of same age and sex, treated with chelators, without heart failure, nonsplenectomized, and do not differ in the presence of hepatitis C. Ferritin levels, left ventricular systolic functions (ejection fraction [EF], shortening fraction [SF]), left ventricular measurements, left ventricular diastolic functions, T2* image on cardiac magnetic resonance, heart rate variables in 24 hours, and Holter rhythm were evaluated to show the early failure of cardiac functions. In this study the authors confirmed that iron-related cardiac toxicity damages electrical activity earlier than myocardial contractility. Left ventricular diastolic diameter (LVDd), left ventricular mass (LVM), and LV systolic diameter (LVDs) levels were significantly higher in the patient group with ectopia. Patients with ectopia are the ones in whom LVM and LVDd are increased. In thalassemia major patients with ectopia, LF/HF ratio was markedly increased, QTc dispersion was clearly found higher in patients with ectopia rather than nonectopic patients. The standard deviation all normal RR interval series (SDNN) was found clearly lower in thalassemia major group with ectopia than control group because it is assumed that increase in cardiac sympathetic neuronal activity is related to exposure to chronic diastolic and systolic failure.

Comparison of tissue Doppler imaging with MRI t2* and 24-hour rhythm holter heart rate variability for diagnosing early cardiac impairment in thalassemia major patients.

Objectives: Cardiology follow up is important in thalassemia major patients. The object of this study is to define parameters which can be used in the early detection of cardiac impairment. Material and Methods: Forty seven beta thalassemia major patients (mean age 16.3 ± 4.47 years; 22 boys, 25 girls) whose left ventricular systolic functions were normal and a healthy control group of fifty age and gender matched children were included in the study. M-mode echocardiographic measurements, systolic and diastolic functions with PW and tissue Doppler and heart rate variabilities (HRVs) were compared between the two groups. The patients were also grouped according to MRT2*, ferritin and left ventricular diastolic diameters (LVDds) to compare the echocardiographic and Holter parameters among them. Results: None of the children in the study group had symptomatic congestive heart failure. PW Doppler late diastolic forward flow in pulmonary artery was higher in the thalassemia group when compared with the control group (P = 0.01) indicating decreased compliance of the right ventricle. While the systolic and diastolic functions were normal, all the HRV parameters in the thalassemia group were significantly lower than the control group (P = 0.005). Conclusions: Significant decrease in HRV and increase in PW late diastolic forward flow in pulmonary artery in the absence of systolic or diastolic dysfunction, points out that these parameters can be useful in detection of early cardiac impairment.