Tissue Plasminogen Activator Use in Pediatric Patients: A Single Center Experience.

INTRODUCTION: Thrombosis is rare in children and antithrombolytic treatment is controversial. Most commonly used thrombolytic agent is tissue plasminogen activator (t-PA) in pediatrics. In this study, we report our experience in the use of thrombolytic treatment. METHODS: Eighteen patients who had received systemic t-PA between January 2006 and December 2013 were recorded. The response to t-PA was evaluated as complete, partial, and no. The bleeding complication during t-PA administration was graded as minor or major. RESULTS: There were 18 patients (2 mo to 12 y) who received systemic t-PA. Three patients had venous, 14 patients had arterial, and 1 patient had intracardiac thrombosis. Thrombosis was related to cardiac catheterization (61.1%), central venous catheterization (16.7%), cardiac surgery (11.1%), and arrhythmia (5.5%). In 1 patient thrombosis occurred spontaneously (5.5%). Eighteen patients received 25 courses of systemic t-PA (0.15 to 0.3 mg/kg/h). A total of 55.6% of cases had complete, 27.8% had partial, and 16.6% showed no resolution. CONCLUSION: t-PA infusion at doses of median 0.2 mg/kg/h (0.15 to 0.3) seems effective and safe. There is still no consensus on indications and dosing of antithrombolytic treatment in children but in selected patients it decreases long-term complications due to thrombosis.

Toxicity of Vincristine Combined With Posaconazole in Children With Acute Lymphoblastic Leukemia.

BACKGROUND: Vincristine (VCR) is one of the main drugs of acute lymphoblastic leukemia (ALL) treatment. Azole antifungal medications are used for treatment or prophylaxis of invasive fungal infections in acute leukemia. Coadministration of these drugs increases the risk of VCR toxicity. OBSERVATIONS: We presented a girl with ALL using posaconazole prophylaxis. She developed VCR toxicity that included tubulopathy, high blood pressure, neuropathic pain, difficulty walking, diffuse muscular weakness, constipation, abdominal pain. CONCLUSIONS: There are limited data in children with ALL for posaconazole prophylaxis. We recommend that VCR side effects should be evaluated by careful monitoring of the patients who are on this combination therapy.

Elevated plasma asymmetric dimethylarginine levels in children with beta-thalassemia major may be an early marker for endothelial dysfunction.

OBJECTIVES: Beta-thalassemia major is associated with the increased risk of cardiovascular morbidity and mortality. Asymmetric dimethylarginine (ADMA) has been implicated in the pathogenesis of endothelial dysfunction and atherosclerosis. In this study, we aimed to investigate circulating ADMA concentrations in children with beta-thalassemia major. METHODS: Thirty-one beta-thalassemia major children aged between 4 and 16 year old and age, gender-matched 36 healthy controls were enrolled in the study. Plasma ADMA was measured along with the soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), P-selectin, and Pentraxin-3. RESULTS: Age, gender and body mass index were similar in two groups. Plasma ADMA, sVCAM-1, and sICAM-1 measurements were significantly higher in beta-thalassemia major patients than the control group (p < 0.004 for ICAM-1, p < 0.001 for other parameters). There were positive significant correlations between ADMA, sVCAM-1 and sICAM-1 (r = 0.437, p < 0.001; r = 0.544, p < 0.001; r = 0.405, p < 0.001, respectively) in the whole group. DISCUSSION: The findings of the current study show us that increased plasma ADMA levels in children with beta-thalassemia major may be an early marker for endothelial dysfunction and may play a role in the development of premature atherosclerosis in beta-thalassemia major patients.

Effects of respiratory viruses on febrile neutropenia attacks in children.

Respiratory tract viruses have an important effect on morbidity and mortality in patients with febrile neutropenia (FN). The aim of this study was to determine frequency and clinical influence of viral respiratory viruses as potential etiologic agents in episodes of FN in children. A total of 100 children (62 boys, 38 girls) with 166 FN episodes were included in this prospective study. Nasopharyngeal aspirate samples were analyzed for respiratory viral agents using multiplex real-time polymerase chain reaction. The origin of the fever could be defined in 111 (67%) of the episodes. We detected viral agents in 86 (51.8%), bacterial agents in 19 (11.4%), and fungal agents in 5 (3%) of the episodes. The most common detected viruses were rhinovirus (n= 27), respiratory syncytial virus (n=17), and coronavirus (n=16). Parainfluenza virus, influenza A and B, adenovirus, human metapneumovirus, enterovirus, bocavirus and parechovirus were the remaining detected agents. More than one virus positivity occurred in 13 FN episodes. Forty-three patients had multiple FN episodes. Only four patients had the same viral agent in consecutive attacks. Respiratory symptoms (cough, nasal discharge and congestion, sneezing, wheezing), physical examination signs (rales and rhonchi) and radiological findings were significantly more common in viral agent positive patients (p < 0.05). This study showed that respiratory viruses make a substantial contribution on the etiology of FN episodes in children. Identifying viral agents may help to constitute individualized infection-management algorithms in these patients.

Evaluation of engraftment syndrome in children following full-matched related donor hematopoietic stem cell transplantations.

The term "ES" has been widely used for describing a clinical condition consisting of skin rash, fever, and weight gain that occur during neutrophil recovery period following HSCT. In this study, the incidence, clinical features, risk factors, and outcomes of ES were evaluated in 169 children following allogeneic HSCT from full-matched related donor according to the Spitzer criteria. Seventeen patients (10.1%) presented with clinical conditions suggesting ES. In both univariate and multivariate analysis underlying malignant disease and early release of monocytes to the PB, and in univariate analysis using only CsA for GVHD prophylaxis were found to be the significant risk factors for the development of ES. Patients with ES experienced significantly higher incidence of acute and chronic GVHD and propensity toward a higher rate of TRM. OS did not differ between the patient groups. Thirteen of 17 patients received steroid therapy, and all but one patient responded to therapy. Monitoring for early detection of ES and early intervention with steroid therapy is the key for recovery. The most crucial approach for this purpose mainly is to find out and use the most useful and feasible diagnostic criteria for routine medical practice.

Idiopathic Pulmonary Hemosiderosis With Allergic Asthma Diagnosis in a Pediatric Patient.

Idiopathic pulmonary hemosiderosis (IPH) is a rare disorder with unknown pathogenesis that usually presents in the first decade of life. As a result of diffuse alveolar hemorrhage, respiratory symptoms such as cough attacks, hemoptysis, dyspnea, and recurrent and refractory iron-deficiency anemia (IDA) are observed. We present an 8-year-old girl who was followed up with recurrent IDA and allergic asthma and later diagnosed with IPH. IPH was confirmed by the presence of hemosiderin-laden macrophages in bronchoalveolar lavage obtained by bronchoscopy and exclusion of the secondary causes of pulmonary hemosiderosis. Glucocorticoids and iron supplementation were started. Clinical and laboratory improvement was observed with therapy. Our case illustrates that refractory/recurrent IDA with any pulmonary symptoms may be the only presenting feature of IPH.

The impact of donor age and sex on the nucleated cell count and CD34 count in healthy bone marrow donors.

BM remains an important source of stem cells. The BM characteristics change with age but the estimation of CD34 calculation of one CD34+ cell per 100 nucleated cells is used for all donors including pediatric donors in the operating room before getting the actual CD34 count. In order to see whether this formula is applicable for pediatric donors, we designed a retrospective study to see the affect of the age and sex on the BM NCC, CD34 count, and CD34/NCC ratios. Ninety-eight BM collections from 91 related donors were evaluated retrospectively (median age: nine yr [1.5-54 yr]; M/F: 41/50). A significant negative correlation was found between the donor age and NCC (r = -0.229, p < 0.05), CD34 count (r = -0.563, p < 0.01), and CD34/NCC (r = -0.664, p < 0.01). The negative correlation for CD34 count and CD34/NCC persisted in female and male donor groups. When donors younger than 16 yr of age were compared with the older donor group, the median NCC, median CD34 count, and CD34/NCC were significantly lower in the older group (p < 0.01). Age and sex have to be taken into consideration to avoid unnecessary high-volume collections and increased operating room time in the younger donors.

A novel protein C inhibitor gene mutation in pediatric stroke patients after bone marrow transplantation.

Protein C inhibitor is a heparin dependent serine protease inhibitor found in human plasma, urine and other body fluids. It was originally identified as an inhibitor of activated protein C. Stroke is an important cause of morbidity and mortality in the pediatric age group. In this study we analyzed the protein C inhibitor gene mutations in Turkish pediatric stroke patients. We found a missense mutation of G to A at nucleotide 6760 in exon 2, resulting in a transition serine to asparagine (p.Ser188Asp) and in a child and his father and also we found same alteration in exon 2 in an another pediatric stroke case following bone marrow transplantation.

Blood group genotyping in multi-transfused patients.

BACKGROUND: In chronically transfused patients, the classical hemagglutination assays may be inaccurate in defining the RBC phenotypes of the patients due to previous transfusions. DESIGN: DNA samples from 39 multi-transfused patients including thalassemia and sickle cell disease were used for red blood cell genotyping. The Rh-Type and KKD-Type (BAGene, BAG Healthcare) were used to determine the polymorphisms associated with antigen expression for RHD, RHCE and Kell, Kidd, Duffy blood group systems, respectively. Results were compared with previously determined phenotyping results for RhD, RhCcEe and Kell by hemagglutination method. RESULTS: Nineteen out of the 37(51%) patients had discrepancies between genotyping and phenotyping results in a total of 25 alleles. In 12 patients, the discrepancies had the potential of alloimmunization. CONCLUSION: Blood group genotyping has vital importance in transfusion management of chronically transfused patients especially if the patients were not phenotyped before starting the initial transfusions.

Primary adrenal insufficiency in a child after busulfan and cyclophosphamide-based conditioning for hematopoietic stem cell transplantation.

High rates of skeletal complications, growth disturbances, thyroid and gonadal dysfunction have been described in children undergoing stem cell transplantation. Although secondary adrenal insufficiency has been diagnosed, no primary adrenal insufficiency has been reported after busulfan and cyclophosphamide (Bu/Cy)-based conditioning regimens for stem cell transplantation in children. A 9-year-old girl with myelodysplastic syndrome was treated with stem cell transplantation of allogeneic origin. She received myeloablative conditioning chemotherapy, Bu and Cy. Her serum cortisol level was normal before stem cell transplantation. Then, 17 months after stem cell transplantation, chronic graft-versus-host disease developed and was treated with methyl prednisolone for 3 months. The control endocrinological investigation revealed low serum cortisol and high serum adrenocorticotropin (ACTH) levels 6 months after completion of methyl prednisolone treatment. The ACTH stimulation test demonstrated primary adrenal insufficiency, and the other etiologies of primary adrenal insufficiency were excluded. The patient received oral prednisolone replacement therapy. She was followed-up for 44 months and required increases in steroid doses during stress periods. Primary adrenal insufficiency which was observed in our patient after Bu/Cy-based conditioning regimen for stem cell transplantation has not been reported in children and adrenal function should be closely monitored in these patients both before stem cell transplantation and after stem cell transplantation.

Relation of soluble endothelial protein C receptor and cytokines after allogeneic hematopoietic stem cell transplantation.

AIM: The objective of this study was to elucidate the effects of tumor necrosis factor α (TNF-α), interleukin 1ß (IL-1ß), interleukin 2 (IL-2), interleukin 6 (IL-6), and interleukin 8 (IL-8) on the expression of soluble endothelial protein C receptor (sEPCR) in the pathogenesis of thrombotic complications after hematopoietic stem cell transplantation (HSCT). METHODS: The relationship between plasma concentrations of proinflammatory cytokines (TNF-α, IL-1ß, IL-2, IL-6, and IL-8) and sEPCR was evaluated in 32 consecutive allogeneic hematopoietic stem cell-transplanted patients prior to conditioning regimen and randomly once between +5 and +30 days after transplantation and compared these results with 20 healthy controls. RESULTS: Soluble endothelial protein C receptor levels did not indicate any significant difference between pre- and posttransplantation period, and sEPCR levels showed a significantly negative correlation between IL-6 and IL-8 (sEPCR and IL-6, r = -.43, P < .01; sEPCR and IL-8, r = -.57, P < .01). There was no correlation between sEPCR levels and TNF-α, IL-1ß, or IL-2 (sEPCR and TNF-α, r = -.13, P > .05; sEPCR and IL-1ß, r = -.1, P ≥ .05; sEPCR and IL-2, r = -.07, P > .05). CONCLUSIONS: Our results suggest that the production of sEPCR was not affected by allogeneic HSCT. Soluble endothelial protein C receptor did not show any positive correlation between these proinflammatory cytokines (TNF-α, IL-1ß, IL-2, IL-6, and IL-8), on the contrary a significantly negative correlation was determined between sEPCR and either IL-6 or IL-8. This negative correlation may be a protective mechanism in the pathway of protein C activation.

The role of tumor necrosis factor-alpha -308 G/A and transforming growth factor-beta 1 -915 G/C polymorphisms in childhood idiopathic thrombocytopenic purpura.

OBJECTIVE: To increase our understanding of the etiology of idiopathic thrombocytopenic purpura (ITP) some cytokine gene polymorphisms were analyzed for susceptibility to the disease. The aim of this study was to investigate the role of tumor necrosis factor-alpha (TNF-α) -308 G/A and transforming growth factor-beta 1 (TGF-ß1) -915 G/C polymorphisms in the development and clinical progression of childhood ITP. METHODS: In all, 50 pediatric patients with ITP (25 with acute ITP and 25 with chronic ITP) and 48 healthy controls were investigated via LightCycler® PCR analysis for TNF-α -308 G/A and TGF-ß1 -915 G/C polymorphisms. RESULTS: The frequency of TNF-α -308 G/A polymorphism was 20%, 16%, and 22.9% in the acute ITP patients, chronic ITP patients, and controls, respectively (p>0.05). The frequency of TGF-ß1 -915 G/C polymorphism was 16%, 8%, and 8.3% in the acute ITP patients, chronic ITP patients, and controls, respectively (p>0.05). The risk of developing ITP and clinical progression were not associated with TNF-α -308 G/A (OR: 0.738, 95% CI: 0.275-1.981, and OR: 0.762, 95% CI: 0.179-3.249) or TGF-ß1 -915 G/C (OR: 1.5, 95% CI: 0.396-5.685, and OR: 0.457, 95% CI: 0.076-2.755) polymorphisms. CONCLUSION: The frequency of TNF-α -308 G/A and TGF-ß1 -915 G/C polymorphisms did not differ between pediatric ITP patients and healthy controls, and these polymorphisms were not associated with susceptibility to the development and clinical progression of the disease.

Invasive Candida infections in children: the clinical characteristics and species distribution and antifungal susceptibility of Candida spp.

The aims of the study were to examine the distribution of Candida spp. isolated from sterile body sites, the antifungal susceptibility of the isolates to amphotericin B, fluconazole, voriconazole, and caspofungin, and factors affecting mortality with invasive Candida infections in children. Thirty-five children with invasive candidiasis between January 2004 and January 2008 were evaluated retrospectively. The antifungal susceptibility of isolated Candida species was studied by Etest. Of the invasive Candida infections, 65.7% were due to C. albicans. The second most common isolated species was C. parapsilosis (11.4%). The rates of resistance to fluconazole, amphotericin B and voriconazole were 8.5%, 2.8% and 5.7%, respectively. Caspofungin was the most effective antifungal agent. 22.8% of the patients died in the first 30 days. In univariate analyses, increased mortality was associated with stay in the intensive care unit, the presence of central venous catheter (CVC), failure to remove CVC, and mechanical ventilation.

Mixed chimerism following hematopoietic stem cell transplantation in pediatric thalassemia major patients: a single center experience.

OBJECTIVE: Stable mixed chimerism (MC) may result in cure for thalassemia major patients following hematopoietic stem cell transplantation (HSCT), but rejection can occur. Twenty-eight HSCTs for thalassemia major were reviewed retrospectively to evaluate the clinical course of MC with possible risk factors and predictors of outcome, with a median follow-up of 1669 days (811-3576 days). METHODS: Chimerism was detected by fluorescence in situ hybridization (FISH) or multiplex polymerase chain reaction depending on the sex match between the donor and the recipient. RESULTS: Primary rejection, stable MC and full donor chimerism was detected in 3.6%, 17.8% and 78.6% of patients, respectively. Clinically, 4/5 patients with stable MC had thalassemia trait with donor chimerism as low as 14%. One patient was started on pRBC transfusions at 2.5 years postHSCT. CONCLUSION: Stable MC can result in cure for thalassemia major patients. The clinical picture remains as the best guide for intervention until a more reliable predictor is available.

Prospective evaluation of acute and chronic renal function in children following matched related donor hematopoietic stem cell transplantation.

Acute and chronic renal impairment are important complications after HSCT. A prospective study was conducted to investigate the glomerular renal function in children who received allogeneic HSCT from matched related donors. Non-radiation conditioning regimens were used in all but one patient. CrCl and serial measurements of serum creatinine were evaluated prior to HSCT, within the first 100 days and one yr after. AKI was defined as at least a 1.5-fold rise in pre-HSCT serum creatinine within the first 100 days and classified as grade 1 to 3 according to the new definition criteria proposed by "AKI Network." Fifty-seven patients were enrolled in the study and 24 patients (42%) had AKI. CsA, amphotericin B, and SOS were found as risk factors for AKI. One yr after HSCT five patients (10%) had CKD and none of them required dialysis. None of the parameters were found as a predictor for CKD. We conclude that AKI is an important complication of HSCT. Careful monitoring of renal function, minimizing the use of nephrotoxic medication, prophylaxis, and effective treatment of SOS might be effective preventive measures to decrease the incidence of AKI.

Excessive naked megakaryocyte nuclei in myelodysplastic syndrome mimicking idiopathic thrombocytopenic purpura: a complicated pre- and post-transplantation course.

A boy 3 years 7 months old with thrombocytopenia and history of intracranial hemorrhage who underwent bone marrow transplantation is presented. He was refractory to steroids, immunoglobulin G, vincristine, azathioprine, cyclosporine A, interleukin-11, chemotherapy, and splenectomy. Idiopathic thrombocytopenic purpura was excluded by light /electron microscopic and flow cytometric findings; the diagnosis of refractory cytopenia, a subgroup of pediatric myelodysplastic syndrome, was made. Naked megakaryocyte nuclei were 55.38 +/- 28.2% vs. 31.67 +/- 23.22% of all megakaryocytes in the patient and the control group of 9 patients with idiopathic thrombocytopenic purpura, respectively (p = .016). The posttransplatation course was complicated by delayed platelet engraftment, bronchiolitis obliterans associated with pneumocystis carinii pneumonia, which resolved completely.

Extramedullary hematopoiesis with spinal cord compression in a child with thalassemia intermedia.

Spinal cord compression due to extramedullary hematopoiesis is an extremely rare complication of thalassemia intermedia. No cases with this complication have been reported in the first decade of life, because masses of heterotropic marrow developed in patients as a result of continuous erythropoiesis. We report the 9-year-old patient suffering from thalassemia intermedia and presenting spinal cord compression. We also review the literature about treatment options, because there is no consensus about the optimal treatment of these patients. Our patient was successfully treated with radiation therapy followed by hydroxyurea. With this combination therapy, he had no recurrence during the 4-year follow-up period. Clinical awareness of this phenomenon with the early treatment is essential for optimizing the successful outcome.

Early detection of myocardial dysfunction in children with beta-thalassaemia major.

To evaluate left and right ventricular myocardial performance using pulsed-tissue Doppler imaging (TDI) and its relation to BNP levels in patients with beta-thalassaemia major (beta-TM). We enrolled 36 thalassaemic patients (21 male, 15 female; mean age: 14.2 +/- 4.1 years) with normal left ventricular systolic and diastolic functions with conventional echocardiography and 30 healthy control subjects (18 male, 12 female, and 12.5 +/- 4.2 years). Myocardial performance indexes (MPI) of left ventricular (LV) lateral wall, interventricular septum (IVS) and right ventricular (RV) lateral wall were calculated with TDI. Plasma BNP levels were measured in all patients. MPIs and other echocardiographic parameters of patients with beta-TM were compared with control group. All the patients' plasma BNP levels were within normal limits. There were no differences between conventional echocardiographic parameters of patients and control group. MPI of LV, IVS, and RV of patients were significantly higher than control group (P = 0.01, and P < 0.01, and P < 0.001, respectively). Our study confirms that MPI obtained by TDI seems to be an early sensitive parameter of cardiac dysfunction in beta-TM. We concluded that MPI obtained by TDI may be an adjunctive parameter to conventional echocardiography for detecting early myocardial damage.

Related donor hematopoietic stem cell transplantation for Fanconi anemia without radiation: a single center experience in Turkey.

Eight children with FA underwent allogeneic HSCT without using irradiation for the conditioning regimen. Patients received two different conditioning regimens: first two patients received BU 1.5 mg/kg/day for four days and CY 10 mg/kg/day for four days and the other regimen was: Flu 30 mg/m(2)/day for five days, CY 10 mg/kg/day for two days, and ATG-Fresenius 9-10 mg/kg/day for four days. GVHD prophylaxis consisted of CsA + MTX for the first two patients and only CsA for the others. All patients received HLA-identical stem cells from related donors. Primary engraftment was demonstrated in all patients. No patient developed acute GVHD and one patient had chronic GVHD. Only one patient who received BU based regimen died because of VOD. Overall, seven patients (87.5%) are alive with stable full donor chimerism at a median follow-up time of 2.5 yr (range: 1.7-8.9 yr). None of the patients developed secondary malignancy. Based on our data, we conclude that Flu-based, non-irradiation conditioning regimen was safe with low organ toxicity and stable engraftment in FA patients undergoing HSCT from matched related donors.