SummarySporadic essential thrombocythaemia (ET) is rare in paediatrics, and the diagnostic and clinical approach to paediatric cases cannot be simply copied from experience with adults. Here, we assessed 89 children with a clinical diagnosis of ET and found that 23 patients (25Á8%) had a clonal disease. The JAK2 V617F mutation was identified in 14 children, 1 child had the MPL W515L mutation, and 6 had CALR mutations. The monoclonal X-chromosome inactivation pattern was seen in six patients (two with JAK2 V617F and two with CALR mutations). The other 66 patients (74Á2%) had persistent thrombocytosis with no clonality. There were no clinical or haematological differences between the clonal and non-clonal patients. The relative proportion of ET-specific mutations in the clonal children was much the same as in adults. The higher prevalence of nonclonal cases suggests that some patients may not have myeloproliferative neoplasms, with significant implications for their treatment.

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Introduction We have evaluated Antithrombin (AT) values and Whole Blood Rotation Thromboelastometry (ROTEM) profiles in children affected by acute lymphoblastic leukemia (ALL), followed at the Clinic of Pediatric Hematology Oncology of Padua. L-Asparaginase, used in protocols for pediatric ALL, is an inhibitor of protein synthesis. Typical collateral effects are coagulation disturbances. Guidelines for identification of patients at risk of thrombosis and hemorrhages are not yet established. AT levels are the only reliable parameter for thrombotic risk. Very low levels of fibrinogen are not correctly detected by classical Clauss method; ROTEM test using FIBTEM is considered a valid tool to identify hypofibrinogenemia and hemorrhagic risk in surgical patients. The aim of the study was to analyze coagulation patterns during treatment with Pegilated L-Asparaginase (Peg-Asp). Methods Forty-two children (25 males, 17 females; 31 pB-ALL; 11 T-ALL; 23 at standard/medium risk; 19 at high risk) were consecutively diagnosed and treated with AIEOP BFM ALL 2009 protocol from June 2012 to March 2014. They received 3 (standard/medium risk) or 8 (high risk) doses of Peg-Asp (2500UI/mq/dose). ROTEM and AT determinations were performed at 5 fixed time-points before and after each Peg-Asp administration. Prothrombin time (PT), fibrinogen plasma levels and platelets counts were recorded. Maximum Clot Firmness (MCF; normal value 9-25 mm), measuring the maximum amplitude reached in FIBTEM thromboelastogram, assessed the specific role of fibrinogen in the whole blood clot formation following platelets inhibition by Cytocalasin D. Results: 798 AT and 706 FIBTEM tests were performed; details are reported in Table. We divided abnormal MCF in 3 grade levels. Only values of MCF >9 mm had a linear correlation with fibrinogen levels. Plasma fibrinogen values <1 g/l were seen only in 45/286 (15%) cases with low MCF, without the possibility to discriminate the 3 MCF groups. Hemorrhagic risk was not suggested by PT, which was highly prolonged only in 5 cases (MCF 4-8 mm). Supplementation with AT or fibrinogen concentrates was suggested for patients with AT <50% or MCF <2 and decided on clinical basis. Twenty six children had a complete set of tests available during Induction phase (2 doses of Peg-Asp). They showed two different patterns of AT and MCF behavior. In 13 patients, mean AT levels decreased until 12-14 days after Peg-Asp, never being <50% and increased thereafter. The other thirteen patients had low AT levels from day 12 after Peg-Asp, required supplementation even before the second dose of Peg-Asp and did not show recovery until the forth week after treatment (figure 1). In 11 patients , MCF were never <9mm , without any trend to reduction. In 15 patients, who had at least 2 tests of MCF <9mm, mean MCF decreased regularly from first Peg-Asp dose until day 21, showing a trend to recovery at day 28 (figure 2). One child had a cerebral sinus thrombosis at the end of induction; one child had extensive thrombosis, strongly related to the central line used for dialysis. Thromboses were not related to fibrinogen concentrates administration or low AT levels. No bleedings were observed. Conclusions: Extensive analysis of coagulation parameters in children undergoing chemotherapy for ALL containing PEG Asp showed abnormalities of AT in 88% of patients and of MCF in 30%. These tests identified patients with significant abnormalities more closely than classical methods. Careful use of AT dosage and FIBTEM can help in managing coagulation disturbances, by identifying patients at risk and suggesting prevention measures. Table: AT and FIBTEM analysis in ALL patients Total N. pts / total N. tests AT 42/798 MCF 42/706 Pts with pathological tests AT<50% 37 (88%) MCF<9mm 13 (30%) N. of Pathological tests AT<50% 158 (19%) MCF<9 mm 286 (40%) MCF 5-9 mm 212 (30.5%) MCF 3-4 mm 56 (7%) MCF <2 mm 18 (2.5%) Supplementation with AT or FC AT<50% 58 units in 24 pts MCF<2 mm 18 units in 11 pts Figure 1: Mean AT levels in ALL patients during induction (according to AT supplementation) Figure 1:. Mean AT levels in ALL patients during induction (according to AT supplementation) Figure 2: Mean MCF levels in ALL patients during induction (MCF>9 and MCF <9mm) Figure 2:. Mean MCF levels in ALL patients during induction (MCF>9 and MCF <9mm) Disclosures No relevant conflicts of interest to declare.

Fusarium species are ubiquitous pathogens causing opportunistic infections in immunocompromised patients. Clinical presentation depends on a host’s immunity and can be localized or disseminated. Since there are few reports of disseminated fusariosis in children, we described an unusual case of Fusarium solani infection in a 9-year-old child with acute lymphoblastic leukemia (ALL). This patient presented a deep wound in the elbow at diagnosis. During the induction phase of chemotherapy, he developed multiple skin lesions and severe pneumonia; Fusarium solani was cultured from the skin lesions. He was treated with a high dose of liposomal amphotericin B, followed by voriconazole. Starting from this peculiar case, we collected all patients with acute leukemia affected by Fusarium infection, treated in the pediatric Onco-Hematology Division of Padua University Hospital during the last 20 years. We identified another six cases: all these patients were affected by acute myeloid leukemia (AML) and five of them presented a relapsed/refractory disease. Two out of seven patients died because of infection; five patients recovered from infection, but three out of seven died because of leukemia. Skin lesions in immunocompromised patients should rise the suspicion of disseminated fusariosis. Furthermore, considering the emergence of filamentous fungi in immunocompromised patients, we all should be aware of Fusarium infection, reminding us that the diagnosis is important to cure the infection.

The relationship between myocardial iron load and eccentric myocardial remodeling remains an under-investigated area; it was thought that remodeling is rather linked to fibrosis. This study aims to determine whether or not measures of remodeling can be used as predictors of myocardial iron. For this purpose, 60 patients with thalassemia were studied with 3D echocardiography and myocardial relaxometry (T2*) by Cardiac MRI. 3D derived sphericity index was significantly higher in patients with myocardial iron load. It was correlated with T2* with a 100% sensitivity and specificity (cut-off value of 0.34) to discriminate between patients with and without myocardial iron overload.

Introduction. Chronic hypoxia, transfusional iron overload and chelation therapy are all contributing factors to the deterioration of renal function in thalassemia major (TM ) patients. Among chelators, deferasirox (DFX) is considered the most toxic drug for kidneys: increment of more than 30% of serum creatinine levels is used for dosage modulation or interruption. Recently tubular abnormalities have also been described. We have observed renal toxicity in nine children affected by TM and treated with DFX or deferiprone (DFP) and described the differences in glomerular or tubular function between the two oral chelators. Material and methods. Nine children, 4 males and 5 females, aged 3-17 years (median 7 y), were retrospectively evaluated. They were regularly transfused every 2-3 weeks, receiving a median of 260 g erythrocytes concentrates/kg/year. The median serum ferritin level at baseline before starting oral chelation was 1763 ug/L (range 1127-4198). Four patients (pts) received only one type of chelator (1 DFP and 3 DFX). Five pts received both DFX or DFP in different periods. Overall 8 DFX treatments (dosage 15-30 mg/kg, for 18-112 months, mean 40) and 6 DFP treatments (dosage 75-130 mg/kg for 14-54 months, mean 24) were administered. Three pts had previously received deferoxamine; 3/8 DFX pts and 1/6 DFP pts were naïf to chelation before first renal evaluation. The following renal indices were considered: − glomerular function: serum creatinine and cystatine C levels, estimated glomerular filtration rate (eGFR), according to modified Schwartz formula; urine albumin to creatinine ratio (ACR), urine protein excretion. − tubular function: glycosuria, urinary N-acetyl-beta-D-glucosamidase activity/u-creatinine (u-NAG/u-cr), (index of acute tubular damage); urine daily Beta2 microglobulin (B2MG) and Alfa1 microglobulin (A1MG) excretion (both indices of chronic tubular damage). Analyses were performed at different intervals, according to clinical conditions and patients' age, with different frequency among children. Creatinine impairment was defined as an increase over 30% of basal level. All indices were graded according to local laboratory range. Toxicity was considered significant when the tests were abnormal in at least 25% of evaluations. Results. Initial renal function was normal in all patients (median eGFR 209 ml/min/1.73 m2, range 157-295) and eGFR remained stable over time in all cases. A total of 5 pts with DFX and 3 pts with DFP showed an increase of creatinine over 30% of basal levels. Increase of ACR > 30 mg/g cr was seen in 6/8 pts (75%) in DFX and in 1/6 pts (17%) in DFP; 2 pts (1/8 in DFX and 1/6 in DFP) had macroalbuminuria (ACR >300 mg/g creatinine). No association was found between cumulative DFP dose and eGFR over time (Pearson coefficient, r = 0.06), while a moderate association was found with DFX (r = 0.5; p = 0.06). Symptomatic acute tubular toxicity was observed in 2 pts, with tubular acidosis, glycosuria and abnormal acute tubular indices (u-NAG/u-cr). A1MG and B2MG were also altered, suggesting a chronic injury substrate. Both pts were in DFX group (receiving a dose of 20 and 40 mg/kg/day, respectively) and had experienced a fast reduction in ferritin levels over a short period of time. No signs of concomitant infection were detected. u-NAG/u-cr was always abnormal in all children in both groups; mean values were 2.8 U/mmol for DFX and 2.4 U/mmol for DFP. B2MG was altered in 6/8 DFX pts and in 2/6 DFP pts (75% vs 33%). Median values were 3.0 mg/24 h for DFX and 0.5 mg/24 h for DFP, respectively. A1MG was altered in 4/8 DFX pts and 3/6 DFP pts, with median values of 164 mg/24 h for DFX and 55 mg/24 h for DFP, respectively. Conclusions. Patients withTM can experience abnormalities in renal function, especially as regards tubular damage. Acute tubular damage indices were altered in all chelated pts, whereas tests for chronic damage were abnormal more often in the DFX group than in DFP-treated pts. Albeit the significance of our findings needs further confirmation in a longer follow up, these results suggest that extensive renal evaluation is needed, in particular in children whose life expectancy is open and long-term prognosis for multiple organ function is an important issue. Disclosures No relevant conflicts of interest to declare.

Background: Among patients with beta-thalassemia early detection of transfusion-induced myocardial iron loading and its intervention with aggressive chelation therapy may delay or reverse heart failure. Three dimensional speckle tracking echocardiography (3D-STE) is a novel tool that may early detect myocardial affection in these patients. Methods: Thirty-two thalassemic patients with a mean age of 18.1± 7.03 years and 30 aged matched healthy control subjects have been included in the study. Patients have been recruited from pediatric hematology clinics in both Cairo University, Egypt (n=18) and Padova University, Italy (n=14). 3D-STE was performed to all patients and control subjects in addition to the myocardial relaxometry T2* by cardiac MRI. Results: The left ventricular ejection fraction (LVEF) derived from 3D echocardiography among the studied thalassemia patients was within normal range 62.5± 5.6%. Compared to the normal subjects, thalassemia patients had a statistical significant reduction of the left ventricular global longitudinal strain (-16.81± 0.93% vs -18.76 ± 1.12 %, p=0.001), the left ventricular global circumferential strain (-10.56 ± 0.61% vs -11.83 ± 0.71 %, p=0.001 ) and the left ventricular global area strain (-20.13 ±1.18% vs -22.48 ±,1.29 %, p=0.001). No statistical significant correlation was found between the severity of myocardial iron overload measured by T2* and the measured left ventricular global strain. Conclusion: In asymptomatic thalassemia patients with preserved left ventricular global systolic function 3D-STE derived strain can detect early subtle myocardial dysfunction. The observed subtle myocardial deformation dysfunction is not related to the extent of myocardial iron deposition. Disclosures No relevant conflicts of interest to declare.