Limited data are available on the serum levels of different sphingomyelin (CerPCho) and ceramide (CER) species in sickle-cell disease (SCD). This study was aimed at identifying the levels of C16-C24 CerPCho and C16-C24 CER in serum obtained from SCD patients and controls. Circulating levels of neutral sphingomyelinase (N-SMase) activity, ceramide-1-phosphate (C1P), and sphingosine-1-phosphate (S1P) were also determined. Blood was collected from 35 hemoglobin (Hb)A volunteers and 45 homozygous HbSS patients. Serum levels of C16-C24 CerPCho and C16-C24 CER were determined by an optimized multiple reaction monitoring (MRM) method using ultrafast liquid chromatography (UFLC) coupled with tandem mass spectrometry (MS/MS). Serum activity of N-SMase was assayed by standard kit methods, and C1P and S1P levels were determined by enzyme-linked immunosorbent assay. A significant decrease was observed in the serum levels of C18-C24 CerPCho in patients with SCD compared to controls. No significant difference was found in C16 CerPCho levels between the two groups. Very-long-chain C22-C24 CER were significantly decreased in SCD, while long-chain C16-C20 CER levels showed no significant difference between SCD patients and controls. Significant positive correlation was found between the serum total cholesterol levels and C18-C24 CerPCho and C22-C24 CER in SCD patients. Patients with SCD had significantly elevated serum activity of N-SMase as well as increased circulating levels of C1P and S1P compared to controls. The decrease in serum levels of C18-C24 CerPCho in patients with SCD was accompanied by decreased levels of C22-C24 CER. Future studies are needed to understand the role of decreased CerPCho and CER in the pathophysiology of SCD.

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INTRODUCTION: Allogeneic hematopoietic cell transplantation (HCT) is a diffuse curative option for transfusion dependent thalassemia (TDT) and sickle cell disease (SCD). To verify transplant activity, distribution, demography, policies and outcomes the Hemoglobinopathy Registry was established inside the European Group for Blood and Marrow Transplantation (EBMT). After a previous analysis limited to TDT for the 2000-2010 period data (BMT 2016; 51:536-41), we performed an updated report considering TDT and SCD patients transplanted in the last eighteen years (years 2000-2017). METHODS: Data on pediatric patients transplanted between Jan 1st, 2000 through Dec 31st, 2017 were extracted by the EBMT promise Hemoglobinopathy registry database. Only first transplants were considered. Data are expressed as median with range unless specifically indicated. Survival probabilities were calculated with the method of Kaplan and Meier and expressed as means and 95% confidence intervals (95%CI). Differences between survival probabilities were tested by means of the log-rank test. RESULTS: In the above-specified period 3856 consecutive pediatric patients affected by TDT (2936, 76%) or SCD (920, 24%) were transplanted in 166 HCT centers distributed in 36 countries in Europe, Asia and Africa. Median age at transplant was 7.2 years (range 0.48-17.9). 3342 (87%) transplants were performed on patients <14 years, 514 (13%) on patients aged 14-17.9 years. 2593 (67%) patients received transplant from an HLA identical sibling donor. Figure 1 reports pediatric transplant activity inside the EBMT showing an increased numbers of patients transplanted after year 2010. After a median follow up of 24 months, the 2 years overall survival (OS) and event-free survival (EFS) were 91% (95%CI 90-92) and 86% (95%CI 85-87) for the entire population. In TDT, OS and EFS were 90% (95%CI 89-92) and 84% (95%CI 82-85), respectively. In SCD, OS and EFS were 94% (95%CI 92-96) and 92% (95%CI 90-94), respectively. In both diseases no outcome difference was recorded on the basis of year of transplant (data not shown). Source of hematopoietic cells was bone marrow in 70% of TDT transplants and 81% of SCD transplants. In both diseases better results were recorded with the use of bone marrow versus peripheral blood [OS 91% versus 85% (P< 0.001); 95% versus 84% (P= 0.004) for TDT and SCD, respectively]. Similar results were recorded when EFS was analyzed. 176 patients received hematopoietic cells from single cord blood donors. Of them only 21 were from an unrelated donor. 119 patients received cord blood + bone marrow. Results of related HLA identical cord blood were similar to that of HLA identical related bone marrow (data not shown). Transplantation from an HLA identical sibling offered the best results in OS and EFS compared to other donor options (P< 0.001), both for TDT and SCD. Transplant results by donor type are reported in table 1. The threshold age for optimal transplant outcomes is confirmed 14 years, with OS 92% (95%CI 91-93), EFS 87% (95%CI 85-88) versus OS 85% (95%CI 82-89), EFS 81% (95%CI 77-85) ( P<0.001) comparing younger versus older patients in the entire populations. These differences were confirmed either in TDT and SCD. The two years incidence of cumulative extensive chronic graft versus host disease was 4.1% in TDT and 4.4 % in SCD (P=ns). CONCLUSIONS: Allogeneic HCT for TDT and SCD is a widely available curative approach; the procedure has been increasing and internationally performed during the years with excellent results. The emerging gene therapy approach will have to be compared to these well-established results. Disclosures Zecca: Chimerix: Honoraria. Forni:Novartis: Other: travel expenses, Research Funding; Celgene: Research Funding; Roche: Consultancy; Shire: Research Funding; Apopharma: Other: DSM Board. Bader:Medac: Patents & Royalties, Research Funding; Neovii: Research Funding; Novartis: Consultancy, Speakers Bureau; Riemser: Research Funding; Cellgene: Consultancy. Angelucci:Vertex Pharmaceuticals Incorporated (MA) and CRISPR CAS9 Therapeutics AG (CH): Other: Chair DMC; Novartis: Honoraria, Other: Chair Steering Comiittee TELESTO Protocol; Roche Italy: Other: Local (national) advisory board; Jazz Pharmaceuticals Italy: Other: Local ( national) advisory board; Celgene: Honoraria, Other: Chair DMC.

Bone marrow transplantation is a significant stressor, especially for mothers. Clinicians should address the child and family as a whole in assessments and be aware of psychiatric symptoms in mothers and children who have had such a life-threatening condition.

Although the incidence of pediatric thrombosis has increased over the last decade, noncatheter-related deep venous thrombosis (nCDVT) is rare in children. Congenital and acquired hypercoagulable states may play an important role in the pathogenesis of nCDVT. In this study, we evaluated fibrinolytic parameters by measuring individual concentrations of fibrinolytic proteins and by tissue factor initiated whole blood thromboelastography (TEG), in which a fibrin clot was lyzed by exogenously added tissue plasminogen activator (tPA). Children with nCDVT were compared with age and sex-matched controls. TAFI concentrations were significantly higher in the patient group but there was no difference in the PAI-1, tPA and lipoprotein (a) concentrations. Significantly decreased fibrinolysis was found on TEG in the patient group suggesting that hypofibrinolysis may play an important role in the pathogenesis of nCDVT in children. To our knowledge, this is the first pediatric study that has systematically evaluated the role of fibrinolysis in the pathogenesis of DVT. Given our results, the role of fibrinolysis in the pathogenesis of nCDVT in children should be further evaluated in larger studies.