Haemochromatosis in children: A national retrospective cohort promoted by the A.I.E.O.P. (Associazione Italiana Emato-Oncologia Pediatrica) study group.

Haemochromatosis (HC) encompasses a range of genetic disorders. HFE-HC is by far the most common in adults, while non-HFE types are rare due to mutations of HJV, HAMP, TFR2 and gain-of-function mutations of SLC40A1. HC is often unknown to paediatricians as it is usually asymptomatic in childhood. We report clinical and biochemical data from 24 paediatric cases of HC (10 cases of HFE-, 5 TFR2-, 9 HJV-HC), with a median follow-up of 9.6 years. Unlike in the adult population, non-HFE-HC constitutes 58% (14/24) of the population in our series. Transferrin saturation was significantly higher in TFR2- and HJV-HC compared to HFE-HC, and serum ferritin and LIC were higher in HJV-HC compared to TFR2- and HFE-HC. Most HFE-HC subjects had relatively low ferritin and LIC at the time of diagnosis, so therapy could be postponed for most of them after the age of 18. Our results confirm that HJV-HC is a severe form already in childhood, emphasizing the importance of early diagnosis and treatment to avoid the development of organ damage and reduce morbidity and mortality. Although phlebotomies were tolerated by most patients, oral iron chelators could be a valid option in early-onset HC.

Current use of androgens in bone marrow failure disorders: a report from the Severe Aplastic Anemia Working Party of the European Society for Blood and Marrow Transplantation.

Androgens represent the historical therapeutic backbone of bone marrow failure (BMF) syndromes. However, their role has rarely been analyzed in a prospective setting, and systematic and long-term data regarding their usage, effectiveness and toxicity in both acquired and inherited BMF are currently unavailable. Here, taking advantage of a unique disease-specific international dataset, we retrospectively analyzed the largest cohort so far of BMF patients who received androgens before or in the absence of an allogeneic hematopoietic cell transplantation (HCT), re-evaluating their current use in these disorders. We identified 274 patients across 82 European Society for Blood and Marrow Transplantation (EBMT) affiliated centers: 193 with acquired (median age 32 years) and 81 with inherited (median age 8 years) BMF. With a median duration of androgen treatment of 5.6 and 20 months, respectively, complete and partial remission rates at 3 months were 6% and 29% in acquired and 8% and 29% in inherited disorders. Five-year overall survival and failure-free survival (FFS) were respectively 63% and 23% in acquired and 78% and 14% in inherited BMF. Androgen initiation after second-line treatments for acquired BMF, and after >12 months post diagnosis for inherited BMF were identified as factors associated with improved FFS in multivariable analysis. Androgen use was associated with a manageable incidence of organ-specific toxicity, and low rates of solid and hematologic malignancies. Sub-analysis of transplant-related outcomes after exposure to these compounds showed probabilities of survival and complications similar to other transplanted BMF cohorts. This study delivers a unique opportunity to track androgen use in BMF syndromes and represents the basis for general recommendations on this category of therapeutics on behalf of the Severe Aplastic Anemia Working Party of the EBMT.

Graft-versus-host disease and relapse/rejection-free survival after allogeneic transplantation for idiopathic severe aplastic anemia: a comprehensive analysis from the SAAWP of the EBMT.

Survival after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for severe idiopathic aplastic anemia (SAA) has improved in recent years, approaching 75% at 5 years. However, an SAA-adapted composite endpoint, graft-versus-host disease (GvHD) and relapse/rejection-free survival (GRFS), may more accurately assess patient outcomes beyond survival. We analyzed GRFS to identify risk factors and specific causes of GRFS failure. Our retrospective analysis from the Severe Aplastic Anemia Working Party of the European Society for Blood and Marrow Transplantation included 479 patients with idiopathic SAA who underwent allo-HSCT in two conventional situations: i) upfront allo-HSCT from a matched related donor (MRD) (upfront cohort), and ii) allo-HSCT for relapsed or refractory SAA (rel/ref cohort). Relevant events for GRFS calculation included graft failure, grade 3-4 acute GvHD, extensive chronic GvHD, and death. In the upfront cohort (n=209), 5-year GRFS was 77%. Late allo-HSCT (i.e., >6 months after SAA diagnosis) was the main poor prognostic factor, specifically increasing the risk of death as the cause of GRFS failure (hazard ratio [HR]=4.08; 95% confidence interval [CI]: 1.41-11.83; P=0.010). In the rel/ref cohort (n=270), 5-year GRFS was 61%. Age was the main factor significantly increasing the risk of death (HR=1.04; 95% CI: 1.02-1.06; P<0.001), acute GvHD (HR=1.03; 95% CI: 1.00-1.07; P=0.041), and chronic GvHD (HR=1.04; 95% CI: 1.01-1.08; P=0.032) as the cause of GRFS failure. GRFS after upfront MRD allo-HSCT was very good, notably with early allo-HSCT, confirming that younger patients with an MRD should be transplanted immediately. GRFS was worse in cases of salvage allo-HSCT, most notably in older patients, questioning the utility of allo-HSCT earlier in the disease course.

Autoimmune Lymphoproliferative Syndrome (ALPS) Disease and ALPS Phenotype: Are They Two Distinct Entities?

Autoimmune lymphoproliferative syndrome (ALPS) is an inherited disorder of lymphocyte homeostasis classically due to mutation of FAS, FASL, and CASP10 genes (ALPS-FAS/CASP10). Despite recent progress, about one-third of ALPS patients does not carry classical mutations and still remains gene orphan (ALPS-U, undetermined genetic defects). The aims of the present study were to compare the clinical and immunological features of ALPS-FAS/CASP10 versus those of ALPS-U affected subjects and to deepen the genetic characteristics of this latter group. Demographical, anamnestic, biochemical data were retrieved from medical record of 46 ALPS subjects. An enlarged panel of genes (next-generation sequencing) was applied to the ALPS-U group. ALPS-U subjects showed a more complex phenotype if compared to ALPS-FAS/CASP10 group, characterized by multiorgan involvement (P = 0.001) and positivity of autoimmune markers (P = 0.02). Multilineage cytopenia was present in both groups without differences with the exception of lymphocytopenia and autoimmune neutropenia that were more frequent in ALPS-U than in the ALPS-FAS/CASP10 group (P = 0.01 and P = 0.04). First- and second-line treatments were able to control the symptoms in 100% of the ALPS-FAS/CASP10 patients, while 63% of ALPS-U needed >2 lines of treatment and remission in some cases was obtained only after target therapy. In the ALPS-U group, we found in 14 of 28 (50%) patients 19 variants; of these, 4 of 19 (21%) were known as pathogenic and 8 of 19 (42%) as likely pathogenic. A characteristic flow cytometry panel including CD3CD4-CD8-+TCRαß+, CD3+CD25+/CD3HLADR+, TCR αß+ B220+, and CD19+CD27+ identified the ALPS-FAS/CASP10 group. ALPS-U seems to represent a distinct entity from ALPS-FAS/CASP10; this is relevant for management and tailored treatments whenever available.

Iron Overload Following Hematopoietic Stem Cell Transplantation: Prevalence, Severity, and Management in Children and Adolescents with Malignant and Nonmalignant Diseases.

Iron overload (IOL) is a frequently reported complication following hematopoietic stem cell transplantation (HSCT) that has been investigated extensively in the field of hemoglobinopathies but has not been thoroughly characterized after HSCT in pediatric malignancies. Our aim was to assess prevalence, severity, risk factors, and management of IOL, as defined using biochemical (serum ferritin) and radiologic tools (T2*-weighted magnetic resonance imaging [MRI]), in a cohort of pediatric patients who underwent HSCT for either malignant or benign diseases. This monocentric, retrospective, observational study included all the 163 patients alive and in continuous remission at 24 months post-HSCT out of the 219 consecutive children and adolescents who underwent HSCT at our institution between 2012 and 2018, were included in the study. IOL was classified into 4 categories: absent, mild, moderate, and severe. Among the 163 patients, 73% had some degree of IOL (mild in 37%, moderate in 29%, and severe in 7%). Moderate/severe IOL was more frequent among patients diagnosed with a malignant disease versus those with a benign disease (43% versus 19%; P = .0065). Trend lines for serum ferritin showed a "bell-shaped" distribution, with the highest levels recorded during the first 6 months post-HSCT, followed by a spontaneous reduction. Both pre-HSCT (1659 ng/mL versus 617 ng/mL; P < .001) and maximum post-HSCT (2473 ng/mL versus 1591 ng/mL; P < .001) median ferritin levels were statistically higher in the patients with malignancies. Radiologic assessment of IOL confirmed a more severe degree in patients with malignant disorders compared to those with benign disorders (median T2*-MRI, 4.20 msec [interquartile range (IQR), 3.0 to 6.40 msec] versus 7.40 msec [IQR, 4.90 to 11.00 msec]; P = .008). T2* levels were associated with the number of transfusions performed (P = .0006), with a steeper drop in T2* values for the first 20 transfusions and a milder slope for subsequent transfusions. T2* and ferritin values showed a statistically significant negative exponential relationship (P < .0001), although a ferritin level ≥1000 ng/mL showed poor specificity (48%) and low positive predictive value (53%) for discriminating moderate-to-severe IOL from absent-mild IOL as assessed by T2*-MRI, but with high sensitivity (92%) and negative predictive value (91%). In a multivariable model, >20 transfusions (odds ratio [OR], 4.07; 95% confidence interval [CI], 1.61 to 10.68; P = .003) and higher pre-HSCT ferritin level (P < .001) were associated with the risk of developing moderate-to-severe IOL. Use of a sibling donor (OR, .29; 95% CI, .10 to .77; P = .015) and a nonmalignancy (OR, .27; 95% CI, .08 to .82; P = .026) were protective factors. Phlebotomy (66%), low-dose oral chelators (9%), or a combined approach (25%) were started at a median of 12 months after HSCT in 78% of the patients with IOL. Six percent of the patients treated exclusively with phlebotomy (median, 14, significantly higher in patients >40 kg) discontinued phlebotomy owing to poor venous access, lack of compliance, or hypotension, whereas 39% of patients treated with chelators developed mild renal or hepatic side effects that resolved after tapering or discontinuation. Patients with malignancies showed statistically higher pre-HSCT and post-HSCT ferritin levels and lower T2* values. High ferritin level recorded on T2*-MRI showed unsatisfactory diagnostic accuracy in predicting IOL; thus, T2*-MRI should be considered a key tool for confirming IOL after HSCT in patients with an elevated serum ferritin level. IOL treatment is feasible after HSCT.

Pediatric immune myelofibrosis (PedIMF) as a novel and distinct clinical pathological entity.

Myelofibrosis is a rare myeloproliferative disorder. The detailed descriptions of myelofibrosis in children and adolescents is limited to a few case series and case reports describing fewer than 100 patients, thus suggesting the extreme rarity of this condition prior to adulthood. Though pediatric patients rarely present the typical features and outcomes usually observed in older people, pediatric myelofibrosis is not considered an independent entity. Here we aim to describe patients with pediatric myelofibrosis, showing different clinical and pathological features when compared to the World Health Organization 2016 Primary Myelofibrosis classification. We retrospectively collected and analyzed 14 consecutive pediatric myelofibrosis diagnosed in our Pediatric hematology outpatient clinic over a six-year period. According to clinical data and bone marrow biopsy findings, patients were classified into three subgroups: adult-like myelofibrosis, pediatric immune myelofibrosis, idiopathic myelofibrosis. Pediatric Immune Myelofibrosis was the predominant subgroup in our cohort (7/14). Pediatric Immune Myelofibrosis is characterized by peculiar bone marrow features (i.e., T lymphocyte infiltration) and a milder course compared to the other patients Pediatric Immune Myelofibrosis is a novel and distinct pathological entity. We suggest to carefully consider Pediatric Immune Myelofibrosis in case of bone marrow biopsies showing myelofibrosis that do not fulfill WHO criteria.

Haplo-identical or mismatched unrelated donor hematopoietic cell transplantation for Fanconi anemia: Results from the Severe Aplastic Anemia Working Party of the EBMT.

Allogeneic hematopoietic cell transplantation (HCT) is the only curative option for bone marrow failure or hematopoietic malignant diseases for Fanconi anemia (FA) patients. Although results have improved over the last decades, reaching more than 90% survival when a human leukocyte antigen (HLA)-identical donor is available, alternative HCT donors are still less reported. We compared HCT outcomes using HLA-mismatched unrelated donors (MMUD; n = 123) or haplo-identical donors (HDs), either using only in vivo T cell depletion (n = 33) or T cells depleted in vivo with some type of graft manipulation ex vivo (n = 59) performed for FA between 2000 and 2018. Overall survival (OS) by 24 months was 62% (53-71%) for MMUD, versus 80% (66-95%) for HDs with only in vivo T cell depletion and 60% (47-73%) for HDs with in vivo and ex vivo T cell depletion (p = .22). Event-free survival (EFS) was better for HD-transplanted FA patients with only in vivo T cell depletion 86% (73-99%) than for those transplanted from a MMUD 58% (48-68%) or those with graft manipulation 56% (42-69%) (p = .046). Grade II-IV acute graft-versus-host disease (GVHD) was 41% (MMUD) versus 40% (HDs with no graft manipulation) versus 17% (HDs with T cell depleted graft), (p = .005). No differences were found for the other transplant related outcomes. These data suggest that HDs might be considered as an alternative option for FA patients with better EFS using unmanipulated grafts.

A 20-year long term experience of the Italian Diamond-Blackfan Anaemia Registry: RPS and RPL genes, different faces of the same disease?

Diamond-Blackfan anaemia (DBA) is a rare and heterogeneous disease characterised by hypoplastic anaemia, congenital anomalies and a predisposition for malignancies. The aim of this paper is to report the findings from the Italian DBA Registry, and to discuss the Registry's future challenges in tackling this disease. Our 20-year long work allowed the connection of 50 Italian Association of Paediatric Haematology and Oncology (AIEOP) centres and the recruitment of 283 cases. Almost all patients have been characterised at a molecular level (96%, 271/283), finding a causative mutation in 68% (184/271). We confirm the importance of determination of erythrocyte adenosine deaminase activity (eADA) and of ribosomal RNA assay in the diagnostic pipeline and characterisation of a remission state. Patients with mutations in large ribosomal subunit protein (RPL) genes had a significant correlation with the incidence of malformations, higher eADA levels and more severe outcomes, compared to patients with mutations in small ribosomal subunit protein (RPS) genes. Furthermore, as a consequence of our findings, particularly the incidence of malignancies and the high percentage of patients aged >18 years, we stress the importance of collaboration with adult clinicians to guarantee regular multi-specialist follow-up. In conclusion, this study highlights the importance of national registries to increase our understanding and improve management of this complex disease.

A Prospective Study of Hematologic Complications and Long-Term Survival of Italian Patients Affected by Shwachman-Diamond Syndrome.

OBJECTIVE: To describe the hematologic outcome and long-term survival of patients enrolled in the Shwachman-Diamond syndrome Italian Registry. STUDY DESIGN: A retrospective and prospective study of patients recorded in the Shwachman-Diamond syndrome Italian Registry. RESULTS: The study population included 121 patients, 69 males and 52 females, diagnosed between 1999 and 2018. All patients had the clinical diagnosis confirmed by mutational analysis on the SBDS gene. During the study period, the incidence of SDS was 1 in 153 000 births. The median age of patients with SDS at diagnosis was 1.3 years (range, 0-35.6 years). At the first hematologic assessment, severe neutropenia was present in 25.8%, thrombocytopenia in 25.5%, and anemia in 4.6% of patients. A normal karyotype was found in 40 of 79 patients, assessed whereas the most frequent cytogenetic abnormalities were isochromosome 7 and interstitial deletion of the long arm of chromosome 20. The cumulative incidence of severe neutropenia, thrombocytopenia, and anemia at 30 years of age were 59.9%, 66.8%, and 20.2%, respectively. The 20-year cumulative incidence of myelodysplastic syndrome/leukemia and of bone marrow failure/severe cytopenia was 9.8% and 9.9%, respectively. Fifteen of 121 patients (12.4%) underwent allogeneic stem cell transplantation. Fifteen patients (12.4%) died; the probability of overall survival at 10 and 20 years was 95.7% and 87.4%, respectively. CONCLUSIONS: Despite an improvement in survival, hematologic complications still cause death in patients with SDS. Further studies are needed to optimize type and modality of hematopoietic stem cell transplantation and to assess the long-term outcome in nontransplanted patients.

Monitoring oral iron therapy in children with iron deficiency anemia: an observational, prospective, multicenter study of AIEOP patients (Associazione Italiana Emato-Oncologia Pediatrica).

Oral ferrous salts are standard treatment for children with iron deficiency anemia (IDA). The objective of our study was to monitor oral iron therapy in children, aged 3 months-12 years, with IDA. We prospectively collected clinical and hematological data of children with IDA, from 15 AIEOP (Associazione Italiana di Ematologia ed. Oncologia Pediatrica) centers. Response was measured by the increase of Hb from baseline. Of the 107 analyzed patients, 18 received ferrous gluconate/sulfate 2 mg/kg (ferrous 2), 7 ferrous gluconate/sulfate 4 mg/kg (ferrous 4), 7 ferric iron salts 2 mg/kg (ferric), 62 bis-glycinate iron 0.45 mg/kg (glycinate), and 13 liposomal iron 0.7-1.4 mg/kg (liposomal). Increase in reticulocytes was evident at 3 days, while Hb increase appeared at 2 weeks. Gain of Hb at 2 and 8 weeks revealed a higher median increase in both ferrous 2 and ferrous 4 groups. Gastro-intestinal side effects were reported in 16% (ferrous 2), 14% (ferrous 4), 6% (glycinate), and 0 (ferric and liposomal) patients. The reticulocyte counts significantly increased after 3 days from the start of oral iron supplementation. Bis-glycinate iron formulation had a good efficacy/safety profile and offers an acceptable alternative to ferrous iron preparations.

Rituximab Unveils Hypogammaglobulinemia and Immunodeficiency in Children with Autoimmune Cytopenia.

BACKGROUND: Rituximab (RTX; anti-CD20 mAb) is a treatment option in children with refractory immune thrombocytopenia, autoimmune hemolytic anemia (AHA), and Evans syndrome (ES). Prevalence and clinical course of RTX-induced hypogammaglobulinemia in these patients are poorly known. OBJECTIVE: To evaluate the prevalence and risk factors for persistent hypogammaglobulinemia (PH) after RTX use. METHODS: Clinical and immunologic data from children treated with RTX for immune thrombocytopenia, AHA, and ES were collected from 16 Italian centers and 1 UK center at pre-RTX time point (0), +6 months, and yearly, up to 4 years post-RTX. Patients with previously diagnosed malignancy or primary immune deficiency (PID) were excluded. RESULTS: We analyzed 53 children treated with RTX for immune thrombocytopenia (n = 36), AHA (n = 13), and ES (n = 4). Median follow-up was 30 months (range, 12-48). Thirty-two percent of patients (17 of 53) experienced PH, defined as IgG levels less than 2 SD for age at last follow-up (>12 months after RTX). Significantly delayed B-cell recovery was observed in children experiencing PH (hazard ratio, 0.55; P < .05), and 6 of 17 (35%) patients had unresolved B-cell lymphopenia at last follow-up. PH was associated with IgA and IgM deficiency, younger age at RTX use (51 vs 116 months; P < .01), a diagnosis of AHA/ES, and better response to RTX. Nine patients with PH (9 of 17 [53%]) were eventually diagnosed with a PID. CONCLUSIONS: Post-RTX PH is a frequent condition in children with autoimmune cytopenia; a sizable proportion of patients with post-RTX PH were eventually diagnosed with a PID. In-depth investigation for PID is therefore recommended in these patients.

Nitrite Improves Heart Regeneration in Zebrafish.

Aims: Nitrite is reduced to nitric oxide (NO) under physiological and pathological hypoxic conditions to modulate angiogenesis and improve ischemia-reperfusion injury. Although adult mammals lack the ability to regenerate the heart after injury, this is preserved in neonates and efforts to reactivate this process are of great interest. Unlike mammals, the adult zebrafish maintain the innate ability to regenerate their hearts after injury, providing an important model to study cardiac regeneration. We thus explored the effects of physiological levels of nitrite on cardiac and fin regeneration and downstream cellular and molecular signaling pathways in response to amputation and cryoinjury. Results: Nitrite treatment of zebrafish after ventricular amputation or cryoinjury to the heart in hypoxic water (∼3 parts per million of oxygen) increases cardiomyocyte proliferation, improves angiogenesis, and enhances early recruitment of thrombocytes, macrophages, and neutrophils to the injury. When tested in a fin regeneration model, neutrophil recruitment to the injury site was found to be dependent on NO. Innovation: This is the first study to evaluate effects of physiological levels of nitrite on cardiac regeneration in response to cardiac injury, with the observation that nitrite in water accelerates zebrafish heart regeneration. Conclusion: Physiological and therapeutic levels of nitrite increase thrombocyte, neutrophil, and macrophage recruitment to the heart after amputation and cryoinjury in zebrafish, resulting in accelerated cardiomyocyte proliferation and angiogenesis. Translation of this finding to mammalian models of injury during early development may provide an opportunity to improve outcomes during intrauterine fetal or neonatal cardiac surgery.

Results of a multicenter universal newborn screening program for sickle cell disease in Italy: A call to action.

BACKGROUND: Sickle cell disease (SCD) is a chronic multisystem disorder requiring comprehensive care that includes newborn screening (NBS) as the first step of care. Italy still lacks a national SCD NBS program and policy on blood disorders. Pilot single-center screening programs and a regional targeted screening have been implemented so far, but more evidence is needed in order to impact health policies. POPULATION AND METHODS: NBS was offered to parents of newborns in gynecology clinics in Padova and Monza, tertiary care university hospitals in northern Italy. High-performance liquid chromatography (HPLC) was performed as the first test on samples collected on Guthrie cards. Molecular analysis of the beta-globin gene was performed on positive samples. RESULTS: A total of 5466 newborns were enrolled; for 5439, informed consents were obtained. A similar family origin was seen in the two centers (65% Italians, 9% mixed couples, 26% immigrants). Compared with SCD NBS programs in the United States and Europe, our results show a similar incidence of SCD patients and carriers. All SCD patients had a Sub-Saharan family background; HbS carriers were 15% Caucasians (Italian, Albanians) and 10% from other areas (North Africa-India-South America); carriers of other hemoglobin variants were mainly (47%) from other areas. CONCLUSIONS: Our results demonstrate the feasibility of a multicentric NBS program for SCD, give information on HbS epidemiology in two Northern Italian Areas, and support previous European recommendation for a universal NBS program for SCD in Italy: a high incidence of patients and carriers has been detected, with a high percentage of Caucasian carriers, impossible to identify in a targeted NBS.

Heterozygous Mutation in Adenosine Deaminase Gene in a Patient With Severe Lymphopenia Following Corticosteroid Treatment of Autoimmune Hemolytic Anemia.

We describe a previously healthy 14-year-old girl with acute onset autoimmune hemolytic anemia, associated with severe but transient lymphopenia during corticosteroid therapy, without infectious episodes during follow-up. After detailed investigations to rule out an underlying immunodeficiency, we detected a heterozygous ADA gene mutation. This was associated with slightly increased blood levels of adenosine and deoxyadenosine nucleotides and with reduced ADA activity in red blood cells, but within the normal range. This observation suggests that heterozygous ADA mutation might be a predisposing factor for lymphopenia in patients receiving corticosteroid therapy.

Mesenchymal stromal cells from Shwachman-Diamond syndrome patients fail to recreate a bone marrow niche in vivo and exhibit impaired angiogenesis.

Shwachman-Diamond syndrome (SDS) is a rare multi-organ recessive disease mainly characterised by pancreatic insufficiency, skeletal defects, short stature and bone marrow failure (BMF). As in many other BMF syndromes, SDS patients are predisposed to develop a number of haematopoietic malignancies, particularly myelodysplastic syndrome and acute myeloid leukaemia. However, the mechanism of cancer predisposition in SDS patients is only partially understood. In light of the emerging role of mesenchymal stromal cells (MSCs) in the regulation of bone marrow homeostasis, we assessed the ability of MSCs derived from SDS patients (SDS-MSCs) to recreate a functional bone marrow niche, taking advantage of a murine heterotopic MSC transplant model. We show that the ability of semi-cartilaginous pellets (SCPs) derived from SDS-MSCs to generate complete heterotopic ossicles in vivo is severely impaired in comparison with HD-MSC-derived SCPs. Specifically, after in vitro angiogenic stimuli, SDS-MSCs showed a defective ability to form correct networks, capillary tubes and vessels and displayed a marked decrease in VEGFA expression. Altogether, these findings unveil a novel mechanism of SDS-mediated haematopoietic dysfunction based on hampered ability of SDS-MSCs to support angiogenesis. Overall, MSCs could represent a new appealing therapeutic target to treat dysfunctional haematopoiesis in paediatric SDS patients.

Hydroxyurea prescription, availability and use for children with sickle cell disease in Italy: Results of a National Multicenter survey.

BACKGROUND: The number of patients with sickle cell disease (SCD) has increased in Italy in the past decade due to immigration. In spite of the established efficacy of hydroxyurea (HU) in childhood, population-based data regarding its prescription and effectiveness come mainly from studies performed in adults or outside Europe. POPULATION AND METHODS: The Hydroxyurea in SCD: A Large Nation-wide Cohort Study from Italy was a retrospective cohort study of adult and pediatric patients with SCD attending 32 centers. Pediatric data are analyzed separately. RESULTS: Out of 504 children followed in 11 centers, 206 (40%) were on HU (194 SS/Sß°, 12 SC/Sß+); 74% came from Sub-Saharian Africa and 18% from Europe. HU therapy indications for SS/Sß° patients were as follows: 57% painful vaso-occlusive crisis, acute chest syndrome or both, 24% anemia, 8% anemia, and other reasons (the majority had Hb ≤ 8-8.5 g/dl, revealing scarce acceptance of low Hb values by pediatric hematologist). Mean starting dose was 15.5 mg/kg, and dose at full regimen was 17.1 mg/kg. Mean age at HU therapy was 7.68 years, although it was lower for SS/Sß° patients. Only 10% started HU before 3 years. In 92%, 500 mg capsule was used; in 6%, the galenic was used; and in 2%, 100 mg tablet was used. Significant reduction of clinical events and inpatients admissions, with improvement in hematological parameters, was observed for SS/Sß° patients and a trend toward improvement for SC/Sß+ patients was also observed. CONCLUSIONS: HU effectiveness is demonstrated in a national cohort of children with SCD living in Italy, even at a lower dose than recommended, revealing good adherence to a treatment program by a socially vulnerable group of patients such as immigrants.

A retrospective study of paroxysmal nocturnal hemoglobinuria in pediatric and adolescent patients.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disease, especially in children, characterized by intravascular hemolysis, thrombotic events, serious infections and bone marrow failure. We describe 16 patients who were diagnosed with PNH in childhood or adolescence. The time interval between the onset of symptoms and the PNH diagnosis and its treatment were compared in patients with classic PNH versus PNH associated with bone marrow disorder (PNH/BMD). A greater delay in diagnosis was observed in classic PNH compared to PNH/BMD patients. The first group of patients had higher levels of LDH, total bilirubin and absolute reticulocyte count and a bigger PNH clone size compared to PNH/BMD patients; also thrombotic events were observed only in the classic form of PNH. Conversely, PNH/BMD patients showed lower median levels of platelets. Apart from standard supportive measures, four patients with classic PNH received eculizumab whereas four patients with PNH/BMD underwent hematopoietic stem cell transplantation. Our series confirm that the most frequent presentation of PNH in the pediatric-adolescent age is PNH/BMD. The delay between the onset of symptoms and PNH diagnosis is relevant principally in the classic form. Moreover, our study showed that any case of unexpected thrombosis represents a criterium to perform a PNH screening.