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Background: Empirical antibacterial therapy for febrile neutropenia reduces mortality due to Gram-negative blood stream infections (BSIs). Pediatric guidelines recommend monotherapy with an antipseudomonal beta-lactam or a carbapenem and to add a second anti-Gram-negative agent in selected situations. We evaluated the changes in the proportions of resistance of beta-lactam monotherapies vs. their combination with amikacin, and the possible impact on ICU admission or death. Results: 797 BSIs due to Gram-negative bacteria in 685 patients were included. Combination therapies with amikacin had a lower percentage of isolates resistant to one or to both drugs compared with the respective monotherapy. The highest OR for ICU admission was observed when both drugs of the combination of meropenem–amikacin were resistant. Mortality was significantly associated with relapse or the progression of the underlying malignancy, and resistance to both drugs of the combinations of cefepime–amikacin or meropenem–amikacin. Methods: This study was based on data collected for a large multinational study, in which the susceptibility of Gram-negative bloodstream isolates was categorized following either EUCAST or CLSI according to local laboratory standards. An escalation antibiogram was generated for each selected drug. For resistant bacteria, the conditional susceptibility probability on resistance was calculated. Conclusions: In pediatric cancer patients with Gram-negative BSIs, the proportion of the resistant organism correlates with ICU admission or death, which may be reduced by combination therapy. In patients with suspected or confirmed Gram-negative BSIs that are not-improving or deteriorating under monotherapy, escalation to meropenem may represent the best option. Amikacin should be preferred when combination therapy is considered with ciprofloxacin as an alternative in the case of impaired renal function. [ABSTRACT FROM AUTHOR]

Emergency repair of type II thoracoabdominal aortic aneurysms is burdened by high perioperative morbidity and mortality. We report the case of a symptomatic type II post-dissection thoracoabdominal aortic aneurysm that was treated using a hybrid technique. The repair was carried out in 2 stages. In the first stage, we deployed 2 imbricated stent grafts in the descending thoracic aorta. A left carotid-to-left subclavian artery bypass was pre-emptively performed to obtain a proper proximal landing zone and as part of the manoeuvres to protect the spinal cord. The endovascular first stage was effective in obtaining proximal sealing but, as expected, it did not prevent distal reperfusion of the aneurysmatic false lumen. A few hours later, we moved on to the second stage in which we repaired the aneurysmal distal thoracic and abdominal aortic segment by means of a multibranched synthetic graft. The repair was carried out through a left thoracophreno-laparotomy in the seventh intercostal space. A left passive arterial bypass and selective cold renal and warm visceral perfusion were adopted to provide organ protection. Technical success was achieved and confirmed radiologically. The patient experienced mild postoperative paraplegia, which almost completely regressed after a neuromotor rehabilitation program. [ABSTRACT FROM AUTHOR]

Noonan syndrome (NS) is an autosomal dominant disorder that varies in severity and can involve multiple organ systems. In approximately 50% of cases, it is caused by missense mutations in the PTPN11 gene (12q24.13). NS is associated with a higher risk of cancer occurrence, specifically hematological disorders. Here, we report a case of a child who was diagnosed at birth with a transient myeloproliferative disorder (TMD). After two years, the child developed hyperdiploid B-cell precursor acute lymphoblastic leukemia (BCP-ALL), receiving a two-year course of treatment. During her continuous complete remission (CCR), a heterozygous germline mutation in the PTPN11 gene [c.218 C>T (p.Thr73lle)] was identified. At the age of ten, the child presented with massive splenomegaly, hyperleukocytosis, and thrombocytopenia, resulting in the diagnosis of juvenile myelomonocytic leukemia (JMML). After an initial response to antimetabolite therapy (6-mercaptopurine), she underwent haploidentical hematopoietic stem cell transplantation (HSCT) and is currently in complete remission. The goal of this review is to gain insight into the various hematological diseases associated with NS, starting from our unique case. [ABSTRACT FROM AUTHOR]

Summary: Thrombocytopenia 4 (THC4) is an autosomal‐dominant thrombocytopenia caused by mutations in CYCS, the gene encoding cytochrome c (CYCS), a small haeme protein essential for electron transport in mitochondria and cell apoptosis. THC4 is considered an extremely rare condition since only a few patients have been reported so far. These subjects presented mild thrombocytopenia and no or mild bleeding tendency. In this study, we describe six Italian families with five different heterozygous missense CYCS variants: p.Gly42Ser and p.Tyr49His previously associated with THC4, and three novel variants (p.Ala52Thr, p.Arg92Gly, and p.Leu99Val), which have been classified as pathogenic by bioinformatics and segregation analyses. Moreover, we supported functional effects of p.Ala52Thr and p.Arg92Gly on oxidative growth and respiratory activity in a yeast model. The clinical characterization of the 22 affected individuals, the largest series of THC4 patients ever reported, showed that this disorder is characterized by mild‐to‐moderate thrombocytopenia, normal platelet size, and function, low risk of bleeding, and no additional clinical phenotypes associated with reduced platelet count. Finally, we describe a significant correlation between the region of CYCS affected by mutations and the extent of thrombocytopenia, which could reflect different degrees of impairment of CYCS functions caused by different pathogenetic variants. [ABSTRACT FROM AUTHOR]

Introduction: Autoimmune cytopenias (AICs) are a group of disorders characterized by immune-mediated destruction of blood cells. In children, they are often secondary to immune dysregulation that may require long-lasting immunosuppression. Mycophenolate mofetil and sirolimus represent two welltolerated options to treat these disorders, often as a steroid-sparing option. However, no data are available on the infection risk for patients undergoing longlasting treatments. Patients and methods: The rate of severe infective events was calculated in episodes per 100 persons/months at risk (p/m/r) documented by the analysis of hospitalization charts between January 2015 and July 2023 of patients treated with mycophenolate mofetil or sirolimus given for isolated AIC or AICs associated with autoimmune lymphoproliferative syndrome (ALPS)/ALPS-like syndromes in two large Italian pediatric hematology units. Results: From January 2015 to July 2023, 13 out of 96 patients treated with mycophenolate mofetil or sirolimus developed 16 severe infectious events requiring hospitalization. No patients died. Overall infection rate was 0.24 person/*100 months/risk (95% CI 0.09-0.3). Serious infectious events incidence was higher in patients with ALPS-like compared to others (0.42 versus 0.09; p = 0.006) and lower in patients who underwent mycophenolate treatment alone compared to those who started sirolimus after mycophenolate failure (0.04 versus 0.29, p = 0.03). Considering only patients who started treatment at the beginning of study period, overall cumulative hazard was 18.6% at 60 months (95% CI 3.4-31.4) with higher risk of infectious events after 5 years in ALPS-like patients (26.1%; 95% CI 3.2-43.5) compared to other AICs (4%; 95% CI 0-11.4; p = 0.041). Discussion: To the best of our knowledge, this is the first study to describe the infectious risk related to mycophenolate and sirolimus chronic treatment in patients with AICs and immune dysregulation. Our data highlight that infection rate is very low and mainly related to the underlying hematological condition. Conclusions: Mycophenolate and sirolimus represent a safe immunosuppressive therapy in AICs and immune dysregulation syndromes. [ABSTRACT FROM AUTHOR]

Summary: 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. [ABSTRACT FROM AUTHOR]

Immune thrombocytopenia (ITP) is the most common acquired bleeding disorder. In both children and adults, the primary goal of any therapeutic approach consists of cessation of bleeding and its prevention. Several options are currently available for first-line therapy in Europe, including corticosteroids and intravenous immunoglobulin (IVIg) infusion, which has a similar efficacy and safety profile in both the pediatric and adult populations. When second-line therapy is needed in the pediatric setting, current guidelines recommend eltrombopag as the drug of choice. The aim of this article is to summarize the available evidence and present real-life experience on eltrombopag as second-line therapy in pediatric patients with ITP, with a focus on dosing and response to therapy as well as its tapering and discontinuation. In our setting, eltrombopag is associated with good safety profile as well as promising efficacy; dose de-escalation was feasible in 94% of cases and often reached very low pro/kg dosage, with full discontinuation in 15% of cases. In daily practice, a standardized approach for discontinuation of eltrombopag in pediatric patients with ITP is still lacking. Herein, an easy-to-use scheme for tapering and discontinuation in candidate pediatric patients is proposed that proposes 25% dose reduction every four weeks. In future management of pediatric ITP patients, it will be crucial to assess if thrombopoietin receptor agonists might be more effective in earlier phases of the disease and can modify the course of the disease. [ABSTRACT FROM AUTHOR]