Results of a long-term, prospective study on complications of central venous catheter in pediatric patients with hematologic-oncologic diseases.

BACKGROUND: Central venous catheter (CVC)-related complications remain a significant cause of morbidity in pediatric hematology-oncology. We prospectively surveyed the incidence of CVC-related complications in children with hematologic-oncologic diseases. PROCEDURE: Five-hundred-eighty-one CVCs were inserted in 421 patients from January 2010 to June 2022 (153,731 CVC days observation; follow-up data up to December 31, 2022). RESULTS: Overall, 671 complications were recorded (4.365/1000 CVC days): 49.7% malfunctions (1.88/1000 CVC days, 4.8% of CVC early removals), 23.9% bacteremia (0.90/1000, 15.1%), 19.6% mechanical complications (0.74/1000, 70.2%), 20.1% localized infections (0.76/1000, 17.1%), 0.5% thrombosis (0.02/1000, 33.3%). At multivariate analysis, risk factors for malfunction were Broviac-Hickman type of CVC (hazard ratio [HR] 2.5) or Port-a-cath (HR 3.4) or Proline (HR 4.3), p < .0001; for bacteremia double-lumen CVC (HR 3.2, p < .0001); for mechanical complications age at CVC insertion under median (HR 4.5, p < .0001) and Broviac-Hickman (HR 1.6) or Proline (HR 2.7), p = .01; finally for localized infections Broviac-Hickman (HR 2.9) or Proline (HR 4.4), p = .0001. The 2-year cumulative incidence of premature removal was 23.5%, and risk factors were age at CVC insertion under median (HR 2.4, p < .0001), Broviac-Hickman (HR 2.3) or Proline (HR 4.2), p < .0001. CONCLUSIONS: Premature removal occurs in approximately 20%-25% of long-term CVCs. A surveillance program has a fundamental role in identifying the risk factors for CVC complications and the areas of intervention to improve CVC management.

Letermovir for Cytomegalovirus infection in pediatric patients undergoing allogenic hematopoietic stem cell transplantation: a real-life study by the Infectious Diseases Working Group of Italian Association of Pediatric Hematology-Oncology (AIEOP).

Letermovir prophylaxis revolutionized the approach to Cytomegalovirus infection in adult hematopoietic stem cell transplant (HCT), while data in pediatric setting are still lacking. We retrospectively analyzed 87 HCT children transplanted in 11 AIEOP centers receiving letermovir as off-label indication between January 2020 and November 2022. Letermovir was used as primary, secondary prophylaxis or CMV treatment in 39, 26 and 22 cases, respectively; no discontinuation due to toxicity was reported. Median duration was 100 days (14-256) for primary and 96 days (8-271) for secondary prophylaxis, respectively. None of the patients experienced CMV-clinically significant reactivation during Letermovir primary prophylaxis; one patient developed breakthrough infection during secondary prophylaxis, and 10 and 1 patient experienced asymptomatic CMV-reactivation and CMV-primary infection after drug discontinuation, respectively. Median duration of letermovir in CMV treatment was 40 days (7-134), with 4/22 patients suffering CMV-pneumonia, with an overall response rate of 86.4%. With a median follow-up of 10.7 months (8.2-11.8), estimated 1-year overall survival was 86%; no CMV-related deaths were reported in prophylaxis groups. This is the largest report on Letermovir use in pediatric HCT; real-life data confirm an excellent toxicity profile, with high efficacy as CMV prophylaxis; results in CMV-infection treatment should be investigated in larger, prospective trials.

Gα15 in early onset of pancreatic ductal adenocarcinoma.

The GNA15 gene is ectopically expressed in human pancreatic ductal adenocarcinoma cancer cells. The encoded Gα15 protein can promiscuously redirect GPCR signaling toward pathways with oncogenic potential. We sought to describe the distribution of GNA15 in adenocarcinoma from human pancreatic specimens and to analyze the mechanism driving abnormal expression and the consequences on signaling and clinical follow-up. We detected GNA15 expression in pre-neoplastic pancreatic lesions and throughout progression. The analysis of biological data sets, primary and xenografted human tumor samples, and clinical follow-up shows that elevated expression is associated with poor prognosis for GNA15, but not any other GNA gene. Demethylation of the 5' GNA15 promoter region was associated with ectopic expression of Gα15 in pancreatic neoplastic cells, but not in adjacent dysplastic or non-transformed tissue. Down-modulation of Gα15 by shRNA or CRISPR/Cas9 affected oncogenic signaling, and reduced adenocarcimoma cell motility and invasiveness. We conclude that de novo expression of wild-type GNA15 characterizes transformed pancreatic cells. The methylation pattern of GNA15 changes in preneoplastic lesions coincident with the release a transcriptional blockade that allows ectopic expression to persist throughout PDAC progression. Elevated GNA15 mRNA correlates with poor prognosis. In addition, ectopic Gα15 signaling provides an unprecedented mechanism in the early steps of pancreas carcinogenesis distinct from classical G protein oncogenic mutations described previously in GNAS and GNAQ/GNA11.

mTOR and STAT3 Pathway Hyper-Activation is Associated with Elevated Interleukin-6 Levels in Patients with Shwachman-Diamond Syndrome: Further Evidence of Lymphoid Lineage Impairment.

Shwachman-Diamond syndrome (SDS) is a rare inherited bone marrow failure syndrome, resulting in neutropenia and a risk of myeloid neoplasia. A mutation in a ribosome maturation factor accounts for almost all of the cases. Lymphoid involvement in SDS has not been well characterized. We recently reported that lymphocyte subpopulations are reduced in SDS patients. We have also shown that the mTOR-STAT3 pathway is hyper-activated in SDS myeloid cell populations. Here we show that mTOR-STAT3 signaling is markedly upregulated in the lymphoid compartment of SDS patients. Furthermore, our data reveal elevated IL-6 levels in cellular supernatants obtained from lymphoblasts, bone marrow mononuclear and mesenchymal stromal cells, and plasma samples obtained from a cohort of 10 patients. Of note, everolimus-mediated inhibition of mTOR signaling is associated with basal state of phosphorylated STAT3. Finally, inhibition of mTOR-STAT3 pathway activation leads to normalization of IL-6 expression in SDS cells. Altogether, our data strengthen the hypothesis that SDS affects both lymphoid and myeloid blood compartment and suggest everolimus as a potential therapeutic agent to reduce excessive mTOR-STAT3 activation in SDS.

Endothelin-1 receptor blockade as new possible therapeutic approach in multiple myeloma.

New effective treatments are needed to improve outcomes for multiple myeloma (MM) patients. Receptors with restricted expression on plasma cells (PCs) represent attractive new therapeutic targets. The endothelin-1 (EDN1) axis, consisting of EDN1 acting through EDN-receptor A (EDNRA) and B (EDNRB), was previously shown to be overexpressed in several tumours, including MM. However, there is incomplete understanding of how EDN1 axis regulates MM growth and response to therapy. Besides EDNRA, the majority of MM cell lines and primary malignant PCs express high levels of EDNRB and release EDN1. Similarly, bone-marrow microenvironment cells also secrete EDN1. Investigating the extent of epigenetic dysregulation of EDNRB gene in MM, we found that hypermethylation of EDNRB promoter and subsequent down-regulation of EDNRB gene was observed in PCs or B lymphocytes from healthy donors compared to EDNRB-expressing malignant PCs. Pharmacological blockade with the dual EDN1 receptor antagonist bosentan decreased cell viability and MAPK activation of U266 and RPMI-8226 cells. Interestingly, the combination of bosentan and the proteasome inhibitor bortezomib, currently approved for MM treatment, resulted in synergistic cytotoxic effects. Overall, our data has uncovered EDN1-mediated autocrine and paracrine mechanisms that regulate malignant PCs growth and drug response, and support EDN1 receptors as new therapeutic targets in MM.

Antiplatelet Agents Inhibit the Generation of Platelet-Derived Microparticles.

Platelet microparticles (PMPs) contribute to thrombogenesis but the effects of antiplatelet drugs on PMPs generation is undefined. The present study investigated the cellular events regulating PMPs shedding, testing in vitro platelet agonists and inhibitors. Platelet-rich plasma from healthy subjects was stimulated with arachidonic acid (AA), U46619, collagen type-I (10 and 1.5 µg/mL), epinephrine, ADP or TRAP-6 and pre-incubated with acetylsalicylic acid (ASA, 100 and 10 µmol/L), SQ-29,548, apyrase, PSB-0739, or eptifibatide. PMPs were detected by flow-cytometry using CD61 and annexin-V as fluorescent markers. Platelet agonists induced annexin V-positive PMPs shedding. The strongest response was to high concentration collagen. ADP-triggered PMPs shedding was dose-independent. ASA reduced PMPs induced by AA- (645, 347-2946 vs. 3061, 446-4901 PMPs/µL; median ad range, n = 9, P < 0.001), collagen 10 µg/mL (5317, 2027-15935 vs. 10252, 4187-46316 PMPs/µL; n = 13, P < 0.001), collagen 1.5 µg/mL (1078, 528-2820 vs. 1465, 582-5948 PMPs/µL; n = 21, P < 0.001) and TRAP-6 (2008, 1621-2495 vs. 2840, 2404-3031 PMPs/µL; n = 3, P < 0.01) but did not affect the response to epinephrine or ADP. The ADP scavenger apyrase reduced PMPs induced by U46619 (1256, 395-2908 vs. 3045, 1119-5494 PMPs/µL, n = 6, P < 0.05), collagen 1.5 µg/mL (1006, 780-1309 vs. 2422, 1839-3494 PMPs/µL, n = 3, P < 0.01) and TRAP-6 (904, 761-1224 vs. 2840, 2404-3031 PMPs/µL, n = 3, P < 0.01). The TP receptor antagonist SQ-29,548 and the P2Y12 receptor antagonist PSB-0739 markedly inhibited PMPs induced by low doses of collagen. Except for high-dose collagen, eptifibatide abolished agonist-induced PMPs release. Both TXA2 generation and ADP secretion are required as amplifiers of PMP shedding. The crucial role of the fibrinogen receptor and the collagen receptor in PMPs generation, independently of platelet aggregation, was identified.

Role of calcium desensitization in the treatment of myocardial dysfunction after deep hypothermic circulatory arrest.

INTRODUCTION: Rewarming from deep hypothermic circulatory arrest (DHCA) produces calcium desensitization by troponin I (cTnI) phosphorylation which results in myocardial dysfunction. This study investigated the acute overall hemodynamic and metabolic effects of epinephrine and levosimendan, a calcium sensitizer, on myocardial function after rewarming from DHCA. METHODS: Forty male Wistar rats (400 to 500 g) underwent cardiopulmonary bypass (CPB) through central cannulation and were cooled to a core temperature of 13°C to 15°C within 30 minutes. After DHCA (20 minutes) and CPB-assisted rewarming (60 minutes) rats were randomly assigned to 60 minute intravenous infusion with levosimendan (0.2 µg/kg/min; n = 15), epinephrine (0.1 µg/kg/min; n = 15) or saline (control; n = 10). Systolic and diastolic functions were evaluated at different preloads with a conductance catheter. RESULTS: The slope of left ventricular end-systolic pressure volume relationship (Ees) and preload recruitable stroke work (PRSW) recovered significantly better with levosimendan compared to epinephrine (Ees: 85 ± 9% vs 51 ± 11%, P<0.003 and PRSW: 78 ± 5% vs 48 ± 8%, P<0.005; baseline: 100%). Levosimendan but not epinephrine reduced left ventricular stiffness shown by the end-diastolic pressure-volume relationship and improved ventricular relaxation (Tau). Levosimendan preserved ATP myocardial content as well as energy charge and reduced plasma lactate concentrations. In normothermia experiments epinephrine in contrast to Levosimendan increased cTnI phosphorylation 3.5-fold. After rewarming from DHCA, cTnI phosphorylation increased 4.5-fold in the saline and epinephrine group compared to normothermia but remained unchanged with levosimendan. CONCLUSIONS: Levosimendan due to prevention of calcium desensitization by cTnI phosphorylation is more effective than epinephrine for treatment of myocardial dysfunction after rewarming from DHCA.

Cardioprotective effect of δ-opioid receptor agonist vs. mild therapeutic hypothermia in a rat model of cardiac arrest with extracorporeal life support.

BACKGROUND: To compare the effect of δ-opioid receptor agonist, d-Ala2-d-Leu5 enkephalin (DADLE) with normothermic control and therapeutic hypothermia on post resuscitation myocardial function in a model of extracorporeal life support (ECLS). METHODS: Ventricular fibrillation (VF) was induced in male Wistar rats. After 10 min of untreated VF, venoarterial ECLS was instituted for 60 min. At the beginning of ECLS animals were randomized to three groups of ten: normothermia, hypothermia (32 °C) and DADLE intravenous infusion (1 mg/kg/h). Cooling to 32 °C or normothermia or drug infusion lasted for the entire ECLS. Plasma samples and myocardial biopsies were obtained and left-ventricular (LV) function was assessed by a conductance catheter at baseline and after weaning from ECLS. RESULTS: DADLE administration resulted in a significantly enhanced recovery of LV systolic function expressed by slope of the LV end-systolic pressure volume relationship (Ees) and preload recruitable stroke work (PRSW) than hypothermia and normothermia. LV stiffness indicated by end-diastolic pressure volume relationship (EDPVR) was significantly lower after DADLE administration (P<0.01). LV relaxation described by Tau was preserved after DADLE treatment but not after normothermia or mild hypothermia (P<0.01). Plasma lactate concentrations were lower in DADLE group (P<0.05). DADLE and not conventional hypothermia significantly increased phosphorylation of the kinases ERK1 and 2 (3.9±0.3 and 3.1±0.5 vs. 0.4±0.1 and 0.3±0.1-fold of baseline levels) (P<0.001). Both DADLE and hypothermia but not normothermia increase phosphorylation of Akt. CONCLUSIONS: DADLE was more effective than mild therapeutic hypothermia in recovering myocardial function and activation of the pro-survival kinases Akt and ERK after ECLS.