Vemurafenib Treatment of Pleomorphic Xanthoastrocytoma in a Child With Down Syndrome

Brain tumors are the most common solid neoplasms of childhood, but they are very rarely reported in children with Down Syndrome (DS), who develop more commonly different types of malignancies. In particular, we hereby report the case of an 8-years-old child with DS that presented to our attention for neurological and endocrinological issues. Brain imaging revealed the presence of a mass that was partially resected revealing a histological diagnosis of Pleomorphic Xanthoastrocytoma (PXA), a rare WHO grade II tumor extending from the diencephalic region into the surrounding brain tissue. These tumors can harbor the BRAF mutation p.V600E, targetable by the specific inhibitor Vemurafenib. After confirming the presence of the mutation in the tumor, the patient was treated with Vemurafenib. The treatment proved to be effective, leading to a partial response and a stabilization of the disease. Usually, in patients with DS a reduction of the dose of chemotherapeutic drugs is necessary. Vemurafenib was instead well-tolerated as the only observed adverse effect was grade I skin toxicity. This is, to our knowledge, the first case of a PXA reported in a child with DS and the first DS patient treated with Vemurafenib

Highly specific memory B cells generation after the 2nd dose of BNT162b2 vaccine compensate for the decline of serum antibodies and absence of mucosal IgA

Specific memory B cells and antibodies are a reliable read-out of vaccine efficacy. We analysed these biomarkers after one and two doses of BNT162b2 vaccine. The second dose significantly increases the level of highly specific memory B cells and antibodies. Two months after the second dose, specific antibody levels decline, but highly specific memory B cells continue to increase, thus predicting a sustained protection from COVID-19. We show that although mucosal IgA is not induced by the vaccination, memory B cells migrate in response to inflammation and secrete IgA at mucosal sites. We show that the first vaccine dose may lead to an insufficient number of highly specific memory B cells and low concentration of serum antibodies, thus leaving vaccinees without the immune robustness needed to ensure viral elimination and herd immunity. We also clarify that the reduction of serum antibodies does not diminish the force and duration of the immune protection induced by vaccination. The vaccine does not induce sterilizing immunity. Infection after vaccination may be caused by the lack of local preventive immunity because of the absence of mucosal IgA

The clinical effectiveness of an integrated multidisciplinary evidence-based program to prevent intraoperative pressure injuries in high-risk children undergoing long-duration surgical procedures: a quality improvement study

The prevention of hospital-acquired pressure injuries (HAPIs) in children undergoing long-duration surgical procedures is of critical importance due to the potential for catastrophic sequelae of these generally preventable injuries for the child and their family. Long-duration surgical procedures in children have the potential to result in high rates of HAPI due to physiological factors and the difficulty or impossibility of repositioning these patients intraoperatively. We developed and implemented a multi-modal, multi-disciplinary translational HAPI prevention quality improvement program at a large European Paediatric University Teaching Hospital. The intervention comprised the establishment of wound prevention teams, modified HAPI risk assessment tools, specific education, and the use of prophylactic dressings and fluidized positioners during long-duration surgical procedures. As part of the evaluation of the effectiveness of the program in reducing intraoperative HAPI, we conducted a prospective cohort study of 200 children undergoing long-duration surgical procedures and compared their outcomes with a matched historical cohort of 200 children who had undergone similar surgery the previous year. The findings demonstrated a reduction in HAPI in the intervention cohort of 80% (p < 0.01) compared to the comparator group when controlling for age, pathology, comorbidity, and surgical duration. We believe that the findings demonstrate that it is possible to significantly decrease HAPI incidence in these highly vulnerable children by using an evidence-based, multi-modal, multidisciplinary HAPI prevention strategy

Mobilization of healthy donors with plerixafor affects the cellular composition of T-cell receptor (TCR)-αβ/CD19-depleted haploidentical stem cell grafts

Background: HLA-haploidentical hematopoietic stem cell transplantation (HSCT) is suitable for patients lacking related or unrelated HLA-matched donors. Herein, we investigated whether plerixafor (MZ), as an adjunct to G-CSF, facilitated the collection of mega-doses of hematopoietic stem cells (HSC) for TCR-αβ/CD19-depleted haploidentical HSCT, and how this agent affects the cellular graft composition. Methods: Ninety healthy donors were evaluated. Single-dose MZ was given to 30 ‘poor mobilizers’ (PM) failing to attain ≥40 CD34+ HSCs/μL after 4 daily G-CSF doses and/or with predicted apheresis yields ≤12.0x106 CD34+ cells/kg recipient’s body weight. Results: MZ significantly increased CD34+ counts in PM. Naïve/memory T and B cells, as well as natural killer (NK) cells, myeloid/plasmacytoid dendritic cells (DCs), were unchanged compared with baseline. MZ did not further promote the G-CSF-induced mobilization of CD16+ monocytes and the down-regulation of IFN-γ production by T cells. HSC grafts harvested after G-CSF + MZ were enriched in myeloid and plasmacytoid DCs, but contained low numbers of pro-inflammatory 6-sulfo-LacNAc+ (Slan)-DCs. Finally, children transplanted with G-CSF + MZ-mobilized grafts received greater numbers of monocytes, myeloid and plasmacytoid DCs, but lower numbers of NK cells, NK-like T cells and Slan-DCs. Conclusions: MZ facilitates the collection of mega-doses of CD34+ HSCs for haploidentical HSCT, while affecting graft composition

Use of Meropenem and Other Antimicrobial Lock Therapy in the Treatment of Catheter-Related Blood Stream Infections in Neonates: A Retrospective Study.

BACKGROUND: Newborns admitted to Neonatal Intensive Care Units (NICUs) often require the placement of central vascular catheters (CVC), which are a major risk factor for hospital infection. Numerous strategies exist to prevent central line-associated blood stream infections (CLABSIs) and catheter-related bloodstream infections (CRBSIs), with only a few offering options to save the catheter when it is impossible to replace. CRBSIs continue to be a major problem for neonates in NICUs. Most CRBSIs are resistant to systemic antibiotics due to the presence of intraluminal bacterial biofilm. Therefore, catheter removal is frequently necessary when a CRBSI occurs. The so-called Antibiotic Lock Therapy (ALT) is an antimicrobial therapeutic strategy which seems to be promising in neonates when catheter removal is difficult due to critical conditions. To date, evidence about the use of ALT in the neonatal period is still fragmentary, since only poor and heterogeneous data exist. METHODS: We report our successful experience with ALT in seriously ill neonates with CRBSI for whom the replacement of the catheter could have been life threatening. RESULTS: ALT repetitively performed for at least 12 h was effective in 11 out of 13 infants (84.6%). It was not effective in two infants in whom ALT was performed for only 6 h. Moreover, we present new data about the stability testing of meropenem for its use during ALT in neonates. CONCLUSIONS: When CRBSI occurs-bearing in mind that the optimal management is catheter removal if antibiotic therapy is not effective within 48 h-ALT seems to be a valid alternative therapy when removal is impractical due to critical conditions

High-Dose Micafungin for Preterm Neonates and Infants with Invasive and Central Nervous System Candidiasis

High doses of micafungin are advocated in neonates with systemic candidiasis but limited pharmacokinetic (PK) and safety data are available to support their use. Eighteen preterm neonates and infants with systemic candidiasis, 3 with meningitis, were treated for at least 14 days with 8 to 15 mg/kg/day of intravenous micafungin. Plasma concentrations (4 measurements) were determined after the third dose and cerebrospinal-fluid (CSF) concentrations were also obtained in three patients. Population PK analyses were used to identify the optimal model and further validated using external data (n=5). The safety of micafungin was assessed through liver and kidney function biomarkers. The mean (standard deviation) age and weight at administration was 2.33 (1.98) months and 3.24 (1.61) kg, respectively. The optimal PK model was one that scaled plasma clearance to weight and the transaminase ratio. The CSF was sampled in three patients with observed concentrations between 0.80-1.80 mg/L. The model predicted mean (SD) micafungin AUC24 values is 336 (165) h•mg/L with a 10 mg/kg/day dosage. Eighteen of the 23 subjects (78.2%) had clinical resolution of their infection but five had neurologic impairments. Among transaminases, alkaline phosphatase measurements were significantly higher post-treatment with a geometric mean ratio [90% confidence interval] of 1.17 [1.01, 1.37]. Furthermore, marked elevations in gamma-glutamyl transferase (GGT) was observed in three patients treated with 10-15 mg/kg/day doses and improvement in GGT was noted after dose reduction. Higher weight-based doses of micafungin are generally well tolerated in neonates and infants and achieve pharmacokinetic profiles predictive of effect

Preparation and In Vitro Evaluation of RITUXfab-Decorated Lipoplexes to Improve Delivery of siRNA Targeting C1858T PTPN22 Variant in B Lymphocytes

Autoimmune endocrine disorders, such as type 1 diabetes (T1D) and thyroiditis, at present are treated with only hormone replacement therapy. This emphasizes the need to identify personalized effective immunotherapeutic strategies targeting T and B lymphocytes. Among the genetic variants associated with several autoimmune disorders, the C1858T polymorphism of the protein tyrosine phosphatase non-receptor type 22 (PTPN22) gene, encoding for Lyp variant R620W, affects the innate and adaptive immunity. We previously exploited a novel personalized immunotherapeutic approach based on siRNA delivered by liposomes (lipoplexes) that selectively inhibit variant allele expression. In this manuscript, we improved lipoplexes carrying siRNA for variant C1858T by functionalizing them with Fab of Rituximab antibody (RituxFab-Lipoplex) to specifically target B lymphocytes in autoimmune conditions, such as T1D. RituxFab-Lipoplexes specifically bind to B lymphocytes of the human Raji cell line and of human PBMC of healthy donors. RituxFab-Lipoplexes have impact on the function of B lymphocytes of T1D patients upon CpG stimulation showing a higher inhibitory effect on total cell proliferation and IgM+ plasma cell differentiation than the not functionalized ones. These results might open new pathways of applicability of RituxFab-Lipoplexes, such as personalized immunotherapy, to other autoimmune disorders, where B lymphocytes are the prevalent pathogenic immunocytes

Safety of Monoclonal Antibodies in Children Affected by SARS-CoV-2 Infection

Monoclonal antibody therapies for COVID-19 have been frequently used in adults, whereas there are little data regarding the safety or efficacy of monoclonal antibody treatments in pediatric patients affected by COVID-19. We report our experience in the administration of mAb as a treatment for SARS-CoV-2 infection in children aged from 24 days to 18 years old

Impact of Continuous Kidney Replacement Therapy and Hemoadsorption with CytoSorb on Antimicrobial Drug Removal in Critically Ill Children with Septic Shock: A Single-Center Prospective Study on a Pediatric Cohort

Background: Extracorporeal therapies (ET) are increasingly used in pediatric settings as adjuvant therapeutic strategies for overwhelming inflammatory conditions. Although these treatments seem to be effective for removing inflammatory mediators, their influence on antimicrobials pharmacokinetic should not be neglected. Methods: A prospective observational study of children admitted to the pediatric intensive care unit (PICU) with a diagnosis of sepsis/septic shock. All critically ill children received hemoadsorption treatment with CytoSorb (CS) in combination with CKRT. Therapeutic drug monitoring has been performed on 10 critically ill children, testing four antimicrobial molecules: meropenem, ceftazidime, amikacin and levofloxacin. In order to evaluate the total and isolated CKRT and CS contributions to antibiotic removal, blood samples at each circuit point (post-hemofilter, post-CS and in the effluent line) were performed. Therefore, the clearance and mass Removal (MR) of the hemofilter and CS were calculated. Results: Our preliminary report describes a different impact of CS on these target drugs removal: CS clearance was low for amikacine (6–12%), moderate for ceftazidime (43%) and moderate to high for levofloxacine (52–72%). Higher MR and clearance were observed with CKRT compared to CS. To the best of our knowledge, this is the first report regarding pharmacokinetic dynamics in critically ill children treated with CKRT and CS for septic shock