Brensocatib (an oral, reversible inhibitor of dipeptidyl peptidase-1) attenuates disease progression in two animal models of rheumatoid arthritis.

Rheumatoid arthritis (RA) is a painful and incurable disease characterized by chronic joint inflammation and a progressive destruction of cartilage and bone. Although current treatments have improved clinical outcomes for some patients, the high relapse rates and sizeable proportion of non-responders emphasize the need for further research. Arthritic joints are massively infiltrated by neutrophils, which influence inflammatory and immune processes by releasing cytokines, chemokines, eicosanoids, and neutrophil serine proteases (NSPs) - all of which are known to contribute to RA initiation and progression. Active NSPs are generated from zymogens at the promyelocytic stage of neutrophil differentiation under the action of dipeptidyl peptidase 1 (DPP-1) and DPP-1 knockout mice are resistant to the development of arthritis. Thus, DPP-1 inhibition represents a promising therapeutic approach in RA. In this study, we assessed the efficacy of a potent and highly selective DPP-1 inhibitor, brensocatib, in two well established RA models - rat collagen-induced arthritis (CIA) and mouse collagen antibody-induced arthritis (CAIA). In both models, brensocatib at 3 and 30 mg/kg/day significantly reduced bone marrow NSP levels, in keeping with prior pharmacodynamic studies in rodents. More importantly, brensocatib treatment significantly improved disease score at both dosages in both rodent models. In the mouse CAIA model, brensocatib even proved at least as potent as anti-TNF antibodies in diminishing both the histopathological score and neutrophil infiltration into arthritic joints. Together, these results show that brensocatib alters RA disease progression in rodents and supports the need for its further evaluation as a potential therapeutic option, or to complement existing RA treatments.

The pharmacokinetic profile of brensocatib and its effect on pharmacodynamic biomarkers including NE, PR3, and CatG in various rodent species.

Brensocatib is a novel, oral, selective, reversible inhibitor of dipeptidyl peptidase 1 (DPP1), which activates several neutrophil serine proteases (NSPs), including neutrophil elastase (NE), proteinase 3 (PR3), and cathepsin G (CatG) in the bone marrow during the early stage of neutrophil maturation. These NSPs are associated with pathogen destruction and inflammatory mediation; their dysregulated activation can result in excess secretion of active NSPs causing damaging inflammation and contributing to neutrophil-mediated inflammatory and autoimmune diseases. Pharmacological inhibition of DPP1 in the bone marrow could therefore represent an attractive strategy for these neutrophil-driven diseases. A completed Phase 2 trial in non-cystic fibrosis bronchiectasis patients (ClinicalTrials.gov number NCT03218917; EudraCT number: 2017-002533-32) indeed demonstrated that administration of brensocatib attenuated the damaging effects of chronic inflammation by inhibiting the downstream activation of NSPs. To support a range of preclinical programs and further understand how rodent species and strains may affect brensocatib's pharmacokinetic (PK) profile and its pharmacodynamic (PD) effects on NE, PR3, and CatG, an extensive naïve dosing study with brensocatib at different dosing levels, frequencies, and durations was undertaken. Dose-dependent PK exposure responses (AUC and Cmax) were observed regardless of the rodent species and strain. Overall, mice showed greater reduction in NSP activities compared to rats. Both mice and rats dosed once daily (QD) had equivalent NSP activity reduction compared to BID (twice a day) dosing when the QD dose was 1.5-times the BID daily dose. For both mouse strains, CatG activity was reduced the most, followed by NE, then PR3; whereas, for both rat strains, PR3 activity was reduced the most, followed by CatG, and then NE. Maximum reduction in NSP activities was observed after ∼7 days and recoveries were nearly symmetrical. These results may facilitate future in vivo brensocatib study dosing considerations, such as the timing of prophylactic or therapeutic administration, choice of species, dosage and dosing frequency.

Lower levels of Th1 and Th2 cytokines in cerebrospinal fluid (CSF) at the time of initial CSF shunt placement in children are associated with subsequent shunt revision surgeries.

OBJECTIVE: We compare cytokine profiles at the time of initial CSF shunt placement between children who required no subsequent shunt revision surgeries and children requiring repeated CSF shunt revision surgeries for CSF shunt failure. We also describe the cytokine profiles across surgical episodes for children who undergo multiple subsequent revision surgeries. METHODS: This pilot study was nested within an ongoing prospective multicenter study collecting CSF samples and clinical data at the time of CSF shunt surgeries since August 2014. We selected cases where CSF was available for children who underwent an initial CSF shunt placement and had no subsequent shunt revision surgeries during >=24 months of follow-up (n = 7); as well as children who underwent an initial CSF shunt placement and then required repeated CSF shunt revision surgeries (n = 3). Levels of 92 human cytokines were measured using the Olink immunoassay and 41 human cytokines were measured using Luminex based bead array on CSF obtained at the time of each child's initial CSF shunt placement and were displayed in heat maps. RESULTS: Qualitatively similar profiles for the majority of cytokines were observed among the patients in each group in both Olink and Luminex assays. Lower levels of MCP-3, CASP-8, CD5, CXCL9, CXCL11, eotaxin, IFN-γ, IL-13, IP-10, and OSM at the time of initial surgery were noted in the children who went on to require multiple surgeries. Pro- and anti-inflammatory cytokines were selected a priori and shown across subsequent revision surgeries for the 3 patients. Cytokine patterns differed between patients, but within a given patient pro-inflammatory and anti-inflammatory cytokines acted in a parallel fashion, with the exception of IL-4. CONCLUSIONS: Heat maps of cytokine levels at the time of initial CSF shunt placement for each child undergoing only a single initial CSF shunt placement and for each child undergoing repeat CSF shunt revision surgeries demonstrated qualitatively similar profiles for the majority of cytokines. Lower levels of MCP-3, CASP-8, CD5, CXCL9, CXCL11, eotaxin, IFN-γ, IL-13, IP-10, and OSM at the time of initial surgery were noted in the children who went on to require multiple surgeries. Better stratification by patient age, etiology, and mechanism of failure is needed to develop a deeper understanding of the mechanism of inflammation in the development of hydrocephalus and response to shunting in children.

Brensocatib, an oral, reversible inhibitor of dipeptidyl peptidase 1, mitigates interferon-α-accelerated lupus nephritis in mice.

Neutrophils have been implicated in initiating and perpetuating systemic lupus erythematosus and the resultant kidney damage in lupus nephritis (LN) patients, in part through an excessive release of neutrophil serine proteases (NSPs). NSP zymogens are activated by dipeptidyl peptidase 1 (DPP1) during neutrophil maturation and released by mature neutrophils in response to inflammatory stimuli. Thus, a potential strategy to attenuate disease progression in LN would be to inhibit DPP1. We tested whether brensocatib, a highly selective and reversible DPP1 inhibitor, could mitigate LN progression in an interferon-alpha (IFNα)-accelerated NZB/W F1 mouse model. To confirm brensocatib's pharmacodynamic effect on NSPs in this mouse strain, repeated dose studies were conducted for 7 and 14 days in naïve NZB/W F1 mice via oral gavage twice a day. Brensocatib at 2 and 20 mg/kg/day achieved a significant reduction in bone marrow NSP activities after 7 days of daily administration. To initiate LN disease progression, the mice were injected with an IFNα-expressing adenovirus. After 2 weeks, three brensocatib doses (or vehicle) were administered for 6 more weeks. Throughout the 8-week study, brensocatib treatment (20 mg/kg/day) significantly reduced the occurrence of severe proteinuria compared to the vehicle control. Brensocatib treatment also entailed a significant reduction in the urine albumin-to-creatinine ratio, indicating decreased kidney damage, as well as a significant reduction in blood urea nitrogen level, suggesting improved renal function. Based on kidney histopathology analysis, brensocatib treatment significantly lowered both the renal tubular protein score and the nephropathy score compared to the vehicle group. A trend towards reduced glomerulonephritis score with brensocatib treatment was also observed. Lastly, brensocatib significantly reduced LN mouse kidney infiltration by various inflammatory cells. In conclusion, these results suggest that brensocatib alters disease progression in LN mice and warrant further evaluation of DPP1 inhibition in LN.

Characterization of cerebrospinal fluid (CSF) microbiota at the time of initial surgical intervention for children with hydrocephalus.

OBJECTIVE: To characterize the microbiota of the cerebrospinal fluid (CSF) from children with hydrocephalus at the time of initial surgical intervention. STUDY DESIGN: CSF was obtained at initial surgical intervention. One aliquot was stored in skim milk-tryptone-glucose-glycerol (STGG) medium and the second was unprocessed; both were then stored at -70°C. Bacterial growth for CSF samples stored in STGG were subsequently characterized using aerobic and anaerobic culture on blood agar and MALDI-TOF sequencing. All unprocessed CSF samples underwent 16S quantitative polymerase chain reaction (qPCR) sequencing, and a subset underwent standard clinical microbiological culture. CSF with culture growth (either after storage in STGG or standard clinical) were further analyzed using whole-genome amplification sequencing (WGAS). RESULTS: 11/66 (17%) samples stored in STGG and 1/36 (3%) that underwent standard clinical microbiological culture demonstrated bacterial growth. Of the organisms present, 8 were common skin flora and 4 were potential pathogens; only 1 was also qPCR positive. WGAS findings and STGG culture findings were concordant for only 1 sample, identifying Staphylococcus epidermidis. No significant difference in time to second surgical intervention was observed between the STGG culture-positive and negative groups. CONCLUSION(S): Using high sensitivity methods, we detected the presence of bacteria in a subset of CSF samples at the time of first surgery. Therefore, the true presence of bacteria in CSF of children with hydrocephalus cannot be ruled out, though our findings may suggest these bacteria are contaminants or false positives of the detection methods. Regardless of origin, the detection of microbiota in the CSF of these children may not have any clinical significance.

Comparison of outcomes in the management of abdominal pseudocyst in children with shunted hydrocephalus: a Hydrocephalus Clinical Research Network study.

OBJECTIVE: Abdominal pseudocyst (APC) can cause distal site failure in children with ventriculoperitoneal shunts and is specifically designated as an infection in Hydrocephalus Clinical Research Network (HCRN) protocols. Specific management and outcomes of children with APCs have not been reported in a multicenter study. In this study, the authors investigated the management and outcomes of APC in children with shunted hydrocephalus who were treated at centers in the HCRN. METHODS: The HCRN Registry was queried to identify children < 18 years old with shunts who were diagnosed with an APC (i.e., a loculated abdominal fluid collection containing the peritoneal catheter with abdominal distention and/or displacement of peritoneal contents). The primary outcome was shunt failure after APC treatment. The primary variable was reimplantation of the distal catheter after pseudocyst treatment back into the peritoneum versus implantation in a nonperitoneal site. Other risk factors for shunt failure after APC treatment and variability in APC management were investigated. RESULTS: Among 141 children from 14 centers who underwent first-time management of an APC over a 14-year period, the median time from previous shunt surgery to APC diagnosis was 3.8 months. Overall, 17.7% of children had a positive culture: APC cultures were positive in 14.2% and CSF cultures in 15.6%. Six other children underwent shunt revision without removal; all underwent reoperation within 1 month. There was no difference in shunt survival (log-rank test, p = 0.42) or number of subsequent revisions within 6, 12, or 24 months for shunts reimplanted in the abdomen versus those implanted in a nonperitoneal location. Nonperitoneal implantation was associated with more noninfectious revisions (42.3% vs 22.9%, p = 0.019), whereas infection was more common after reimplantation in the abdomen (25.7% vs 7.0%, p = 0.003). Univariable analysis demonstrated that younger age at APC diagnosis (8.3 vs 12.2 years, p = 0.006) and prior shunt procedure within 12 weeks of APC diagnosis (59.5% vs 40.5%, p = 0.012) were associated with shunt failure after APC treatment. Multivariable modeling confirmed that prior shunt surgery within 12 weeks of APC diagnosis was independently associated with failure (HR 1.79 [95% CI 1.04-3.07], p = 0.035). CONCLUSIONS: In the HCRN, APCs in the setting of CSF shunts are usually managed with externalization. Shunt surgery within 12 weeks of APC diagnosis was associated with risk of failure after APC treatment. Although no differences were found in overall shunt failure rate, noninfectious shunt revisions were more common in the nonperitoneal distal catheter sites, and infection was a more common reason for failure after reimplantation of the shunt in the abdomen.

Mapping the Landscape of Equitable Access to Advanced Neurotechnologies in Canada.

Geographic, social, political, and economic factors shape access to advanced neurotechnologies, yet little previous research has explored the barriers, enablers, and areas of opportunity for equitable and meaningful access for diverse patient communities across Canada. We applied a mixed-mode approach involving semi-structured interviews and rating scale questions to consult with 24 medical experts who are involved in the care of patients who undergo functional neurosurgery targeting the brain. Seven major themes emerged from the qualitative analysis: Health care system, Neurotechnology features, Patient demographics, Target condition features, Ethics, Upstream barriers and enablers, and Areas of opportunity. Descriptive statistics of the Likert-scale responses suggest that interviewees perceive a disparity between the imperative of access to advanced neurotechnologies for people living in rural and remote areas and the likelihood of achieving such access. The results depict a complex picture of access to functional neurosurgery in Canada with pockets of excellence and a motivation to improve the availability of care for vulnerable populations through the expansion of distributed care models, improved health care system efficiencies, increasing funding and support for patient travel, and increasing awareness about and advocacy for advanced neurotechnologies.

Phosphoinositol 3-kinase-driven NET formation involves different isoforms and signaling partners depending on the stimulus.

Neutrophil extracellular traps (NETs) serve to immobilize and kill pathogens, but also can contribute to the progression of several inflammatory and auto-immune diseases, as well as cancer. Whence the importance of elucidating the mechanisms underlying NET formation. In this regard, the PI3K signaling pathway has been shown to be crucial; yet little is known about which of its components are involved. Here, we identified the PI3K isoforms and associated signaling partners that are mobilized in response to different classes of physiological NET inducers (inflammatory cytokines, growth factors, chemoattractants). NET generation was assessed by microscopy and signalling molecule activation by immunoblot using phospho-antibodies. Across the various stimuli, PI3Kα and PI3Kγ isoforms clearly contributed to NET induction, while the participation of other isoforms was stimulus-dependent. Some PI3K isoforms were also found to signal through Akt, the canonical downstream effector of PI3K, while others did not. Downstream of PI3K, mTOR and PLCγ2 were used by all stimuli to control NET generation. Conversely, the involvement of other kinases depended on the stimulus - both TNFα and GM-CSF relied on PDK1 and Akt; and both TNFα and fMLP additionally used S6K. We further established that all PI3K isoforms and downstream effectors act belatedly in NET generation, as reported previously for PI3K. Finally, we revisited the PI3K-PDK1-Akt signaling hierarchy in human neutrophils and again found stimulus-dependent differences. Our data uncover unsuspected complexity and redundancy in the signaling machinery controlling NET formation through the all-important PI3K pathway. Conserved signaling molecules represent therapeutic targets for pathologies involving NETs and in this regard, the existence of drugs currently used in the clinic or undergoing clinical trials (which target PI3K isoforms, mTOR or Akt), underscores the translational potential of our findings.

Inhibition of PI3K/C/EBPß axis in tolerogenic bone marrow-derived dendritic cells of NOD mice promotes Th17 differentiation and diabetes development.

Dendritic cells (DCs) are key regulators of the adaptive immune response. Tolerogenic dendritic cells play a crucial role in inducing and maintaining immune tolerance in autoimmune diseases such as type 1 diabetes in humans as well as in the NOD mouse model. We previously reported that bone marrow-derived DCs (BM.DCs) from NOD mice, generated with a low dose of GM-CSF (GM/DCs), induce Treg differentiation and are able to protect NOD mice from diabetes. We had also found that the p38 MAPK/C/EBPß axis is involved in regulating the phenotype, as well as the production of IL-10 and IL-12p70, by tolerogenic GM/DCs. Here, we report that the inhibition of the PI3K signaling switched the cytokine profile of GM/DCs toward Th17-promoting cytokines without affecting their phenotype. PI3K inhibition abrogated the production of IL-10 by GM/DCs, whereas it enhanced their production of IL-23 and TGFß. Inhibition of PI3K signaling in tolerogenic GM/DCs also induced naive CD4+ T cells differentiation toward Th17 cells. Mechanistically, PI3K inhibition increased the DNA-binding activity of C/EBPß through a GSK3-dependent pathway, which is important to maintain the semimature phenotype of tolerogenic GM/DCs. Furthermore, analysis of C/EBPß-/- GM/DCs demonstrated that C/EBPß is required for IL-23 production. Of physiological relevance, the level of protection from diabetes following transfusion of GM/DCs into young NOD mice was significantly reduced when NOD mice were transfused with GM/DCs pretreated with a PI3K inhibitor. Our data suggest that PI3K/C/EBPß signaling is important in controlling tolerogenic function of GM/DCs by limiting their Th17-promoting cytokines.

Establishment of a ccRCC patient-derived chick chorioallantoic membrane model for drug testing.

Clear cell renal cell carcinoma (ccRCC) is an aggressive subtype of renal cell carcinoma accounting for the majority of deaths in kidney cancer patients. Advanced ccRCC has a high mortality rate as most patients progress and develop resistance to currently approved targeted therapies, highlighting the ongoing need for adequate drug testing models to develop novel therapies. Current animal models are expensive and time-consuming. In this study, we investigated the use of the chick chorioallantoic membrane (CAM), a rapid and cost-effective model, as a complementary drug testing model for ccRCC. Our results indicated that tumor samples from ccRCC patients can be successfully cultivated on the chick chorioallantoic membrane (CAM) within 7 days while retaining their histopathological characteristics. Furthermore, treatment of ccRCC xenografts with sunitinib, a tyrosine kinase inhibitor used for the treatment of metastatic RCC, allowed us to evaluate differential responses of individual patients. Our results indicate that the CAM model is a complementary in vivo model that allows for rapid and cost-effective evaluation of ccRCC patient response to drug therapy. Therefore, this model has the potential to become a useful platform for preclinical evaluation of new targeted therapies for the treatment of ccRCC.

Acetazolamide to treat symptomatic ruptured arachnoid cysts: illustrative cases.

BACKGROUND: Arachnoid cysts are benign, often asymptomatic intracranial mass lesions that, when ruptured, may cause seizures, raised intracranial pressure, hemorrhage, and/or loss of consciousness. There is no widely agreed upon treatment, and there is debate as to whether a nonoperative or surgical approach is the best course of action. The carbonic anhydrase inhibitor acetazolamide may be an effective nonoperative approach in treating ruptured arachnoid cysts. OBSERVATIONS: The Pediatric Neurosurgery Clinical Database at BC Children's Hospital from 2000 to 2020 was queried, and four pediatric patients who were treated with acetazolamide after presentation with a ruptured middle cranial fossa arachnoid cyst were identified. All patients showed some degree of symptom improvement. Three of the patients showed complete reabsorption of their subdural collections in the ensuing 6 months. One patient had an inadequate response to acetazolamide and required surgical management. LESSONS: Acetazolamide is a safe and reasonable primary treatment option in pediatric patients with ruptured middle cranial fossa arachnoid cysts, and it may help avoid the need for surgery.

Endoscopic third ventriculostomy in previously shunt-treated patients.

OBJECTIVE: Endoscopic third ventriculostomy (ETV) is an option for treatment of hydrocephalus, including for patients who have a history of previous treatment with CSF shunt insertion. The purpose of this study was to report the success of postshunt ETV by using data from a multicenter prospective registry. METHODS: Prospectively collected data in the Hydrocephalus Clinical Research Network (HCRN) Core Data Project (i.e., HCRN Registry) were reviewed. Children who underwent ETV between 2008 and 2019 and had a history of previous treatment with a CSF shunt were included. A Kaplan-Meier survival curve was created for the primary outcome: time from postshunt ETV to subsequent CSF shunt placement or revision. Univariable Cox proportional hazards models were created to evaluate for an association between clinical and demographic variables and subsequent shunt surgery. Postshunt ETV complications were also identified and categorized. RESULTS: A total of 203 children were included: 57% male and 43% female; 74% White, 23% Black, and 4% other race. The most common hydrocephalus etiologies were postintraventricular hemorrhage secondary to prematurity (56, 28%) and aqueductal stenosis (42, 21%). The ETV Success Score ranged from 10 to 80. The median patient age was 4.1 years. The overall success of postshunt ETV at 6 months was 41%. Only the surgeon's report of a clear view of the basilar artery was associated with a lower likelihood of postshunt ETV failure (HR 0.43, 95% CI 0.23-0.82, p = 0.009). None of the following variables were associated with postshunt ETV success: age at the time of postshunt ETV, etiology of hydrocephalus, sex, race, ventricle size, number of previous shunt operations, ETV performed at time of shunt infection, and use of external ventricular drainage. Overall, complications were reported in 22% of patients, with CSF leak (8.6%) being the most common complication. CONCLUSIONS: Postshunt ETV was successful in treating hydrocephalus, without subsequent need for a CSF shunt, in 41% of patients, with a clear view of the basilar artery being the only variable significantly associated with success. Complications occurred in 22% of patients. ETV is an option for treatment of hydrocephalus in children who have previously undergone shunt placement, but with a lower than expected likelihood of success.

Clinician preferences for neurotechnologies in pediatric drug-resistant epilepsy: A discrete choice experiment.

OBJECTIVE: Novel and minimally invasive neurotechnologies offer the potential to reduce the burden of epilepsy while avoiding the risks of conventional resective surgery. Few neurotechnologies have been tested in randomized controlled trials with pediatric populations, leaving clinicians to face decisions about whether to recommend these treatments with insufficient evidence about the relevant risks and benefits. This study specifically explores the preferences of clinicians for treating pediatric drug-resistant epilepsy (DRE) with novel neurotechnologies. METHODS: A discrete-choice experiment (DCE) was designed to elicit the preferences of clinicians with experience in treating children with DRE using novel neurotechnological interventions. The preferences for six key attributes used when making treatment decisions (chances of clinically significant improvement in seizures, major and minor risks from intervention, availability of evidence, financial burden for the family, and access to the intervention) were estimated using a conditional logit model. The estimates from this model were then used to predict the adoption of existing novel neurotechnological interventions. RESULTS: Sixty-eight clinicians completed the survey: 33 neurosurgeons, 28 neurologists, and 7 other clinicians. Most clinicians were working in the United States (74%), and the remainder (26%) in Canada. All attributes, apart from the nearest location with access to the intervention, influenced preferences significantly. The chance of clinically significant improvement in seizures was the most positive influence on clinician preferences, but low-quality evidence and a higher risk of major complications could offset these preferences. Of the existing neurotechnological interventions, vagus nerve stimulation was predicted to have the highest likelihood of adoption; deep brain stimulation had the lowest likelihood of adoption. SIGNIFICANCE: The preferences of clinicians are drive primarily by the likelihood of achieving seizure freedom for their patients, but preferences for an intervention are largely eradicated if only low quality of evidence supporting the intervention is available. Until better evidence supporting the use of potentially effective, novel neurotechnologies becomes available, clinicians are likely to prefer more established treatments.

The Hydrocephalus Clinical Research Network quality improvement initiative: the role of antibiotic-impregnated catheters and vancomycin wound irrigation.

OBJECTIVE: Two previous Hydrocephalus Clinical Research Network (HCRN) studies have demonstrated that compliance with a standardized CSF shunt infection protocol reduces shunt infections. In this third iteration, a simplified protocol consisting of 5 steps was implemented. This analysis provides an updated evaluation of protocol compliance and evaluates modifiable shunt infection risk factors. METHODS: The new simplified protocol was implemented at HCRN centers on November 1, 2016, for all shunt procedures, excluding external ventricular drains, ventricular reservoirs, and subgaleal shunts. Procedures performed through December 31, 2019, were included (38 months). Compliance with the protocol, use of antibiotic-impregnated catheters (AICs), and other variables of interest were collected at the index operation. Outcome events for a minimum of 6 months postoperatively were recorded. The definition of infection was unchanged from the authors' previous report. RESULTS: A total of 4913 procedures were performed at 13 HCRN centers. The overall infection rate was 5.1%. Surgeons were compliant with all 5 steps of the protocol in 79.4% of procedures. The infection rate for the protocol alone was 8.1% and dropped to 4.9% when AICs were added. Multivariate analysis identified having ≥ 2 complex chronic conditions (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.26-2.44, p = 0.01) and a history of prior shunt surgery within 12 weeks (OR 1.84, 95% CI 1.37-2.47, p < 0.01) as independent risk factors for shunt infection. The use of AICs (OR 0.70, 95% CI 0.50-0.97, p = 0.05) and vancomycin irrigation (OR 0.36, 95% CI 0.21-0.62, p < 0.01) were identified as independent factors protective against shunt infection. CONCLUSIONS: The authors report the third iteration of their quality improvement protocol to reduce the risk of shunt infection. Compliance with the protocol was high. These updated data suggest that the incorporation of AICs is an important, modifiable infection prevention measure. Vancomycin irrigation was also identified as a protective factor but requires further study to better understand its role in preventing shunt infection.

Understanding Attributes that Influence Physician and Caregiver Decisions About Neurotechnology for Pediatric Drug-Resistant Epilepsy: A Formative Qualitative Study to Support the Development of a Discrete Choice Experiment.

OBJECTIVE: This study reports formative qualitative research used to analyze decision making regarding neurotechnological interventions for pediatric drug-resistant epilepsy from the perspective of physicians and caregivers and the derivation of attributes for a discrete choice experiment. METHODS: Purposive and convenience sampling was used to recruit physicians and caregivers. Physician focus group sessions were held at key national conferences in the USA and Canada. Caregivers were approached through clinics with established epilepsy surgery programs in the USA and Canada. Thematic analysis was used to identify critical features of decisions about treatment outcomes, procedural trade-offs, values, and concerns surrounding conventional and novel pediatric drug-resistant epilepsy interventions among physicians and caregivers. RESULTS: The results highlight the presence of central attributes that are considered by both groups in decision making, such as "chances of seizure freedom", "risk", "availability of evidence", and "cost to families", as well as attributes that reflect important differences between groups. Physicians were focused on the specifics of treatment options, while caregivers thought more holistically, considering the overall well-being of their children. DISCUSSION: The findings shaped the development of a discrete choice experiment to understand the likely uptake of different neurotechnologies. We identified differences in decision making and thus designed two discrete choice experiments to elicit preferences for pediatric drug-resistant epilepsy treatments, one aimed at clinicians and one at caregivers. The variation we observed highlights the value of seeking to understand the influences at the point of clinical decision making and incorporating this information into care.

Impact of ventricle size on neuropsychological outcomes in treated pediatric hydrocephalus: an HCRN prospective cohort study.

OBJECTIVE: In pediatric hydrocephalus, shunts tend to result in smaller postoperative ventricles compared with those following an endoscopic third ventriculostomy (ETV). The impact of the final treated ventricle size on neuropsychological and quality-of-life outcomes is currently undetermined. Therefore, the authors sought to ascertain whether treated ventricle size is associated with neurocognitive and academic outcomes postoperatively. METHODS: This prospective cohort study included children aged 5 years and older at the first diagnosis of hydrocephalus at 8 Hydrocephalus Clinical Research Network sites from 2011 to 2015. The treated ventricle size, as measured by the frontal and occipital horn ratio (FOR), was compared with 25 neuropsychological tests 6 months postoperatively after adjusting for age, hydrocephalus etiology, and treatment type (ETV vs shunt). Pre- and posttreatment grade point average (GPA), quality-of-life measures (Hydrocephalus Outcome Questionnaire [HOQ]), and a truncated preoperative neuropsychological battery were also compared with the FOR. RESULTS: Overall, 60 children were included with a mean age of 10.8 years; 17% had ≥ 1 comorbidity. Etiologies for hydrocephalus were midbrain lesions (37%), aqueductal stenosis (22%), posterior fossa tumors (13%), and supratentorial tumors (12%). ETV (78%) was more commonly used than shunting (22%). Of the 25 neuropsychological tests, including full-scale IQ (q = 0.77), 23 tests showed no univariable association with postoperative ventricle size. Verbal learning delayed recall (p = 0.006, q = 0.118) and visual spatial judgment (p = 0.006, q = 0.118) were negatively associated with larger ventricles and remained significant after multivariate adjustment for age, etiology, and procedure type. However, neither delayed verbal learning (p = 0.40) nor visual spatial judgment (p = 0.22) was associated with ventricle size change with surgery. No associations were found between postoperative ventricle size and either GPA or the HOQ. CONCLUSIONS: Minimal associations were found between the treated ventricle size and neuropsychological, academic, or quality-of-life outcomes for pediatric patients in this comprehensive, multicenter study that encompassed heterogeneous hydrocephalus etiologies.

Anterior versus posterior entry site for ventriculoperitoneal shunt insertion: a randomized controlled trial by the Hydrocephalus Clinical Research Network.

OBJECTIVE: The primary objective of this trial was to determine if shunt entry site affects the risk of shunt failure. METHODS: The authors performed a parallel-design randomized controlled trial with an equal allocation of patients who received shunt placement via the anterior entry site and patients who received shunt placement via the posterior entry site. All patients were children with symptoms or signs of hydrocephalus and ventriculomegaly. Patients were ineligible if they had a prior history of shunt insertion. Patients received a ventriculoperitoneal shunt after randomization; randomization was stratified by surgeon. The primary outcome was shunt failure. The planned minimum follow-up was 18 months. The trial was designed to achieve high power to detect a 10% or greater absolute difference in the shunt failure rate at 1 year. An independent, blinded adjudication committee determined eligibility and the primary outcome. The study was conducted by the Hydrocephalus Clinical Research Network. RESULTS: The study randomized 467 pediatric patients at 14 tertiary care pediatric hospitals in North America from April 2015 to January 2019. The adjudication committee, blinded to intervention, excluded 7 patients in each group for not meeting the study inclusion criteria. For the primary analysis, there were 229 patients in the posterior group and 224 patients in the anterior group. The median patient age was 1.3 months, and the most common etiologies of hydrocephalus were postintraventricular hemorrhage secondary to prematurity (32.7%), myelomeningocele (16.8%), and aqueductal stenosis (10.8%). There was no significant difference in the time to shunt failure between the entry sites (log-rank test, stratified by age < 6 months and ≥ 6 months; p = 0.061). The hazard ratio (HR) of a posterior shunt relative to an anterior shunt was calculated using a univariable Cox regression model and was nonsignificant (HR 1.35, 95% CI, 0.98-1.85; p = 0.062). No significant difference was found between entry sites for the surgery duration, number of ventricular catheter passes, ventricular catheter location, and hospital length of stay. There were no significant differences between entry sites for intraoperative complications, postoperative CSF leaks, pseudomeningoceles, shunt infections, skull fractures, postoperative seizures, new-onset epilepsy, or intracranial hemorrhages. CONCLUSIONS: This randomized controlled trial comparing the anterior and posterior shunt entry sites has demonstrated no significant difference in the time to shunt failure. Anterior and posterior entry site surgeries were found to have similar outcomes and similar complication rates.

Early and Late Processes Driving NET Formation, and the Autocrine/Paracrine Role of Endogenous RAGE Ligands.

Neutrophil extracellular trap (NET) formation has emerged as an important response against various pathogens; it also plays a role in chronic inflammation, autoimmunity, and cancer. Despite a growing understanding of the mechanisms underlying NET formation, much remains to be elucidated. We previously showed that in human neutrophils activated with different classes of physiological stimuli, NET formation features both early and late events that are controlled by discrete signaling pathways. However, the nature of these events has remained elusive. We now report that PAD4 inhibition only affects the early phase of NET generation, as do distinct signaling intermediates (TAK1, MEK, p38 MAPK). Accordingly, the inducible citrullination of residue R2 on histone H3 is an early neutrophil response that is regulated by these kinases; other arginine residues on histones H3 and H4 do not seem to be citrullinated. Conversely, elastase blockade did not affect NET formation by several physiological stimuli, though it did so in PMA-activated cells. Among belated events in NET formation, we found that chromatin decondensation is impaired by the inhibition of signaling pathways controlling both early and late stages of the phenomenon. In addition to chromatin decondensation, other late processes were uncovered. For instance, unstimulated neutrophils can condition themselves to be poised for rapid NET induction. Similarly, activated neutrophils release endogenous proteic factors that promote and largely mediate NET generation. Several such factors are known RAGE ligands and accordingly, RAGE inbibition largely prevents both NET formation and the conditioning of neutrophils to rapidly generate NETs upon stimulation. Our data shed new light on the cellular processes underlying NET formation, and unveil unsuspected facets of the phenomenon that could serve as therapeutic targets. In view of the involvement of NETs in both homeostasis and several pathologies, our findings are of broad relevance.

Choice and Trade-offs: Parent Decision Making for Neurotechnologies for Pediatric Drug-Resistant Epilepsy.

This qualitative study investigated factors that guide caregiver decision making and ethical trade-offs for advanced neurotechnologies used to treat children with drug-resistant epilepsy. Caregivers with affected children were recruited to semi-structured focus groups or interviews at one of 4 major epilepsy centers in Eastern and Western Canada and the USA (n = 22). Discussions were transcribed and qualitative analytic methods applied to examine values and priorities (eg, risks, benefits, adherence, invasiveness, reversibility) of caregivers pertaining to novel technologies to treat drug-resistant epilepsy. Discussions revealed 3 major thematic branches for decision making: (1) features of the intervention-risks and benefits, with an emphasis on an aversion to perceived invasiveness; (2) decision drivers-trust in the clinical team, treatment costs; and (3) quality of available information about neurotechnological options. Overall, caregivers' definition of treatment success is more expansive than seizure freedom. The full involvement of their values and priorities must be considered in the decision-making process.