Longitudinal natural history studies based on real-world data in rare diseases: Opportunity and a novel approach.

Growing interest in therapeutic development for rare diseases necessitate a systematic approach to the collection and curation of natural history data that can be applied consistently across this group of heterogenous rare diseases. In this study, we discuss the challenges facing natural history studies for leukodystrophies and detail a novel standardized approach to creating a longitudinal natural history study using existing medical records. Prospective studies are uniquely challenging for rare diseases. Delays in diagnosis and overall rarity limit the timely collection of natural history data. When feasible, prospective studies are often cross-sectional rather than longitudinal and are unlikely to capture pre- or early- symptomatic disease trajectories, limiting their utility in characterizing the full natural history of the disease. Therapeutic development in leukodystrophies is subject to these same obstacles. The Global Leukodystrophy Initiative Clinical Trials Network (GLIA-CTN) comprises of a network of research institutions across the United States, supported by a multi-center biorepository protocol, to map the longitudinal clinical course of disease across leukodystrophies. As part of GLIA-CTN, we developed Standard Operating Procedures (SOPs) that delineated all study processes related to staff training, source documentation, and data sharing. Additionally, the SOP detailed the standardized approach to data extraction including diagnosis, clinical presentation, and medical events, such as age at gastrostomy tube placement. The key variables for extraction were selected through face validity, and common electronic case report forms (eCRF) across leukodystrophies were created to collect analyzable data. To enhance the depth of the data, clinical notes are extracted into "original" and "imputed" encounters, with imputed encounter referring to a historic event (e.g., loss of ambulation 3 months prior). Retrospective Functional Assessments were assigned by child neurologists, using a blinded dual-rater approach and score discrepancies were adjudicated by a third rater. Upon completion of extraction, data source verification is performed. Data missingness was evaluated using statistics. The proposed methodology will enable us to leverage existing medical records to address the persistent gap in natural history data within this unique disease group, allow for assessment of clinical trajectory both pre- and post-formal diagnosis, and promote recruitment of larger cohorts.

Developmental delay can precede neurologic regression in early onset metachromatic leukodystrophy.

OBJECTIVE: Metachromatic leukodystrophy (MLD) is a rare neurodegenerative disorder. Emerging therapies are most effective in the presymptomatic phase, and thus defining this window is critical. We hypothesize that early development delay may precede developmental plateau. With the advent of presymptomatic screening platforms and transformative therapies, it is essential to define the onset of neurologic disease. METHODS: The specific ages of gain and loss of developmental milestones were captured from the medical records of individuals affected by MLD. Milestone acquisition was characterized as: on target (obtained before the age limit of 90th percentile plus 2 standard deviations compared to a normative dataset), delayed (obtained after 90th percentile plus 2 standard deviations), or plateau (skills never gained). Regression was defined as the age at which skills were lost. LI-MLD was defined by age at onset before 2.5 years. RESULTS: Across an international cohort, 351 subjects were included (n = 194 LI-MLD subcohort). The median age at presentation of the LI-MLD cohort was 1.4 years (25th-75th %ile: 1.0-1.5). Within the LI-MLD cohort, 75/194 (39%) had developmental delay (or plateau) prior to MLD clinical presentation. Among the LI-MLD cohort with a minimum of 1.5 years of follow-up (n = 187), 73 (39.0%) subjects never attained independent ambulation. Within LI-MLD + delay subcohort, the median time between first missed milestone target to MLD decline was 0.60 years (maximum distance from delay to onset: 1.9 years). INTERPRETATION: Early developmental delay precedes regression in a subset of children affected by LI-MLD, defining the onset of neurologic dysfunction earlier than previously appreciated. The use of realworld data prior to diagnosis revealed an early deviation from typical development. Close monitoring for early developmental delay in presymptomatic individuals may help in earlier diagnosis with important consequences for treatment decisions.

Diuretic Tolerance to Repeated-Dose Furosemide in Infants Born Very Preterm with Bronchopulmonary Dysplasia.

OBJECTIVES: To assess the presence and timing of furosemide diuretic tolerance in infants with bronchopulmonary dysplasia (BPD), and to determine if tolerance is modified by thiazide co-administration. STUDY DESIGN: We performed a retrospective cohort study among infants born very preterm with BPD exposed to repeated-dose furosemide for 72 hours, measuring net fluid balance (total intake minus total output) as a surrogate of diuresis in the 3 days before and after exposure. The primary comparison was the difference in fluid balance between the first and third 24 hours of furosemide exposure. We fit a general linear model for within-subject repeated measures of fluid balance over time, with thiazide co-administration as an interaction variable. Secondary analyses included an evaluation of weight trajectories over time. RESULTS: In 83 infants, median fluid balance ranged between + 43.6 and + 52.7 ml/kg/d in the 3 days prior to furosemide exposure. Fluid balance decreased to a median of + 29.1 ml/kg/d in the first 24 hours after furosemide, but then increased to +47.5 ml/kg/d by the third 24-hour interval, consistent with tolerance (P < .001). Thiazides did not modify the change in fluid balance during furosemide exposure for any time-period. Weight decreased significantly in the first 24 hours after furosemide and increased thereafter (P < .001). CONCLUSIONS: The net fluid balance response to furosemide decreases rapidly during repeated-dose exposures in infants with BPD, consistent with diuretic tolerance. Clinicians should consider this finding in the context of an infant's therapeutic goals. Further research efforts to identify safe and effective furosemide dosage strategies are needed.

Evaluating Airway Management in Patients With Trisomy 21 in the PICU and Cardiac ICU: A Retrospective Cohort Study.

OBJECTIVES: Children with trisomy 21 often have anatomic and physiologic features that may complicate tracheal intubation (TI). TI in critically ill children with trisomy 21 is not well described. We hypothesize that in children with trisomy 21, TI is associated with greater odds of adverse airway outcomes (AAOs), including TI-associated events (TIAEs), and peri-intubation hypoxemia (defined as > 20% decrease in pulse oximetry saturation [Sp o2 ]). DESIGN: Retrospective database study using the National Emergency Airway Registry for Children (NEAR4KIDS). SETTING: Registry data from 16 North American PICUs and cardiac ICUs (CICUs), from January 2014 to December 2020. PATIENTS: A cohort of children under 18 years old who underwent TI in the PICU or CICU from in a NEAR4KIDS center. We identified patients with trisomy 21 and selected matched cohorts within the registry. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We included 8401 TIs in the registry dataset. Children with trisomy 21 accounted for 274 (3.3%) TIs. Among those with trisomy 21, 84% had congenital heart disease and 4% had atlantoaxial instability. Cervical spine protection was used in 6%. The diagnosis of trisomy 21 (vs. without) was associated with lower median weight 7.8 (interquartile range [IQR] 4.5-14.7) kg versus 10.6 (IQR 5.2-25) kg ( p < 0.001), and more higher percentage undergoing TI for oxygenation (46% vs. 32%, p < 0.001) and ventilation failure (41% vs. 35%, p = 0.04). Trisomy 21 patients had more difficult airway features (35% vs. 25%, p = 0.001), including upper airway obstruction (14% vs. 8%, p = 0.001). In addition, a greater percentage of trisomy 21 patients received atropine (34% vs. 26%, p = 0.004); and, lower percentage were intubated with video laryngoscopy (30% vs. 37%, p = 0.023). After 1:10 (trisomy 21:controls) propensity-score matching, we failed to identify an association difference in AAO rates (absolute risk difference -0.6% [95% CI -6.1 to 4.9], p = 0.822). CONCLUSIONS: Despite differences in airway risks and TI approaches, we have not identified an association between the diagnosis of trisomy 21 and higher AAOs.

Tracheal Intubation by Advanced Practice Registered Nurses in Pediatric Critical Care: Retrospective Study From the National Emergency Airway for Children Registry (2015-2019).

OBJECTIVES: To describe tracheal intubation (TI) practice by Advanced Practice Registered Nurses (APRNs) in North American PICUs, including rates of TI-associated events (TIAEs) from 2015 to 2019. DESIGN/SETTING: Retrospective study using the National Emergency Airway Registry for Children with all TIs performed in PICU and pediatric cardiac ICU between January 2015 and December 2019. The primary outcome was first attempt TI success rate. Secondary outcomes were TIAEs, severe TIAEs, and hypoxemia. SUBJECTS: Critically ill children requiring TI in a PICU or pediatric cardiac ICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among 11,012 TIs, APRNs performed 1,626 (14.7%). Overall, TI by APRNs, compared with other clinicians, occurred less frequently in patients with known difficult airway (11.1% vs. 14.3%; p < 0.001), but more frequently in infants younger than 1 year old (55.9% vs. 44.4%; p < 0.0001), and in patients with cardiac disease (26.3% vs. 15.9%; p < 0.0001).There was lower odds of success in first attempt TI for APRNs vs. other clinicians (adjusted odds ratio, 0.70; 95% CI, 0.62-0.79). We failed to identify a difference in rates of TIAE, severe TIAE, and oxygen desaturation events for TIs by APRNs compared with other clinicians. The TI first attempt success rate improved with APRN experience (< 1 yr: 54.2%, 1-5 yr: 59.4%, 6-10 yr: 67.6%, > 10 yr: 63.1%; p = 0.021). CONCLUSIONS: TI performed by APRNs was associated with lower odds of first attempt success when compared with other ICU clinicians although there was no appreciable difference in procedural adverse events. There appears to be a positive relationship between experience and success rates. These data suggest there is an ongoing need for opportunities to build on TI competency with APRNs.

Adverse Tracheal Intubation Events in Critically Ill Underweight and Obese Children: Retrospective Study of the National Emergency Airway for Children Registry (2013-2020).

OBJECTIVES: Extremes of patient body mass index are associated with difficult intubation and increased morbidity in adults. We aimed to determine the association between being underweight or obese with adverse airway outcomes, including adverse tracheal intubation (TI)-associated events (TIAEs) and/or severe peri-intubation hypoxemia (pulse oximetry oxygen saturation < 80%) in critically ill children. DESIGN/SETTING: Retrospective cohort using the National Emergency Airway for Children registry dataset of 2013-2020. PATIENTS: Critically ill children, 0 to 17 years old, undergoing TI in PICUs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Registry data from 24,342 patients who underwent TI between 2013 and 2020 were analyzed. Patients were categorized using the Centers for Disease Control and Prevention weight-for-age chart: normal weight (5th-84th percentile) 57.1%, underweight (< 5th percentile) 27.5%, overweight (85th to < 95th percentile) 7.2%, and obese (≥ 95th percentile) 8.2%. Underweight was most common in infants (34%); obesity was most common in children older than 8 years old (15.1%). Underweight patients more often had oxygenation and ventilation failure (34.0%, 36.2%, respectively) as the indication for TI and a history of difficult airway (16.7%). Apneic oxygenation was used more often in overweight and obese patients (19.1%, 19.6%) than in underweight or normal weight patients (14.1%, 17.1%; p < 0.001). TIAEs and/or hypoxemia occurred more often in underweight (27.1%) and obese (24.3%) patients ( p < 0.001). TI in underweight children was associated with greater odds of adverse airway outcome compared with normal weight children after adjusting for potential confounders (underweight: adjusted odds ratio [aOR], 1.09; 95% CI, 1.01-1.18; p = 0.016). Both underweight and obesity were associated with hypoxemia after adjusting for covariates and site clustering (underweight: aOR, 1.11; 95% CI, 1.02-1.21; p = 0.01 and obesity: aOR, 1.22; 95% CI, 1.07-1.39; p = 0.002). CONCLUSIONS: In underweight and obese children compared with normal weight children, procedures around the timing of TI are associated with greater odds of adverse airway events.

Ketamine Use in the Intubation of Critically Ill Children with Neurological Indications: A Multicenter Retrospective Analysis.

BACKGROUND: Ketamine has traditionally been avoided for tracheal intubations (TIs) in patients with acute neurological conditions. We evaluate its current usage pattern in these patients and any associated adverse events. METHODS: We conducted a retrospective observational cohort study of critically ill children undergoing TI for neurological indications in 53 international pediatric intensive care units and emergency departments. We screened all intubations from 2014 to 2020 entered into the multicenter National Emergency Airway Registry for Children (NEAR4KIDS) registry database. Patients were included if they were under the age of 18 years and underwent TI for a primary neurological indication. Usage patterns and reported periprocedural composite adverse outcomes (hypoxemia < 80%, hypotension/hypertension, cardiac arrest, and dysrhythmia) were noted. RESULTS: Of 21,562 TIs, 2,073 (9.6%) were performed for a primary neurological indication, including 190 for traumatic brain injury/trauma. Patients received ketamine in 495 TIs (23.9%), which increased from 10% in 2014 to 41% in 2020 (p < 0.001). Ketamine use was associated with a coindication of respiratory failure, difficult airway history, and use of vagolytic agents, apneic oxygenation, and video laryngoscopy. Composite adverse outcomes were reported in 289 (13.9%) Tis and were more common in the ketamine group (17.0% vs. 13.0%, p = 0.026). After adjusting for location, patient age and codiagnoses, the presence of respiratory failure and shock, difficult airway history, provider demographics, intubating device, and the use of apneic oxygenation, vagolytic agents, and neuromuscular blockade, ketamine use was not significantly associated with increased composite adverse outcomes (adjusted odds ratio 1.34, 95% confidence interval CI 0.99-1.81, p = 0.057). This paucity of association remained even when only neurotrauma intubations were considered (10.6% vs. 7.7%, p = 0.528). CONCLUSIONS: This retrospective cohort study did not demonstrate an association between procedural ketamine use and increased risk of peri-intubation hypoxemia and hemodynamic instability in patients intubated for neurological indications.

A Pediatric Interprofessional Cardiac Intensive Care Unit Intervention: CICU Teams and Loved Ones Communicating (CICU TALC) is Feasible, Acceptable, and Improves Clinician Communication Behaviors in Family Meetings.

Parents of children in the pediatric cardiac intensive care unit (CICU) are often unprepared for family meetings (FM). Clinicians often do not follow best practices for communicating with families, adding to distress. An interprofessional team intervention for FM is feasible, acceptable, and positively impacts family preparation and conduct of FM in the CICU. We implemented a family- and team-support intervention for conducting FM and conducted a pretest-posttest study with parents of patients selected for a FM and clinicians. We measured feasibility, fidelity to intervention protocol, and parent acceptability via questionnaire and semi-structured interviews. Clinician behavior in meetings was assessed through semantic content analyses of meeting transcripts tracking elicitation of parental concerns, questions asked of parents, and responses to parental empathic opportunities. Logistic and ordinal logistic regression assessed intervention impact on clinician communication behaviors in meetings comparing pre- and post-intervention data. Sixty parents (95% of approached) were enrolled, with collection of 97% FM and 98% questionnaire data. We accomplished > 85% fidelity to intervention protocol. Most parents (80%) said the preparation worksheet had the right amount of information and felt positive about families receiving this worksheet. Clinicians were more likely to elicit parental concerns (adjusted odds ratio = 3.42; 95%CI [1.13, 11.0]) in post-intervention FM. There were no significant differences in remaining measures. Implementing an interprofessional team intervention to improve family preparation and conduct of FM is locally feasible, acceptable, and changes clinician behaviors. Future research should assess broader impact of training on clinicians, patients, and families.

Implementation of Video Laryngoscope-Assisted Coaching Reduces Adverse Tracheal Intubation-Associated Events in the PICU.

OBJECTIVES: To evaluate implementation of a video laryngoscope (VL) as a coaching device to reduce adverse tracheal intubation associated events (TIAEs). DESIGN: Prospective multicenter interventional quality improvement study. SETTING: Ten PICUs in North America. PATIENTS: Patients undergoing tracheal intubation in the PICU. INTERVENTIONS: VLs were implemented as coaching devices with standardized coaching language between 2016 and 2020. Laryngoscopists were encouraged to perform direct laryngoscopy with video images only available in real-time for experienced supervising clinician-coaches. MEASUREMENTS AND MAIN RESULTS: The primary outcome was TIAEs. Secondary outcomes included severe TIAEs, severe hypoxemia (oxygen saturation < 80%), and first attempt success. Of 5,060 tracheal intubations, a VL was used in 3,580 (71%). VL use increased from baseline (29.7%) to implementation phase (89.4%; p < 0.001). VL use was associated with lower TIAEs (VL 336/3,580 [9.4%] vs standard laryngoscope [SL] 215/1,480 [14.5%]; absolute difference, 5.1%; 95% CI, 3.1-7.2%; p < 0.001). VL use was associated with lower severe TIAE rate (VL 3.9% vs SL 5.3%; p = 0.024), but not associated with a reduction in severe hypoxemia (VL 15.7% vs SL 16.4%; p = 0.58). VL use was associated with higher first attempt success (VL 71.8% vs SL 66.6%; p < 0.001). In the primary analysis after adjusting for site clustering, VL use was associated with lower adverse TIAEs (odds ratio [OR], 0.61; 95% CI, 0.46-0.81; p = 0.001). In secondary analyses, VL use was not significantly associated with severe TIAEs (OR, 0.72; 95% CI, 0.44-1.19; p = 0.20), severe hypoxemia (OR, 0.95; 95% CI, 0.73-1.25; p = 0.734), or first attempt success (OR, 1.28; 95% CI, 0.98-1.67; p = 0.073). After further controlling for patient and provider characteristics, VL use was independently associated with a lower TIAE rate (adjusted OR, 0.65; 95% CI, 0.49-0.86; p = 0.003). CONCLUSIONS: Implementation of VL-assisted coaching achieved a high level of adherence across the PICUs. VL use was associated with reduced adverse TIAEs.

Adverse Effects of α-2 Adrenergic Agonists and Stimulants in Preschool-age Attention-deficit/Hyperactivity Disorder: A Developmental-Behavioral Pediatrics Research Network Study.

OBJECTIVES: To characterize and compare the type and frequency of a range of common and uncommon adverse effects (AEs) associated with α-2 adrenergic agonist (A2A) and stimulant treatment of attention-deficit/hyperactivity disorder at preschool-age as well as to evaluate the impact of age on common AEs. STUDY DESIGN: This was a retrospective electronic medical record review of children <72 months of age (n = 497) evaluated at outpatient developmental-behavioral pediatric practices at 7 US academic medical centers within the Developmental-Behavioral Pediatrics Research Network. Data on AEs were abstracted for children who had treatment initiated by a developmental-behavioral pediatrician with an A2A or stimulant medication between January 2013 and July 2017; follow-up was complete by February 2019. RESULTS: A2A and stimulants had distinctive AE profiles. A2A compared with stimulants had a greater proportion with daytime sleepiness and headaches; stimulants had significantly greater proportions for most other AE, including moodiness/irritability, difficulty with sleep, appetite suppression, stomachaches, skin picking/repetitive behaviors, withdrawn behavior, and weight loss. Younger age was associated with disruptive behavior and difficulty with sleep. CONCLUSIONS: Stimulants had a greater rate of most AEs compared with A2A. AE profiles, together with efficacy, should inform clinical decision-making. Prospective randomized clinical trials are needed to fully compare efficacy and AE profiles of A2A and stimulants.

Effect of apneic oxygenation with intubation to reduce severe desaturation and adverse tracheal intubation-associated events in critically ill children.

BACKGROUND: Determine if apneic oxygenation (AO) delivered via nasal cannula during the apneic phase of tracheal intubation (TI), reduces adverse TI-associated events (TIAEs) in children. METHODS: AO was implemented across 14 pediatric intensive care units as a quality improvement intervention during 2016-2020. Implementation consisted of an intubation safety checklist, leadership endorsement, local champion, and data feedback to frontline clinicians. Standardized oxygen flow via nasal cannula for AO was as follows: 5 L/min for infants (< 1 year), 10 L/min for young children (1-7 years), and 15 L/min for older children (≥ 8 years). Outcomes were the occurrence of adverse TIAEs (primary) and hypoxemia (SpO2 < 80%, secondary). RESULTS: Of 6549 TIs during the study period, 2554 (39.0%) occurred during the pre-implementation phase and 3995 (61.0%) during post-implementation phase. AO utilization increased from 23 to 68%, p < 0.001. AO was utilized less often when intubating infants, those with a primary cardiac diagnosis or difficult airway features, and patient intubated due to respiratory or neurological failure or shock. Conversely, AO was used more often in TIs done for procedures and those assisted by video laryngoscopy. AO utilization was associated with a lower incidence of adverse TIAEs (AO 10.5% vs. without AO 13.5%, p < 0.001), aOR 0.75 (95% CI 0.58-0.98, p = 0.03) after adjusting for site clustering (primary analysis). However, after further adjusting for patient and provider characteristics (secondary analysis), AO utilization was not independently associated with the occurrence of adverse TIAEs: aOR 0.90, 95% CI 0.72-1.12, p = 0.33 and the occurrence of hypoxemia was not different: AO 14.2% versus without AO 15.2%, p = 0.43. CONCLUSION: While AO use was associated with a lower occurrence of adverse TIAEs in children who required TI in the pediatric ICU after accounting for site-level clustering, this result may be explained by differences in patient, provider, and practice factors. Trial Registration Trial not registered.

Pediatric Cholelithiasis in the United States: National Hospitalization Trends, 2006 to 2019.

OBJECTIVES: Previous studies have shown increasing hospitalizations for pediatric cholelithiasis, but recent trends are unknown. We conducted a national study of pediatric cholelithiasis to characterize recent hospitalization rate trends. METHODS: Retrospective repeated cross-sectional analysis of pediatric (age < 18 years) cholelithiasis-associated hospitalizations combining data from the 2006 through 2019 Kids' Inpatient Database releases. The primary outcome of interest was the national hospitalization rate (per 100,000 children). We examined rates stratified by age group and sex and characterized hospitalization outcomes and characteristics for pediatric cholelithiasis. RESULTS: Twenty-nine thousand one hundred two hospital records representing 42,282 gallstone-associated hospitalizations were identified. The hospitalization rate declined from 12.9 [95% confidence interval (CI): 12.6-13.2] in 2006 to 9.1 (95% CI: 8.8-9.3) in 2019. Consistent with the literature, hospitalizations occurred most often among teenagers (71%) and individuals with female sex (72%). The proportion of hospitalizations at freestanding children's hospitals increased significantly (from 18.2% to 35.1%). Finally, the proportion of hospitalizations involving a potentially medical predisposing condition increased significantly. CONCLUSIONS: The estimated US hospitalization rate for pediatric cholelithiasis declined by 30% between 2006 and 2019. Female patients and teenagers had the largest decline, and hospitalizations increasingly occurred at freestanding children's hospitals. Potential explanations include potential changes in delivery of care as well as changes in population disease burden.

Dopamine agonists and risk of lung cancer in patients with restless legs syndrome.

PURPOSE: To examine the association between long-term use of dopamine agonists (DAs) and the risk of lung cancer in patients with restless legs syndrome (RLS). METHODS: We conducted a retrospective cohort study using Optum Clinformatics® database. We included adults ≥40 years diagnosed with RLS during the study period (1/2006-12/2016). Follow-up started with the first RLS diagnosis and ended on the earliest of: incident diagnosis of lung cancer, end of enrollment in the database or end of the study period. The exposure of interest was cumulative duration of DAs use, measured in a time-varying manner. We constructed a multivariable Cox regression model to estimate HRs and 95% CIs for the association between lung cancer and cumulative durations of DA use, adjusting for potential confounding variables. RESULTS: We identified 295 042 patients with a diagnosis of RLS. The mean age of the cohort was 62.9; 66.6% were women and 82.3% were white. The prevalence of any DA exposure was 40.3%. Compared to the reference group (no use and ≤1 year), the crude HRs for lung cancer were 1.16 (95% CI 0.99-1.36) and 1.14 (95% CI 0.86-1.51) for 1-3 years and >3 years of cumulative DA use, respectively. The adjusted HR for lung cancer was 1.05 (95% CI 0.88-1.25) for 1-3 years and 1.02 (95% CI 0.76-1.37) for >3 years of cumulative DA use, respectively. CONCLUSIONS: At typical doses for the clinical management of RLS, long-term DA use was not associated with risk of lung cancer.

SARS-CoV-2 mRNA-based vaccines in the Aicardi Goutières Syndrome.

Aicardi Goutières Syndrome (AGS) is an autoinflammatory disorder resulting in sustained interferon activation through defects in nucleic acid modification and sensing pathways. Thus, mRNA-based vaccination used against SARS-CoV-2, raise disease-specific safety concerns. To assess interferon signaling, we tested mRNA SARS-CoV-2 vaccines in AGS whole blood samples. Interferon activation is measured through quantitation of interferon signaling gene (ISG) expression and is increased in AGS patients. There was no increase in ISG scores from baseline following treatment with the nucleoside modified mRNA formulation compared to an increase with unmodified. A patient-family survey reported that the vaccines were well tolerated. These findings suggest that COVID vaccination using nucleoside-modified forms of mRNA vaccines are unlikely to directly stimulate ISG expression in response to mRNA internalization in AGS tissues. With continued community spread, we recommend vaccination using nucleoside-modified mRNA vaccines in this rare disease group in individuals for whom vaccines were previously well tolerated.

Hematologic abnormalities in Aicardi Goutières Syndrome.

BACKGROUND: Because of the broad clinical spectrum, heritable autoinflammatory diseases present a management and therapeutic challenge. The most common genetic interferonopathy, Aicardi Goutières Syndrome (AGS), is associated with early onset neurologic disability and systemic inflammation. The chronic inflammation of AGS is the result of dysregulation of interferon (IFN) expression by one of nine genes within converging pathways. While each AGS subtype shares common features, distinct patterns of severity and potential for systemic complications amongst the genotypes are emerging. Multilineage cytopenias are a potentially serious, but poorly understood, complication of AGS. As immunomodulatory treatment options are developed, it is important to characterize the role of the disease versus treatment in hematologic abnormalities. This will allow for better understanding and management of cytopenia. METHODS: In total, 142 individuals with molecularly-confirmed AGS were included. Information on genotype, demographics, and all available hematologic laboratory values were collected from existing medical records. As part of a clinical trial, a subset of this cohort (n = 52) were treated with a janus kinase inhibitor (baricitinib), and both pre- and post-treatment values were included. Abnormal values were graded based on Common Terminology Criteria for Adverse Events (CTCAE v5.0), supplemented with grading definitions for thrombocytosis, and were compared across genotypes and baricitinib exposure. RESULTS: In total, 11,184 laboratory values were collected over a median of 2.54 years per subject (range 0-22.68 years). To reduce bias from repeated sampling within a limited timeframe, laboratory results were restricted to the most abnormal value within a month (n = 8485). The most common abnormalities were anemia (noted in 24% of subjects prior to baricitinib exposure), thrombocytopenia (9%), and neutropenia (30%). Neutropenia was most common in the SAMHD1 cohort and increased with baricitinib exposure (38/69 measurements on baricitinib versus 14/121 while not on baricitinib). Having an abnormality prior to treatment was associated with having an abnormality on treatment for neutropenia and thrombocytopenia. CONCLUSION: By collecting available laboratory data throughout the lifespan, we were able to identify novel patterns of hematologic abnormalities in AGS. We found that AGS results in multilineage cytopenias not limited to the neonatal period. Neutropenia, anemia, and thrombocytopenia were common. Moderate-severe graded events of neutropenia, anemia, and leukopenia were more common on baricitinib, but rarely of clinical consequence. Based on these results, we would recommend careful monitoring of hematologic parameters of children affected by AGS throughout the lifespan, especially while on therapy, and consideration of AGS as a potential differential diagnosis in children with neurologic impairment of unclear etiology with hematologic abnormalities. Trial registration ClinicalTrials.gov Identifier: NCT01724580 ClinicalTrials.gov Identifier: NCT03921554.

Dialysis Nonadherence and Kidney Transplant Outcomes: A Retrospective Cohort Study.

RATIONALE & OBJECTIVE: Concerns about nonadherent behaviors often prevent dialysis patients from entering waitlists for transplant even though there is an inconsistent association of these behaviors with posttransplant outcomes. We examined the association between plausible metrics of nonadherence related to dialysis treatment and posttransplant outcomes. STUDY DESIGN: Retrospective cohort. We linked national dialysis treatment data with transplant registry data. SETTING AND PARTICIPANTS: Adult patients receiving maintenance hemodialysis from January 1, 2004, through December 31, 2014, who received a kidney transplant at a US center. EXPOSURES: We examined 5 nonadherence metrics: serum potassium level (≥5.2 mEq/L), serum phosphorus level (>5.5 mg/dL), interdialytic weight gain (IDWG; ≥5 L), shortened treatments (≥30 min), and missed treatments (≥1); missed treatment data were available only for 2004-2009. These metrics were characterized per proportion of time under observation. Dialysis observation time was divided into 3-month intervals (quarters), and the number of nonadherent measurements in each domain was calculated for each quarter. OUTCOMES: Allograft loss, mortality, and acute rejection in the first posttransplant year. ANALYTICAL APPROACH: Using Cox proportional hazards and logistic regression, we estimated the hazard ratios for graft loss and mortality and odds ratios for rejection. RESULTS: 9,543 patients met inclusion criteria. In our primary model, hyperphosphatemia (adjusted hazard ratio [aHR], 1.27 [95% CI, 1.08-1.49]), large IDWG (aHR, 1.39 [95% CI, 1.23-1.59]), and shortened treatments (aHR, 1.54 [95% CI, 1.12-2.13]) were associated with greater rates of allograft loss, but hyperkalemia was not. Large IDWG (aHR, 1.49 [95% CI, 1.29-1.73]) and shortened treatments (aHR, 1.34 [95% CI, 1.13-1.58]) were associated with mortality, whereas hyperkalemia and hyperphosphatemia were not. Only shortened treatments were associated with an increased risk of acute rejection (adjusted odds ratio, 3.88 [95% CI, 1.98-7.58]). In models limited to the years 2004-2009 that included missed treatments, missed treatments were associated only with mortality. LIMITATIONS: Unmeasured confounding (eg, dietary data); adherence metrics used may have multiple, complex causes. CONCLUSIONS: Plausible measures of dialysis nonadherence have long-term associations with allograft and patient survival. Behavioral metrics were more closely associated with outcomes than laboratory markers were. The implications of nonadherent behaviors for dialysis patients must be carefully considered before patients are excluded from transplantation.

Age- and sex-specific rates of gall bladder disease in children with sickle cell disease.

BACKGROUND: Children with sickle cell disease (SCD) have an increased risk for gallstones due to chronic hyperbilirubinemia from hemolysis. Although gallstones are a known complication, there is variability in estimates of disease burden and uncertainty in the association between sex and gall bladder disease (GBD). METHODS: This was a retrospective cohort study of children with SCD using administrative claims data (January 1, 2014-December 31, 2018). Population-averaged multivariable panel-data logistic regression models were used to evaluate the association between GBD clinical encounters (outcome) and two exposures (age and sex). Annual GBD risk was calculated using predictive margins, adjusting for disease severity, transfusion frequency, and hydroxyurea exposure. RESULTS: A total of 13,745 individuals (of 21,487 possible) met inclusion criteria. The population was evenly split across sex (49.5% female) with predominantly Medicaid insurance (69%). A total of 946 individuals (6.9%) had GBD, 432 (3.1%) had a gallstone complication, and 487 (3.5%) underwent cholecystectomy. The annual risk of GBD rose nonlinearly from 1 to 5% between ages 1 and 19 years with no difference between males and females. Cholecystectomy occurred primarily in individuals with GBD (87%), and neither age nor sex was associated with cholecystectomy in this population. High disease severity (compared with low) more than doubled the annual risk of GBD at all ages. CONCLUSIONS: GBD is associated with age but not sex in children with SCD. Neither age nor sex is associated with risk of cholecystectomy. High disease severity increases the rate of GBD at all ages.

Sustained Improvement in Tracheal Intubation Safety Across a 15-Center Quality-Improvement Collaborative: An Interventional Study From the National Emergency Airway Registry for Children Investigators.

OBJECTIVES: To evaluate the effect of a tracheal intubation safety bundle on adverse tracheal intubation-associated events across 15 PICUs. DESIGN: Multicenter time-series study. SETTING: PICUs in the United States. PATIENTS: All patients received tracheal intubations in ICUs. INTERVENTIONS: We implemented a tracheal intubation safety bundle as a quality-improvement intervention that includes: 1) quarterly site benchmark performance report and 2) airway safety checklists (preprocedure risk factor, approach, and role planning, preprocedure bedside "time-out," and immediate postprocedure debriefing). We define each quality-improvement phase as baseline (-24 to -12 mo before checklist implementation), benchmark performance reporting only (-12 to 0 mo before checklist implementation), implementation (checklist implementation start to time achieving > 80% bundle adherence), early bundle adherence (0-12 mo), and sustained (late) bundle adherence (12-24 mo). Bundle adherence was defined a priori as greater than 80% of checklist use for tracheal intubations for 3 consecutive months. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the adverse tracheal intubation-associated event, and secondary outcomes included severe tracheal intubation-associated events, multiple tracheal intubation attempts, and hypoxemia less than 80%.From January 2013 to December 2015, out of 19 participating PICUs, 15 ICUs (79%) achieved bundle adherence. Among the 15 ICUs, the adverse tracheal intubation-associated event rates were baseline phase: 217/1,241 (17.5%), benchmark reporting only phase: 257/1,750 (14.7%), early 0-12 month complete bundle compliance phase: 247/1,591 (15.5%), and late 12-24 month complete bundle compliance phase: 137/1,002 (13.7%). After adjusting for patient characteristics and clustering by site, the adverse tracheal intubation-associated event rate significantly decreased compared with baseline: benchmark: odds ratio, 0.83 (0.72-0.97; p = 0.016); early bundle: odds ratio, 0.80 (0.63-1.02; p = 0.074); and late bundle odds ratio, 0.63 (0.47-0.83; p = 0.001). CONCLUSIONS: Effective implementation of a quality-improvement bundle was associated with a decrease in the adverse tracheal intubation-associated event that was sustained for 24 months.

Changes in Body Composition, Muscle Strength, and Fat Distribution Following Kidney Transplantation.

RATIONALE & OBJECTIVE: Low muscle mass relative to fat mass (relative sarcopenia) has been associated with mortality and disability but has not been examined after kidney transplantation. We studied how measures of body composition change after receipt of a kidney allograft. STUDY DESIGN: Prospective longitudinal cohort study. SETTING & PARTICIPANTS: 60 kidney transplant recipients, aged 20-60 years, at the University of Pennsylvania. EXPOSURE: Kidney transplantation. OUTCOME: Dual-energy x-ray absorptiometry measures of fat mass index (FMI) and appendicular lean mass index (ALMI, representing muscle mass), computed tomography measures of muscle density (low density represents increased intramuscular adipose tissue), dynamometer measures of leg muscle strength, and physical activity. ALMI relative to FMI (ALMFMI) is an established index of relative sarcopenia. ANALYTICAL APPROACH: Measures expressed as age, sex, and race-specific z scores for transplant recipients were compared with 327 healthy controls. Regression models were used to identify correlates of change in outcome z scores and compare transplant recipients with controls. RESULTS: At transplantation, ALMI, ALMIFMI, muscle strength, and muscle density z scores were lower versus controls (all P≤0.001). Transplant recipients received glucocorticoids throughout. The prevalence of obesity increased from 18% to 45%. Although ALMI increased after transplantation (P<0.001) and was comparable with the controls from 6 months onward, gains were outpaced by increases in FMI, resulting in persistent ALMIFMI deficits (mean z score of-0.31 at 24 months; P=0.02 vs controls). Muscle density improved after transplantation despite gains in FMI (P=0.02). Muscle strength relative to ALMI also improved (P=0.04) but remained low compared with controls (P=0.01). Exercise increased in the early months after transplantation (P<0.05) but remained lower than controls (P = 0.02). LIMITATIONS: Lack of muscle biopsies precluded assessment of muscle histology and metabolism. CONCLUSIONS: The 2-year interval after kidney transplantation was characterized by gains in muscle mass and strength that were outpaced by gains in fat mass, resulting in persistent relative sarcopenia.

Randomized Clinical Trial of First-Line Genome Sequencing in Pediatric White Matter Disorders.

OBJECTIVE: Genome sequencing (GS) is promising for unsolved leukodystrophies, but its efficacy has not been prospectively studied. METHODS: A prospective time-delayed crossover design trial of GS to assess the efficacy of GS as a first-line diagnostic tool for genetic white matter disorders took place between December 1, 2015 and September 27, 2017. Patients were randomized to receive GS immediately with concurrent standard of care (SoC) testing, or to receive SoC testing for 4 months followed by GS. RESULTS: Thirty-four individuals were assessed at interim review. The genetic origin of 2 patient's leukoencephalopathy was resolved before randomization. Nine patients were stratified to the immediate intervention group and 23 patients to the delayed-GS arm. The efficacy of GS was significant relative to SoC in the immediate (5/9 [56%] vs 0/9 [0%]; Wild-Seber, p < 0.005) and delayed (control) arms (14/23 [61%] vs 5/23 [22%]; Wild-Seber, p < 0.005). The time to diagnosis was significantly shorter in the immediate-GS group (log-rank test, p = 0.04). The overall diagnostic efficacy of combined GS and SoC approaches was 26 of 34 (76.5%, 95% confidence interval = 58.8-89.3%) in <4 months, greater than historical norms of <50% over 5 years. Owing to loss of clinical equipoise, the trial design was altered to a single-arm observational study. INTERPRETATION: In this study, first-line GS provided earlier and greater diagnostic efficacy in white matter disorders. We provide an evidence-based diagnostic testing algorithm to enable appropriate clinical GS utilization in this population. ANN NEUROL 2020;88:264-273.