Biallelic Loss of Function Variants in SENP7 Cause Immunodeficiency with Neurologic and Muscular Phenotypes.

To evaluate a novel candidate disease gene, we engaged international collaborators and identified rare, biallelic, specifically homozygous, loss of function variants in SENP7 in 4 children from 3 unrelated families presenting with neurodevelopmental abnormalities, dysmorphism, and immunodeficiency. Their clinical presentations were characterized by hypogammaglobulinemia, intermittent neutropenia, and ultimately death in infancy for all 4 patients. SENP7 is a sentrin-specific protease involved in posttranslational modification of proteins essential for cell regulation, via a process referred to as deSUMOylation. We propose that deficiency of deSUMOylation may represent a novel mechanism of primary immunodeficiency.

Characterization of SARS-CoV-2 and common cold coronavirus-specific T-cell responses in MIS-C and Kawasaki disease children.

The immunopathogenesis of multisystem inflammatory syndrome (MIS-C) in children that may follow exposure to SARS-CoV-2 is incompletely understood. Here, we studied SARS-CoV-2-specific T cells in MIS-C, Kawasaki disease (KD), and SARS-CoV-2 convalescent controls using peptide pools derived from SARS-CoV-2 spike or nonspike proteins, and common cold coronaviruses (CCC). Coordinated CD4+ and CD8+ SARS-CoV-2-specific T cells were detected in five MIS-C subjects with cross-reactivity to CCC. CD4+ and CD8+ T-cell responses alone were documented in three and one subjects, respectively. T-cell specificities in MIS-C did not correlate with disease severity and were similar to SARS-CoV-2 convalescent controls. T-cell memory and cross-reactivity to CCC in MIS-C and SARS-CoV-2 convalescent controls were also similar. The chemokine receptor CCR6, but not CCR9, was highly expressed on SARS-CoV-2-specific CD4+ but not on CD8+ T cells. Only two of 10 KD subjects showed a T-cell response to CCC. Enumeration of myeloid APCs revealed low cell precursors in MIS-C subjects compared to KD. In summary, children with MIS-C mount a normal T-cell response to SARS-CoV-2 with no apparent relationship to antecedent CCC exposure. Low numbers of tolerogenic myeloid DCs may impair their anti-inflammatory response.

Selective Valve Removal for Melody Valve Endocarditis: Practice Variations in a Multicenter Experience.

Guidelines for management of Melody transcatheter pulmonary valve (TPV) infective endocarditis (IE) are lacking. We aimed to identify factors associated with surgical valve removal versus antimicrobial therapy in Melody TPV IE. Multicenter retrospective analysis of all patients receiving Melody TPV from 10/2010 to 3/2019 was performed to identify cases of IE. Surgical explants versus non-surgical cases were compared. Of the 663 Melody TPV implants, there were 66 cases of IE in 59 patients (59/663, 8.8%). 39/66 (59%) were treated with IV antimicrobials and 27/66(41%) underwent valve explantation. 26/59 patients (44%) were treated medically without explantation or recurrence with average follow-up time of 3.5 years (range:1-9). 32% of Streptococcus cases, 53% of MSSA, and all MRSA cases were explanted. 2 of the 4 deaths had MSSA. CART analysis demonstrated two important parameters associated with explantation: a peak echo gradient ≥ 47 mmHg at IE diagnosis(OR 10.6, p < 0.001) and a peak echo gradient increase of > 24 mmHg compared to baseline (OR 6.7, p = 0.01). Rates of explantation varied by institution (27 to 64%). In our multicenter experience, 44% of patients with Melody IE were successfully medically treated without valve explantation or recurrence. The degree of valve stenosis at time of IE diagnosis was strongly associated with explantation. Rates of explantation varied significantly among the institutions.

Comparison of RT-PCR Cycle Threshold Values from Respiratory Specimens in Symptomatic and Asymptomatic Children with SARS-CoV-2 Infection.

BACKGROUND: Understanding viral kinetics of SARS-CoV-2 is important to assess risk of transmission, manage treatment, and determine the need for isolation and protective equipment. The impact of viral load in asymptomatic infected children is important to understand transmission potential. We sought to determine whether children deemed to be asymptomatic had a difference in the PCR cycle threshold (Ct) value of respiratory samples from symptomatic children with SARS-CoV-2 infection. METHODS: This was a retrospective cross-sectional study to compare PCR Ct values of children who tested positive for SARS-CoV-2 by respiratory samples collected over a 4-month period at a large tertiary care children's hospital. RESULTS: We analyzed 728 children who tested positive for SARS-CoV-2 by RT-PCR from a respiratory sample over a 4-month period and for whom data was available in the electronic medical record. Overall, 71.2% of infected children were symptomatic. The mean Ct value for symptomatic patients (Ct mean 19.9, SD 6.3) was significantly lower than asymptomatic patients (Ct mean 23.5, SD 6.5) (P value < 0.001, CI 95th 2.6 - 4.6). The mean PCR Ct value was lowest in children less than 5 years of age. CONCLUSIONS: In this retrospective review of children who tested positive by RT-PCR for SARS CoV-2, the mean Ct was significantly lower in symptomatic children and was lowest in children under 5 years of age, indicating that symptomatic children and younger children infected with SARS-CoV-2 may have a higher viral load in the nasopharynx compared to asymptomatic children. Further studies are needed to assess the transmission potential from asymptomatic children.

Comparison of Reverse-Transcription Polymerase Chain Reaction Cycle Threshold Values From Respiratory Specimens in Symptomatic and Asymptomatic Children With Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

BACKGROUND: Understanding viral kinetics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is important to assess risk of transmission, manage treatment, and determine the need for isolation and protective equipment. The impact of viral load in asymptomatic infected children is important to understand transmission potential. We sought to determine whether children deemed to be asymptomatic had a difference in the polymerase chain reaction (PCR) cycle threshold (Ct) value of respiratory samples from symptomatic children with SARS-CoV-2 infection. METHODS: This was a retrospective cross-sectional study to compare PCR Ct values of children who tested positive for SARS-CoV-2 by respiratory samples collected over a 4-month period at a large tertiary care children's hospital. RESULTS: We analyzed 728 children who tested positive for SARS-CoV-2 by reverse-transcription PCR (RT-PCR) from a respiratory sample over a 4-month period and for whom data were available in the electronic medical record. Overall, 71.2% of infected children were symptomatic. The mean Ct value for symptomatic patients (Ct mean, 19.9 [standard deviation, 6.3]) was significantly lower than for asymptomatic patients (Ct mean, 23.5 [standard deviation, 6.9]) (P < .001; 95% confidence interval, 2.6-4.6). The mean PCR Ct value was lowest in children <5 years of age. CONCLUSIONS: In this retrospective review of children who tested positive by RT-PCR for SARS-CoV-2, the mean Ct was significantly lower in symptomatic children and was lowest in children <5 years of age, indicating that symptomatic children and younger children infected with SARS-CoV-2 may have a higher viral load in the nasopharynx compared to asymptomatic children. Further studies are needed to assess the transmission potential from asymptomatic children.

Clinical application of cell-free next-generation sequencing for infectious diseases at a tertiary children's hospital.

BACKGROUND: Children affected by infectious diseases may not always have a detectable infectious etiology. Diagnostic uncertainty can lead to prolonged hospitalizations, inappropriately broad or extended courses of antibiotics, invasive diagnostic procedures, and difficulty predicting the clinical course and outcome. Cell-free plasma next-generation sequencing (cfNGS) can identify viral, bacterial, and fungal infections by detecting pathogen DNA in peripheral blood. This testing modality offers the ability to test for many organisms at once in a shotgun metagenomic approach with a rapid turnaround time. We sought to compare the results of cfNGS to conventional diagnostic test results and describe the impact of cfNGS on clinical care in a diverse pediatric population at a large academic children's hospital. METHODS: We performed a retrospective chart review of hospitalized subjects at a tertiary pediatric hospital to determine the diagnostic yield of cfNGS and its impact on clinical care. RESULTS: We describe the clinical application of results from 142 cfNGS tests in the management of 110 subjects over an 8-month study period. In comparison to conventional testing as a reference standard, cfNGS was found to have a positive percent agreement of 89.6% and negative percent agreement of 52.3%. Furthermore, 32.4% of cfNGS results were directly applied to make a clinical change in management. CONCLUSIONS: We demonstrate the clinically utility of cfNGS in the management of acutely ill children. Future studies, both retrospective and prospective, are needed to clarify the optimal indications for testing.

The Evaluation of Hematologic Screening and Perioperative Management in Patients with Noonan Syndrome: A Retrospective Chart Review.

OBJECTIVES: To assess the potential impact of using screening recommendations for bleeding disorders in patients with Noonan syndrome on perioperative bleeding complications. STUDY DESIGN: We performed a retrospective, single-site cohort study; patients were identified by query of the electronic medical record. All patients with a clinical diagnosis of Noonan syndrome over a 10-year period were included. Data on surgeries, hematologic evaluation, bleeding symptoms, and bleeding complications were extracted. Surgeries were graded as major or minor. RESULTS: We identified 101 patients with Noonan syndrome, 70 of whom required surgery for a total of 164 procedures. Nine patients (9/70; 12.8%) had bleeding complications, occurring in those without comprehensive testing or perioperative intervention and undergoing major or dental surgery. Based on these findings, the risk of a bleeding complication for patients with Noonan syndrome who did not have comprehensive testing or perioperative intervention was 6.2% (95% CI 2.3%-10.1%), indicating the number needed to treat or screen would be 16 to prevent 1 bleeding complication (95% CI 9.9-43.9). The majority of patients had either no or incomplete evaluation (59 of 101; 58.4%). CONCLUSIONS: With proper evaluation and management, the bleeding risk in patients with Noonan syndrome can be minimized. Efforts are needed to address the knowledge and implementation gap in this evaluation.

Emerging Role of Plasma Microbial Cell-free DNA in the Diagnosis of Pediatric Mucormycosis.

Mucormycosis is a rare and devastating angioinvasive infection that can be challenging to diagnose due to the low sensitivity of current noninvasive diagnostics and the lack of a "gold standard" reference test. We describe a retrospective case series of children with suspected mucormycosis where plasma microbial cell-free DNA testing was utilized in the diagnostic evaluation to illustrate the ways in which microbial cell-free DNA testing can noninvasively contribute to the evaluation and management of at-risk, immunosuppressed patients suspected of mucormycosis.

Application of cell-free plasma next-generation sequencing technology in the diagnosis and management of pediatric meningitis.

This retrospective study evaluates the clinical utility of CFPNGS in the diagnosis and management of pediatric meningitis. CFPNGS identified a causative pathogen in 36% of 28 subjects, compared to 50% for diverse conventional testing (57% combined). CFPNGS may be considered as an adjunct to standard testing.

Pathogen kinetics and detection by next-generation sequencing in pediatric complicated pneumonia.

Pediatric pneumonia can be severe and result in empyema. Next-generation sequencing (NGS) may broadly detect pathogens though, optimal timing and impact of sample type on diagnostic yield is unknown. This is a prospective, single-center pilot study of children aged 3 months through 17 years admitted to the PICU with a primary diagnosis of complicated pneumonia. Plasma, endotracheal, nasopharyngeal, and pleural fluid samples were collected at three time points during hospitalization. After nucleic acid extraction, combined libraries were enriched with an NGS enrichment panel kit (RPIP, Illumina), sequenced and quantitative organism detections were analyzed. NGS identified the same bacterial pathogen as traditional testing in all samples, regardless of antibiotic pre-treatment or time collected. Conventional culture methods only identified the pathogen reliably in invasively obtained pleural fluid or endotracheal aspirates. Future application of NGS may allow for non-invasive pathogen detection at a broader range of time points and more targeted antibiotic coverage.

Universal Digital High-Resolution Melt Analysis for the Diagnosis of Bacteremia.

Fast and accurate diagnosis of bloodstream infection is necessary to inform treatment decisions for septic patients, who face hourly increases in mortality risk. Blood culture remains the gold standard test but typically requires approximately 15 hours to detect the presence of a pathogen. We, therefore, assessed the potential for universal digital high-resolution melt (U-dHRM) analysis to accomplish faster broad-based bacterial detection, load quantification, and species-level identification directly from whole blood. Analytical validation studies demonstrated strong agreement between U-dHRM load measurement and quantitative blood culture, indicating that U-dHRM detection is highly specific to intact organisms. In a pilot clinical study of 17 whole blood samples from pediatric patients undergoing simultaneous blood culture testing, U-dHRM achieved 100% concordance when compared with blood culture and 88% concordance when compared with clinical adjudication. Moreover, U-dHRM identified the causative pathogen to the species level in all cases where the organism was represented in the melt curve database. These results were achieved with a 1-mL sample input and sample-to-answer time of 6 hours. Overall, this pilot study suggests that U-dHRM may be a promising method to address the challenges of quickly and accurately diagnosing a bloodstream infection.

Evolving Management of Acute Mastoiditis: Analysis of the Pediatric Health Information System Database.

OBJECTIVE: The optimal management of acute mastoiditis remains controversial. Most existing studies are retrospective single-institutional experiences with small cohorts. Our objectives were to analyze the treatment of acute mastoiditis by pediatric centers across the United States and changes in management over time. STUDY DESIGN: Retrospective analysis. SETTING: Administrative database study using Pediatric Health Information System. METHODS: Patients ≤18 years of age who were admitted with a principal diagnosis of acute mastoiditis from January 1, 2010 to December 31, 2019 were included. Trends were assessed by Cochran-Armitage Trend Test. χ2 and Wilcoxon rank sum tests were used to compare outcomes between the surgical and nonsurgical groups. RESULTS: A total of 2170 patients met the inclusion criteria, with 1248 (57.5%) requiring surgical management. The rate of surgical procedures decreased significantly over time. The rate of myringotomy decreased from 64% in 2010 to 47% in 2019 (p < .001), and mastoidectomy decreased from 22% in 2010 to 10% in 2019 (p < .001). On admission, 29% of the cohort presented with mastoiditis-related complications. Patients treated surgically were younger (p < .001), more likely to present with complications (37.5% vs 17.5%, p < .001), required longer length of stay (3.7 vs 2.3 days, p < .001), and had higher intensive care unit utilization (8.6% vs 2.2%, p < .001). However, the rate of 30-day readmission, emergency department return, and in-hospital mortality were all similar. CONCLUSION: Acute mastoiditis has been successfully treated with declining rates of a surgery over time. Younger patients who present with complications are more likely to be managed surgically, and the overall outcomes remain excellent.

Universal digital high resolution melt analysis for the diagnosis of bacteremia.

Fast and accurate diagnosis of bloodstream infection is necessary to inform treatment decisions for septic patients, who face hourly increases in mortality risk. Blood culture remains the gold standard test but typically requires ∼15 hours to detect the presence of a pathogen. Here, we assess the potential for universal digital high-resolution melt (U-dHRM) analysis to accomplish faster broad-based bacterial detection, load quantification, and species-level identification directly from whole blood. Analytical validation studies demonstrated strong agreement between U-dHRM load measurement and quantitative blood culture, indicating that U-dHRM detection is highly specific to intact organisms. In a pilot clinical study of 21 whole blood samples from pediatric patients undergoing simultaneous blood culture testing, U-dHRM achieved 100% concordance when compared with blood culture and 90.5% concordance when compared with clinical adjudication. Moreover, U-dHRM identified the causative pathogen to the species level in all cases where the organism was represented in the melt curve database. These results were achieved with a 1 mL sample input and sample-to-answer time of 6 hrs. Overall, this pilot study suggests that U-dHRM may be a promising method to address the challenges of quickly and accurately diagnosing a bloodstream infection. Universal digital high resolution melt analysis for the diagnosis of bacteremia: April Aralar, Tyler Goshia, Nanda Ramchandar, Shelley M. Lawrence, Aparajita Karmakar, Ankit Sharma, Mridu Sinha, David Pride, Peiting Kuo, Khrissa Lecrone, Megan Chiu, Karen Mestan, Eniko Sajti, Michelle Vanderpool, Sarah Lazar, Melanie Crabtree, Yordanos Tesfai, Stephanie I. Fraley.

Plasma cell free next-generation sequencing detects an unusual pneumonia pathogen in an immunocompetent adolescent with acute respiratory distress syndrome.

This case details a rapid diagnosis of legionella pneumonia causing severe acute respiratory distress syndrome (ARDS) in an otherwise healthy adolescent through plasma microbial cell-free DNA next generation sequencing (mcfDNA-NGS). Diagnosis by mcfDNA-NGS of this unexpected pathogen led to narrowing of antimicrobials and the addition of glucocorticoids as adjunctive therapy for ARDS.

Pediatric Osteoarticular Infections Caused by Mycobacteria Tuberculosis Complex: A 26-Year Review of Cases in San Diego, CA.

BACKGROUND: Osteoarticular infections (OAIs) account for 10%-20% of extrapulmonary Mycobacteria tuberculosis (MTB) complex infections in children and 1%-2% of all pediatric tuberculosis infections. Treatment regimens and durations typically mirror recommendations for other types of extrapulmonary MTB, but there are significant variations in practice, with some experts suggesting a treatment course of 12 months or longer. METHODS: We conducted a retrospective review of children diagnosed with MTB complex OAI and cared for between December 31, 1992, and December 31, 2018, at a tertiary care pediatric hospital near the United States-Mexico border. RESULTS: We identified 21 children with MTB complex OAI during the study period. Concurrent pulmonary disease (9.5%), meningitis (9.5%), and intra-abdominal involvement (14.3%) were all observed. MTB complex was identified by culture from operative samples in 15/21 children (71.4%); 8/15 (53.3%) cultures were positive for Mycobacterium bovis. Open bone biopsy was the most common procedure for procurement of a tissue sample and had the highest culture yield. The median duration of antimicrobial therapy was 52 weeks (interquartile range, 46-58). Successful completion of therapy was documented in 15 children (71.4%). Nine children (42.9%) experienced long-term sequelae related to their infection. CONCLUSION: Among the 21 children with MTB complex OAI assessed, 8 of 15 (53.3%) children with a positive tissue culture had M. bovis, representing a higher percentage than in previous reports and potentially reflecting its presence in unpasteurized dairy products in the California-Baja region. Bone biopsy produced the highest culture yield in this study. Given the rarity of this disease, multicenter collaborative studies are needed to improve our understanding of the presentation and management of pediatric MTB complex OAI.

Impact of Cell-Free Next-Generation Sequencing on Management of Pediatric Complicated Pneumonia.

BACKGROUND: Community-acquired pneumonia (CAP) is common in pediatrics. More severe complicated CAP (cCAP) requires broad-spectrum empirical therapy. Cell-free plasma next-generation sequencing (cfNGS), a DNA-based diagnostic tool, could be used to guide therapy. We retrospectively compared the pathogen identification rate of cfNGS to that of standard culture methods and assessed the impact of cfNGS on antibiotic therapy in children hospitalized for cCAP. METHODS: We conducted a retrospective review of children aged 3 months to 18 years hospitalized for cCAP with cfNGS results from January 24, 2018, to December 31, 2020. We compared the positivity rate of conventional microbiologic diagnostic testing with that of cfNGS and the impact on clinical management, including changes in antibiotic therapy. RESULTS: We identified 46 hospitalized children with cCAP with cfNGS results. Of these children, 34 also had blood cultures (1 positive for pathogen; 3%) and 37 had pleural fluid cultures (10 positive for pathogen; 27%). Of the 46 children, positive cfNGS testing results were positive for pathogen in 45 (98%), with the causative pathogen identified in 41 (89%). cfNGS was the only method for pathogen identification in 32 children (70%). cfNGS results changed management in 36 (78%) of 46 children, with the antibiotic spectrum narrowed in 29 (81%). CONCLUSIONS: cfNGS provided a higher diagnostic yield in our pediatric cCAP cohort compared with conventional diagnostic testing and affected management in 78% of children. Prospective studies are needed to better characterize the clinical outcome, cost-effectiveness, and antimicrobial stewardship benefits of cfNGS in pediatric cCAP.

AN 8-YEAR-OLD CALIFORNIA GIRL WITH ASYMPTOMATIC HEPATIC CYSTS.

Echinococcus infections are rare in the United States but may present a growing public health threat. We present the case of an 8-year-old female patient from Southern California who was diagnosed with hepatic echinococcosis after the incidental discovery of large hepatic cysts.

Management of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Onboard a U.S. Navy Hospital Ship Amid a Global Omicron Surge.

INTRODUCTION: We present a real-world experience of a U.S. Navy Hospital Ship deployed amid a global Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surge and the challenges of navigating policy while maintaining a mission-focused itinerary in an operational environment. MATERIALS AND METHODS: We performed a chart review of SARS-CoV-2 cases from April 18 to September 20, 2022, within a closed population of fully vaccinated adults onboard the USNS Mercy (T-AH 19) during the 5-month 2022 Pacific Partnership mission to Guam, Vietnam, Palau, Philippines, and the Solomon Islands. RESULTS: There were 123 total SARS-CoV-2 cases over the course of the mission, constituting 16.6% of the total crew (123/741). No more than 14 service members were actively infected at a given time (1.9%, 14/741). The average number of active cases at any given time was 0.8 (1.9 SD, 0.1% [0.8/741]), and just 14 of these were shipboard secondary cases. No significant operational requirements of the ship were impacted by infection-related manning shortages, there were no hospitalizations, and all infected members experienced full recovery. CONCLUSIONS: Despite ongoing cases throughout the majority of the mission, a healthy immunized crew experienced no serious cases and minimal impact on operational effectiveness.

An 11-Year-old Male With X-linked Agammaglobulinemia and Persistent Abdominal Pain.

Metagenomic next-generation sequencing is a promising tool for detecting pathogens that are difficult to isolate by traditional modalities, particularly in the diagnosis of complex infections in immunocompromised children. We describe a child with X-linked agammaglobulinemia and chronic abdominal pain diagnosed with a multiorganism infection (Helicobacter cinaedi, Campylobacter coli and Parainfluenza) identified by various diagnostic tools, including plasma metagenomic next-generation sequencing.