Partial Lipodystrophy Affecting the Extremities in a Young Woman With Autoimmune Polyglandular Syndrome 1.

Autoimmune polyglandular syndrome 1 (APS1) is an autosomal recessive disorder due to biallelic pathogenic variants in the autoimmune regulator (AIRE) gene that manifests with chronic mucocutaneous candidiasis, primary hypoparathyroidism, and adrenal insufficiency. We report a 39-year-old woman with APS1 who developed partial lipodystrophy during adulthood. She presented with diaper rashes, oral thrush, and tetany during infancy due to candidiasis and hypoparathyroidism. During childhood, she developed hypothyroidism, primary adrenal insufficiency, and ovarian insufficiency. At age 14, she received a sibling-matched allogenic bone marrow transplant due to multiple antibiotic-refractory fungal infections. At age 35, her serum triglycerides were 914 mg/dL (10.32 mmol/L) and she had loss of subcutaneous fat from the upper and lower extremities and hips. A whole-body dual-energy x-ray absorptiometry revealed lower-extremity fat at less than the first percentile. Whole-exome sequencing on DNA extracted from saliva revealed pathogenic variants, p.Leu28Pro and p.Arg257* in AIRE but none in the known lipodystrophy genes. Phage-immunoprecipitation-sequencing revealed the presence of autoantibodies to MAGEB1, MAGEB4, and RFX6, which have been previously reported in APS1. Our case suggests that patients with APS1 may develop partial lipodystrophy due to autoantibodies against novel adipocyte-expressed proteins. A causal relationship of high levels of autoantibodies in our patient to adipose tissue-expressed ODC1, NUCKS1, or FNBP1L and lipodystrophy remains uncertain.

Infection characteristics among Serratia marcescens capsule lineages.

Serratia marcescens is a healthcare-associated pathogen that causes bloodstream infections, pneumonia, and urinary tract infections. The capsule polysaccharide of S. marcescens is a critical fitness determinant during infection and recent work established the relationship between capsule locus (KL) genetic sequences within the species. Strains belonging to KL1 and KL2 capsule clades produce sialylated polysaccharides and represent the largest subpopulation of isolates from clinical origin while the S. marcescens type strain and other environmental isolates were classified as KL5. In this work, the contribution of these and other capsules to pathogenesis in multiple infection models was determined. Using a murine tail vein injection model of bacteremia, clinical strains demonstrated capsule-dependent colonization of spleen, liver, and kidney following inoculation. The KL5 strain, in contrast, exhibited no loss of survival in this model when capsule genes were deleted. Furthermore, the wild-type KL5 strain was cleared more rapidly from both the spleen and liver compared to a KL1 strain. Similar results were observed in a bacteremic pneumonia model in that all tested strains of clinical origin demonstrated a requirement for capsule in both the primary lung infection site and for bloodstream dissemination to other organs. Finally, strains from each KL clade were tested for the role of capsule in internalization by bone marrow-derived macrophages. Only the sialylated KL1 and KL2 clade strains, representing the majority of clinical isolates, exhibited capsule-dependent inhibition of internalization, suggesting that capsule-mediated resistance to macrophage phagocytosis may enhance survival and antibacterial defenses during infection.

Diagnostic Utility of Pre-Genomic Hepatitis B RNA in the Evaluation of HBV/HIV Coinfection.

Background: Newer biomarkers of Hepatitis B virus (HBV) infection and treatment response have not been well-characterized in individuals with HBV/HIV coinfection. Methods: Pre-genomic RNA (pgRNA) and quantitative HBsAg (qHBsAg) were used to evaluate the associations with baseline characteristics. Participants included two separate groups - 236 with HBV/HIV coinfection enrolled in a cross-sectional cohort in Ghana and 47 from an HBV nucleoside/nucleotide treatment trial comparing tenofovir to adefovir in the United States. Results: In both cohorts, HBe antigenemia was highly associated with pgRNA and HBV DNA levels. In the treatment cohort, pre-treatment pgRNA serum concentration was 7.0 log10 U/mL, and mean qHBsAg was 201,297 IU/mL. The observed treatment-associated decrease in pgRNA was consistent with a biphasic decline curve that reached second-phase kinetics following treatment week 12. Changes from baseline were significantly correlated with changes in serum ALT (r = - 0.518; P = 0.023) but not with changes in HBV DNA (r = 0.132, P = NS). qHBsAg also correlated with ALT change (r = - 0.488, P = 0.034). Conclusion: pgRNA and qHBsAg represent newer biomarkers of HBV replication that may help monitor response and treatment outcomes. HBV pgRNA is highly associated with both HBeAg and ALT and may predict both active replication from the closed circular DNA (cccDNA) template as well as hepatic injury.

Molecular mimicry in multisystem inflammatory syndrome in children.

Multisystem inflammatory syndrome in children (MIS-C) is a severe, post-infectious sequela of SARS-CoV-2 infection1,2, yet the pathophysiological mechanism connecting the infection to the broad inflammatory syndrome remains unknown. Here we leveraged a large set of samples from patients with MIS-C to identify a distinct set of host proteins targeted by patient autoantibodies including a particular autoreactive epitope within SNX8, a protein involved in regulating an antiviral pathway associated with MIS-C pathogenesis. In parallel, we also probed antibody responses from patients with MIS-C to the complete SARS-CoV-2 proteome and found enriched reactivity against a distinct domain of the SARS-CoV-2 nucleocapsid protein. The immunogenic regions of the viral nucleocapsid and host SNX8 proteins bear remarkable sequence similarity. Consequently, we found that many children with anti-SNX8 autoantibodies also have cross-reactive T cells engaging both the SNX8 and the SARS-CoV-2 nucleocapsid protein epitopes. Together, these findings suggest that patients with MIS-C develop a characteristic immune response to the SARS-CoV-2 nucleocapsid protein that is associated with cross-reactivity to the self-protein SNX8, demonstrating a mechanistic link between the infection and the inflammatory syndrome, with implications for better understanding a range of post-infectious autoinflammatory diseases.

Measurement of transcranial Doppler insonation angles from three-dimensional reconstructions of CT angiography scans.

Blood velocities measured by Transcranial Doppler (TCD) are dependent on the angle between the incident ultrasound beam and the direction of blood flow (known as the Doppler angle). However, when TCD examinations are performed without imaging the Doppler angle for each vessel segment is not known. We have measured Doppler angles in the basal cerebral arteries examined with TCD using three-dimensional (3D) vessel models generated from computed tomography angiography (CTA) scans. This approach produces angle statistics that are not accessible during non-imaging TCD studies. We created 3D models of the basal cerebral arteries for 24 vasospasm patients. Standard acoustic windows were mapped to the specific anatomy of each patient. Virtual ultrasound transmit beams were generated that originated from the acoustic window and intersected the centerline of each arterial segment. Doppler angle measurements were calculated and compiled for each vessel segment. Doppler angles were smallest for the middle cerebral artery M1 segment (median 24.6°) and ophthalmic artery (median 25.0°), and largest for the anterior cerebral artery A2 segment (median 76.4°) and posterior cerebral artery P2 segment (median 75.8°). The ophthalmic artery had the highest proportion of Doppler angles that were less than 60° (99%) while the anterior cerebral artery A2 segment had the lowest proportion of Doppler angles that were less than 60° (10%). These angle measurements indicate the expected deviation between measured and true velocities in the cerebral arteries, highlighting specific segments that may be prone to underestimation of velocity.

Multiple Valvular Heart Disease in the Transcatheter Era: A State-of-the-Art Review.

Although existing guidelines offer strong recommendations for single valvular dysfunction, the growing prevalence of multiple valvular heart disease (MVHD) in our aging population is challenging the clarity of clinical guidance. Traditional diagnostic modalities, such as echocardiography, face inherent constraints in precisely quantifying valvular dysfunction due to the hemodynamic interactions that occur with multiple valve involvement. Therefore, many patients with MVHD present at a later stage in their disease course and with an elevated surgical risk. The expansion of transcatheter therapy for the treatment of valvular heart disease has added new opportunities for higher-risk patients. However, the impact of isolated valve therapies on patients with MVHD is still not well understood. This review focuses on the etiology, diagnostic challenges, and therapeutic considerations for some of the most common concomitant valvular abnormalities that occur in our daily clinic population.

Endoscopic duodenal-jejunal bypass liner treatment of moderate obstructive sleep apnoea-A pilot study.

We aimed to assess the extent to which people with type 2 diabetes or pre-diabetes, obesity (BMI 30-45 kg/m2) and moderate obstructive sleep apnoea (OSA) requiring continuous positive airway pressure ventilation (CPAP) were able to discontinue CPAP following EndoBarrier-related weight loss. We assessed sleep and metabolic parameters before, during and after EndoBarrier in 12 participants with moderate OSA requiring CPAP (75% female, 8/12 [66%] type 2 diabetes, 4/12 [34%] prediabetes, mean ± SD age 52.6 ± 9.7 years, BMI 37.4 ± 3.5 kg/m2, median duration of OSA while on CPAP 9.0 [7.0-15.0] months). With EndoBarrier in-situ, mean ± SD Apnoea Hypopnoea Index (AHI) fell by 9.1 ± 5.0 events/h from 18.9 ± 3.8 to 9.7 ± 3.0 events/h (p < .001) with an associated reduction in symptoms of daytime sleepiness (mean Epworth Sleepiness Score) such that all the 12 participants no longer required CPAP according to National Institute for Health and Care Excellence criteria. After EndoBarrier removal, 10/12 (83%) patients attended follow-up and at 12 months after removal, AHI remained below 15 in 5/10 (50%) patients but in other five the AHI rose above 15 such that restarting CPAP was recommended as justified by their symptoms. Rather than restart CPAP, two patients lost the regained weight and their AHI dropped below 15 again. Thus, 7/10 (70%) of patients were able to remain off CPAP 12 or more months after EndoBarrier removal. These results demonstrate major benefit of EndoBarrier in moderate OSA, allowing all patients to discontinue CPAP during treatment, and with maintenance of improvement at follow-up in 70%. They confirm previously demonstrated metabolic improvements in diabetes and obesity.

A multi-year heavy metal analysis of 72 dark chocolate and cocoa products in the USA.

Introduction: Contamination of cocoa containing products, such as dark chocolate, with heavy metals including lead, cadmium and arsenic has been reported in the US. However, a formal exploration into the significance of this contamination, nor multi-year trends in the degree or scope remain unresolved. Methods: From 2014 to 2022, 72 consumer cocoa-containing products were purchased and analyzed for heavy metal contamination with lead (Pb), cadmium (Cd), and arsenic (As) in 4 distinct cohorts (2014, 2016, 2019, 2022). The thresholds used to assess heavy metal contamination were set to Prop 65 maximum allowable dose levels (MADLs) of 0.5 mcg/day, 4.1 mcg/day, 10 mcg/day for Pb, Cd, and As, respectively. Results and discussion: Our analysis reports that 43, 35, and 0% of the products tested exceed Prop 65 MADLs for heavy metal concentrations, respectively, of Pb, Cd, and As, while 97.2% (70 of 72) fall below US FDA IRL limits established for Pb. Median concentrations of each metal tested were lower than even the conservative Prop 65 MADLs, indicating a potentially large effect of product outliers. This indicates that heavy metal contamination-in more than half of products tested-may not pose any appreciable risk for the average person when consumed as a single serving; however, consuming some of the products tested, or more than one serving per day in combination with non-cocoa derived sources heavy metals, may add up to exposure that would exceed the Prop 65 MADLs. Notably, "organic" products were significantly more likely to demonstrate higher levels of both Cd and Pb.

Parasternal thoracotomy via sternocostal disarticulation: a novel surgical approach to the canine thorax.

OBJECTIVE: To describe the technique and outcomes of a modified paramedian thoracic approach in dogs involving a parasternal thoracotomy via rib disarticulation at the sternocostal joint. ANIMALS: 93 client-owned dogs. METHODS: Medical records of dogs that underwent parasternal thoracotomy at a private practice between the years 2015 and 2021 were reviewed. Signalment, weight, clinical presentation, surgical details, complications, and short-term outcomes were recorded. Cox proportional hazards regression models were utilized to analyze the impact of covariates on hazard events. Kaplan-Meier curves were employed to evaluate survival functions for select variables. RESULTS: Parasternal thoracotomy via sternocostal disarticulation was performed in 93 dogs. Eighty-eight dogs (94.6%) survived the procedure. Eighty-three dogs (89.2%) survived to discharge from the hospital. Age, weight, postoperative time to eating, postoperative ambulation, and surgical or anesthetic duration were not significantly associated with survival to discharge. Thoracostomy tube duration significantly decreased the likelihood for survival to discharge; for each additional hour of thoracostomy tube placement, the odds of survival to discharge diminished by 5.7% (hazard ratio, 0.94; 95% CI, 0.912 to 0.976). CLINICAL RELEVANCE: Parasternal thoracotomy via rib disarticulation at the sternocostal joints may be a viable alternative to median sternotomy that does not require specialized equipment for bilateral hemithoracic visualization. Postoperative complications and short-term outcomes are comparable to those reported for the traditional median sternotomy approach. Prolonged thoracostomy tube duration may impact survival to discharge.

Oculometric biomarkers of visuomotor deficits in clinically asymptomatic patients with systemic lupus erythematosus undergoing long-term hydroxychloroquine treatment.

Introduction: This study examines a set of oculomotor measurements, or "oculometric" biomarkers, as potential early indicators of visual and visuomotor deficits due to retinal toxicity in asymptomatic Systemic Lupus Erythematosus (SLE) patients on long-term hydroxychloroquine (HCQ) treatment. The aim is to identify subclinical functional impairments that are otherwise undetectable by standard clinical tests and to link them to structural retinal changes. Methods: We measured oculomotor responses in a cohort of SLE patients on chronic HCQ therapy using a previously established behavioral task and analysis technique. We also examined the relationship between oculometrics, OCT measures of retinal thickness, and standard clinical perimetry measures of visual function in our patient group using Bivariate Pearson Correlation and a Linear Mixed-Effects Model (LMM). Results: Significant visual and visuomotor deficits were found in 12 asymptomatic SLE patients on long-term HCQ therapy compared to a cohort of 17 age-matched healthy controls. Notably, six oculometrics were significantly different. The median initial pursuit acceleration was 22%, steady-state pursuit gain 16%, proportion smooth 7%, and target speed responsiveness 31% lower, while catch-up saccade amplitude was 46% and fixation error 46% larger. Excluding the two patients with diagnosed mild toxicity, four oculometrics, all but fixation error and proportion smooth, remained significantly impaired compared to controls. Across our population of 12 patients (24 retinae), we found that pursuit latency, initial acceleration, steady-state gain, and fixation error were linearly related to retinal thickness even when age was accounted for, while standard measures of clinical function (Mean Deviation and Pattern Standard Deviation) were not. Discussion: Our data show that specific oculometrics are sensitive early biomarkers of functional deficits in SLE patients on HCQ that could be harnessed to assist in the early detection of HCQ-induced retinal toxicity and other visual pathologies, potentially providing early diagnostic value beyond standard visual field and OCT evaluations.

Transcatheter tricuspid valve intervention in the presence of a cardiac implantable electronic device; state of the art review.

A large proportion of patients referred for transcatheter tricuspid valve intervention (TTVI) will have the presence of a cardiac implantable electronic device (CIED). In such patients, surgical correction of tricuspid regurgitation (TR) is associated with high rates of morbidity and mortality. Transvenous lead extraction (TLE) could potentially ameliorate CIED-induced TR; however, it carries inherent risks and frequently does not result in TR improvement. As multiple TTVI devices are in trial to gain regulatory approval, understanding which therapy is most appropriate among patients with a CIED is essential. This review centers on the nonsurgical treatment, including TLE and transcatheter tricuspid valve repair and replacement options, aimed at enhancing outcomes in patients with TR who also have concurrent CIEDs.

Fitness factor genes conserved within the multi-species core genome of Gram-negative Enterobacterales species contribute to bacteremia pathogenesis.

There is a critical gap in knowledge about how Gram-negative bacterial pathogens, using survival strategies developed for other niches, cause lethal bacteremia. Facultative anaerobic species of the Enterobacterales order are the most common cause of Gram-negative bacteremia, including Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Citrobacter freundii, and Enterobacter hormaechei. Bacteremia often leads to sepsis, a life-threatening organ dysfunction resulting from unregulated immune responses to infection. Despite a lack of specialization for this host environment, Gram-negative pathogens cause nearly half of bacteremia cases annually. Based on our existing Tn-Seq fitness factor data from a murine model of bacteremia combined with comparative genomics of the five Enterobacterales species above, we prioritized 18 conserved fitness genes or operons for further characterization. Mutants were constructed for all genes in all five species. Each mutant was used to cochallenge C57BL/6 mice via tail vein injection along with each respective wild-type strain to determine competitive indices for each fitness gene. Five fitness factor genes, when mutated, attenuated mutants in four or five species in the spleen and liver (tatC, ruvA, gmhB, wzxE, arcA). Five additional fitness factor genes or operons were validated as outcompeted by wild-type in three, four, or five bacterial species in the spleen (xerC, prc, apaGH, atpG, aroC). Overall, 17 of 18 fitness factor mutants were attenuated in at least one species in the spleen or liver. Together, these findings allow for the development of a model of bacteremia pathogenesis that may include future targets of therapy against bloodstream infections.

Phage Immunoprecipitation-Sequencing Reveals CDHR5 Autoantibodies in Select Patients With Interstitial Lung Disease.

OBJECTIVE: Interstitial lung diseases (ILDs) are a heterogeneous group of disorders that can develop in patients with connective tissue diseases. Establishing autoimmunity in ILD impacts prognosis and treatment. Patients with ILD are screened for autoimmunity by measuring antinuclear autoantibodies, rheumatoid factors, and other nonspecific tests. However, this approach may miss autoimmunity that manifests as autoantibodies to tissue antigens not previously defined in ILD. METHODS: We use Phage Immunoprecipitation-Sequencing (PhIP-Seq) to conduct an autoantibody discovery screen of patients with ILD and controls. We screened for novel autoantigen candidates using PhIP-Seq. We next developed a radio-labeled binding assay and validated the leading candidate in 398 patients with ILD recruited from two academic medical centers and 138 blood bank individuals that formed our reference cohort. RESULTS: PhIP-Seq identified 17 novel autoreactive targets, and machine learning classifiers derived from these targets discriminated ILD serum from controls. Among the 17 candidates, we validated CDHR5 and found CDHR5 autoantibodies in patients with rheumatologic disorders and importantly, patients not previously diagnosed with autoimmunity. Using survival and transplant free-survival data available from one of the two centers, patients with CDHR5 autoantibodies showed worse survival compared with other patients with connective tissue disease ILD. CONCLUSION: We used PhIP-Seq to define a novel CDHR5 autoantibody in a subset of select patients with ILD. Our data complement a recent study showing polymorphisms in the CDHR5-IRF7 gene locus strongly associated with titer of anticentromere antibodies in systemic sclerosis, creating a growing body of evidence suggesting a link between CDHR5 and autoimmunity.

Acquired ductopenia: an insight into imaging findings.

Hepatic ductopenia is a pathologic diagnosis characterized by a decrease in the number of intrahepatic bile ducts as a consequence of various underlying etiologies. Some etiologies, such as primary sclerosing cholangitis, primary biliary cholangitis, and ischemic cholangitis, often have distinctive imaging findings. In contrast, other causes such as chronic rejection following liver transplantation, drug-induced biliary injury, infection, malignancy such as lymphoma, and graft-versus-host disease may only have ancillary or non-specific imaging findings. Thus, diagnosing ductopenia in conditions with nonspecific imaging findings requires a multidimensional approach, including clinical evaluation, serological testing, imaging, and liver histology to identify the underlying cause. These etiologies lead to impaired bile flow, resulting in cholestasis, liver dysfunction, and, ultimately, cirrhosis and liver failure if the underlying cause remains untreated or undetected. In the majority of instances, individuals diagnosed with ductopenia exhibit a positive response to treatment addressing the root cause or cessation of the causative agent. This article focuses on acquired causes of ductopenia, its clinical manifestation, histopathology, imaging diagnosis, and management.

Checkpoint Inhibitor-Induced Autoimmune Diabetes: An Autoinflammatory Disease.

Immunomodulatory agents targeting immune checkpoints are now the state-of-the-art for the treatment of many cancers, but at the same time have led to autoimmune side effects, including autoimmune diabetes: immune checkpoint inhibitor-induced diabetes (CPI-DM). Emerging research shows the importance of preexisting autoimmune disease risk that has been identified through genetics, and autoantibodies. Key associated clinical findings also include increased levels of lipase before diagnosis suggesting that the inflammatory process in the pancreas extends beyond the islets of Langerhans. There is selectivity for the blockade of programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) for this adverse event, consistent with the role of this checkpoint in maintaining tolerance to autoimmune diabetes.

Hepatitis B Virus in People who Inject Drugs and Men who Have Sex With Men With HIV in India: A Cross-sectional Study.

Background: People with HIV (PWH) who are coinfected with hepatitis B virus (HBV) have a higher risk of mortality compared with PWH alone. Populations such as people who inject drugs (PWID) and men who have sex with men (MSM) are particularly at high risk for HBV acquisition; yet, limited epidemiological data from these populations exist on HBV prevalence from low- and middle-income country settings (LMICs). Methods: We characterized the prevalence and correlates of HBV serological markers in a sample of PWID and MSM with HIV recruited across 15 Indian cities using hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), and hepatitis B surface antibody (anti-HBs). Testing of stored specimens for the presence of these markers was performed on the Abbott ARCHITECT i1000 as per the manufacturer's instructions. Correlates of ever being infected with HBV (reactive for anti-HBc and/or HBsAg) and chronic HBV (reactive for HBsAg) among those ever infected were assessed using univariable and multivariable multilevel logistic regression models accounting for site-level clustering. Results: A total of 2198 (95%) of the 2314 participants recruited for the trial were screened for HBV markers. The median age among the PWID and MSM participants was 30 and 32 years, respectively. The prevalence of ever being infected with HBV was 75.6% vs 46.9% in PWID vs MSM, respectively (P < .01); prevalence of chronic infection was also higher in PWID vs MSM (14.1% vs 9.5%; P < .01). Correlates of ever being infected with HBV among PWID included unstable housing (adjusted odds ratio [aOR], 5.02) and sharing injection paraphernalia (aOR, 2.70), and among MSM, correlates included history of injection drug use (aOR, 4.87) and gender identity. The prevalence of isolated core (anti-HBc in the absence of anti-HBs) was 34.7% vs 29.4% in PWID vs MSM (P < .05). Vaccination serostatus was <10% in both populations. Conclusions: In this large sample of PWID and MSM with HIV, we observed a high prevalence of serology consistent with HBV infection and low vaccination, highlighting the need for routine screening and catch-up vaccination. The high prevalence of isolated anti-HBc reactivity highlights the need to understand the risk of reactivation with this serological pattern.

Sequence Notes: Near Full-Length Genome Analysis of the First-Reported HIV-1 Circulating Recombinant Form (CRF)_10CD in Uganda.

HIV-1 is characterized by remarkable genetic diversity resulting from its high replication rate, error-prone reverse transcriptase enzyme and recombination events. In Uganda, HIV-1 subtype diversity is mostly dominated by subtypes A, D, and A1/D Unique Recombinant Forms (URFs). In this study, deep sequences of HIV from patients with known antiretroviral therapy (ART) status were analyzed to determine the subtypes and to identify drug-resistance mutations circulating in the study population. Of the 187 participant samples processed for next-generation sequencing (NGS), 137 (73%) were successfully classified. The majority of HIV-1 strains were classified as subtype A (75, 55%), D (43, 31%), with other subtypes including C (3, 2%), A1/D (9, 7%) and CRF10_CD (1, <1%). Recombinant analysis of nine complete A1/D HIV genomes identified novel recombination patterns described herein. Furthermore, we report for the first time in Uganda, an HIV-1 CRF10_CD strain from a fisherfolk in a Lake Victoria Island fishing community.

Reducing contaminating noise effects when calculating low-boom loudness levels.

During NASA X-59 quiet supersonic aircraft community response tests, low-boom recordings will contain contaminating noise from instrumentation and ambient acoustical sources. This noise can inflate sonic boom perception metrics by several decibels. This paper discusses the development and comparison of robust lowpass filtering techniques for removing contaminating noise effects from low-boom recordings. The two filters are a time-domain Butterworth-magnitude filter and a frequency-domain Brick Wall filter. Both filters successfully reduce noise contamination in metric calculations for simulated data with real-world contaminating noise and demonstrate comparable performance to a modified ISO 11204 correction. The Brick Wall filter's success indicates that further attempts to match boom spectrum high-frequency roll-off beyond the contaminating noise floor are unnecessary and have marginal improvements on final metric calculations. Additionally, the Butterworth filter removes statistical correlation between ambient and boom levels for a real-world flight campaign, adding evidence that these techniques also work on other boom shapes. Overall, both filters can produce accurate metric calculations with only a few hundred hertz of positive signal-to-noise ratio. This work describes methods for accurate metric calculations in the presence of moderate noise contamination that should benefit X-59 and future low-boom supersonic aircraft testing.

Transcobalamin receptor antibodies in autoimmune vitamin B12 central deficiency.

Vitamin B12 is critical for hematopoiesis and myelination. Deficiency can cause neurologic deficits including loss of coordination and cognitive decline. However, diagnosis relies on measurement of vitamin B12 in the blood, which may not accurately reflect the concentration in the brain. Using programmable phage display, we identified an autoantibody targeting the transcobalamin receptor (CD320) in a patient with progressive tremor, ataxia, and scanning speech. Anti-CD320 impaired cellular uptake of cobalamin (B12) in vitro by depleting its target from the cell surface. Despite a normal serum concentration, B12 was nearly undetectable in her cerebrospinal fluid (CSF). Immunosuppressive treatment and high-dose systemic B12 supplementation were associated with increased B12 in the CSF and clinical improvement. Optofluidic screening enabled isolation of a patient-derived monoclonal antibody that impaired B12 transport across an in vitro model of the blood-brain barrier (BBB). Autoantibodies targeting the same epitope of CD320 were identified in seven other patients with neurologic deficits of unknown etiology, 6% of healthy controls, and 21.4% of a cohort of patients with neuropsychiatric lupus. In 132 paired serum and CSF samples, detection of anti-CD320 in the blood predicted B12 deficiency in the brain. However, these individuals did not display any hematologic signs of B12 deficiency despite systemic CD320 impairment. Using a genome-wide CRISPR screen, we found that the low-density lipoprotein receptor serves as an alternative B12 uptake pathway in hematopoietic cells. These findings dissect the tissue specificity of B12 transport and elucidate an autoimmune neurologic condition that may be amenable to immunomodulatory treatment and nutritional supplementation.