Biolayer-Interferometry-Guided Functionalization of Screen-Printed Graphene for Label-Free Electrochemical Virus Detection.

Additive manufacturing holds promise for rapid prototyping and low-cost production of biosensors for diverse pathogens. Among additive manufacturing methods, screen printing is particularly desirable for high-throughput production of sensing platforms. However, this technique needs to be combined with carefully formulated inks, rapid postprocessing, and selective functionalization to meet all requirements for high-performance biosensing applications. Here, we present screen-printed graphene electrodes that are processed with thermal annealing to achieve high surface area and electrical conductivity for sensitive biodetection via electrochemical impedance spectroscopy. As a proof-of-concept, this biosensing platform is utilized for electrochemical detection of SARS-CoV-2. To ensure reliable specificity in the presence of multiple variants, biolayer interferometry (BLI) is used as a label-free and dynamic screening method to identify optimal antibodies for concurrent affinity to the Spike S1 proteins of Delta, Omicron, and Wild Type SARS-CoV-2 variants while maintaining low affinity to competing pathogens such as Influenza H1N1. The BLI-identified antibodies are robustly bound to the graphene electrode surface via oxygen moieties that are introduced during the thermal annealing process. The resulting electrochemical immunosensors achieve superior metrics including rapid detection (55 s readout following 15 min of incubation), low limits of detection (approaching 500 ag/mL for the Omicron variant), and high selectivity toward multiple variants. Importantly, the sensors perform well on clinical saliva samples detecting as few as 103 copies/mL of SARS-CoV-2 Omicron, following CDC protocols. The combination of the screen-printed graphene sensing platform and effective antibody selection using BLI can be generalized to a wide range of point-of-care immunosensors.

Improvement in Disease Activity in Refractory Juvenile Dermatomyositis Following Abatacept Therapy.

OBJECTIVE: This open-label, 24-week study was conducted to evaluate the safety and efficacy of abatacept in patients with refractory juvenile dermatomyositis (DM). METHODS: Ten patients ≥7 years of age with moderate disease activity were enrolled in a 24-week study to examine the safety of subcutaneous abatacept and patient responses to the treatment. The primary endpoint was the International Myositis Assessment and Clinical Studies (IMACS) group Definition Of Improvement (DOI). Secondary endpoints included safety, changes in the core set activity measures (CSMs) of the IMACS group and the Pediatric Rheumatology International Trials Organization, and improvements in disease activity based on the American College of Rheumatology (ACR)/EULAR response criteria for juvenile DM. Radiologists blinded with regard to participant data assessed magnetic resonance images (MRIs) of patient thigh muscles. Interferon (IFN)-regulated gene score was performed on whole-blood RNA samples using a NanoString assay, and cytokines were assessed using a Luminex assay. RESULTS: Five patients achieved DOI at week 12, and 9 patients achieved DOI at week 24, including 2 patients with minimal, 4 patients with moderate, and 3 patients with major improvement by the 2016 ACR/EULAR response criteria for juvenile DM when patients were assessed using the CSMs of the IMACS Group. Improvements from baseline were seen in all CSMs at weeks 12 and 24, except in muscle enzymes. Daily glucocorticoid doses decreased from a mean of 16.7 mg at baseline to 10.2 mg at week 24 (P = 0.002). Average MRI muscle edema scores decreased from a mean baseline score of 5.3 to 2.3 at week 24 (P = 0.01). Six patients had down-trending IFN-regulated gene scores and galectin-9 expression at week 24. Decreases in IFN-regulated gene scores and in levels of interferon-γ-inducible protein 10kDa, galectin-9, and interleukin-2 correlated with improvements in disease activity and in muscle edema shown on MRI. Eleven grade 2 or 3 treatment-emergent adverse events were observed. CONCLUSION: This open-label study demonstrated that abatacept may be beneficial for patients with treatment-refractory juvenile DM.

Rapid genome sequencing identifies novel variants in complement factor I.

Complement factor I deficiency (CFID; OMIM #610984) is a rare immunodeficiency caused by deficiencies in the serine protease complement factor I (CFI). CFID is characterized by predisposition to severe pneumococcal infection, often in infancy. We report a previously healthy adolescent male who presented with respiratory failure secondary to pneumococcal pneumonia and severe systemic inflammatory response. Rapid genome sequencing (rGS) identified compound heterozygous variants in CFI in the proband, with a novel maternally inherited likely pathogenic variant, a single nucleotide deletion resulting in premature stop (c.1646del; p.Asn549ThrfsTer25) and a paternally inherited novel likely pathogenic deletion (Chr 4:110685580-110692197del).

Aerosol-jet-printed graphene electrochemical immunosensors for rapid and label-free detection of SARS-CoV-2 in saliva.

Rapid, inexpensive, and easy-to-use coronavirus disease 2019 (COVID-19) home tests are key tools in addition to vaccines in the world-wide fight to eliminate national and local shutdowns. However, currently available tests for SARS-CoV-2, the virus that causes COVID-19, are too expensive, painful, and irritating, or not sufficiently sensitive for routine, accurate home testing. Herein, we employ custom-formulated graphene inks and aerosol jet printing (AJP) to create a rapid electrochemical immunosensor for direct detection of SARS-CoV-2 Spike Receptor-Binding Domain (RBD) in saliva samples acquired non-invasively. This sensor demonstrated limits of detection that are considerably lower than most commercial SARS-CoV-2 antigen tests (22.91 ± 4.72 pg/mL for Spike RBD and 110.38 ± 9.00 pg/mL for Spike S1) as well as fast response time (~30 mins), which was facilitated by the functionalization of printed graphene electrodes in a single-step with SARS-CoV-2 polyclonal antibody through the carbodiimide reaction without the need for nanoparticle functionalization or secondary antibody or metallic nanoparticle labels. This immunosensor presents a wide linear sensing range from 1 to 1000 ng/mL and does not react with other coexisting influenza viruses such as H1N1 hemagglutinin. By combining high-yield graphene ink synthesis, automated printing, high antigen selectivity, and rapid testing capability, this work offers a promising alternative to current SARS-CoV-2 antigen tests.

Electrochemical Sensing of Neonicotinoids Using Laser-Induced Graphene.

Neonicotinoids are the fastest-growing insecticide accounting for over 25% of the global pesticide market and are capable of controlling a range of pests that damage croplands, home yards/gardens, and golf course greens. However, widespread use has led to nontarget organism decline in pollinators, insects, and birds, while chronic, sublethal effects on humans are still largely unknown. Therefore, there is a need to understand how prevalent neonicotinoids are in the environment as there are currently no commercially available field-deployable sensors capable of measuring neonicotinoid concentrations in surface waters. Herein, we report the first example of a laser-induced graphene (LIG) platform that utilizes electrochemical sensing for neonicotinoid detection. These graphene-based sensors are created through a scalable direct-write laser fabrication process that converts polyimide into LIG, which eliminates the need for chemical synthesis of graphene, ink formulation, masks, stencils, pattern rolls, and postprint annealing commonly associated with other printed graphene sensors. The LIG electrodes were capable of monitoring four major neonicotinoids (CLO, IMD, TMX, and DNT) with low detection limits (CLO, 823 nM; IMD, 384 nM; TMX, 338 nM; and DNT, 682 nM) and a rapid response time (∼10 s) using square-wave voltammetry without chemical/biological functionalization. Interference testing exhibited negligible responses from widely used pesticides including the broad-leaf insecticides parathion, paraoxon, and fipronil, as well as systemic herbicides glyphosate (roundup), atrazine, dicamba, and 2,4-dichlorophenoxyacetic acid. These scalable, graphene-based sensors have the potential for wide-scale mapping of neonicotinoids in watersheds and potential use in numerous electrochemical sensor devices.

Kawasaki Disease Outcomes and Response to Therapy in a Multiethnic Community: A 10-Year Experience.

OBJECTIVES: To describe the epidemiology, response to therapy, and outcomes of Kawasaki disease in a multiethnic community with a large Hispanic and Asian population. STUDY DESIGN: We analyzed prospectively collected data from 788 unselected patients with Kawasaki disease diagnosed and treated at a single medical center over a 10-year period. RESULTS: The average incidence of Kawasaki disease in children <5 years in San Diego County over the 10 years from 2006 to 2015 was 25 per 100 000 children, with the greatest incidence (50 per 100 000) for Asian/Pacific Islanders. Compared with other race/ethnicities, Asian/Pacific Islander patients with Kawasaki disease were younger, were diagnosed earlier in the course of their fever, had higher levels of inflammatory markers, and were more likely to develop aneurysms. There was no difference across race/ethnicity groups in response to intravenous immunoglobulin therapy. Filipino children had the highest recurrence rates (9.1%; 95% CI, 3.0%-22.6%) and 12 of 788 patients (1.5%) had a first- or second-degree relative with a history of Kawasaki disease. After correcting for age of onset, sex, and illness day at diagnosis, Asian/Pacific Islander children had an increased risk of developing aneurysms (aOR, 2.37; 95% CI, 1.37-4.11; P = .002). Overall, 180 of 788 patients (22.8%) had a maximal Z score of 2.5-10.0 and 14 of the 788 patients (1.8%) had a maximal Z score ≥10.0 despite 84% of these patients being treated within 10 days of fever onset. CONCLUSIONS: Our data provide new insights into the natural history of treated Kawasaki disease in a multiethnic population. Patient race/ethnicity influenced susceptibility to Kawasaki disease, timing of diagnosis, coronary artery outcome, and recurrence rates.

Mutations of complement factor I and potential mechanisms of neuroinflammation in acute hemorrhagic leukoencephalitis.

PURPOSE: Acute Hemorrhagic Leukoencephalitis (AHLE) is a rare demyelinating disorder of acute onset, rapid deterioration and significant morbidity and mortality. Most often described as a post-infectious complication of an upper respiratory illness, its precise pathophysiology remains unclear. We describe two pediatric patients with AHLE with partial complement factor I (FI) deficiency whose successful treatment included the interleukin-1 (IL-1) receptor antagonist, anakinra, implicating a role for FI and IL-1 in this disorder. METHODS: Extensive clinical workup of two patients presenting with AHLE revealed complement abnormalities, specifically related to the alternative pathway and its regulator, FI. Aggressive management with steroids, immunoglobulin, and anakinra ultimately led to improvement of clinical status and near return to neurologic baseline in both patients. Genetic sequencing of the FI coding regions of the patients and their families was performed. In vitro protein expression studies and immunohistochemistry of fixed brain tissue was used to investigate pathogenic mechanisms. RESULTS: Two novel mutations in FI were identified in our patients, which result in failure to secrete FI. Immunohistochemical evaluation of brain tissue demonstrated positive staining for C3, membrane attack complex (MAC) and IL-1. CONCLUSIONS: We propose AHLE is an unreported, rare phenotype for partial FI deficiency. The upregulation of C3, MAC and IL-1 with subsequent demyelination support a pathologic role for complement activation in AHLE, and suggest anakinra as an important adjunctive therapy in this disease.