Modulation of FGF pathway signaling and vascular differentiation using designed oligomeric assemblies.

Many growth factors and cytokines signal by binding to the extracellular domains of their receptors and driving association and transphosphorylation of the receptor intracellular tyrosine kinase domains, initiating downstream signaling cascades. To enable systematic exploration of how receptor valency and geometry affect signaling outcomes, we designed cyclic homo-oligomers with up to 8 subunits using repeat protein building blocks that can be modularly extended. By incorporating a de novo-designed fibroblast growth factor receptor (FGFR)-binding module into these scaffolds, we generated a series of synthetic signaling ligands that exhibit potent valency- and geometry-dependent Ca2+ release and mitogen-activated protein kinase (MAPK) pathway activation. The high specificity of the designed agonists reveals distinct roles for two FGFR splice variants in driving arterial endothelium and perivascular cell fates during early vascular development. Our designed modular assemblies should be broadly useful for unraveling the complexities of signaling in key developmental transitions and for developing future therapeutic applications.

Design of protein-binding proteins from the target structure alone.

The design of proteins that bind to a specific site on the surface of a target protein using no information other than the three-dimensional structure of the target remains a challenge1-5. Here we describe a general solution to this problem that starts with a broad exploration of the vast space of possible binding modes to a selected region of a protein surface, and then intensifies the search in the vicinity of the most promising binding modes. We demonstrate the broad applicability of this approach through the de novo design of binding proteins to 12 diverse protein targets with different shapes and surface properties. Biophysical characterization shows that the binders, which are all smaller than 65 amino acids, are hyperstable and, following experimental optimization, bind their targets with nanomolar to picomolar affinities. We succeeded in solving crystal structures of five of the binder-target complexes, and all five closely match the corresponding computational design models. Experimental data on nearly half a million computational designs and hundreds of thousands of point mutants provide detailed feedback on the strengths and limitations of the method and of our current understanding of protein-protein interactions, and should guide improvements of both. Our approach enables the targeted design of binders to sites of interest on a wide variety of proteins for therapeutic and diagnostic applications.

Cryo-EM analyses of KIT and oncogenic mutants reveal structural oncogenic plasticity and a target for therapeutic intervention.

The receptor tyrosine kinase KIT and its ligand stem cell factor (SCF) are required for the development of hematopoietic stem cells, germ cells, and other cells. A variety of human cancers, such as acute myeloid leukemia, gastrointestinal stromal tumor, and mast cell leukemia, are driven by somatic gain-of-function KIT mutations. Here, we report cryo electron microscopy (cryo-EM) structural analyses of full-length wild-type and two oncogenic KIT mutants, which show that the overall symmetric arrangement of the extracellular domain of ligand-occupied KIT dimers contains asymmetric D5 homotypic contacts juxtaposing the plasma membrane. Mutational analysis of KIT reveals in D5 region an "Achilles heel" for therapeutic intervention. A ligand-sensitized oncogenic KIT mutant exhibits a more comprehensive and stable D5 asymmetric conformation. A constitutively active ligand-independent oncogenic KIT mutant adopts a V-shaped conformation solely held by D5-mediated contacts. Binding of SCF to this mutant fully restores the conformation of wild-type KIT dimers, including the formation of salt bridges responsible for D4 homotypic contacts and other hallmarks of SCF-induced KIT dimerization. These experiments reveal an unexpected structural plasticity of oncogenic KIT mutants and a therapeutic target in D5.

Novel Organoid Culture System for Improved Safety Assessment of Nanomaterials.

Over the past few decades, the increased application of nanomaterials has raised questions regarding their safety and possible toxic effects. Organoids have been suggested as promising tools, offering efficient assays for nanomaterial-induced toxicity evaluation. However, organoid systems have some limitations, such as size heterogeneity and poor penetration of nanoparticles because of the extracellular matrix, which is necessary for organoid culture. Here, we developed a novel system for the improved safety assessment of nanomaterials by establishing a 3D floating organoid paradigm. In addition to overcoming the limitations of two-dimensional systems including the lack of in vitro-in vivo cross-talk, our method provides multiple benefits as compared with conventional organoid systems that rely on an extracellular matrix for culture. Organoids cultured using our method exhibited relatively uniform sizing and structural integrity and were more conducive to the internalization of nanoparticles. Our floating culture system will accelerate the research and development of safe nanomaterials.

Homogeneously Mixed Cu-Co Bimetallic Catalyst Derived from Hydroxy Double Salt for Industrial-Level High-Rate Nitrate-to-Ammonia Electrosynthesis.

Electrocatalytic nitrate reduction reaction (NO3RR) presents an innovative approach for sustainable NH3 production. However, selective NH3 production is hindered by the multiple intermediates involved in the NO3RR process and the competitive hydrogen evolution reaction. Hence, the development of highly efficient NO3RR catalysts is paramount. Herein, we report highly efficient bimetallic catalysts derived from hydroxy double salt (HDS). Under NO3RR conditions, Cu1Co1-HDS undergoes in situ reconstruction, forming nanocomposites of homogeneously distributed metallic Cu0 and Co(OH)2. Reconstruction-induced Cu0 rapidly converts NO3- to NO2-, which is further hydrogenated to NH3 by Co(OH)2. Homogeneously mixed Cu and Co species maximize this synergistic effect, achieving outstanding NO3RR performance including the highest NH3 yield rate (4.625 mmol h-1 cm-2) reported for powder-type NO3RR catalysts. Integration of Cu1Co1-HDS with a commercial Si solar cell attained 4.53% solar-to-ammonia efficiency from industrial wastewater-level concentrations of NO3- (2000 ppm), demonstrating practical application potential for solar-driven NH3 production. This study provides a strategy for enhancing the NH3 yield rate by optimizing the compositions and distributions of Cu and Co.

Wideband PRM: Highly Accurate and Sensitive Method for High-Throughput Targeted Proteomics.

Targeted mass spectrometry (MS) approaches, which are powerful methods for uniquely and confidently quantifying a specific panel of proteins in complex biological samples, play a crucial role in validating and clinically translating protein biomarkers discovered through global proteomic profiling. Common targeted MS methods, such as multiple reaction monitoring (MRM) and parallel-reaction monitoring (PRM), employ specific mass spectrometric technologies to quantify protein levels by comparing the transitions of surrogate endogenous (ENDO) peptides with those of stable isotope-labeled (SIL) peptide counterparts. These methods utilizing amino acid analyzed (AAA) SIL peptides warrant sensitive and precise measurements required for targeted MS assays. Compared with MRM, PRM provides higher experimental throughput by simultaneously acquiring all transitions of the target peptides and thereby compensates for different ion suppressions among transitions of a target peptide. However, PRM still suffers different ion suppressions between ENDO and SIL peptides due to spray instability, as the ENDO and SIL peptides were monitored at different liquid chromatography (LC) retention times. Here we introduce a new targeted MS method, termed wideband PRM (WBPRM), that is designed for high-throughput targeted MS analysis. WBPRM employs a wide isolation window for simultaneous fragmentation of both ENDO and SIL peptides along with multiplexed single ion monitoring (SIM) scans for enhanced MS sensitivity of the target peptides. Compared with PRM, WBPRM was demonstrated to provide increased sensitivity, precision, and reproducibility of quantitative measurements of target peptides with increased throughput, allowing more target peptide measurements in a shortened experiment time. WBPRM is a straightforward adaptation to a manufacturer-provided MS method, making it an easily implementable technique, particularly in complex biological samples where the demand for higher precision, sensitivity, and efficiency is paramount.

The autoimmune response induced by α-synuclein peptides drives neuronal cell death and glial cell activation.

Parkinson's disease (PD) is a progressive neurodegenerative disorder associated with the loss of dopaminergic neurons and neuroinflammation. Recent studies have identified a role of T cells in the pathogenesis of PD. Additionally, these studies suggested that α-synuclein (α-Syn) is related to abnormal T-cell responses and may act as an epitope and trigger autoimmune T-cell responses. However, it is unclear whether the α-Syn-mediated autoimmune response occurs and whether it is related to neuronal cell death and glial cell activation. In this study, we investigated the autoimmune T-cell response induced by α-Syn peptides and evaluated the neurotoxic effect of the α-Syn peptide-mediated autoimmune response. The immunization of mice with α-Syn peptides resulted in enhanced autoimmune responses, such as the peptide recall response, polarization toward Th1/Th17 cells, and regulatory T cell imbalance. Furthermore, the α-Syn autoimmune response led to the death of primary neurons cocultured with splenocytes. Treatment with conditioned media from α-Syn peptide-immunized splenocytes induced microglia and toxic A1-type astrocyte activation. Taken together, our results provide evidence of the potential role of the α-Syn-initiated autoimmune response and its contribution to neuronal cell death and glial cell activation.

Antiviral activity of adenoviral vector expressing human interferon lambda-4 against influenza virus.

Interferon lambda (IFNλ), classified as a type III IFN, is a representative cytokine that plays an important role in innate immunity along with type I IFN. IFNλ can elicit antiviral states by inducing peculiar sets of IFN-stimulated genes (ISGs). In this study, an adenoviral vector expression system with a tetracycline operator system was used to express human IFNλ4 in cells and mice. The formation of recombinant adenovirus (rAd-huIFNλ4) was confirmed using immunohistochemistry assays and transmission electron microscopy. Its purity was verified by quantifying host cell DNA and host cell proteins, as well as by confirming the absence of the replication-competent adenovirus. The transduction of rAd-huIFNλ4 induced ISGs and inhibited four subtypes of the influenza virus in both mouse-derived (LA-4) and human-derived cells (A549). The antiviral state was confirmed in BALB/c mice following intranasal inoculation with 109 PFU of rAd-huIFNλ4, which led to the inhibition of four subtypes of the influenza virus in mouse lungs, with reduced inflammatory lesions. These results imply that human IFNλ4 could induce antiviral status by modulating ISG expression in mice.

Sialylated IVIg promotes clinical improvements in a rabbit dry eye model by regulating inflammatory cytokines.

Dry eye disease (DED) is caused by a loss of homeostasis of the tear film, which results in visual disturbance, ocular surface inflammation and damage, and neurosensory abnormalities. Although it is prevalent in 5-50% of the global population, there are limited clinical options for its treatment. This study explored the potential use of human intravenous immunoglobulin (IVIg) and its enriched fractions of sialylation, sialylated IVIg (sIVIg), as a treatment for DED. Fifteen female New Zealand white rabbits were topically instilled with 0.2% benzalkonium chloride (BAC) twice daily for five consecutive days to induce experimental dry eye. Saline, 0.4% IVIg, or 0.04% sIVIg eye drops were instilled twice daily for 20 consecutive days. Clinical evaluations, such as non-invasive tear break-up time (NIBUT) and corneal fluorescein staining (CFS), were conducted. mRNA levels of mucin 4, mucin 16, TNF-α, IL-1ß, MMP9, IL-10, TGF-ß, and CD209 in rabbit conjunctival tissues were examined using reverse transcription polymerase chain reaction (RT-PCR) or quantitative RT-PCR (qRT-PCR). The relationships between CD209 family members in rabbits and various mammalian species were analyzed using a phylogenetic tree. IVIg or sIVIg treatment resulted in clinical improvements in the rabbit DED model. The inflammatory cytokines, TNF-α and IL-1ß, were increased and mucin 4 and mucin 16, cell surface-associated mucins, were decreased in BAC-induced dry eye. Following IVIg or sIVIg treatment, inflammatory cytokines decreased, whereas the anti-inflammatory cytokine, IL-10, increased substantially. Moreover, a 10-fold lower sIVIg treatment dose resulted in prolonged IL-10 production, representing a significantly improved DED compared to IVIg. Furthermore, the expression of rabbit CD209 mRNA in the rabbit conjunctiva and its close relationship with primate homologs suggest that it may interact with IVIg or sIVIg to promote IL-10 expression, as previously described in humans. At a lower dosage, sIVIg showed a more efficient improvement in DED, making it a promising new candidate medication for DED.

First-year cumulative myeloperoxidase-ANCA titres are associated with all-cause mortality in patients with microscopic polyangiitis.

OBJECTIVES: We investigated whether first-year cumulative myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA) and proteinase 3 (PR3)-ANCA titres were associated with all-cause mortality and relapse during follow-up in patients with microscopic polyangiitis (MPA) and granMETHODS: Altogether, 74 patients with MPA and 40 with GPA were included in this study. Their clinical data at diagnosis were collected. First-year cumulative ANCA titres were defined as the area under the curve (AUC) of ANCA titres during the first year after MPA or GPA diagnosis, which was obtained using the trapezoidal rule. All-cause mortality and relapse were considered poor outcomes of MPA and GPA. RESULTS: The median ages of patients with MPA and GPA were 65.5 and 60.5 years, respectively. No significant correlation was observed between ANCA titres at diagnosis and concurrent MPA and GPA activity or the inflammatory burden. First-year cumulative MPO-ANCA titres exhibited a significant AUC for all-cause mortality during follow-up in patients with MPA. The optimal cut-off of first-year cumulative MPO-ANCA titres for all-cause mortality was determined as 720.8 IU/mL using receiver operating characteristic curve analysis. MPA patients with first-year cumulative MPO-ANCA titres ≥720.8 IU/mL exhibited a significantly higher risk for all-cause mortality than those without (relative risk 13.250). Additionally, MPA patients with first-year cumulative MPO-ANCA titres ≥720.8 IU/mL exhibited a significantly lower cumulative patients' survival rate than those without. CONCLUSIONS: This is the first study to demonstrate the association between first-year cumulative MPO-ANCA titres and all-cause mortality during follow-up in patients with MPA.

Serum Wnt3A levels are significantly associated with cross-sectional vasculitis activity and end-stage kidney disease during follow-up of patients with antineutrophil cytoplasmic antibody-associated vasculitis.

OBJECTIVES: In this study, we investigated whether serum Wnt3A levels at diagnosis reflected cross-sectional activity and predicted poor outcomes during follow-up in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). METHODS: This study included 80 patients who were newly diagnosed with AAV at a tertiary hospital. At diagnosis, whole blood was obtained from patients and sera was immediately isolated and stored at -80℃. Moreover, AAV activity was assessed using the Birmingham Vasculitis Activity Score (BVAS), and a high BVAS was defined as the highest tertile. Poor outcomes including all-cause mortality and end-stage kidney disease (ESKD) were recorded. RESULTS: The patients had a median age of 63.5 years, with 40% being male and 60% female patients. Serum levels of Wnt3A at diagnosis were correlated with the cross-sectional BVAS and serum Wnt3A ≥411.7 pg/mL exhibited an increased risk of high BVAS. In addition, serum Wnt3A levels at diagnosis significantly correlated with cross-sectional acute-phase reactants and serum albumin levels. Furthermore, serum Wnt3A levels at diagnosis were associated with AAV exacerbation, leading to ESKD. Particularly, serum Wnt3A ≥407.1 pg/mL also demonstrated an elevated risk of ESKD (relative risk 3.867). Additionally, patients with serum Wnt3A ≥407.1 pg/mL exhibited a significantly lower cumulative ESKD-free survival rate than those with lower serum Wnt3A levels. CONCLUSIONS: This study is the first to demonstrate the clinical potential of serum Wnt3A levels at diagnosis for estimating cross-sectional activity and partially predicting the advancement to ESKD during follow-up in patients with AAV.

Earliest total vascular damage index scores independently predict all-cause mortality in patients with ANCA-associated vasculitis.

OBJECTIVES: This study investigated whether the earliest total Vasculitis Damage Index (VDI) score could significantly predict all-cause mortality during follow-up in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). METHODS: This study included AAV patients who were first diagnosed at this hospital from 2001 to 2022. The earliest total VDI score was defined as the first VID assessed more than 3 months after AAV diagnosis in 93.5% of patients or after the first AAV presentation in 6.5% of patients. The optimal cut-off of the earliest total VDI score for all-cause mortality was obtained using the receiver operating characteristic curve. RESULTS: The median age and earliest VDI score were 60.0 years (35.5% men), and 3.0. The most common damaged system in the earliest VDI was the pulmonary (55.3%) system. Among the AAV patients, 39 (13.3%) died. When the optimal cut-off of the earliest total VDI score for all-cause mortality was set at 3.0 (sensitivity 64.1%, specificity 75.2%), AAV patients with the earliest total VDI score ≥3.0 exhibited a significantly higher risk for all-cause mortality than those without (relative risk 6.090). AAV patients with the earliest total VDI score ≥3.0 exhibited a significantly lower cumulative patients' survival rate than those without. In the multivariable Cox hazards model analyses, not only the earliest total VDI score but also the earliest total VDI score ≥3.0 were independently associated with all-cause mortality. CONCLUSIONS: This study was the first to demonstrate that the earliest total VDI score could predict all-cause mortality during follow-up in AAV patients.

Hypophysitis and central nervous system involvement in association with Sjögren's syndrome along with hypoparathyroidism: a case report.

BACKGROUND: Patients with autoimmune diseases can develop multiple autoimmune diseases over a long period of time, and the presence of more than one autoimmune disease in a single patient is defined as polyautoimmunity. Polyautoimmunity may be clinical evidence that autoimmune diseases share similar immunological mechanisms. CASE PRESENTATION: We report a 30-year-old woman with a unique combination of autoimmune diseases predominantly affecting the central nervous system, with hypoparathyroidism, hypophysitis, medulla involvement, and pons and temporal lobe involvement associated with primary Sjögren's syndrome (pSS), occurring independently over a long period. The patient who had a history of muscle cramps and one seizure incident, presented with vomiting and blurred vision. She was diagnosed with hypophysitis and hypoparathyroidism with calcifications in the basal ganglia and cerebellum. She recovered after four months of corticosteroid treatment for hypophysitis and was started on treatment for hypoparathyroidism. Eight months later, she developed vomiting, hiccups, vertigo, and ataxia with a focal lesion in the medulla. She recovered with immunosuppressive treatment for 2 years. Fifty-eight months after the onset of hypophysitis, she developed diplopia and dry mouth and eyes. MRI showed infiltrative lesions in the left pons and left temporal lobe. Based on positive anti-Sjögren's syndrome-related antigen A antibodies and low unstimulated whole salivary flow rate, pSS was diagnosed. She received corticosteroids and continued mycophenolate mofetil treatment with recovery of neurological symptoms. CONCLUSION: This case highlights the need for long-term follow-up to detect autoimmune disease processes involving various organs.

Changes in the intrinsic severity of severe acute respiratory syndrome coronavirus 2 according to the emerging variant: a nationwide study from February 2020 to June 2022, including comparison with vaccinated populations.

BACKGROUND: As the population acquires immunity through vaccination and natural infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), understanding the intrinsic severity of coronavirus disease (COVID-19) is becoming challenging. We aimed to evaluate the intrinsic severity regarding circulating variants of SARS-CoV-2 and to compare this between vaccinated and unvaccinated individuals. METHODS: With unvaccinated and initially infected confirmed cases of COVID-19, we estimated the case severity rate (CSR); case fatality rate (CFR); and mortality rate (MR), including severe/critical cases and deaths, stratified by age and compared by vaccination status according to the period regarding the variants of COVID-19 and vaccination. The overall rate was directly standardized with age. RESULTS: The age-standardized CSRs (aCSRs) of the unvaccinated group were 2.12%, 5.51%, and 0.94% in the pre-delta, delta, and omicron period, respectively, and the age-standardized CFRs (aCFRs) were 0.60%, 2.49%, and 0.63% in each period, respectively. The complete vaccination group had lower severity than the unvaccinated group over the entire period showing under 1% for the aCSR and 0.5% for the aCFR. The age-standardized MR of the unvaccinated group was 448 per million people per month people in the omicron period, which was 11 times higher than that of the vaccinated group. In terms of age groups, the CSR and CFR sharply increased with age from the 60 s and showed lower risk reduction in the 80 s when the period changed to the omicron period. CONCLUSIONS: The intrinsic severity of COVID-19 was the highest in the delta period, with over 5% for the aCSR, whereas the completely vaccinated group maintained below 1%. This implies that when the population is vaccinated, the impact of COVID-19 will be limited, even if a new mutation appears. Moreover, considering the decreasing intrinsic severity, the response to COVID-19 should prioritize older individuals at a higher risk of severe disease.

Visualizing reactive astrocyte-neuron interaction in Alzheimer's disease using 11C-acetate and 18F-FDG.

Reactive astrogliosis is a hallmark of Alzheimer's disease (AD). However, a clinically validated neuroimaging probe to visualize the reactive astrogliosis is yet to be discovered. Here, we show that PET imaging with 11C-acetate and 18F-fluorodeoxyglucose (18F-FDG) functionally visualizes the reactive astrocyte-mediated neuronal hypometabolism in the brains with neuroinflammation and AD. To investigate the alterations of acetate and glucose metabolism in the diseased brains and their impact on the AD pathology, we adopted multifaceted approaches including microPET imaging, autoradiography, immunohistochemistry, metabolomics, and electrophysiology. Two AD rodent models, APP/PS1 and 5xFAD transgenic mice, one adenovirus-induced rat model of reactive astrogliosis, and post-mortem human brain tissues were used in this study. We further curated a proof-of-concept human study that included 11C-acetate and 18F-FDG PET imaging analyses along with neuropsychological assessments from 11 AD patients and 10 healthy control subjects. We demonstrate that reactive astrocytes excessively absorb acetate through elevated monocarboxylate transporter-1 (MCT1) in rodent models of both reactive astrogliosis and AD. The elevated acetate uptake is associated with reactive astrogliosis and boosts the aberrant astrocytic GABA synthesis when amyloid-ß is present. The excessive astrocytic GABA subsequently suppresses neuronal activity, which could lead to glucose uptake through decreased glucose transporter-3 in the diseased brains. We further demonstrate that 11C-acetate uptake was significantly increased in the entorhinal cortex, hippocampus and temporo-parietal neocortex of the AD patients compared to the healthy controls, while 18F-FDG uptake was significantly reduced in the same regions. Additionally, we discover a strong correlation between the patients' cognitive function and the PET signals of both 11C-acetate and 18F-FDG. We demonstrate the potential value of PET imaging with 11C-acetate and 18F-FDG by visualizing reactive astrogliosis and the associated neuronal glucose hypometablosim for AD patients. Our findings further suggest that the acetate-boosted reactive astrocyte-neuron interaction could contribute to the cognitive decline in AD.

Structures of ß-klotho reveal a 'zip code'-like mechanism for endocrine FGF signalling.

Canonical fibroblast growth factors (FGFs) activate FGF receptors (FGFRs) through paracrine or autocrine mechanisms in a process that requires cooperation with heparan sulfate proteoglycans, which function as co-receptors for FGFR activation. By contrast, endocrine FGFs (FGF19, FGF21 and FGF23) are circulating hormones that regulate critical metabolic processes in a variety of tissues. FGF19 regulates bile acid synthesis and lipogenesis, whereas FGF21 stimulates insulin sensitivity, energy expenditure and weight loss. Endocrine FGFs signal through FGFRs in a manner that requires klothos, which are cell-surface proteins that possess tandem glycosidase domains. Here we describe the crystal structures of free and ligand-bound ß-klotho extracellular regions that reveal the molecular mechanism that underlies the specificity of FGF21 towards ß-klotho and demonstrate how the FGFR is activated in a klotho-dependent manner. ß-Klotho serves as a primary 'zip code'-like receptor that acts as a targeting signal for FGF21, and FGFR functions as a catalytic subunit that mediates intracellular signalling. Our structures also show how the sugar-cutting enzyme glycosidase has evolved to become a specific receptor for hormones that regulate metabolic processes, including the lowering of blood sugar levels. Finally, we describe an agonistic variant of FGF21 with enhanced biological activity and present structural insights into the potential development of therapeutic agents for diseases linked to endocrine FGFs.

Epidemiology of Respiratory Viruses in Korean Children Before and After the COVID-19 Pandemic: A Prospective Study From National Surveillance System.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic led to a decrease in the seasonal incidence of many respiratory viruses worldwide due to the impact of nonpharmaceutical interventions (NPIs). However, as NPI measures were relaxed, respiratory viral infections re-emerged. We aimed to characterize the epidemiology of respiratory viruses in Korean children during post-COVID-19 pandemic years compared to that before the pandemic. METHODS: A nationwide prospective ongoing surveillance study has been conducted for detection of respiratory viruses between January 2017 and June 2023. We included data on adenovirus (AdV), human bocavirus (HBoV), human coronavirus (HCoV), human metapneumovirus (HMPV), human rhinovirus (HRV), influenza virus (IFV), parainfluenza virus (PIV), and respiratory syncytial virus (RSV), which were detected in children and adolescents younger than 20 years. We analyzed the weekly detection frequency of individual viruses and the age distribution of the affected children. The study period was divided into prepandemic (2017-2019) and postpandemic (2021-2023) periods. RESULTS: A total of 19,589 and 14,068 samples were collected in the pre- and postpandemic periods, respectively. The overall detection rate of any virus throughout the study period was 63.1%, with the lowest occurring in the 2nd half of 2020 (50.6%) and the highest occurring in the 2nd half of 2021 (72.3%). Enveloped viruses (HCoV, HMPV, IFV, PIV, and RSV) almost disappeared, but nonenveloped viruses (AdV, HBoV, and HRV) were detected even during the peak of the COVID-19 pandemic. The codetection rate increased from 15.0% prepandemic to 19.1% postpandemic (P < 0.001). During the postpandemic period, a large out-of-season PIV and HMPV epidemic occurred, but the usual seasonality began to be restored in 2023. The mean age of children with each virus detected in 2023 was significantly greater than that in prepandemic years (P = 0.003 and 0.007 for AdV and HCoV, respectively; P < 0.001 for others). The mean age of children with IFV increased in 2022 (11.1 ± 5.2 years) from prepandemic years (7.9 ± 4.6 years) but decreased to 8.7 ± 4.1 years in 2023. CONCLUSION: With the relaxation of NPI measures, several seasonal respiratory viruses cocirculated with unusual seasonal epidemic patterns and were associated with increasing age of infected children.

Anti-TCP1 Antibody Is a Potential Biomarker for Diagnosing Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is a chronic inflammatory disease caused by autoantibodies. Serum samples from patients with SLE (n = 10) were compared with those from normal controls (NCs, n = 5) using 21K protein chip analysis to identify a biomarker for SLE, revealing 63 SLE-specific autoantibodies. The anti-chaperonin-containing t-complex polypeptide-1 (TCP1) antibody exhibited higher expression in patients with SLE than in NCs. To validate the specificity of the anti-TCP1 antibody in SLE, dot blot analysis was conducted using sera from patients with SLE (n = 100), rheumatoid arthritis (RA; n = 25), Behçet's disease (BD; n = 28), and systemic sclerosis (SSc; n = 30) and NCs (n = 50). The results confirmed the detection of anti-TCP1 antibodies in 79 of 100 patients with SLE, with substantially elevated expression compared to both NCs and patients with other autoimmune diseases. We performed an enzyme-linked immunosorbent assay to determine the relative amounts of anti-TCP1 antibodies; markedly elevated anti-TCP1 antibody levels were detected in the sera of patients with SLE (50.1 ± 17.3 arbitrary unit (AU), n = 251) compared to those in NCs (33.9 ± 9.3 AU), RA (35 ± 8.7 AU), BD (37.5 ± 11.6 AU), and SSc (43 ± 11.9 AU). These data suggest that the anti-TCP1 antibody is a potential diagnostic biomarker for SLE.

Circulating cold-inducible RNA-binding protein levels in microscopic polyangiitis and granulomatosis with polyangiitis : Correlation with disease activity.

OBJECTIVE: This study investigated whether circulating cold-inducible RNA-binding protein (CIRP) could be a biomarker to reflect the current activity, function, and damage status in patients with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA). METHODS: This study selected 39 MPA and 26 GPA patients. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)-specific indices include the Birmingham Vasculitis Activity Index (BVAS), five-factor score (FFS), the Korean version of the Short-Form 36-Item Health Survey (SF-36) physical component summary (PCS) and mental component summary (MCS), and the vasculitis damage index (VDI). The highest tertile of BVAS was defined as high activity of AAV. RESULTS: The median age of the study subjects was 65.0 years and 53.8% were women. The median BVAS, FFS, SF-36 PCS, MCS, and VDI scores were 12.0, 2.0, 47.5, 50.3, and 3.0, respectively. The median circulating CIRP level was 6.4 ng/mL. Among the four AAV-specific indices, circulating CIRP was significantly correlated with BVAS (r = 0.256). Using the receiver operator characteristic curve, the cut-off of circulating CIRP for high activity of AAV was 6.16 ng/mL. High activity of AAV was identified more frequently in patients with circulating CIRP ≥ 6.16 ng/mL than in those with circulating CIRP < 6.16 ng/mL (48.6% vs. 21.4%). In addition, patients with circulating CIRP ≥ 6.16 ng/mL exhibited a significantly higher risk for high activity of AAV than those with circulating CIRP < 6.16 ng/mL (relative risk 3.474). CONCLUSION: This study suggests the clinical potential of circulating CIRP as a biomarker for reflecting the current BVAS and predicting high activity of AAV in patients with MPA and GPA.

Application of the 2022 ACR/EULAR criteria for Takayasu arteritis to previously diagnosed patients based on the 1990 ACR criteria.

OBJECTIVES: Recently, a joint group of the American College of Rheumatology (ACR) and the European Alliance of Associations for Rheumatology (EULAR) proposed new criteria for Takayasu arteritis (TAK) (the 2022 ACR/EULAR criteria). This study applied the 2022 ACR/EULAR criteria to patients with previously diagnosed TAK based on the 1990 ACR criteria and investigated the concordance rate between the two criteria according to the four imaging modalities. METHODS: This study reviewed the medical records of 179 patients who met the 1990 ACR criteria for TAK. The imaging modalities included conventional angiography, computed tomography angiography, fluorodeoxyglucose-positron emission tomography, and magnetic resonance angiography. RESULTS: Regardless of the imaging modalities, the concordance rate between the two criteria was 85.5% when including all patients, whereas it increased to 98.1% when only patients aged ≤60 years were included. Among the four imaging modalities, computed tomography angiography exhibited the highest concordance rate between the two criteria (85.6%). The concordance rate among patients aged >60 years was 95.7%. Only one patient aged 50-60 years was reclassified as having both TAK and giant cell arteritis. CONCLUSIONS: The concordance rate was 85.5% regardless of the imaging modalities and increased to 86.9% on simultaneous computed tomography angiography and fluorodeoxyglucose-positron emission tomography imaging.