Unraveling the molecular mechanisms for COVID-19-associated encephalopathy and its immunopathology is crucial for developing effective treatments. Here, we utilized single-cell transcriptomic analysis and integrated clinical observations and laboratory examination to dissect the host immune responses and reveal pathological mechanisms in COVID-19-associated pediatric encephalopathy. We found that lymphopenia was a prominent characteristic of immune perturbation in COVID-19 patients with encephalopathy, especially those with acute necrotizing encephalopathy (AE). This was characterized a marked reduction of various lymphocytes (e.g., CD8⁺ T and CD4⁺ T cells) and significant increases in other inflammatory cells (e.g., monocytes). Further analysis revealed activation of multiple cell apoptosis pathways (e.g., granzyme/perforin-, FAS- and TNF-induced apoptosis) may be responsible for lymphopenia. A systemic S100A12 upregulation, primarily from classical monocytes, may have contributed to cytokine storms in patients with AE. A dysregulated type I interferon (IFN) response was observed which may have further exacerbated the S100A12-driven inflammation in patients with AE. In COVID-19 patients with AE, myeloid cells (e.g., monocytic myeloid-derived suppressor cells) were the likely contributors to immune paralysis. Finally, the immune landscape in COVID-19 patients with encephalopathy, especially for AE, were also characterized by NK and T cells with widespread exhaustion, higher cytotoxic scores and inflammatory response as well as a dysregulated B cell-mediated humoral immune response. Taken together, this comprehensive data provides a detailed resource for elucidating immunopathogenesis and will aid development of effective COVID-19-associated pediatric encephalopathy treatments, especially for those with AE.

Objective: Community-acquired pneumonia (CAP) is the primary cause of death for children under five years of age globally. Hence, it is essential to investigate new early biomarkers and potential mechanisms involved in disease severity. Methods: Proteomics combined with metabolomics was performed to identify biomarkers suitable for early diagnosis of severe CAP. In the training cohort, proteomics and metabolomics were performed on serum samples obtained from 20 severe CAPs (S-CAPs), 15 non-severe CAPs (NS-CAPs) and 15 healthy controls (CONs). In the verification cohort, selected biomarkers and their combinations were validated using ELISA and metabolomics in an independent cohort of 129 subjects. Finally, a combined proteomics and metabolomics analysis was performed to understand the major pathological features and reasons for severity of CAP. Results: The proteomic and metabolic signature was markedly different between S-CAPs, NS-CAPs and CONs. A new serum biomarker panel including 2 proteins [C-reactive protein (CRP), lipopolysaccharide (LBP)] and 3 metabolites [Fasciculol C, PE (14:0/16:1(19Z)), PS (20:0/22:6(4Z, 7Z, 10Z, 13Z, 16Z, 19Z))] was developed to identify CAP and to distinguish severe pneumonia. Pathway analysis of changes revealed activation of the cell death pathway, a dysregulated complement system, coagulation cascade and platelet function, and the inflammatory responses as contributors to tissue damage in children with CAP. Additionally, activation of glycolysis and higher levels of nucleotides led to imbalanced deoxyribonucleotide pools contributing to the development of severe CAP. Finally, dysregulated lipid metabolism was also identified as a potential pathological mechanism for severe progression of CAP. Conclusion: The integrated analysis of the proteome and metabolome might open up new ways in diagnosing and uncovering the complexity of severity of CAP.

Mycoplasma pneumoniae (MP) is an important causative agent of morbidity and mortality among all age groups, especially among patients of extreme ages. Improved and readily available tests for accurate, sensitive and rapid diagnosis of MP infection is sorely needed. Here, we developed a CRISPR-Cas12b-based detection platform on the basis of recombinase polymerase amplification (RPA) for rapid, simple, and accurate diagnosis of MP infection, named MP-RPA-CRISPR. The RPA was employed for amplifying the community-acquired respiratory distress syndrome (CARDS) toxin gene of MP strains at the optimal reaction temperature 37°C. The resulting amplicons were decoded by the CRISPR-Cas12b-based detection platform, which was interpreted by real-time PCR system and by naked eye under blue light. The MP-RPA-CRISPR can detected down to 5 fg of genomic DNA templates of MP strains and accurately distinguish MP strains from non-MP strains without any cross-reactivity. A total of 96 bronchoalveolar lavage fluid (BALF)samples collected from patients suspected of respiratory infection were used to evaluate the clinical performance of the MP-RPA-CRISPR assay. As a result, our assay accurately diagnosed 45 MP-infected samples and 51 non-MP infected sample, and the results obtained from MP-RPA-CRISPR were consistent with microfluidic chip technology. In conclusion, our MP-RPA-CRISPR assay is a simple, rapid, portable and highly sensitive method to diagnose MP infection, which can be used as a promising tool in a variety of settings including clinical, field, and resource-limited aeras.

Pseudomonas aeruginosa (P. aeruginosa) is an important bacterial pathogen involved in a wide range of infections and antimicrobial resistance. Rapid and reliable diagnostic methods are of vital important for early identification, treatment, and stop of P. aeruginosa infections. In this study, we developed a simple, rapid, sensitive, and specific detection platform for P. aeruginosa infection diagnosis. The method integrated recombinase polymerase amplification (RPA) technique with clustered regularly interspaced short palindromic repeat (CRISPR)–CRISPR-associated protein 12a (Cas12a) biosensing system and was termed P. aeruginosa–CRISPR–RPA assay. The P. aeruginosa–CRISPR–RPA assay was subject to optimization of reaction conditions and evaluation of sensitivity, specificity, and clinical feasibility with the serial dilutions of P. aeruginosa genomic DNA, the non–P. aeruginosa strains, and the clinical samples. As a result, the P. aeruginosa–CRISPR–RPA assay was able to complete P. aeruginosa detection within half an hour, including RPA reaction at 42°C for 20 min and CRISPR-Cas12a detection at 37°C for 10 min. The diagnostic method exhibited high sensitivity (60 fg per reaction, ~8 copies) and specificity (100%). The results of the clinical samples by P. aeruginosa–CRISPR–RPA assay were consistent to that of the initial result by microfluidic chip method. These data demonstrated that the newly developed P. aeruginosa–CRISPR–RPA assay was reliable for P. aeruginosa detection. In summary, the P. aeruginosa–CRISPR–RPA assay is a promising tool to early and rapid diagnose P. aeruginosa infection and stop its wide spread especially in the hospital settings.

The ongoing outbreak of the monkeypox, caused by monkeypox virus (MPXV), has been a public health emergency of international concern, indicating an urgent need for rapid and sensitive MPXV detection. Here, we designed a diagnostic test based on loop-mediated isothermal amplification (LAMP) and nanoparticle-based lateral flow biosensor(LFB)for diagnosis of MPXV infection, termed MPX-LAMP-LFB. A set of six LAMP primers was designed based the ATI gene of MPXV, and LAMP amplification of MPXV templates was performed at 63°C for only 40 min. The results were rapidly and visually decided using the LFB test within 2 min. The MPX-LAMP-LFB assay can specifically detect MPXV strains without cross-reaction with non-MPXV pathogens. The sensitivity of the MPX-LAMP-LFB assay is as low as 5 copies/μl of plasmid template and 12.5 copies/μl of pseudovirus in human blood samples. The whole process of the MPX-LAMP-LFB assay could be completed ~1 h, including rapid template preparation (15 min), LAMP reaction (40 min)and result reporting (<2 min). Collectively, MPX-LAMP-LFB assay developed here is a useful tool for rapid and reliable diagnosis of MPXV infection.

Background: Sepsis is a primary global health threat and costs a lot, requiring effective and affordable treatments. We performed this meta-analysis to explore the treatment of hydrocortisone, ascorbic acid, and thiamine (HAT) in sepsis and septic shock.Methods: We searched Ovid MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials from inception to August 14, 2021. We included randomized controlled trials (RCTs) that evaluated the HAT treatments in sepsis and septic shock. The primary outcome was the change in SOFA score over the 72 h. The second outcomes were the hospital, and 28-/30-day mortality, the duration of vasopressors, PCT clearance, hospital length of stay (LOS), and ICU LOS. We performed a subgroup analysis and a trial sequential analysis (TSA). The Der Simonian–Laird random-effects models were used to report the pooled risk ratios (RR) or mean difference (MD) with confidence intervals (CI).Results: Nine RCTs, enrolling 1427 patients of sepsis and septic shock treated with HAT (717) or only standard care (710), were included. There was a significant difference between the two groups in the change in SOFA score over the first 72 h (MD 0.65, 95% CI 0.30 to 1.00), the duration of vasopressors (MD − 18.16, 95% CI − 25.65 to − 10.68) and the PCT clearance (MD 14.54, 95% CI 0.64 to 28.43). In addition, there was no significant difference in the hospital mortality (RR 1.07, 95% CI 0.85 to 1.34), the 28-/30-day mortality (RR 0.96, 95% CI 0.80 to 1.15), the hospital LOS (MD 0.78, 95% CI − 0.30 to 1.86), and ICU LOS (MD 0.12, 95% CI − 0.53 to 0.78).Conclusions: The HAT combination improves the SOFA score in the first 72 h and reduces the duration of vasopressors in patients with sepsis. Given the minor mean difference of the change in SOFA score, the mortality benefit has not been observed.Trial registration: PROSPERO, CRD42020203166.