BACKGROUND: Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) share similar clinical manifestations, including cardiovascular complications, suggesting similar underlying immunopathogenic processes. Aberrant neutrophil activation may play a crucial role in the shared pathologies of KD and MIS-C; however, the associated pathogenic mechanisms and molecular drivers remain unknown. METHODS: We performed a single-cell meta-analysis of neutrophil activation with 103 pediatric single-cell transcriptomic peripheral blood mononuclear cell data across 9 cohorts, including healthy controls, KD, MIS-C, compared with dengue virus infection, juvenile idiopathic arthritis, and pediatric celiac disease. We used a series of computational analyses to investigate the shared neutrophil transcriptional programs of KD and MIS-C that are linked to systemic damage and cardiac pathologies, and suggested Food and Drug Administration–approved drugs to consider as KD and MIS-C treatment. RESULTS: We meta-analyzed 521 950 high-quality cells. We found that blood signatures associated with risks of cardiovascular events are enriched in neutrophils of KD and MIS-C. We revealed the expansion of CD177 ⁺ neutrophils harboring hyperactivated effector functions in both KD and MIS-C, but not in healthy controls or in other viral-, inflammatory-, or immune-related pediatric diseases. KD and MIS-C CD177 ⁺ neutrophils had highly similar transcriptomes, marked by conserved signatures and pathways related to molecular damage. We found the induction of a shared neutrophil expression program, potentially regulated by SPI1 (Spi-1 proto-oncogene), which confers enhanced effector functions, especially neutrophil degranulation. CD177 and shared neutrophil expression program expressions were associated with acute stages and attenuated during KD intravenous immunoglobulin treatment and MIS-C recovery. Network analysis identified hub genes that correlated with the high activation of CD177 ⁺ neutrophils. Disease-gene association analysis revealed that the KD and MIS-C CD177 ⁺ neutrophils' shared expression program was associated with the development of coronary and myocardial disorders. Last, we identified and validated TSPO (translocator protein) and S100A12 (S100 calcium-binding protein A12) as main molecular targets, for which the Food and Drug Administration–approved drugs methotrexate, zaleplon, metronidazole, lorazepam, clonazepam, temazepam, and zolpidem, among others, are primary candidates for drug repurposing. CONCLUSIONS: Our findings indicate that CD177 ⁺ neutrophils may exert systemic pathological damage contributing to the shared morbidities in KD and MIS-C. We uncovered potential regulatory drivers of CD177 ⁺ neutrophil hyperactivation and pathogenicity that may be targeted as a single therapeutic strategy for either KD or MIS-C.

Triple-negative breast cancer (TNBC) is treated with neoadjuvant chemotherapy (NAC). The response to NAC, particularly the probability of a complete pathological response (pCR), guides the surgical approach and adjuvant therapy. We developed a prediction model using a nomogram integrating blood tests and pre-treatment ultrasound findings for predicting pCR in patients with stage II or III operable TNBC receiving NAC. Clinical data before and after the first cycle of NAC collected from patients between 2012 and 2019 were analyzed using univariate and multivariate analyses to identify correlations with pCR. The coefficients of the significant parameters were calculated using logistic regression, and a nomogram was developed based on the logistic model to predict the probability of pCR. Eighty-eight patients were included. Five parameters correlated with the probability of pCR, including the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte (PLR) ratio, percentage change in PLR, presence of echogenic halo, and tumor height-to-width ratio. The discrimination performance of the nomogram was indicated by an area under the curve of 87.7%, and internal validation showed that the chi-square value of the Hosmer–Lemeshow test was 7.67 (p = 0.363). Thus, the integrative prediction model using clinical data can predict the probability of pCR in patients with TNBC receiving NAC.

In eukaryotic cells, reactive oxygen species (ROS) serve as crucial signaling components. ROS are potentially toxic, so constant adjustments are needed to maintain cellular health. Here we describe a single-cell, mass cytometry-based method that we call signaling network under redox stress profiling (SN-ROP) to monitor dynamic changes in redox-related pathways during redox stress. SN-ROP quantifies ROS transporters, enzymes, oxidative stress products and associated signaling pathways to provide information on cellular redox regulation. Applied to diverse cell types and conditions, SN-ROP reveals unique redox patterns and dynamics including coordinated shifts in CD8⁺ T cells upon antigen stimulation as well as variations in CAR-T cell persistence. Furthermore, SN-ROP analysis uncovers environmental factors such as hypoxia and T cell exhaustion for influencing redox balance, and also reveals distinct features in patients on hemodialysis. Our findings thus support the use of SN-ROP to elucidate intricate redox networks and their implications in immune cell function and disease.

Kawasaki disease (KD) is the most recognized childhood vasculitis and the leading cause of pediatric-acquired heart disease in developed countries.¹ Increased KD incidence among East Asian children, a high risk among siblings and twins, and familial occurrence suggest a genetic predisposition.^1,2 However, genetic factors alone cannot explain seasonal variations, periodic outbreaks, or the continued increase in KD incidence.² Many other factors, including exposure to infectious agents, pollution, and elevated atmospheric biological particle concentrations, are associated with KD.²

Background: Hymenoptera stings can induce dysregulated inflammation and immediate hypersensitivity reactions including anaphylaxis. However, the molecular mechanisms underlying peripheral immune responses during Hymenoptera venom allergy (HVA) remain elusive.Methods: Here we determined the single‐cell transcriptomic profiling from highly heterogeneous peripheral blood cells in patients with HVA through unbiased single‐cell RNA sequencing and multiple models of computational analyses.Results: Through clustering analysis by uniform manifold approximation and projection, we revealed an increased number of monocytes in the acute phase and identified innate immune responses, leukocyte activation, and cellular detoxification as the main involved biological processes. We used filter analysis to identify that CLU that encodes clusterin was highly expressed in monocytes, and the co‐expressed genes of CLU further supported the key role of monocyte. We further used pseudo‐temporal ordering of cells and scRNA velocity analysis to delineate disease‐associated monocyte lineages and states in patients with HVA.Conclusions: Our comprehensive molecular profiling of blood samples from patients with HVA revealed previously unknown molecular changes, providing important insights into the mechanism of venom allergy and potential therapeutic targets.