Immediate hypersensitivity reactions to iodinated contrast media despite drug prophylaxis-a comparative retrospective cohort study of breakthrough reactions in Bern (Switzerland) and Seoul (South Korea).

Background: Although several studies deal with breakthrough reactions (BTRs) in patients with contrast media (CM) hypersensitivity reactions, the phenomenon is still unclear. Therefore, this study aimed to analyse in depth patients with BTR in two countries. Methods: We retrospectively analysed the electronic medical records of in- and outpatients (random sample enrolment) from two academic hospitals of tertiary care (Seoul/South Korea, with a special monitoring system exclusively for CM hypersensitivity, and Bern/Switzerland, manually operated) with respect to basic epidemiological data, number of BTRs per patient, and severity grades of severity in follow-up analyses. The study period lasted from 2013 (2000 Bern) to 2017. Results: We identified 445 BTR-patients (91.5% from Seoul) with 691 BTRs (94.5% from Seoul). Most reactions were mild, 11% moderate and 3.9% severe. In Seoul, we found patients with up to 10 BTRs, and in Bern, there were only patients with one BTR. Fatal reactions or deaths did not occur. In most cases, the severity of the BTRs and of the index reactions were identical (80.8%). Mild index reactions remained constant in 90.6%. In contrast, in moderate index reactions the severity decreased/remained identically in 86.8% and increased in 13.2%. In severe index reactions, 55.6% of BTR reactions were severe again, in 44.4% the severity decreased. In 158 BTRs (22.9%) the culprit iodinated contrast medium (ICM) of the index reaction induced the BTR. In the other 482 BTRs (69.8%) the culprit ICM was changed to another non-culprit ICM. Conclusions: To the best of our knowledge, this is the largest study on patients with BTRs, and the first study showing BTRs in two centers in two countries of two continents. The main differences between the two centers result from the different hospital size, the number of patients, and the different documentation [manual (Bern) vs. electronical screening (Seoul)]. BTRs are no contraindications for further ICM-application. We recommend performing an allergy skin test as basis for the decision-making process of the next contrast-enhanced image-guided examination.

Neuromuscular blocking agent re-exposure in a retrospective cohort with neuromuscular blocking agent-associated anaphylaxis.

BACKGROUND: Neuromuscular blocking agents (NMBAs) are one of the most common causes of perioperative anaphylaxis. Although skin test positivity may help identify reactive NMBAs, it is unclear whether skin test negativity can guarantee the safety of systemically administered NMBAs. OBJECTIVE: This study aimed to evaluate the real-world safety of alternative NMBAs screened using skin tests in patients with suspected NMBA-induced anaphylaxis. METHODS: A retrospective cohort of suspected NMBA-induced anaphylaxis were recruited among patients at Seoul National University Hospital from June 2009 to May 2021, and their characteristics and outcomes were assessed. RESULTS: A total of 47 cases (0.017%) of suspected anaphylaxis occurred in 282,707 patients who received NMBAs. Cardiovascular manifestations were observed in 95.7%, whereas cutaneous findings were observed in 59.6%. Whereas 83% had a history of undergoing general anesthesia, 17% had no history of NMBA use. In skin tests, the overall positivity to any NMBA was 94.6% (81.1% to culprit NMBAs) and the cross-reactivity was 75.7%, which is related to the chemical structural similarity among NMBAs; the cross-reactivity and chemical structure similarity of rocuronium were 85.3% and 0.814, respectively, with vecuronium; this is in contrast to 50% and 0.015 with cisatracurium and 12.5% and 0.208 with succinylcholine. There were 15 patients who underwent subsequent surgery with a skin test-negative NMBA; whereas 80.0% (12/15) safely completed surgery, 20.0% (3/15) experienced hypotension. CONCLUSION: Similarities in chemical structure may contribute to the cross-reactivity of NMBAs in skin tests. Despite the high negative predictability of skin tests for suspected NMBA-induced anaphylaxis, the potential risk of recurrent anaphylaxis has not been eliminated.

Regulation of c-SMAC formation and AKT-mTOR signaling by the TSG101-IFT20 axis in CD4+ T cells.

CD4+ T cells play major roles in the adaptive immune system, which requires antigen recognition, costimulation, and cytokines for its elaborate orchestration. Recent studies have provided new insight into the importance of the supramolecular activation cluster (SMAC), which comprises concentric circles and is involved in the amplification of CD4+ T cell activation. However, the underlying mechanism of SMAC formation remains poorly understood. Here, we performed single-cell RNA sequencing of CD4+ T cells left unstimulated and stimulated with anti-CD3 and anti-CD28 antibodies to identify novel proteins involved in their regulation. We found that intraflagellar transport 20 (IFT20), previously known as cilia-forming protein, was upregulated in antibody-stimulated CD4+ T cells compared to unstimulated CD4+ T cells. We also found that IFT20 interacted with tumor susceptibility gene 101 (TSG101), a protein that endocytoses ubiquitinated T-cell receptors. The interaction between IFT20 and TSG101 promoted SMAC formation, which led to amplification of AKT-mTOR signaling. However, IFT20-deficient CD4+ T cells showed SMAC malformation, resulting in reduced CD4+ T cell proliferation, aerobic glycolysis, and cellular respiration. Finally, mice with T-cell-specific IFT20 deficiency exhibited reduced allergen-induced airway inflammation. Thus, our data suggest that the IFT20-TSG101 axis regulates AKT-mTOR signaling via SMAC formation.

Intravenous Mesenchymal Stem Cell Administration Modulates Monocytes/Macrophages and Ameliorates Asthmatic Airway Inflammation in a Murine Asthma Model.

Although asthma is a common chronic airway disease that responds well to anti-inflammatory agents, some patients with asthma are unresponsive to conventional treatment. Mesenchymal stem cells (MSCs) have therapeutic potential for the treatment of inflammatory diseases owing to their immunomodulatory properties. However, the target cells of MSCs are not yet clearly known. This study aimed to determine the effect of human umbilical cord-derived MSCs (hUC-MSCs) on asthmatic lungs by modulating innate immune cells and effector T cells using a murine asthmatic model. Intravenously administered hUC-MSCs reduced airway resistance, mucus production, and inflammation in the murine asthma model. hUC-MSCs attenuated not only T helper (Th) 2 cells and Th17 cells but also augmented regulatory T cells (Tregs). As for innate lymphoid cells (ILC), hUC-MSCs effectively suppressed ILC2s by downregulating master regulators of ILC2s, such as Gata3 and Tcf7. Finally, regarding lung macrophages, hUC-MSCs reduced the total number of macrophages, particularly the proportion of the enhanced monocyte-derived macrophage population. In a closer examination of monocyte-derived macrophages, hUC-MSCs reduced the M2a and M2c populations. In conclusion, hUC-MSCs can be considered as a potential anti- asthmatic treatment given their therapeutic effect on the asthmatic airway inflammation in a murine asthma model by modulating innate immune cells, such as ILC2s, M2a, and M2c macrophages, as well as affecting Tregs and effector T cells.

Diagnosis and Prevention of Hypersensitivity Reactions to Iodinated Contrast Media.

Iodinated contrast media (ICM) have become one of the major causes of drug hypersensitivity reactions (HSRs) related to increasing numbers of ICM-based radiological imaging procedures. Strategies for diagnosing and preventing ICM-induced HSRs have not been uniformly standardized yet. However, advances have been made based on the results of recent research. A previous history of hypersensitivity to ICM is the most significant risk factor for developing HSR by ICM. Avoidance of culprit agents and premedication is the main strategy to prevent recurrences of HSRs in high-risk patients. In addition, we strongly recommend identifying sensitized ICM using skin tests to determine immunoglobulin E-mediated or delayed-type allergy and to guide the choice of an alternative contrast agent. ICM provocation test procedures have been established and are helpful in selected cases. In this paper, we review how to evaluate patients who have experienced immediate or delayed HSRs caused by ICM to minimize the risk of recurrence and discuss unmet needs that require further research.

The Role of Autophagy in the Function of CD4+ T Cells and the Development of Chronic Inflammatory Diseases.

Uncontrolled acute inflammation progresses to persistent inflammation that leads to various chronic inflammatory diseases, including asthma, Crohn's disease, rheumatoid arthritis, multiple sclerosis, and systemic lupus erythematosus. CD4+ T cells are key immune cells that determine the development of these chronic inflammatory diseases. CD4+ T cells orchestrate adaptive immune responses by producing cytokines and effector molecules. These functional roles of T cells vary depending on the surrounding inflammatory or anatomical environment. Autophagy is an important process that can regulate the function of CD4+ T cells. By lysosomal degradation of cytoplasmic materials, autophagy mediates CD4+ T cell-mediated immune responses, including cytokine production, proliferation, and differentiation. Furthermore, through canonical processes involving autophagy machinery, autophagy also contributes to the development of chronic inflammatory diseases. Therefore, a targeted intervention of autophagy processes could be used to treat chronic inflammatory diseases. This review focuses on the role of autophagy via CD4+ T cells in the pathogenesis and treatment of such diseases. In particular, we explore the underlying mechanisms of autophagy in the regulation of CD4+ T cell metabolism, survival, development, proliferation, differentiation, and aging. Furthermore, we suggest that autophagy-mediated modulation of CD4+ T cells is a promising therapeutic target for treating chronic inflammatory diseases.

The Role of CD4+ T Cells and Microbiota in the Pathogenesis of Asthma.

Asthma, a chronic respiratory disease involving variable airflow limitations, exhibits two phenotypes: eosinophilic and neutrophilic. The asthma phenotype must be considered because the prognosis and drug responsiveness of eosinophilic and neutrophilic asthma differ. CD4+ T cells are the main determinant of asthma phenotype. Th2, Th9 and Tfh cells mediate the development of eosinophilic asthma, whereas Th1 and Th17 cells mediate the development of neutrophilic asthma. Elucidating the biological roles of CD4+ T cells is thus essential for developing effective asthma treatments and predicting a patient's prognosis. Commensal bacteria also play a key role in the pathogenesis of asthma. Beneficial bacteria within the host act to suppress asthma, whereas harmful bacteria exacerbate asthma. Recent literature indicates that imbalances between beneficial and harmful bacteria affect the differentiation of CD4+ T cells, leading to the development of asthma. Correcting bacterial imbalances using probiotics reportedly improves asthma symptoms. In this review, we investigate the effects of crosstalk between the microbiota and CD4+ T cells on the development of asthma.

Electrochemical Generation of Mesopores and Residual Oxygen for the Enhanced Activity of Silver Electrocatalysts.

The development of stable and efficient electrocatalysts is of key importance for the establishment of a sustainable society. The activity of a metal electrocatalyst is determined by its electrochemically active surface area and intrinsic activity, which can be increased using highly porous structures and heteroatomic doping, respectively. Herein, we propose a general strategy of generating mesopores and residual oxygen in metal electrocatalysts by reduction of metastable metal oxides using Ag2O3 electrodeposited onto carbon paper as a model system and demonstrating that the obtained multipurpose porous Ag electrocatalyst has high activity for the electroreduction of O2 and CO2. The presence of mesopores and residual oxygen is confirmed by electrochemical and spectroscopic techniques, and quantum mechanical simulations prove the importance of residual oxygen for electrocatalytic activity enhancement. Thus, the adopted strategy is concluded to allow the synthesis of highly active metal catalysts with controlled mesoporosity and residual oxygen content.

Variation of clinical manifestations according to culprit drugs in DRESS syndrome.

PURPOSE: Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare but serious condition that systematically damages various internal organs through T-cell-mediated immunological drug reactions. We aimed to investigate whether clinical manifestations of DRESS syndrome differ according to culprit drugs. METHODS: We retrospectively analyzed data from 123 patients with probable/definite DRESS syndrome based on the RegiSCAR criteria (January 2011 to July 2016). The data were obtained from the Korean Severe Cutaneous Adverse Reaction Registry. Causality was assessed using the World Health Organization-Uppsala Monitoring Centre criteria. The culprit drugs were categorized as allopurinol, carbamazepine, anti-tuberculosis drug, vancomycin, cephalosporins, dapsone, and nonsteroidal anti-inflammatory drugs. RESULTS: Differences were observed among culprit drugs regarding the frequencies of hepatitis (P < 0.01), renal dysfunction (P < 0.0001), lymphadenopathy (P < 0.01), and atypical lymphocyte (P < 0.01). Latency period differed among culprit drugs (P < 0.0001), being shorter in vancomycin and cephalosporin. In terms of clinical severity, admission duration (P < 0.01) and treatment duration (P < 0.05) differed among culprit drugs, being longer in vancomycin and anti-tuberculosis drugs, respectively. CONCLUSIONS: Based on the findings, clinical manifestations, including latency period and clinical severity, may differ according to culprit drugs in DRESS syndrome.

Social Relationships and Suicidal Ideation Among the Elderly Who Live Alone in Republic of Korea: A Logistic Model.

With population aging and change in family structure, the number of the elderly who live alone is rapidly increasing in Korea. The aim of this study was to explore the association between social relationships-especially newly formed formal social relationships (FSRs)-and suicidal ideation among Korean elderly who live alone. The elderly who live alone (N = 2509) from the 2014 Survey of Living Conditions and Welfare Needs of Older Koreans were analyzed using logistic regression. This study found that informal social relationships (ISRs) (eg, children, friends and neighbors) of the elderly who live alone had statistically significant association with suicidal ideation, whereas FSRs (eg, formal helper and social participation) did not have significant association with suicidal ideation. The findings of this study suggest that the Korean Government needs to strengthen public system for alleviating social isolation of the elderly living alone. Therefore, this study proposed 2 strategic approaches to maintain and strengthen ISRs and to develop different types of FSRs (eg, the measures to combine FSRs with ISRs, gatekeepers, etc).

A Case of Schnitzler's Syndrome without Monoclonal Gammopathy-Associated Chronic Urticaria Treated with Anakinra.

Chronic urticaria may often be associated with interleukin (IL)-1-mediated autoinflammatory disease, which should be suspected if systemic inflammation signs are present. Here, we report a case of Schnitzler's syndrome without monoclonal gammopathy treated successfully with the IL-1 receptor antagonist anakinra. A 69-year-old man suffered from a pruritic urticarial rash for 12 years. It became aggravated episodically and was accompanied by high fever, arthralgia, leukocytosis, and an elevated C-reactive protein and erythrocyte sedimentation rate. The episodes each lasted for over one week. Neutrophilic and eosinophilic inflammation was found on skin biopsy. However, serum and urine electrophoresis showed no evidence of monoclonal gammopathy. The cutaneous lesions were unresponsive to various kinds of anti-histamines, systemic glucocorticoids, colchicine, cyclosporine, dapsone, and methotrexate, which were administered over a span of 3 years immediately preceding successful treatment. A dramatic response, however, was observed after a daily administration of anakinra. This observation suggests that the correct diagnosis of this case is Schnitzler's syndrome without monoclonal gammopathy. For an adult patient with refractory chronic urticaria and systemic inflammation, Schnitzler's syndrome could be considered as a possible differential diagnosis. Although the typical form of Schnitzler's syndrome exhibits the presence of monoclonal gammopathy as a diagnostic criterion, monoclonal gammopathy may be absent in an atypical form. In such a situation, an IL-1 antagonist should be effective for the management of chronic urticaria.