Recent research on mast cell biology has turned its focus on MRGPRX2, a new member of the Mas-related G protein-coupled subfamily of receptors (Mrgprs), originally described in nociceptive neurons of the dorsal root ganglia. MRGPRX2, a member of this group, is present not only in neurons but also in mast cells (MCs), specifically, and potentially in other cells of the immune system, such as basophils and eosinophils. As emerging new functions for this receptor are studied, a variety of both natural and pharmacologic ligands are being uncovered, linked to the ability to induce receptor-mediated MC activation and degranulation. The diversity of these ligands, characterized in their human, mice, or rat homologues, seems to match that of the receptor’s interactions. Natural ligands include host defense peptides, basic molecules, and key neuropeptides such as substance P and vasointestinal peptide (known for their role in the transmission of pain and itch) as well as eosinophil granule-derived proteins. Exogenous ligands include MC secretagogues such as compound 48/80 and mastoparan, a component of bee wasp venom, and several peptidergic drugs, among which are members of the quinolone family, neuromuscular blocking agents, morphine, and vancomycin. These discoveries shed light on its capacity as a multifaceted participant in naturally occurring responses within immunity and neural stimulus perception, as in responses at the center of immune pathology. In host defense, the mice Mrgprb2 has been proven to aid mast cells in the detection of peptidic molecules from bacteria and in the release of peptides with antimicrobial activities and other immune mediators. There are several potential actions described for it in tissue homeostasis and repair. In the realm of pathologic response, there is evidence to suggest that this receptor is also involved in chronic inflammation. Furthermore, MRGPRX2 has been linked to the pathophysiology of non-IgE-mediated immediate hypersensitivity drug reactions. Different studies have shown its possible role in other allergic diseases as well, such as asthma, atopic dermatitis, contact dermatitis, and chronic spontaneous urticaria. In this review, we sought to cover its function in physiologic processes and responses, as well as in allergic and nonallergic immune disease.

Purpose of review: To outline currently validated in vitro tests for the diagnosis of drug hypersensivity reactions (DHRs) and to provide useful strategies to optimise the utility of these tools. Recent findings: Regarding in vitro tests for DHR, the main concern, at present, is low sensitivity. Thus, most of the efforts are currently directed towards improving the existing techniques and developing new assays with better diagnostic performance. Summary: The management of DHRs is particularly challenging. Current strategies for diagnosis are focused on taking a thorough clinical history, evaluating sensitization using skin testing and performing supervised challenges. In vitro tests may potentially add information to the diagnostic algorithms for the management of DHRs. The presently available assays, however, pose significant limitations in terms of availability and validation. Maximizing their yield and accuracy, therefore, requires a tailored approach, focused on an appropriate clinical characterisation of the reaction. The time elapsed between drug administration and symptom presentation, as well as symptom duration, should be closely taken into consideration. In this review, existing validated in vitro techniques that may support the diagnosis of both immediate and non-immediate DHRs are summarised. Clues for optimizing their diagnostic yield are given.

Purpose of Review: The goal of this paper is to review drug allergy alert systems (DAAS), to summarise their key components, and to overview potential benefits and challenges associated with these tools. Methods for validation of their effects on patient safety, alternative uses, and strategies to streamline DAAS’ functions and reduce system fatigue are discussed. Recent Findings: DAAS are clinical decision support systems (CDSS) that focus on preventing drug adverse events within healthcare settings. The advent of electronic medical records has facilitated the development of digital DAAS. Existing versions use different methods to document diagnosed allergies, and rely on distinct rules and matching strategies for the generation of real-time alerts. DAAS promote the automation of several processes, facilitate prompt patient referral, and may be customised. Information overload, alert overrides by clinicians, and the development of “alert fatigue” may interfere with their usefulness. The newest strategies to streamline the function of DAAS include the use of artificial intelligence (AI) and other predictive techniques. Summary: The rising prevalence of drug allergies underscores the importance of effective DAAS. Further research is needed to evaluate their usefulness, to optimise their performance, to explore different algorithms and data sources, and to enhance the standardised integration of these systems into clinical practice.