[MRGPRX2, pseudo-allergies reloaded: a step forward and two backwards].

Area of Science:

• Pharmacology
• Immunology
• Dermatology

Background:

• The MRGPRX2 receptor on mast cells, identified in 2015, is implicated in pseudoallergic drug reactions.
• Pseudoallergic reactions are distinct from IgE-mediated allergies, lacking prior sensitization.
• The list of drugs known to induce these reactions is expanding.

Purpose of the Study:

• To review recent advancements in understanding MRGPRX2-mediated pseudoallergic drug reactions.
• To highlight how new findings challenge established allergology concepts.
• To summarize key discoveries from the past four years in this field.

Main Methods:

• Literature review of scientific publications from the last four years.
• Analysis of studies focusing on MRGPRX2 receptor function and pseudoallergic reactions.
• Synthesis of current knowledge on drug-induced pseudoallergy.

Main Results:

• Pseudoallergic reactions are dose-dependent, predictable, and preventable by adjusting drug administration.
• These reactions do not require prior sensitization, differentiating them from true allergies.
• Genetic factors may influence susceptibility, but diagnostic tools are currently unavailable.

Conclusions:

• Recent research is reshaping the understanding of pseudoallergic drug reactions.
• The MRGPRX2 receptor plays a crucial role in these non-IgE-mediated hypersensitivity responses.
• Further research is needed to develop diagnostic tools for genetically predisposed individuals.