Role of Mast Cells in Human Health and Disease: Controversies and Novel Therapies

Mast cells have been implicated in allergic diseases such as asthma, rhinitis, conjunctivitis, atopic dermatitis, urticaria, and anaphylaxis. However, it is now well established that they also fulfill critical roles in tissue homeostasis, repair, and defense. Despite considerable progress, their ontogeny, proliferation, and differentiation remain subjects of debate, as does their involvement in a wide spectrum of diseases, including cancer and cardiovascular disorders. What remains indisputable is their essential contribution to both innate and adaptive immune responses. Importantly, the activity of their effector molecules can elicit either protective or deleterious outcomes. A complete absence of mast cells (MCs) in humans would undoubtedly provide valuable insight into their fundamental role in immunity, much as neutropenia and agranulocytosis have historically clarified the functions of neutrophils. In this review, we provide a comprehensive overview of mast cell (MC) biology, emphasizing their functional diversity and pathogenic potential. Furthermore, we highlight emerging therapeutic strategies, particularly the use of inhibitors and monoclonal antibodies, which are reshaping current approaches to conditions such as allergy, mastocytosis, and related disorders.