From the Guidelines
Mast cell disease, also known as mastocytosis, is a condition where abnormal mast cells accumulate in various tissues of the body, releasing substances like histamine during allergic reactions, and can be managed with a multidisciplinary team approach, preferably in specialized centers with expertise in the treatment of patients with mast cell disorders, as recommended by the most recent guidelines 1.
Key Characteristics of Mast Cell Disease
Mast cells are immune cells that play a crucial role in allergic reactions, and in mastocytosis, these cells multiply excessively and can gather in the skin, causing reddish-brown spots (cutaneous mastocytosis), or in internal organs like the bone marrow, liver, spleen, and lymph nodes (systemic mastocytosis).
Symptoms and Diagnosis
Symptoms of mastocytosis vary widely but often include:
- Skin lesions
- Flushing
- Itching
- Abdominal pain
- Diarrhea
- Anaphylaxis in severe cases The diagnosis of mastocytosis and its subtypes is based on the 2017 WHO Criteria Classification and requires a combination of histopathologic, clinical, laboratory, and cytogenetic/molecular analyses, including molecular testing for KIT D816V and mast cell immunophenotyping using flow cytometry and/or immunohistochemistry 1.
Treatment and Management
Treatment focuses on managing symptoms with:
- Antihistamines
- Mast cell stabilizers
- Avoiding triggers like certain foods, alcohol, temperature changes, and specific medications In aggressive forms, chemotherapy or targeted therapies may be necessary to control mast cell proliferation and prevent organ damage, and enrollment in well-designed clinical trials investigating state-of-the-art therapeutic strategies is encouraged 1.
From the Research
Definition and Role of Mast Cells
- Mast cells are members of the immune system that play a crucial role in allergic reactions and other physiological and pathological conditions 2, 3.
- They contain, synthesize, store, and secrete various substances that initiate or participate in different reactions, including those related to tissue deterioration, malignant tumors, angiogenesis, wound healing, and pregnancy 2.
Functions and Characteristics of Mast Cells
- Mast cells can synthesize, store, and secrete hormones characteristic of endocrine glands and transport them to the site of requirement or produce and employ them locally 2.
- The effect of mast cells is often controversial and dual, with both stimulatory and inhibitory effects on the same organ or process, likely due to their heterogeneity in morphology and cell content 2.
- Mast cells are transported in an unmatured form by the blood circulation and are exposed to microenvironmental effects that influence their maturation 2.
Mast Cell Activation Disorders
- Mast cell activation disorders, including anaphylaxis, mast cell activation syndrome (MCAS), and mastocytosis, are interrelated yet distinct conditions characterized by pathologic mast cell activation 4.
- These disorders can co-exist in the same patient and require diagnosis based on diagnostic consensus criteria 4.
- Treatment options for MCAS and mastocytosis include blockade of mediator receptors, inhibition of mediator synthesis, and anti-IgE therapy, as well as epinephrine and corticosteroids for acute episodes 5.
Treatment of Mast Cell Activation Syndromes
- H1-antihistamines have been shown to be effective in the treatment of primary MCAS, with significant improvements in quality of life, symptom control, and reduction in itching and whealing 6.
- However, there is a need for large, well-designed, double-blind, placebo-controlled randomized trials to investigate the effectiveness, cost-effectiveness, and safety of second-generation H1-antihistamines in the treatment of primary MCAS 6.