ABSTRACT
Mastocytosis is a complex heterogenous multisystem disorder that is characterized by pathologic activation or accumulation of neoplastic mast cells (MCs) in one or more organs. This clonal MC expansion is often associated with a somatic gain-of-function mutation (D816V in most of the cases) in the KIT gene, encoding for the MC surface receptor KIT (CD117), a stem cell growth factor receptor. Based on clinical and biochemical criteria, the World Health Organization (WHO) divided mastocytosis into different subclasses. The exact prevalence of mastocytosis remains elusive, but it is estimated that the disease affects approximately 1 in 10,000 persons. The clinical presentation of mastocytosis varies significantly, ranging from asymptomatic patients to a life-threatening disease with multiple organ involvement, potentially leading to cytopenia, malabsorption, hepatosplenomegaly, lymphadenopathy, ascites or osteolytic bone lesions with pathological fractures. Patients with mastocytosis may experience symptoms related to release of MC mediators, such as flushing or diarrhea or even more severe symptoms such as anaphylaxis. Recently, a new genetic trait, hereditary alpha tryptasemia (HaT), was described which involves a copy number variation in the TPSAB1-gene. Its role as standalone multisystem syndrome is heavily debated. There is emerging evidence suggesting there might be a link between HaT and due to the increased prevalence of HaT in patients with SM. The aim of this review is to provide a practical roadmap for diagnosis and management of mastocytosis and its associated entities, since there are still many misconceptions about these topics.Abbreviations: AdvSM: Advanced systemic mastocytosis; ASM: Aggressive systemic mastocytosis; aST: acute serum tryptase; BM: Bone marrow; BMM: Bone marrow mastocytosis; bST: baseline serum tryptase; CM: Cutaneous mastocytosis; DCM: Diffuse cutaneous mastocytosis; HVA: Hymenoptera venom allergy; HaT: Hereditary alpha tryptasemia; ISM: Indolent systemic mastocytosis; MC: Mast cell; MCA: Mast cell activation; MCAS: Mast cell activation syndrome; MCL: Mast cell leukemia; MIS: Mastocytosis in the skin; MMAS: Monoclonal mast cell activation syndrome; MPCM: Maculopapular cutaneous mastocytosis; SM: Systemic mastocytosis; SM-AHN: Systemic mastocytosis with associated hematological neoplasm; SSM: Smouldering systemic mastocytosis; VIT: Venom immunotherapy.
Subject(s)
Mastocytosis, Cutaneous , Mastocytosis, Systemic , Mastocytosis , Humans , Mastocytosis, Systemic/diagnosis , Mastocytosis, Systemic/genetics , Tryptases , DNA Copy Number Variations , Mastocytosis/diagnosis , Mastocytosis/genetics , Mastocytosis/therapy , Mastocytosis, Cutaneous/diagnosis , Mastocytosis, Cutaneous/pathologyABSTRACT
A 57-year-old woman with advanced non-small cell lung carcinoma developed hypersensitivity reactions to docetaxel. Measures taken to attempt the re-administration of docetaxel failed. For the differential diagnosis, an IgE specific to docetaxel (in terms of cross-reactivity with Taxus baccata), the solubilizing agent polysorbate 80, as well as the possibility of the reaction being non-IgE-mediated, were all considered. The latter was thought to be most likely. Desensitisation has been reported to be safe and effective in protecting patients from severe hypersensitivity reactions in both IgE- and non-IgE-mediated reactions. Desensitisation in this context means the induction of temporary clinical unresponsiveness to the culprit drug. The gradual reintroduction of small doses of the drug at fixed time intervals eventually allows delivery of full therapeutic doses. Desensitisation to docetaxel was successfully carried out in a supervised setting a total of three times in this patient.
