This article provides an overview of recent developments concerning the physiology and pathobiology of mast cells and discusses current diagnostic and therapeutic approaches to mast-cell disorders, ...with an emphasis on mastocytosis.
Mast cells, which are present in most tissues, mature in situ from hematopoietic progenitors and acquire unique features of local effector cells. These features vary, depending on the tissue microenvironment. This article provides an overview of recent developments concerning the physiology and pathobiology of mast cells. We discuss current diagnostic and therapeutic approaches to mast-cell disorders, with an emphasis on mastocytosis.
Physiology and Pathophysiology of Mast Cells
Mast cells develop from hematopoietic progenitors in response to stem-cell factor (KIT ligand), which is the ligand of the CD117 transmembrane tyrosine kinase receptor, encoded by
KIT
. CD117 regulates the growth, migration, . . .
Over the past few years, substantial advances have been made in understanding the pathogenesis, evolution, and complexity of mast cell neoplasms. New diagnostic and prognostic parameters and novel ...therapeutic targets with demonstrable clinical impact have been identified. Several of these new markers, molecular targets, and therapeutic approaches have been validated and translated into clinical practice. At the same time, the classification of mastocytosis and related diagnostic criteria have been refined and updated by the consensus group and the World Health Organization (WHO). As a result, more specific therapies tailored toward prognostic subgroups of patients have been developed. Emerging treatment concepts use drugs directed against KIT and other relevant targets in neoplastic mast cells and will hopefully receive recognition by health authorities in the near future. This article provides an overview of recent developments in the field, with emphasis on the updated WHO classification, refined criteria, additional prognostic parameters, and novel therapeutic approaches. Based on these emerging concepts, the prognosis, quality of life, and survival of patients with advanced mastocytosis are expected to improve in the coming years.
Midostaurin is a multikinase inhibitor that includes mutant and nonmutant KIT D816V as a target. Its use in patients with advanced systemic mastocytosis, including mast-cell leukemia, produced ...responses in 60%, with a median overall survival of 28.7 months.
Systemic mastocytosis is a myeloid neoplasm that is caused by the accumulation of abnormal mast cells in the bone marrow, liver, spleen, and skin.
1
The
KIT
D816V mutation, which is detected in approximately 90% of patients, encodes a constitutively activated receptor tyrosine kinase that drives disease pathogenesis.
2
,
3
The World Health Organization (WHO) classification of advanced systemic mastocytosis includes aggressive systemic mastocytosis, systemic mastocytosis with an associated hematologic neoplasm (also termed systemic mastocytosis with an associated hematologic non–mast-cell-lineage disease), and mast-cell leukemia (Table S1 in the Supplementary Appendix, available with the full text of this article at NEJM.org).
4
Symptoms are caused . . .
The term mast cell activation syndrome (MCAS) is finding increasing use as a diagnosis for subjects who present with signs and symptoms involving the dermis, gastrointestinal track, and ...cardiovascular system frequently accompanied by neurologic complaints. Such patients often have undergone multiple extensive medical evaluations by different physicians in varied disciplines without a definitive medical diagnosis until the diagnosis of MCAS is applied. However, MCAS as a distinct clinical entity has not been generally accepted, nor do there exist definitive criteria for diagnosis. Based on current understanding of this disease “syndrome” and on what we do know about mast cell activation and resulting pathology, we will explore and propose criteria for its diagnosis. The proposed criteria will be discussed in the context of other disorders involving mast cells or with similar presentations and as a basis for further scientific study and validation.
Mast cell activation syndromes Akin, Cem
Journal of allergy and clinical immunology,
August 2017, 2017-Aug, 2017-08-00, 20170801, Letnik:
140, Številka:
2
Journal Article
Recenzirano
Mast cell activation is common and possibly necessary for maintenance of survival. Disordered mast cell activation occurs when mast cells are pathologically overproduced or if their activation is out ...of proportion to the perceived threat to homeostasis. Mast cell activation syndrome refers to a group of disorders with diverse causes presenting with episodic multisystem symptoms as the result of mast cell mediator release. Despite introduction of diagnostic criteria and some advances in treatment in the last decade, many areas of mast cell activation syndrome are in need of research. This article reviews our current knowledge about the various types of mast cell activation disorders, their treatment, and areas of uncertainty in need of future investigation.
Purpose of Review
The aim of this systematic review is to present the proposed theories of pathogenesis for idiopathic anaphylaxis (IA), to discuss its classification, its diagnostic approach, and ...management.
Recent Findings
IA represents a major diagnostic challenge and is diagnosed when excluding the possible identifiable triggers of anaphylaxis. The current research, however, revealed that certain conditions including mastocytosis, mast cell activation syndromes, and hereditary alpha tryptasemia can masquerade and overlap with its symptomatology. Also, newly identified galactose-alpha-1,3-galactose mammalian red meat allergy has recently been recognized as underlying cause of anaphylaxis in some cases that were previously considered as IA.
Summary
IA comprises a heterogenous group of conditions where, in some cases, inherently dysfunctional mast cells play a role in pathogenesis. The standard trigger avoidance strategies are ineffective, and episodes are unpredictable. Therefore, prompt recognition and treatment as well as prophylaxis are critical. The patients should always carry an epinephrine autoinjector.
Mastocytosis is a hematopoietic neoplasm defined by abnormal expansion and focal accumulation of clonal tissue mast cells in various organ-systems. The disease exhibits a complex pathology and an ...equally complex clinical behavior. The classification of the World Health Organization (WHO) divides mastocytosis into cutaneous forms, systemic variants, and localized mast cell tumors. In >80% of patients with systemic mastocytosis (SM), a somatic point mutation in
at codon 816 is found. Whereas patients with indolent forms of the disease have a normal or near-normal life expectancy, patients with advanced mast cell neoplasms, including aggressive SM and mast cell leukemia, have a poor prognosis with short survival times. In a majority of these patients, multiple somatic mutations and/or an associated hematologic neoplasm, such as a myeloid leukemia, may be detected. Independent of the category of mastocytosis and the serum tryptase level, patients may suffer from mediator-related symptoms and/or osteopathy. Depending on the presence of co-morbidities, the symptomatology in such patients may be mild, severe or even life-threatening. Most relevant co-morbidities in such patients are IgE-dependent allergies, psychiatric, psychological or mental problems, and vitamin D deficiency. The diagnosis and management of mastocytosis is an emerging challenge in clinical practice and requires vast knowledge, a multidisciplinary approach, and personalized medicine procedures. In this article, the current knowledge about mastocytosis is reviewed with special emphasis on the multidisciplinary aspects of the disease and related challenges in daily practice.
Mastocytosis is a term used to denote a heterogeneous group of conditions defined by the expansion and accumulation of clonal (neoplastic) tissue mast cells in various organs. The classification of ...the World Health Organization (WHO) divides the disease into cutaneous mastocytosis, systemic mastocytosis, and localized mast cell tumors. On the basis of histomorphologic criteria, clinical parameters, and organ involvement, systemic mastocytosis is further divided into indolent systemic mastocytosis and advanced systemic mastocytosis variants, including aggressive systemic mastocytosis and mast cell leukemia. The clinical impact and prognostic value of this classification has been confirmed in numerous studies, and its basic concept remains valid. However, refinements have recently been proposed by the consensus group, the WHO, and the European Competence Network on Mastocytosis. In addition, new treatment options are available for patients with advanced systemic mastocytosis, including allogeneic hematopoietic stem cell transplantation and multikinase inhibitors directed against KIT D816V and other key signaling molecules. Our current article provides an overview of recent advances in the field of mastocytosis, with emphasis on classification, prognostication, and emerging new treatment options in advanced systemic mastocytosis.
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