A Puzzling Mast Cell Trilogy: Anaphylaxis, MCAS, and Mastocytosis

Beyond the appearances: exploring complexities in anaphylaxis differential diagnosis

PURPOSE OF REVIEW

Anaphylaxis is a severe, and potentially life-threatening hypersensitivity reaction whose diagnosis is based on clinical signs and symptoms and their prompt recognition. The presence of mimics and unusual presentations necessitate a careful evaluation and expertise in the field, due to potential diagnostic errors and hence a delay in the treatment.The aim of this review is to analyze and make an overview of the potential differential diagnosis of anaphylaxis, focusing on the clinical challenges of recognizing these conditions effectively among similar others.

RECENT FINDINGS

The presence of mimics and unusual presentations of anaphylaxis necessitate a careful evaluation, emphasizing the importance of a comprehensive diagnostic approach.Tryptase is well known marker of mast cells activation, and a useful tool assisting the diagnosis of anaphylaxis, helping to differentiate it from atypical mimickers.

SUMMARY

The differential diagnosis of anaphylaxis comprises a very wide setting, and a systematic approach assessing different categories of cardiovascular, skin, respiratory airway, neuropsychiatric, and hematologic systems, can facilitate recognition of the correct diagnosis of this complex and life-threatening condition.

Systemic Mastocytosis: State of the Art

PURPOSE OF REVIEW

Since identification of Systemic mastocytosis (SM) as a distinct disease entity by the World Health Organisation (WHO), there has been a wealth of new research in therapeutic targeting of the pathogenic C-KIT D816V mutation.

RECENT FINDINGS

Avapritinib, the first licensed drug in SM capable of disease modification alongside the increasingly potent, oral and highly selective KIT tyrosine kinase inhibitors (TKIs) Bezuclastinib and now Elenestinib have enabled the prospect of long-term remissions. Studies have shown improved survival and symptomatic control in patients with SM. Of great triumph, this has been achieved in an outpatient setting with apparent tolerable and minimal toxicity. The importance of molecular profiling is being demonstrated in administering combination therapies for SM with an associated haematological neoplasm (AHN), allowing more personalised and streamlined treatment regimes. This review focuses on current management strategies of SM, focusing on state-of-the-art directed therapies, the evidence behind their use with presentation of two clinical cases to highlight key messages.

Beyond the Usual Suspects: Unraveling Spleen Mastocytosis in Hypersplenism Differential Diagnosis

Systemic mastocytosis (SM) poses a diagnostic challenge. This hematologic disorder involves abnormal mast cell proliferation and concurrent tissue infiltration. SM clinical presentation is not uniform, with patients displaying a wide array of symptoms related to different organ infiltration and mast cell mediators. Splenomegaly, while not typical or specific to SM, might be present from an early stage to advanced stage, especially in the presence of thrombocytopenia. Early detection is crucial for optimal patient outcomes. We present an atypical case of SM with spleen involvement in a 63-year-old male patient with a history of persistent thrombocytopenia for five years. Upon splenectomy, histological findings were compatible with infiltration with mast cells. Remarkably, the patient showed improvement and did not require additional cytoreductive therapy. This case underlines the importance of recognizing this rare presentation and highlights the potential therapeutic role of splenectomy in aggressive SM.

Mast cell activation syndrome: An up-to-date review of literature

Mast cells are a subtype of white blood cells and are involved in the immune system. These cells contain many chemical substances called mediators, which are involved in the allergic response. The fact that mast cells play a role in many events that require urgent intervention, especially anaphylaxis, has led to a more detailed study of these cells. The diseases also caused by dysfunctions of mast cells have been examined in many circumstances. For instance, mast cell activation syndrome is known as an augmented number of cells due to decreased cell death, resulting in clinical symptoms affecting many systems. The main common symptoms include flushing, hypotension, urticaria, angioedema, headache, vomiting and diarrhea. Although the underlying mechanism is not yet clearly known, we aim to review the literature in a broad perspective and bring together the existing knowledge in the light of the literature due to the diversity of its involvement in the body and the fact that it is a little known syndrome.

Using the Right Criteria for MCAS

PURPOSE OF REVIEW

The current article aims to provide a comprehensive update on diagnostic criteria for mast cell activation syndrome (MCAS), addressing challenges in diagnosing and classifying MCAS and its variants.

RECENT FINDINGS

In recent years, there has been a significant increase in our knowledge regarding the underlying mechanisms responsible for the activation of mast cells (MCs) in various pathological conditions. Furthermore, a set of criteria and a classification for MCASs have been established. MCAS is characterized by the presence of typical clinical symptoms, a substantial elevation in serum tryptase levels during an attack compared to the patient's baseline tryptase levels, and a response to MC mediator-targeting therapy. In this report, a thorough examination was conducted on the contemporary literature relating to MCAS, with a focus on comparing the specificity, sensitivity, and robustness of MCAS-related parameters within proposals for diagnosing and classifying MCAS and its variants. Moreover, the significance of employing specific consensus criteria in the assessment and categorization of MCAS in individual patients was underscored, due to the escalating occurrence of patients receiving a misdiagnosis of MCAS based on nonspecific criteria.