Search Results (31)

Background: Patients with mastocytosis may present with exacerbated respiratory symptoms and lung diseases resulting from mast cell mediator release. However, their prevalence and severity level remain under debate. The study aims to analyze the prevalence of respiratory symptoms and the usefulness of lung function tests like spirometry, diffusing capacity of the lung for carbon monoxide (DLCO), and high-resolution computed tomography (HRCT) of the chest in mastocytosis patients presenting with dyspnea, cough, and exercise intolerance. Methods: We included 104 patients with mastocytosis and 71 healthy controls. Data collection encompassed patient interview, clinical examination, spirometry, DLCO, and chest HRCT. Diagnosis of mastocytosis included bone marrow biopsies and serum tryptase measurements. Results: Compared to controls, patients with mastocytosis exhibited significantly lower values in FEV1/VC ratio, absolute DLCO/VA, predicted DLCO/VA, absolute DLCOcSB, and predicted DLCOcSB (p < 0.001). Commonly reported respiratory symptoms included dyspnea (36.5%), chest tightness (22.1%), and wheezing (9.6%). Airway obstruction was identified in 7.7% of patients; however, it appeared to be independent of the mastocytosis subtype. A decreased DLCO/VA ratio was observed in 4.8% of patients, but HRCT did not reveal any evidence of underlying lung disease. Conclusions: Mastocytosis appears to be a risk factor for the occurrence and exacerbation of respiratory symptoms. However, airway obstruction and impairment of the alveolar–capillary membrane seem to occur independently of the clinical subtype of mastocytosis. Additionally, the causal relationship between pulmonary involvement, mast cell infiltration of the alveolar–capillary membrane, and the systemic circulation of mast cell mediators remains unclear and requires further research. Full article

Systemic mastocytosis (SM) is a rare and heterogeneous disorder characterized by clonal proliferation and accumulation of neoplastic mast cells in one or more organs, most commonly the bone marrow, liver, spleen, and skin. Among its clinical variants, aggressive SM (ASM) presents organ damage and debilitating symptoms due to extensive mast cell infiltration. The management of ASM remains challenging, primarily because treatment must address both symptom control and disease progression. Background/Objectives: Recent therapeutic approaches have focused on tyrosine kinase inhibitors (TKIs) that target the oncogenic KIT driver mutation, predominantly the D816V mutation, which is implicated in mast cell proliferation. We report a case series of four patients diagnosed with ASM to highlight the real-world experience in the management of ASM. All patients had confirmed KIT D816V mutations and presented with signs of advanced organ dysfunction, such as marked hepatosplenomegaly, cytopenia, and significant bone marrow infiltration. First-line therapies, including cytoreductive agents or other TKIs were used. Responses varied in these patients, and ultimately, they were initiated on or transitioned to midostaurin, a multikinase TKI. Results: All four patients, after the initiation of midostaurin, presented clinical and biological improvement—at least a clinical improvement response according to the International Working Group-Myeloproliferative Neoplasms Research and Treatment & European Competence Network on Mastocytosis (IWG-MRT-ECNM) criteria. These findings highlight the benefits of KIT inhibition in managing ASM, especially for patients with inadequate responses to traditional therapies. The impact of midostaurin on organ function, mast cell burden, and symptom control emphasizes the importance of the timely integration of TKIs into therapeutic protocols. However, optimal treatment duration, long-term safety, and the development of acquired resistance remain critical questions that warrant further studies. Larger prospective trials are needed to better delineate the prognostic factors associated with sustained response, refine patient selection, and explore combination strategies that may enhance therapeutic efficacy. Conclusions: The patients presented in this case series benefited from midostaurin therapy, showing either a clinical improvement or partial response according to the IWG-MRT-ECNM criteria. Our case series illustrates that KIT inhibitors can offer meaningful clinical benefit in ASM, reinforcing their position as an emerging cornerstone option in ASM management. Full article

Hereditary α-tryptasemia (HαT)—a genetic trait caused by increased α-tryptase-encoding typtase alpha/beta-1 (TPSAB1) copy number—is associated with adult mastocytosis. The primary objective was to assess the association between α-tryptase and pediatric mastocytosis. We also want to evaluate whether the KIT p.D816V mutation in peripheral blood leukocytes (PBLs) reliably predicts systemic mastocytosis (SM) in children. A prospective cohort of 68 children from a referral center in Slovenia with cutaneous mastocytosis (CM) underwent tryptase genotyping by droplet digital PCR and examination for KIT p.D816V in PBL using a sensitive PCR test. A significant majority of patients (57 of 68; [83.8%]) had at least one α-tryptase-encoding gene; none had HαT. 7 of the 68 (10.3%) who were positive for KIT p.D816V in PBL, one fulfilled diagnostic criteria for indolent SM, and another was diagnosed with monoclonal mast cell activation syndrome. One of those individuals had an increased basal serum tryptase (BST) level (14.5 ng/mL). We found a high presence of germline α-tryptase in children with CM, but not HαT. By employing sensitive examination for KIT p.D816V in PBL, in combination with clinical data and other examinations, our study suggests that KIT p.D816V in PBL may indicate systemic disease in children with CM. Full article

Mastocytosis is a rare neoplastic disease of the bone marrow. Common symptoms like urticaria, diarrhea, bronchspasm and flushing are caused by mast cell degranulation and are mostly based on mast cell mediator release and Th2 type inflammation that occurs frequently in these patients. Psychological disorders are more prevalent in patients with systemic mastocytosis, though little is known about the mechanism behind this. The aim of the study was to investigate the Th2 cytokine (IL-4, TSLP, IL-31 and IL-33) profile in patients with mastocytosis in relation to classic degranulation symptoms and the psychometric measures of cognition and distress symptoms.In total, 115 patients diagnosed with mastocytosis were enrolled. Mini-Mental State Examination (MMSE) was performed for all subjects. Other variables: Quality of life in mastocytosis, a mood assessment commonly used in systemic mastocytosis by a certified rater—the Hamilton-17 Depression Scale, Pruritus Visual Analog Score, serum tryptase concentration and bone marrow biopsy results (archival) were also analyzed/included. Serum concentrations of IL-4, TSLP, IL-33 and IL-31 were analyzed as primary outcomes. For comparison with continuous variables linear regression was used. The mean MMSE result was 27.9. Regression analysis did not reveal significant correlation between the IL-4 (p = 0.82), IL-31 (p = 0.24) and TSLP (p = 0.37) serum concentrations and MMSE. The IL-33 concentration analysis resulted in 0 for all patients (was not detected). No significant effect was observed with other endpoints as well. One in four patients with mastocytosis presents cognitive decline. This impairment does not correlate with Il-4, TSLP, nor IL-31 serum protein concentrations. Full article

Background: Monitoring of measurable residual disease (MRD) requires highly sensitive flow cytometry protocols to provide an accurate prediction of shorter progression-free survival. High assay sensitivity generally requires rapid processing to avoid cell loss from small bone marrow sample volumes, but this requirement conflicts with the need in most clinical cytometry laboratories for long processing and acquisition times, especially when multiple MRD studies coincide on the same day. Methods: The proposed protocol was applied to 226 human bone marrow and 45 peripheral blood samples submitted for the study of MRD or the detection of rare cells. Samples were processed within 24 h of extraction and acquired with an eight-color flow cytometer. Results: The FACSLyse-Bulk protocol allows for the labelling of millions of cells in under 90 min in small sample volumes without affecting the FSC/SSC pattern or antigen expression, and it also allows antigens to be fixed to the membrane, thus avoiding the capping phenomenon. Conclusions: The proposed protocol would allow clinical flow cytometry laboratories to perform MRD studies in house and easily achieve a limit of detection and limit of quantification <0.001%, thus avoiding the need to outsource analysis to specialized cytometry laboratories. Full article

Background: Mastocytosis (MS) is a rare disease that can involve various organs, including the bone. Given the incidence of the disease in the global population, MS poses a challenge for physicians, and early therapeutic intervention in the initial stages could significantly impact the quality of life of affected patients. Objective: The aim of this scoping review was to provide an overview of secondary osteoporosis in systemic mastocytosis (SM), focusing on the heterogeneity of its manifestations, the benefits of early diagnosis, and appropriate pharmacological treatment. Design: A technical expert panel (TEP) consisting of 8 physicians with expertise in metabolic bone diseases conducted the review following the PRISMA-ScR model. A strength of this study is that it provides various therapeutic approaches for patients with bone involvement in SM, although the limited available literature on the topic constituted a limitation. The TEP sought evidence regarding the following diagnostic and therapeutic modalities in the management of SM: “bisphosphonate therapy”, “zoledronic acid therapy”, “denosumab therapy”, “IFN-alpha therapy”, and “IFN-alpha therapy in combination with pamidronate”. Results: Clinical data showed a correlation between densitometric outcomes, serum tryptase levels, and mast cell infiltration in the bone marrow, between increased bone mineral density and the presence of osteosclerosis in cases of advanced SM, between the severity of osteoporosis and hypertryptasemia, and also provided results on the long-term effects of bisphosphonate therapy, the therapeutic efficacy of zoledronic acid administration, the positive effect of denosumab on the reduction of serum tryptase levels (even if is proved in a limited numbers of cases) and the prevention of new fractures, and the effect of IFN-alpha in more severe cases of SM, either alone or in combination with pamidronate. Conclusions: Studies have demonstrated the effectiveness of various treatments depending on the form of mastocytosis, whether indolent systemic or advanced systemic, in the prognosis of the disease. However, this role should be further investigated in additional clinical studies, considering the limited data on the use of these interventions. Full article

Eosinophils in peripheral blood account for 0.3–5% of leukocytes, which is equivalent to 0.05–0.5 × 10⁹/L. A count above 0.5 × 10⁹/L is considered to indicate eosinophilia, while a count equal to or above 1.5 × 10⁹/L is defined as hypereosinophilia. In bone marrow aspirate, eosinophilia is considered when eosinophils make up more than 6% of the total nuclear cells. In daily clinical practice, the most common causes of reactive eosinophilia are non-hematologic, whether they are non-neoplastic (allergic diseases, drugs, infections, or immunological diseases) or neoplastic (solid tumors). Eosinophilia that is associated with a hematological malignancy may be reactive or secondary to the production of eosinophilopoietic cytokines, and this is mainly seen in lymphoid neoplasms (Hodgkin lymphoma, mature T-cell neoplasms, lymphocytic variant of hypereosinophilic syndrome, and B-acute lymphoblastic leukemia/lymphoma). Eosinophilia that is associated with a hematological malignancy may also be neoplastic or primary, derived from the malignant clone, usually in myeloid neoplasms or with its origin in stem cells (myeloid/lymphoid neoplasms with eosinophilia and tyrosine kinase gene fusions, acute myeloid leukemia with core binding factor translocations, mastocytosis, myeloproliferative neoplasms, myelodysplastic/myeloproliferative neoplasms, and myelodysplastic neoplasms). There are no concrete data in standardized cytological and cytometric procedures that could predict whether eosinophilia is reactive or clonal. The verification is usually indirect, based on the categorization of the accompanying hematologic malignancy. This review focuses on the broad differential diagnosis of hematological malignancies with eosinophilia. Full article

Mast cell disorders range from benign proliferations to systemic diseases that cause anaphylaxis and other diverse symptoms to mast cell neoplasms with varied clinical outcomes. Mastocytosis is the pathologic process of the accumulation of abnormal mast cells in different organs, mostly driven by KIT mutations, and can present as cutaneous mastocytosis, systemic mastocytosis (SM), and mast cell sarcoma. The WHO 5th edition classification divides systemic mastocytosis into bone marrow mastocytosis, indolent systemic mastocytosis, smoldering systemic mastocytosis, aggressive systemic mastocytosis, systemic mastocytosis with an associated hematologic neoplasm, and mast cell leukemia. The new ICC classifies SM slightly differently. The diagnosis of SM requires the integration of bone marrow morphologic, immunophenotypic, and molecular findings, as well as clinical signs and symptoms. Moreover, understanding the wide range of clinical presentations for patients with mast cell disorders is necessary for accurate and timely diagnosis. This review provides an updated overview of mast cell disorders, with a special emphasis on SM, including the latest approaches to diagnosis, prognostic stratification, and management of this rare disease. Full article

Hymenoptera venom–triggered anaphylaxis (HVA) affects up to 8.9% of the general population and is the most frequent cause of anaphylaxis in adults, accounting for approximately 20% of all fatal anaphylaxis cases. Quite often, a fatal reaction is a victim’s first manifestation of HVA. Mastocytosis represents one of the most important risk factors for severe HVA. We analyzed patients with documented fatal HVA for the presence of underlying clonal mast cell disorder (cMCD). Here, we report three cases of fatal HVA, with undiagnosed underlying cMCD identified by the presence of the peripheral blood and/or bone marrow KIT p.D816V missense variant postmortem. In the first case, anaphylaxis was the initial episode and was fatal. In the other two cases, both patients were treated with specific venom immunotherapy (VIT), nevertheless, one died of HVA after VIT discontinuation, and the other during VIT; both patients had cardiovascular comorbidities and were taking beta-blockers and/or ACE inhibitors. Our results point to the importance of screening all high-risk individuals for underlying cMCD using highly sensitive molecular methods for peripheral blood KIT p.D816V variant detection, including severe HVA and possibly beekeepers, for proper management and the need for lifelong VIT to prevent unnecessary deaths. Patients at the highest risk of fatal HVA, with concomitant cardiovascular and cMCD comorbidities, might not be protected from field stings even during regular VIT. Therefore, two adrenaline autoinjectors and lifelong VIT, and possibly cotreatment with omalizumab, should be considered for high-risk patients to prevent fatal HVA episodes. Full article

Neonatal diffuse cutaneous mastocytosis (NDCM) is defined as the infiltration of the epidermis by a clonal proliferation of mast cells, observed at birth, without initial signs of systemic involvement. The typical driver mutation is in the KIT gene. We report a rare case of a boy, born at term, already presenting at birth with generalized subcutaneous nodules on the face, scalp, trunk, back, hands, and feet. The spleen, liver, and inflammatory markers were normal at birth. Tryptase was significantly elevated. A bone marrow biopsy showed no mast cell involvement at age 2 months. A punch biopsy at age 2 months revealed CD117-positive cells diffusely infiltrating the skin, with subsequent DNA NGS sequencing for the formalin-fixed paraffin embedded tissue (FFPE) identifying the pathogenic NM_000222.3:c.1504_1509dup; p.(Ala502_Tyr503dup) variant in the KIT gene previously associated with cutaneous mastocytosis. At 2 years follow-up, he had splenomegaly and multiple cervical and inguinal adenopathy, while the skin nodules persisted, especially on the scalp with accompanying pruritus. He received oral and local sodium cromoglycate, oral antihistamines, antibiotic cream for skin infection, and iron supplementation; however, compliance to treatment was relatively low. The prognosis is difficult to predict, as he developed systemic involvement, failure to thrive, and mild psychomotor delay. A case aggregation of NDCM reported in the literature was performed to provide a comprehensive overview of this rare pathology, to better understand the prognosis. NDCM is a life-threatening disease with severe complications. Almost half had severe complications, such as mast hepatosplenomegaly, adenopathy, bacterial infections, mast cell leukaemia, and systemic involvement. Full article

Mast cells may contribute to osteoporosis development, because patients with age-related or post-menopausal osteoporosis exhibit more mast cells in the bone marrow, and mastocytosis patients frequently suffer from osteopenia. We previously showed that mast cells crucially regulated osteoclastogenesis and bone loss in ovariectomized, estrogen-depleted mice in a preclinical model for post-menopausal osteoporosis and found that granular mast cell mediators were responsible for these estrogen-dependent effects. However, the role of the key regulator of osteoclastogenesis, namely, receptor activator of NFκB ligand (RANKL), which is secreted by mast cells, in osteoporosis development has, to date, not been defined. Here, we investigated whether mast-cell-derived RANKL participates in ovariectomy (OVX)-induced bone loss by using female mice with a conditional Rankl deletion. We found that this deletion in mast cells did not influence physiological bone turnover and failed to protect against OVX-induced bone resorption in vivo, although we demonstrated that RANKL secretion was significantly reduced in estrogen-treated mast cell cultures. Furthermore, Rankl deletion in mast cells did not influence the immune phenotype in non-ovariectomized or ovariectomized mice. Therefore, other osteoclastogenic factors released by mast cells might be responsible for the onset of OVX-induced bone loss. Full article

Streptococcus pseudoporcinus is a nonmotile Gram-positive, catalase, and benzidine negative, arranged in short chains, isolated from the genitourinary tract group B Streptococcus. S. pseudoporcinus was also identified from blood, urine, skin, cervical area, wounds, rectum, and placenta samples. Two cases of infective endocarditis have been reported in the literature. Based on these data, the identification of a case of S. pseudoporcinus infective endocarditis associated with spondylodiscitis in a patient with undiagnosed systemic mastocytosis until the age of 63 years is unusual. Two sets of blood specimens were collected, and both sets were positive for S. pseudoporcinus. Transesophageal echocardiography revealed, multiple vegetations on the mitral valve. A lumbar spine MRI revealed L5-S1 spondylodiscitis that associates prevertebral and right paramedian epidural abscesses with compressive stenosis. The performed bone marrow biopsy, and cellularity examination revealed 5–10% mast cells in the areas of medullary tissue, an aspect that is suggestive of mastocytosis. Antibiotic therapy was initiated, under which the patient presented intermittent fever. A second transesophageal echocardiography revealed a mitral valve abscess. A mitral valve replacement with a mechanical heart valve device through a minimally invasive approach was performed, with a favorable evolution under treatment. S. pseudoporcinus can be responsible for infectious endocarditis in certain immunodepressed cases, but also in a profibrotic, proatherogenic field, as shown by the association with mastocytosis in the presented case. Full article

Mast cell leukemia (MCL) is the leukemic form of SM with at least 20% mostly immature mast cells on bone marrow aspirate. MCL may develop de novo, in the absence of a prior SM, or it may represent a progression from a previous SM. MCL may be sub-divided into the more frequent, aggressive acute form with signs of organ damage (C-findings) and the chronic form lacking C-findings and presenting a more stable course, although over time, progression to acute MCL is common. The 2022 WHO subtype of MCL with an associated hematological neoplasm was renamed MCL with an associated myeloid neoplasm in the 2022 International Consensus Classification (ICC). The relevance of the distinction between the leukemic and aleukemic forms based on the percentage of circulating mast cells is a matter of debate. The current knowledge on MCL is restricted mainly to single reports or case series with a limited number of larger studies. Our aim is to provide a comprehensive overview of this rare disease in terms of clinical manifestations, morphology, phenotype, molecular characteristics, differential diagnosis, outcome and treatment. A general overview on mastocytosis is also included. Full article

The diagnosis of systemic mastocytosis (SM) is based on various clinical, dermatological, serological, and hematological findings but essentially relies on histological evidence of an abnormal increase in tissue-localized mast cells (MCs). The extra-cutaneous organ most frequently affected is the bone marrow (BM), and therefore, histological examination of trephine biopsy specimens of the iliac crest is mandatory on suspicion of SM. At microscopic examination, neoplastic MCs show aberrant morphology, usually with prominent spindling. Immunohistochemistry is a useful tool in the diagnosis of SM because mast cell (MC) infiltrates may be slight and scarce, in a mixed background of lymphohistiocytic cells, eosinophils, and plasma cells. Moreover, neoplastic MCs exhibit an aberrant phenotype. Recent evidence, largely derived from molecular genetics, has enhanced the diagnostic capability of SM, also providing the basis for adequate prognostic and therapeutic evaluation. The cases herein reported illustrate the variable clinical manifestations and disease course of SM, focusing on diagnostic and therapeutic challenges. In accordance with the World Health Organization (WHO) classification and the International Consensus Classification (ICC) systems, our findings emphasize the importance of an integrated diagnostic approach for SM, with proper application of diverse assessment methodologies in order to improve SM classification and treatment effectiveness. Full article

Evidence in the recent literature suggests that the presentation spectrum of mast cell neoplasms is broad. In this article, we elaborate on recent data pertaining to minor diagnostic criteria of systemic mastocytosis (SM), including sensitive testing methods for detection of activating mutations in the KIT gene or its variants, and adjusted serum tryptase levels in cases with hereditary α-tryptasemia. We also summarize entities that require differential diagnosis, such as the recently reclassified SM subtype named bone marrow mastocytosis, mast cell leukemia (an SM subtype that can be acute or chronic); the rare morphological variant of all SM subtypes known as well-differentiated systemic mastocytosis; the extremely rare myelomastocytic leukemia and its differentiating features from mast cell leukemia; and mast cell activation syndrome. In addition, we provide a concise clinical update of the latest adjusted risk stratification model incorporating genomic data to define prognosis in SM and new treatments that were approved for advanced SM (midostaurin, avapritinib). Full article