scholarly journals Systemic Mastocytosis Presenting with a Prominent B Lymphocyte Proliferation in the Bone Marrow and Extensive Fibrosis of the Spleen

2007 ◽  
Vol 23 (3) ◽  
pp. 167-171
Author(s):  
Nalan Neşe ◽  
Seçkin Çağcaron;ırgan ◽  
Yešim Ertan ◽  
Ayhan Sönmez ◽  
Saliha Soydan ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Hodgkin Lymphoma ◽  
Lymphocyte Proliferation ◽  
B Lymphocyte ◽  
Systemic Mastocytosis ◽  
Low Grade ◽  
Mast Cell Tryptase ◽  
Non Hodgkin Lymphoma

Systemic mastocytosis is a disease characterized by multifocal mast cell proliferation in the bone marrow or other extracutaneous organs. Because of loosely scattered and hypo-/agranular mast cells, the diagnosis is sometimes very difficult. In the bone marrow, mast cell infiltration may be associated with prominent lymphoid infiltration leading to a misdiagnosis of a low grade non-Hodgkin lymphoma.A 49-year-old woman presented with right arm and leg pain, psychiatric symptoms, and diarrhea for four years. Physical examination and laboratory investigation revealed hepatosplenomegaly, anemia, mild thrombocytosis, mild leucocytosis and lymphocytosis. In the bone marrow biopsy, there was a prominent B lymphocyte proliferation reminiscent of a low grade non-Hodgkin lymphoma/leukemia and there were some spindle cells aggregates in paratrabecular location. The consecutive bone marrow biopsies were similar to the first. The subsequent splenectomy specimen exhibited striking fibrosis. In the lymph node sections, there was marginal zone hyperplasia.Multifocal accumulations of mast cells were strongly positive with mast cell tryptase and CD117 on immunohistochemical staining, though no metachromasia was identified in Giemsa and Toluidine Blue stained aspirates and tissue sections, probably due to hypo-/agranulation of mast cells.The case was presented to emphasize the importance of the antibody to mast cell tryptase in the diagnosis of mastocytosis and to discuss problems of differential diagnosis of systemic mastocytosis.

Imatinib Mesylate in the Treatment of Systemic Mastocytosis, a Phase I/II Trial.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1516-1516 ◽  
Author(s):  
H.J. Droogendijk ◽  
J.C. Kluin-Nelemans ◽  
P.L.A van Daele
Keyword(s):  
Bone Marrow ◽  
Cell Proliferation ◽  
Mast Cell ◽  
Mast Cells ◽  
Imatinib Mesylate ◽  
Systemic Mastocytosis ◽  
Skin Lesions ◽  
Tissue Response ◽  
Serum Tryptase ◽  
Kit Receptor

Abstract Introduction: mastocytosis comprimes a group of diseases characterized by abnormal proliferation and accumulation of mast cells in one or more organs. A cutaneous and systemic form of mastocytosis is distinguished. Systemic mastocytosis defines the disease process in which mast cell proliferation exceeds the skin. The clinical manifestations of systemic mastocytosis depend on the tissues involved and the tissue response to the accumulation of mast cells. Although in general the disease progresses slowly, it may develop into a malignant disease. Currently there is no cure for systemic mastocytosis. Mast cells develop from pluripotent bone marrow progenitor cells that express CD34 antigen and are dispersed as precursors which undergo proliferation and maturation in different tissues. Normal mast cell development involves the action of stam cell growth factor and c-kit receptors, which are expressed by mast cells at their different developmental stages. Deregulation and/or abnormalities of the c-kit receptor are assumed to play a causal role in disordered mast-cell proliferation. In most patients a mutation in the gene for c-kit exists. One of the mutations is the D816V mutation. Aim of the study:imatinib mesylate, formerly called ST1571, is a potent inhibitor of c-kit receptor tyrosine kinase activity. In this study, we evaluate whether imatinib mesylate is safe and effective in the treatment of patients with systemic mastocytosis. Primary end-points of study are reduction in urinary N-methylhistamine excretion, serum tryptase activity, skin lesions, number of mast cells in sections of bone marrow, hepato-and/or splenomegaly and symptoms.Adverse effects on therapy are also considered. Results: up to now, 10 patients with systemic mastocytosis are treated with 400 mg of imatinib mesylate orally once daily. During the first 2 weeks of the study the patients also received 30 mg of prednisolone daily. In general imatinib mesylate is well tolerated. The first results show a 38–80% reduction in urinary N-methylhistamine excretion and 30–66% reduction in serum tryptase activity. Skin lesions diminish in two of the six patients with cutaneous mastocytosis,. Number of mast cells in sections of bone marrow are reduced in 63% (5/8) of the patients. Hepato-and/or splenomegaly is slightly decreased in two of the three patients with organomegaly. Finally 60 % of all patients experiences relief of symptoms. In eight patients the D816V mutation was found. In contrast with former studies imatinib mesylate is also effective in these patients. Further results are to be awaited. Conclusion: imatinib mesylate is safe and seems effective in the treatment of patients with systemic mastocytosis (including patients with the D816V mutation).

Kit Signaling Regulates Mitf Expression in Mastocytosis.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3601-3601
Author(s):  
Youl-Nam Lee ◽  
Pierre Noel ◽  
Amir Shahlaee ◽  
Melody Carter ◽  
Reuben Kapur ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Systemic Mastocytosis ◽  
Tyrosine Kinase Receptor ◽  
Bone Marrow Biopsies ◽  
Activating Mutations ◽  
Cell Assays ◽  
Mast Cell Disease ◽  
Mitf Expression

Abstract Mastocytosis is a heterogeneous disease arising from abnormal proliferation of mast cells. Activating mutations in codon D816 of the tyrosine kinase receptor, c-kit, are found in the majority of adult patients with systemic mastocytosis, an aggressive form of the disease. Constitutive activation of the Kit signaling pathway is critical to the transformed phenotype, and thus understanding how this pathway regulates downstream events is of great importance. A number of transcription factors are also essential to mast cell development, including the Microphthalmia-associated transcription factor (Mitf). We examined Mitf expression in bone marrow biopsies from nine patients with systemic mastocytosis by immunohistochemistry; we found that Mitf is highly expressed in all cases with the D816V mutation. In contrast, Mitf is not highly expressed in non-malignant mast cells in the bone marrow from patients with aplastic anemia and leukemia, suggesting thatMitf expression is regulated by Kit-dependent signalsMitf may play a role in the transformed phenotype of mastocytosis.We show that in normal mast cells, Kit signaling markedly upregulates Mitf expression. In both normal and malignant mast cells, pharmacologic inhibitors of Kit, and the downstream kinase, PI3K, block Mitf expression. To examine whether Mitf is required for transformed phenotype from constitutive Kit signaling in mast cells, we have used a shRNA-expressing lentivirus to knockdown Mitf expression in mastocytosis cell lines. We found that silencing of Mitf markedly impaired growth in proliferation and colony forming cell assays. This work demonstrates a link between two critical factors, Kit and Mitf, in the development of malignant mast cell disease.

Change In Mast Cell Bone Marrow Burden and In Serum Tryptase Level Are Not Accurate Markers of Response In Patients with Systemic Mastocytosis

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3073-3073
Author(s):  
Alfonso QuintÁs-Cardama, ◽  
Matjaz Sever ◽  
Jorge E. Cortes ◽  
Hagop M. Kantarjian ◽  
Srdan Verstovsek
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Systemic Mastocytosis ◽  
Median Number ◽  
Response To Therapy ◽  
Serum Tryptase ◽  
Bone Marrow Biopsies ◽  
Tryptase Level ◽  
Bone Marrow Mast Cell

Abstract Abstract 3073 Background: Bone marrow involvement, with or without cutaneous or visceral involvement, is almost universal in patients with systemic mastocytosis (SM). The KITD816V mutation is present in most patients with SM, thus confirming its clonal nature. Patients with ASM are usually managed with cytoreductive agents such as hydroxyurea (HU), cladribine (2CDA), or interferon-alpha (IFN-α), although the activity of these therapies is limited as they do not target specifically the malignant clone. Response assessment in SM relies on symptom improvement and reduction in serum tryptase levels and visceral and/or bone marrow mast cell burden (percent mast cell involvement). We contend that the later two relatively objective metrics may not be appropriate markers of response because serum tryptase levels may vary significantly at different time-points in the same patient in the absence of intervention, do not correlate accurately with mast cell burden, and bone marrow mast cell burden determination is subject to sampling bias given the patchy infiltration observed in many cases of SM. Objectives: To assess the utility of bone marrow mast cell burden reduction and serum tryptase level reduction as criteria for response in patients with SM. Patients and Therapy: We studied a cohort of 50 patients with SM for whom at least 2 sequential bone marrow biopsies and 2 serum tryptase level determinations were available at our center. The KITD816V mutation was present in 20 (59%) of 34 assessable patients. No patient carried the JAK2V617F mutation or the FIP1L1-PDGFRA rearrangement. Patients had a diagnosis of indolent SM (ISM, n=25), aggressive SM (ASM, n=16), or SM-AHNMD (n=9). All but 1 patient received SM-directed therapy (median number of therapies 2, range 1–5), including: imatinib (n=16), dasatinib (n=23), RAD001 (n=8), denileukin diftitox (n=7). The median number of bone marrow biopsies available per patient was 4 (range, 2–14) and the median number of tryptase measurements was 6 (range, 2–18), which were obtained both on and off SM-directed therapies. Results: Four patients had a bone marrow complete response: 1 with imatinib, 2 with dasatinib, and 1 with decitabine (with SM-MDS). However none of the responders normalized their tryptase levels. We used the coefficient of variation (CV) as a normalized measure of dispersion of a probability distribution for the percentage of mast cells in bone marrow biopsies and serum tryptase levels. In this manner, the CV summarizes/describes the variation in tryptase levels and bone marrow mast cell percentage from the baseline (first recorded value) in the patients evaluated. We found that among the 49 treated patients, the percentage of bone marrow mast cells varied significantly with a CV ranging from 6 – 173% and an average of 65%. Forty-four percent of patients had a CV equal or higher to the average. Similar results were observed regarding tryptase levels, with an average CV of 19% that ranged from 0 to 96%. Thirty-six percent of patients had a CV higher than average. Conclusion: While most patients fail to respond to currently available SM-directed therapies, sequential bone marrow biopsies and tryptase level determinations exhibit remarkable variation both during and in the absence of SM-directed therapy. Therefore, it seems that single time point measurements of these values do not represent proper tools to assess accurately response to therapy. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Cutaneous Mastocytosis in a 61-year-old Female from a Dermatological and Histopathological Perspective

2020 ◽  
pp. 01-06
Author(s):  
Erisa Kola ◽  
Jorida Memini ◽  
Ina Kola ◽  
Daniela Nakuci ◽  
John Ekladous ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Lymph Nodes ◽  
Systemic Mastocytosis ◽  
World Health ◽  
Systemic Involvement ◽  
Cutaneous Mastocytosis ◽  
Health Organization ◽  
Cell Disorder

First described by Nettleship et al. in 1869 [1], mastocytoses are a heterogeneous group of disorders characterized by the pathologic accumulation of mast cells in various tissues [2-5]. Mastocytosis can be confined to the skin as in cutaneous mastocytosis (CM), or it can involve extracutaneous tissues such as the liver, spleen, bone marrow and lymph nodes, as in systemic mastocytosis [6]. Mastocytosis is a World Health Organization-defined clonal mast cell disorder characterized by significant clinicopathologic heterogeneity [7]. Keywords: Cutaneous mastocytosis; Systemic mastocytosis; Systemic involvement; Mast cells; Mastocytosis.

scholarly journals AK002, a Novel Humanized Monoclonal Antibody to Siglec-8, Inhibits Mast Cell Activity and Depletes Eosinophils in Ex Vivo Bone Marrow Tissue from Patients with Systemic Mastocytosis

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1104-1104 ◽  
Author(s):  
Bradford A Youngblood ◽  
Emily C Brock ◽  
John Leung ◽  
Alan T Chang ◽  
Christopher Bebbington ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Bone Marrow ◽  
Flow Cytometry ◽  
Mast Cell ◽  
Mast Cells ◽  
Ex Vivo ◽  
Systemic Mastocytosis ◽  
Cell Activity ◽  
Receptor Expression ◽  
Long Term Treatment

Abstract INTRODUCTION: Systemic Mastocytosis (SM) is a rare disease characterized by the clonal proliferation and accumulation of mast cells in the bone marrow, respiratory and gastrointestinal tracts, and organs such as the skin, liver, spleen, and brain. Common symptoms include pruritus, flushing, headache, cognitive impairment, fatigue, diarrhea, abdominal pain, hypotension and skin lesions, as well as an increased risk for osteoporosis and anaphylaxis. SM is currently managed with antihistamines, cromolyn sodium, and leukotriene blocking agents, which lack specificity and efficacy. In addition, glucocorticoids can provide temporary relief in some cases; however long-term treatment with steroids is not appropriate due to their many side effects. Siglec-8 is an inhibitory receptor selectively expressed on human mast cells and eosinophils, and therefore represents a novel target for the treatment of SM. Antibodies to Siglec-8 have been shown to inhibit mast cell activity and induce apoptosis of eosinophils. AK002 is a novel, humanized, non-fucosylated IgG1 monoclonal antibody to Siglec-8. This study evaluates the expression of Siglec-8 and ex vivo activity of AK002 on mast cells and eosinophils in bone marrow biopsies from patients with SM. METHODS: Bone marrow aspirates were obtained from patients clinically diagnosed with SM and processed to remove red blood cells. Multi-color flow cytometry was used to quantify eosinophils and mast cells and to evaluate the activation state of mast cells. The ex vivo activity of AK002 against eosinophils and mast cells was evaluated by flow cytometry. The inhibitory activity of AK002 agaist mast cells was also examined by quantifying cytokine levels in cultured bone marrow aspirate supernatants. RESULTS: All mast cells and eosinophils in bone marrow aspirates from SM patients displayed high Siglec-8 receptor expression (Figure 1). These mast cells also expressed the SM specific markers, CD25 (Figure 1) and CD30 and increased levels of cell surface degranulation markers. The expression of CD25 on mast cells significantly decreased following overnight treatment with AK002. AK002 also significantly reduced the level of mast cell-associated cytokines produced in cultured bone marrow supernatants, including IL-6, IL-8, and TNFα (Figure 2A). These changes in mast cell activity after AK002 treatment were not due to a reduction in mast cell numbers. In contrast, overnight incubation of AK002 significantly reduced the number of bone marrow eosinophils compared to an isotype control (Figure 2B). CONCLUSIONS: Bone marrow aspirates from patients with SM had activated mast cells and eosinophils that displayed robust expression of Siglec-8. AK002 demonstrated SM mast cell inhibition in ex vivo bone marrow aspirates. AK002 also had depleting effects on eosinophils, which may be valuable to SM patients with associated eosinophilia. These encouraging results could represent a novel approach for the treatment of SM. Disclosures Youngblood: Allakos, Inc.: Employment. Brock:Allakos, Inc.: Employment. Leung:Allakos, Inc.: Employment. Chang:Allakos, Inc.: Employment. Bebbington:Allakos, Inc.: Employment. Tomasevic:Allakos, Inc.: Employment.

scholarly journals Indolent systemic mastocytosis or just ‘atypical enterocolic mast cell aggregates’?

2021 ◽  
Vol 156 (Supplement_1) ◽  
pp. S56-S56
Author(s):  
U Edema ◽  
Y Fang ◽  
L Qiang ◽  
Y Huang
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Systemic Mastocytosis ◽  
Case Reports ◽  
Cutaneous Lesion ◽  
Cell Aggregates ◽  
Kit Mutation ◽  
Who Criteria ◽  
Systemic Involvement

Abstract Introduction/Objective Mastocytosis is a rare disease in which there are abnormal mast cell accumulation in one or more tissue sites. Multifocal dense mast cell aggregates with atypical morphology or immunohistochemistry are considered as systemic mastocytosis (SM) based on WHO criteria. SM usually involves bone marrow and majority of them also have KIT mutation. There are rare case reports of atypical enterocolic mast cell aggregates (EMCA) confined to gastrointestinal (GI) only with mild or no symptoms. Here we present a case with extensive atypical mast cell aggregates in lower GI tract yet no evidence of involvement of other organs. Methods/Case Report A 34-year-old woman presented with abdominal bloating, diarrhea along with pruritis but no cutaneous lesion. Biopsies from the ascending and descending colons, caecum and rectum consistently showed increased eosinophils and multifocal infiltrates of atypical spindle shaped mast cells which are positive for CD117/tryptase but negative for CD2 and CD25. This is consistent with SM by WHO criteria based on morphology. Bone marrow biopsy showed normal amount of mast cells with normal morphology. Upper gastrointestinal biopsy was unremarkable. Serum tryptase level was normal. No KIT mutation was detected in exon 9, 11, 13 or 17 from colonic mucosa. Patient has been treated with antihistamine and Montelukast and symptoms resolved. Results (if a Case Study enter NA) N/A Conclusion This case met the criteria of SM based on the presence of multifocal mast cell aggregates and atypical spindle morphology >25%. Johncilla et al. previously reported 16 cases of EMCA with atypical morphology or immunohistochemistry, absent to mild localized symptoms, and negative KIT mutation. Based on lack of generalized disease, the authors preferred using descriptive terminology instead of ‘systemic mastocytosis’ for those cases. Our case has broader involvement of lower gastrointestinal tract than any reported case and the patient needs treatment for the symptoms. However, there is no ‘systemic’ involvement of bone marrow or any other organ. The diagnosis of ‘Systemic Mastocytosis’ would cause potential confusion and/or unnecessary anxiety. Further study of more cases is needed to better characterize and categorize the cases of atypical mast cell aggregates localized only to the GI.

Dasatinib (Sprycel™) Therapy for Patients with Systemic Mastocytosis.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3627-3627 ◽  
Author(s):  
Srdan Verstovsek ◽  
Hagop Kantarjian ◽  
Jorge Cortes ◽  
Farhad Ravandi-Kashani ◽  
Gautam Borthakur ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Interferon Alpha ◽  
Systemic Mastocytosis ◽  
Performance Status ◽  
Hypereosinophilic Syndrome ◽  
In Vivo Models ◽  
Recombinant Interferon ◽  
Kit Mutation

Abstract Background Systemic mastocytosis (SM) is characterized by abnormal proliferation and accumulation of neoplastic mast cells. Patients (pts) with SM are treated with recombinant interferon-alpha or cladribine. Responses to these agents are poor. Malignant mast cells in SM carry, in most cases, a mutation involving codon 816 of the c-KIT gene (D816V) resulting in constitutively activated c-kit receptor tyrosine kinase believed to be important for disease progression. Agents that antagonize this mutated form of c-kit may have clinical benefit in SM. Dasatinib is one such agent, proven effective in pre-clinical in vitro and in vivo models of SM. Study Design In pilot Phase II trial for SM, Dasatinib was administered at 70mg PO BID. Response was assessed after minimum of 3 months (3 cycles) of therapy. Therapy was discontinued in pts who showed no response after 6 cycles of therapy. Response was evaluated following guidelines proposed by Valent et al. (Leuk Res. 25;603–625, 2001). In addition, all symptoms related to SM were recorded and monitored. Results Thus far, a total of 30 pts have been treated; 24 are evaluable for response and toxicity, including 6 with aggressive SM (ASM), 4 with SM and associated hematologic non-mast cell disease (SM-AHNMD; 2 with chronic myelomonocytic leukemia and one each with myelofibrosis [SM-MF; JAK2 mutation positive and abnormal cytogenetics] and hypereosinophilic syndrome [SM-HES; FIP1L1-PDGFRa negative]) and 14 with indolent SM (ISM) with uncontrolled symptoms despite optimal supportive care measures. Median age is 57 years (range, 35–73); these were 10 males and 14 females; time from diagnosis to dasatinib therapy 49 months (range, 0–233), performance status 1 in 23 and 2 in 1 pt. Eleven patients were previously treated: imatinib mesylate in 6; denileukin diftitox in 4; and erythropoietin, interferon-alpha, or cladribine in 2 each. One pt, who had undergone splenectomy, had hepatomegaly prior to start of therapy. Median Hb 12.4g/dL (range, 8.5–15.4), WBC 6.7×109/L, (range, 3.5–53.3), and platelets 263×109/L (range, 60–377); no patient was transfusion dependent. Percent bone marrow mast cell varied from <10% in 9 pts, to 60% in 4 pts; blood tryptase level was ≤20ng/mL (not significant) in 7 pts and >200ng/mL (upper limit of the test) in 7 pts. A total of 94 cycles of therapy were administered. The median number of cycles was 4 (range, 1–8). Ten patients stopped therapy: 1 due to progression of AHNMD to acute leukemia, 1 lost a response (symptomatic improvement), 2 had no response after 3 months of therapy, and 6 due to toxicity. No grade 4 toxicity was observed. Twelve patients decreased the dose of dasatinib to 50mg PO BID, of which four to 40mg PO BID. Two patients (8%) achieved complete remission, one with SM-MF, and one with SM-HES. Both were c-KIT mutation negative and had low, not significant tryptase levels. Both were anemic (Hb 9.4g/dL) and failed erythropoietin therapy, and had abnormal WBC differential; one had low platelets (90×109/L). No significant response in % bone marrow mast cells (4 pts are too early in therapy) or blood tryptase levels have been observed in other patients so far. Symptoms related to SM improved significantly in 7 patients (29%). Conclusion Dasatinib is active in SM (overall response rate 37%). Updated clinical and molecular results will be presented.

A Survey on Clinical and Biological Characteristic and Therapy Management of an Italian Series of 455 Adult Patients with Systemic Mastocytosis on Behalf of Italian Registry of Mastocytosis

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3188-3188
Author(s):  
Lisa Pieri ◽  
Patrizia Bonadonna ◽  
Chiara Elena ◽  
Cristina Papayannidis ◽  
Federica Irene Grifoni ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Disease Progression ◽  
Myeloid Leukemia ◽  
Systemic Mastocytosis ◽  
Myeloproliferative Neoplasm ◽  
Large Series ◽  
Refractory Anemia

Abstract Systemic mastocytosis (SM) is a rare myeloproliferative neoplasm characterized by proliferation and hyperactivation of clonal mast cells. Clinical manifestations are heterogeneous and encompass cutaneous lesions, gastrointestinal alterations, osteoporosis, anaphylaxis and involvement of bone marrow and other organs due to neoplastic mast cells (MC) infiltration. As consequence, diagnosis may be difficult and patients (pts) are often evaluated by different specialists before the disease is recognized. To date, only few studies (Lim 2009, Escribano 2009, Cohen 2014) described relatively large series of pts with SM. We performed a multicentre retrospective study to evaluate clinical and biological features and therapeutic management in a large series of pts from 10 Italian centres experienced in management of SM and organized in multidisciplinary groups of specialists. We collected 455 pts diagnosed with SM according to WHO criteria. Additionally 26 pts with mastocytosis in the skin (MIS) evaluated with BM examination did not fulfil criteria for SM, leading to diagnosis of Cutaneous Mastocytosis (CM); however 2/26 pts with CM had both cKITD816V mutation and CD2/CD25 expression on MC in BM, additional 3 showed either cKITD816V or CD2/CD25. Moreover, we found 22 pts without MIS but with features of monoclonal mast cell activation syndrome. Of the 455 pts with WHO-SM (male 56%), 252 (55%) had MIS: median age at MIS diagnosis (dg) was 37 years (y) (range 0-79), while at SM dg it was 46.5 (range 18-82). Time from onset of MIS to dg of SM was 9 y (range 0-43). In 18/252 pts (7%) MIS occurred before age of 18 y (median 9, range 0-17) and persisted over childhood. Median age at dg of SM without MIS (203/455 pts, 45%) was older: 54 y, range 19-79 (p<0.0001). First manifestations of SM were MIS in 46.5% of pts, anaphylaxis in 47.8%, mediator related symptoms in 6.4%, osteoporosis/bone lesions in 5.2%, organomegaly in 3.4%, hematologic alterations in 0.4%. Anaphylaxis was observed in 76/252 (30.1%) pts with MIS, of which 23 had tryptase <20 mcg/L. BM multifocal infiltrates of MC were present in 61.6% of pts, while in 38.4% dg was performed only by using minor criteria. cKIT D816V mutation was detected in BM of 394/432 analysed pts (91.2%). Three D816V-negative pts had different cKIT mutations: M541L, D816H and K546K. In peripheral blood cKIT D816V was evaluated in 165 pts and found in 49.7%. CD2 and/or CD25 expressing MC were found in 99% of pts of the 426 evaluated. Mean tryptase value at dg was 75.9±263 mcg/L. SM subtypes were indolent SM (ISM) 402/455 (88.4%), of which 140 isolated bone marrow mastocytosis (BMM) (34.5% of ISM) and 34 smoldering SM (SSM) (8.4% of ISM), aggressive SM (ASM) 32/455 (7%), SM associated with hematological non mast cell disorders (SM-AHNMD) 20/455 (4.4%), mast cell leukemia (MCL) 1/455 (0.2%). In SM-AHNMD the associated hematologic disease was chronic myelomonocytic leukemia (6/20, 30%), non-Hodgkin lymphoma and refractory anemia with ring sideroblasts and thrombocytosis (3/20 each, 15%), essential thrombocythemia and not otherwise characterized myeloproliferative neoplasm (2/20 each, 10%), myelodysplastic syndrome, myelofibrosis, multiple myeloma and acute myeloid leukemia (AML) (1/20 each, 5%). Median follow up was 23 months (mo), range 2-289. At last follow up, 27/455 pts died (5.9%). 52% of pts had ASM, 18.5% SM-AHNMD, 14.7% SSM, 7.4% ISM and 3.7% each MCL and BMM. Causes of death were disease progression in 21/27 pts (77.8%), other solid neoplasms in 3/27 (11.1%), arterial thrombosis in 2/27 (9.5%), cerebral haemorrhage in 1/27 (3.7%). Disease progression consisted in evolution to AML in 6 pts with ASM, 1 pts with SSM and 1 pts with SM-AHNMD; median time to progression to AML was 30 mo (range 13-149); 2 pts developed other AHNMD: chronic myeloid leukemia and myelofibrosis. 178/455 pts (39%) were treated with anti MC mediators therapies. Of the 60/455 (13%) treated with cytostatic therapy 47% had ASM, 12% SM-AHNMD, 2% MCL, 35% ISM of which 38% were SSM. The ISM cohort was treated mainly due to severe osteoporosis with vertebral fractures not C-findings or disease evolution. First line therapy was interferon (28.3%), hydroxyurea (20%), midostaurine (18.3%), imatinib (13.3%), cladribin (8.3%), dasatinib (6.7%) and masitinib (5%). This is one of the largest series reporting pts with SM that may provide useful information for clinical management of pts with this probably underestimated “rare” disease. Disclosures Martinelli: Novartis: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau; Pfizer: Consultancy; ARIAD: Consultancy.

Frequency and prognostic impact of blood-circulating tumor mast cells in mastocytosis

Blood ◽  
2021 ◽  
Author(s):  
Ana Henriques ◽  
Javier I Muñoz-González ◽  
Laura Sánchez-Muñoz ◽  
Almudena Matito ◽  
Lidia Torres-Rivera ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Mast Cells ◽  
Systemic Mastocytosis ◽  
Prognostic Score ◽  
Mast Cell Activation ◽  
International Prognostic Scoring System ◽  
Prognostic Impact ◽  
Number Of Patients ◽  
Cutaneous Mastocytosis

Circulating tumor mast cells (CTMC) have been identified in the blood of a small number of patients with advanced systemic mastocytosis (SM). However, limited data exists about their frequency and prognostic impact in patients with mast cell activation syndromes (MCAS), cutaneous and non-advanced SM. We investigated the presence of CTMC and mast cell-committed CD34+ precursors in blood of 214 patients with MCAS, cutaneous mastocytosis and SM using highly sensitive next-generation flow cytometry. CTMC were detected at progressively lower counts in almost all advanced SM (96%) and smoldering SM (100%), nearly half (45%) indolent SM cases and few (7%) bone marrow mastocytosis patients, but were systematically absent in cutaneous mastocytosis and MCAS (P&lt;0.0001). In contrast to CTMC counts, the number of mast cell-committed CD34+ precursors progressively decreased from MCAS, cutaneous mastocytosis and bone marrow mastocytosis to indolent SM, smoldering SM and advanced SM (P&lt;0.0001). Clinically, the presence (and number) of CTMC in blood of patients with SM in general and non-advanced SM (indolent SM and bone marrow mastocytosis) in particular was associated with more adverse features of the disease, poorer risk prognostic subgroups as defined by the International Prognostic Scoring System for advanced SM (P&lt;0.0001) and the Global Prognostic Score for mastocytosis (P&lt;0.0001) and a significantly shortened progression-free survival (P&lt;0.0001) and overall survival (P=0.01). Based on our results, CTMC emerge as a novel candidate biomarker of disseminated disease in SM that is strongly associated with advanced SM and poorer prognosis in patients with indolent SM.

Interleukin-13- and Tansforming Growth Factor-β- Producing Mast Cells Are Associated with Fibrosis in Bone Marrow

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3112-3112
Author(s):  
Shoko Nakayama ◽  
Taiji Yokote ◽  
Nobuya Hiraoka ◽  
Toshikazu Akioka ◽  
Takuji Miyoshi ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mast Cell ◽  
Growth Factor ◽  
Mast Cells ◽  
Mutual Aid ◽  
Mast Cell Tryptase ◽  
Bone Marrow Fibrosis ◽  
Significant Difference ◽  
Grade 3 ◽  
Marrow Fibrosis

Abstract Background: Fibrosis in bone marrow is a lethal condition, which currently has no effective treatments. Transforming growth factor (TGF)-β, produced by megakaryocytes and blasts in myelodisplastic syndrome (MDS) with bone marrow fibrosis, is reportedly linked to this condition; however, the underlying mechanism of fibrosis in bone marrow remains uncharacterized. Recently, interleukin (IL)-13- and TGF-β- producing mast cells have been reported to participate in the development of fibrosis in certain fibrotic diseases, such as the IgG4-related diseases. Aim: This study aimed to investigate the pathogenesis of fibrosis in bone marrow through histological examination of mast cell infiltration and the expression of cytokines associated with fibrosis. Methods: We analyzed 22 bone marrow samples from patients with confirmed fibrosis; of these, eight patients had been diagnosed with primary myelofibrosis (PMF), five with post-polycythemia vera (PV)/essential thrombocythemia (ET) MF, and nine with MDS with bone marrow fibrosis. These were compared with 15 control bone marrow samples, using immunohistochemical staining of mast cell tryptase, IL-13, and TGF-β, as well as using dual immunofluorescence assays for the following pairs: mast cell tryptase/ IL-13 and mast cell tryptase/ TGF-β. The extent of fibrosis in bone marrow samples was analyzed by Masson's trichrome staining and silver impregnation staining. Results: Among eight PMF cases, five were identified as grade 2 and three as grade 3; among five post-PV/ET cases, four were grade 2 and one was grade 3; and among nine MDS patients with bone marrow fibrosis, six were grade 2 and three were grade 3. Grading was performed according to the European consensus on grading of bone marrow fibrosis. The number of mast cells in bone marrow samples was significantly higher in cases with fibrosis than in controls, as analyzed by t-test (p < 0.0001) (Figure 1A). Each group of bone marrow samples with fibrosis (primary MF, post-PV/ET MF, and MDS with bone marrow fibrosis) also had significantly more infiltrating mast cells than controls, using multiple comparison with the Tukey's honestly significant difference test (p = 0.0470, < 0.0001, 0.0005, respectively) (Figure 1B). Bone marrow samples with higher fibrotic grades exhibited greater amounts of infiltrating mast cells; for instance, bone marrows with fibrotic grades of 2 or 3 had more infiltrating mast cells than controls (p = 0.0010, < 0.0001, respectively). In addition, bone marrows with a fibrotic grade of 3 had more infiltrating mast cells than those with fibrotic grade 2 (p = 0.0010) (Figure 2). Mast cells were positive for IL-13 (Figure 3) and TGF-β (Figure 4) in dual immunofluorescence assays of mast cell tryptase and IL-13 or TGF-β; however, megakaryocytes and blasts of MDS with bone marrow fibrosis were negative for IL-13 and TGF-β. Conclusion: Based on these findings, we hypothesize that IL-13- and TGF-β- producing mast cells are key elements in the development of fibrosis in bone marrow. Therefore, mast cells are potential therapeutic targets for the treatment of fibrosis in bone marrow. Disclosures Nakayama: the promotion and mutual aid corporation for private schools of Japan: Research Funding.

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