ALBERT

Description: 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

Description: Abstract 3805 Background: Mastocytosis is a rare disease characterized by an abnormal proliferation and accumulation of mast cells (MC) in several organs and tissues such as skin, bone marrow, liver, gastrointestinal tract and lymphnodes. The reported prevalence of mastocytosis (cutaneous or systemic) is lower than 1/50,000. Mastocytosis encompasses a wide range of clinical entities, extremely heterogeneous for symptoms, clinical course and prognosis. The heterogeneity and the complexity of its clinical signs lead to the definition of mastocytosis as a multidisciplinary pathology, involving different specialists such as hematologists, internists, dermatologists, immunologists and pediatricians. Mastocytosis is a MC clonal disease associated to a somatic mutation (D816V) of the proto-oncogene c-kit (KIT), which codifies for the stem cell factor (SCF) receptor. SFC is the main factor stimulating the proliferation, chemotaxis and activation of human mast cells. Different KIT mutations have been found in 15% of patients. Clinical signs and symptoms of mastocytosis mainly depend on the liberation of chemical mediators produced by the mast cells, on the tissue infiltration of the mast cells and on other associated hematological diseases. Aim of the Registry: promoting studies on mastocytosis in Italy aimed at investigating the epidemiology of the disease, its prognostic factors and health technology assessment (HTA) aspects associated to the management of a rare “orphan” disease. Methods: The Italian Mastocytosis Registry was constituted in 2009, with the aim of promoting communication between specialists and collecting data about patients diagnosed with mastocytosis at a national level. Anagraphical, anamnestic, clinical, biological, treatment and follow-up data of patients with mastocytosis are being routinely collected in 15 Italian centers after written informed consent. An on-line database (www.registroitalianomastocitosi.it) has been set up for this purpose. The collected data will allow specialists to: Results: At present, data on 175 patients have been collected. Seventy-nine (45%) have been diagnosed with systemic mastocytosis and 40 (50%) of them progressed from a cutaneous disease. Ninety-four (54%) are females; 81 (46%) are males. Among 49 patients for whom data on familiarity were available, 12 (24%) reported familiar cases of autoimmune diseases (n=3), allergies (n=5) or interestingly mastocytosis (n=4). Sixty-one (35%) patients reported allergies. Of 121 reported lines of therapy, 37 (31%) were described as not specified anti chemical mediators, 51 (42%) anti-H1, 21 (17%) anti-H2, 30 (25%) corticosteroids, 22 (18%) phototherapy, 7 (6%) alpha-interpheron, 8 (7%) chemotherapy and 13 (11%) tyrosine-kinase inhibitors (total exceeds 100% because multiple choice is allowed). As to the histological findings, 82 (47%) patients have data on bone marrow biopsy: 48 (59%) had a positive finding, with a median mast cells infiltrate of 30% (range 3–90%). Among 43 patients tested for tryptase serum level, 41 (95%) had levels above normal values (12.5 ng/ml). Conclusions: This is the first spontaneous observational study on mastocytosis in Italy. The on-line database is a useful tool for data collection at a national level. The Registry is an opportunity to carry out epidemiological studies aimed at estimating occurrence and geographical distribution of the disease. It will also allow specialists to investigate possible prognostic factors and provide a starting point for the research into ad hoc therapies and HTA studies. It will hopefully provide a link with other international registries to improve understanding of this disease. Last but not least, the Italian Registry may support a National Government policy to provide assistance by the Public Health System to patients with mastocytosis. Disclosures: No relevant conflicts of interest to declare.