title: Characterization of Mast Cell Activation Syndrome.
abstract: Mast cell activation syndrome (MCAS), a recently recognized nonneoplastic mast cell disease driving chronic multisystem inflammation and allergy, appears prevalent and thus important. We report the first systematic characterization of a large MCAS population.
  
  
  
  Demographics, comorbidities, symptoms, family histories, physical examination and laboratory findings were reviewed in 298 retrospective and 115 prospective patients with MCAS. Blood samples from prospective subjects were examined by flow cytometry for clonal mast cell disease and tested for cytokines potentially driving the monocytosis frequent in MCAS.
  
  
  
  Demographically, white females dominated. Median ages at symptom onset and diagnosis were 9 and 49 years, respectively (range: 0-88 and 16-92, respectively) and median time from symptom onset to diagnosis was 30 years (range: 1-85). Median numbers of comorbidities, symptoms, and family medical issues were 11, 20, and 4, respectively (range: 1-66, 2-84, and 0-33, respectively). Gastroesophageal reflux, fatigue and dermatographism were the most common comorbidity, symptom and examination finding. Abnormalities in routine laboratories were common and diverse but typically modest. The most useful diagnostic markers were heparin, prostaglandin D2, histamine and chromogranin A. Flow cytometric and cytokine assessments were unhelpful.
  
  
  
  Our study highlights MCAS׳s morbidity burden and challenging heterogeneity. Recognition is important given good survival and treatment prospects.
authors.affiliation: Division of Hematology, Oncology and Transplantation, University of Minnesota (UMN), Minneapolis, Minnesota. Electronic address: afrinl@umn.edu.
authors.forename: Lawrence B
authors.initials: LB
authors.lastname: Afrin
authors.affiliation: Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Sally
authors.initials: S
authors.lastname: Self
authors.affiliation: Clinical and Translational Science Institute (CTSI), University of Minnesota, Minneapolis, Minnesota.
authors.forename: Jeremiah
authors.initials: J
authors.lastname: Menk
authors.affiliation: Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, South Carolina.
authors.forename: John
authors.initials: J
authors.lastname: Lazarchick
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002648:Child; D002675:Child, Preschool; D053379:Chromogranin A / Q000097:blood; D005260:Female; D006493:Heparin / Q000097:blood; D006632:Histamine / Q000097:blood; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008415:Mastocytosis / Q000175:diagnosis / Q000473:pathology*; D008875:Middle Aged; D011446:Prospective Studies; D015230:Prostaglandin D2 / Q000097:blood; D012189:Retrospective Studies; D013577:Syndrome; D055815:Young Adult
chemical_list: D015415:Biomarkers; D053379:Chromogranin A; D006632:Histamine; D006493:Heparin; D015230:Prostaglandin D2
keywords: Chronic inflammatory diseases; Mast cell activation disease; Mast cell activation syndrome