title: High-sensitivity flow cytometric analysis of mast cell clustering in systemic mastocytosis: a quantitative and statistical analysis.
abstract: We characterized recently identified event clusters in systemic mastocytosis (SM) by calculating the coefficient of variation (CV, %) of CD117 and side scatter (SSC), based on the mean fluorescence intensity of mast cells using flow cytometry. Seventy-five samples were from patients with SM and 124 samples from patients negative for SM (non-SM). Discrete cluster formation seen in 50 cases correlated with significantly lower CV for SSC (46.1% vs. 61.0%, p < 0.0001) and CD117 (64.5% vs. 80.5%, p < 0.0001) for SM vs. non-SM samples. A combined CVCD117 + SSC of < 125 showed a sensitivity of 80% and specificity of 80% for SM with PPV of 67% and NPV of 80%. Probability scores of having SM, generated based on CVs for SSC and CD117, were significantly higher in patients with SM than non-SM (0.55 vs. 0.17, respectively; p < 0.001). Flow cytometric-based quantitative analysis of event clustering is a useful approach for diagnosing and monitoring patients with SM.
authors.affiliation: Department of Pathology, Brigham and Women's Hospital , Boston, MA , USA.
authors.forename: Olga
authors.initials: O
authors.lastname: Pozdnyakova
authors.forename: Charlotte D
authors.initials: CD
authors.lastname: Laplante
authors.forename: Betty
authors.initials: B
authors.lastname: Li
authors.forename: Bernard
authors.initials: B
authors.lastname: Rosner
authors.forename: David M
authors.initials: DM
authors.lastname: Dorfman
mesh_terms: D001854:Bone Marrow Cells / Q000473:pathology; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D016130:Immunophenotyping; D016015:Logistic Models; D008407:Mast Cells / Q000145:classification / Q000473:pathology*; D034721:Mastocytosis, Systemic / Q000175:diagnosis* / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D019009:Proto-Oncogene Proteins c-kit
keywords: Systemic mastocytosis; coefficient of variation; discrete mast cell cluster; flow cytometry; logistic regression analysis; new criterion