title: The KIT D816V expressed allele burden for diagnosis and disease monitoring of systemic mastocytosis.
abstract: The activating KIT D816V mutation plays a central role in the pathogenesis, diagnosis, and targeted treatment of systemic mastocytosis (SM). For improved and reliable identification of KIT D816V, we have developed an allele-specific quantitative real-time PCR (RQ-PCR) with an enhanced sensitivity of 0.01-0.1 %, which was superior to denaturing high-performance liquid chromatography (0.5-1 %) or conventional sequencing (10-20 %). Overall, KIT D816 mutations were identified in 146/147 (99 %) of patients (D816V, n = 142; D816H, n = 2; D816Y, n = 2) with SM, including indolent SM (ISM, n = 63, 43 %), smoldering SM (n = 8, 5 %), SM with associated hematological non-mast cell lineage disease (SM-AHNMD, n = 16, 11 %), and aggressive SM/mast cell leukemia ± AHNMD (ASM/MCL, n = 60, 41 %). If positive in BM, the KIT D816V mutation was found in PB of all patients with advanced SM (SM-AHNMD, ASM, and MCL) and in 46 % (23/50) of patients with ISM. There was a strong correlation between the KIT D816V expressed allele burden (KIT D816V EAB) with results obtained from DNA by genomic allele-specific PCR and also with disease activity (e.g., serum tryptase level), disease subtype (e.g., indolent vs. advanced SM) and survival. In terms of monitoring of residual disease, qualitative and quantitative assessment of KIT D816V and KIT D816V EAB was successfully used for sequential analysis after chemotherapy or allogeneic stem cell transplantation. We therefore conclude that RQ-PCR assays for KIT D816V are useful complimentary tools for diagnosis, disease monitoring, and evaluation of prognosis in patients with SM.
authors.affiliation: III. Medizinische Klinik, Universitätsmedizin Mannheim, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Erben
authors.forename: Juliana
authors.initials: J
authors.lastname: Schwaab
authors.forename: Georgia
authors.initials: G
authors.lastname: Metzgeroth
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Horny
authors.forename: Mohamad
authors.initials: M
authors.lastname: Jawhar
authors.forename: Karl
authors.initials: K
authors.lastname: Sotlar
authors.forename: Alice
authors.initials: A
authors.lastname: Fabarius
authors.forename: Martina
authors.initials: M
authors.lastname: Teichmann
authors.forename: Sven
authors.initials: S
authors.lastname: Schneider
authors.forename: Thomas
authors.initials: T
authors.lastname: Ernst
authors.forename: Martin C
authors.initials: MC
authors.lastname: Müller
authors.forename: Michelle
authors.initials: M
authors.lastname: Giehl
authors.forename: Alexander
authors.initials: A
authors.lastname: Marx
authors.forename: Karin
authors.initials: K
authors.lastname: Hartmann
authors.forename: Andreas
authors.initials: A
authors.lastname: Hochhaus
authors.forename: Wolf-Karsten
authors.initials: WK
authors.lastname: Hofmann
authors.forename: Nicholas C P
authors.initials: NC
authors.lastname: Cross
authors.forename: Andreas
authors.initials: A
authors.lastname: Reiter
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D019943:Amino Acid Substitution; D015415:Biomarkers; D002851:Chromatography, High Pressure Liquid; D003937:Diagnosis, Differential; D005260:Female; D006402:Hematologic Diseases / Q000175:diagnosis / Q000235:genetics; D006801:Humans; D053208:Kaplan-Meier Estimate; D007946:Leukemia, Mast-Cell / Q000175:diagnosis / Q000235:genetics; D008297:Male; D034721:Mastocytosis, Systemic / Q000097:blood / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality; D008875:Middle Aged; D020125:Mutation, Missense; D017354:Point Mutation; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D053802:Tryptases / Q000097:blood
chemical_list: D015415:Biomarkers; D019009:Proto-Oncogene Proteins c-kit; D053802:Tryptases