title: Molecular analysis of BRAF V600E mutation in multiple nodules of pulmonary Langerhans cell histiocytosis.
abstract: Pulmonary Langerhans cell histiocytosis (PLCH) is a rare, smoking-related histiocytic disorder with variable clinical symptoms. Like in other non-pulmonary Langerhans cell proliferations, PLCH has recently been shown to harbour BRAF V600E mutations in a significant subset of cases, thus challenging the concept of PLCH being a reactive disorder. Here, we analysed 38 formalin-fixed and paraffin-embedded PLCH nodules of nine patients for BRAF mutation using two different molecular methods. Using pyrosequencing and allele-specific quantitative PCR (AS-PCR), BRAF V600E mutations were found in 16/38 (42%) and 31/37 (84%) nodules, respectively. Analysing different nodules of the same patients with pyrosequencing 3/6 patients showed a concordant BRAF mutation status. When allele-specific quantitative PCR was used, condordant results were found in 5/6 patients. Our findings clearly indicate that (a) the sensitivity of the method used is crucial in analysing BRAF mutation status, (b) AS-PCR is more sensitive in detecting BRAF V600E mutations than pyrosequencing,
authors.affiliation: Institute of Pathology, St. Vincent's Hospital Karlsruhe, Suedendstrasse 37, 76137, Karlsruhe, Germany.
authors.forename: Arno
authors.initials: A
authors.lastname: Dimmler
authors.affiliation: Institute of Pathology, St. Vincent's Hospital Karlsruhe, Suedendstrasse 37, 76137, Karlsruhe, Germany.
authors.forename: Helene
authors.initials: H
authors.lastname: Geddert
authors.affiliation: Institute of Pathology, University of Freiburg, Freiburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Werner
authors.affiliation: Institute of Pathology, St. Vincent's Hospital Karlsruhe, Suedendstrasse 37, 76137, Karlsruhe, Germany. Gerhard.Faller@vincentius-ka.de.
authors.forename: Gerhard
authors.identifier: http://orcid.org/0000-0002-1214-084X
authors.initials: G
authors.lastname: Faller
mesh_terms: D000328:Adult; D000368:Aged; D004252:DNA Mutational Analysis / Q000379:methods*; D005260:Female; D006646:Histiocytosis, Langerhans-Cell / Q000235:genetics* / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction / Q000379:methods*; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D012680:Sensitivity and Specificity
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf
keywords: Allele-specific quantitative PCR; BRAF-mutation; Clonality; Pulmonary Langerhans cell histiocytosis; Pyrosequencing