title: Antibody αPEP13h reacts with lymphangioleiomyomatosis cells in lung nodules.
abstract: BACKGROUND
  Lymphangioleiomyomatosis (LAM) is characterized by the proliferation in the lung, axial lymphatics (eg, lymphangioleiomyomas), and kidney (eg, angiomyolipomas) of abnormal smooth muscle-like LAM cells, which express melanoma antigens such as Pmel17/gp100 and have dysfunctional tumor suppressor tuberous sclerosis complex (TSC) genes TSC2 or TSC1. Histopathologic diagnosis of LAM in lung specimens is based on identification of the Pmel17 protein with the monoclonal antibody HMB-45.
  
  
  METHODS
  We compared the sensitivity of HMB-45 to that of antipeptide antibody αPEP13h, which reacts with a C-terminal peptide of Pmel17. LAM lung nodules were laser-capture microdissected to identify proteins by Western blotting.
  
  
  RESULTS
  HMB-45 recognized approximately 25% of LAM cells within the LAM lung nodules, whereas αPEP13h identified > 82% of LAM cells within these structures in approximately 90% of patients. Whereas HMB-45 reacted with epithelioid but not with spindle-shaped LAM cells, αPEP13h identified both spindle-shaped and epithelioid LAM cells, providing greater sensitivity for detection of all types of LAM cells. HMB-45 recognized Pmel17 in premelanosomal organelles; αPEP13h recognized proteins in the cytoplasm as well as in premelanosomal organelles. Both antibodies recognized a Pmel17 variant of approximately 50 kDa.
  
  
  CONCLUSIONS
  Based on its sensitivity and specificity, αPEP13h may be useful in the diagnosis of LAM and more sensitive than HMB-45.
authors.affiliation: Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health.
authors.forename: Julio C
authors.initials: JC
authors.lastname: Valencia
authors.affiliation: Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health.
authors.forename: Wendy K
authors.initials: WK
authors.lastname: Steagall
authors.affiliation: Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Cytopathology Section, National Institutes of Health, Bethesda, MD.
authors.forename: Patricia
authors.initials: P
authors.lastname: Fetsch
authors.affiliation: Cytopathology Section, National Institutes of Health, Bethesda, MD.
authors.forename: Andrea
authors.initials: A
authors.lastname: Abati
authors.affiliation: Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Tsukada
authors.affiliation: Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health.
authors.forename: Eric
authors.initials: E
authors.lastname: Billings
authors.affiliation: Pigment Cell Biology Section, National Cancer Institute, National Institutes of Health, Bethesda, MD.
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Hearing
authors.affiliation: Pathology Core, National Heart, Lung, and Blood Institute, National Institutes of Health.
authors.forename: Zu-Xi
authors.initials: ZX
authors.lastname: Yu
authors.affiliation: Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Pacheco-Rodriguez
authors.affiliation: Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health. Electronic address: mossj@nhlbi.nih.gov.
authors.forename: Joel
authors.initials: J
authors.lastname: Moss
mesh_terms: D000328:Adult; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D001706:Biopsy; D001999:Bronchoscopy; D002478:Cells, Cultured; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008168:Lung / Q000473:pathology; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology*; D018192:Lymphangioleiomyomatosis / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology*; D058950:Melanoma-Specific Antigens / Q000276:immunology; D008875:Middle Aged; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology*; D058951:gp100 Melanoma Antigen / Q000276:immunology
chemical_list: D000888:Antibodies, Anti-Idiotypic; D058950:Melanoma-Specific Antigens; C548637:PMEL protein, human; D058951:gp100 Melanoma Antigen