title: 18F-Florbetapir Binds Specifically to Myocardial Light Chain and Transthyretin Amyloid Deposits: Autoradiography Study.
abstract: BACKGROUND
  (18)F-florbetapir is a promising imaging biomarker for cardiac light chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). Our aim, using human autopsy myocardial specimens, was to test the hypothesis that (18)F-florbetapir binds specifically to myocardial AL and ATTR amyloid deposits.
  
  
  RESULTS
  We studied myocardial sections from 30 subjects with autopsy-documented AL (n=10), ATTR (n=10), and nonamyloid controls (n=10) using (18)F-florbetapir and cold florbetapir compound and digital autoradiography. Total and nonspecific binding of (18)F-florbetapir was determined using the maximum signal intensity values. Specific binding of (18)F-florbetapir was calculated by subtracting nonspecific from total binding measurements (in decays per minute/mm(2), DPM mm(2)) and was compared with cardiac structure and function on echocardiography and the histological extent of amyloid deposits. Diffuse or focally increased (18)F-florbetapir uptake was noted in all AL and ATTR samples and in none of the control samples. Compared with control samples, mean (18)F-florbetapir-specific uptake was significantly higher in the amyloid samples (0.94±0.43 versus 2.00±0.58 DPM/mm(2); P<0.001), and in the AL compared with the ATTR samples (2.48±0.40 versus 1.52±0.22 DPM/mm(2); P<0.001). The samples from subjects with atypical echocardiographic features of amyloidosis showed quantitatively more intense (18)F-florbetapir-specific uptake compared with control samples (1.50±0.17 versus 0.94±0.43 DPM/mm(2); P=0.004), despite smaller amyloid extent than in subjects with typical echocardiograms.
  
  
  CONCLUSIONS
  (18)F-florbetapir specifically binds to myocardial AL and ATTR deposits in humans and offers the potential to screen for the 2 most common types of myocardial amyloid.
authors.affiliation: From the Division of Nuclear Medicine and Molecular Imaging, Department of Radiology (M.-A.P., A.B., S.D., V.V., M.F.D., S.D.), Noninvasive Cardiovascular Imaging Program, Department of Medicine (Cardiology) and Radiology (V.V., M.F.D., S.D.), Cardiac Amyloidosis Program, Department of Medicine (R.F.P., R.H.F., S.D.), and Department of Pathology (R.F.P., D.H.H.), Brigham and Women's Hospital, Boston, MA.
authors.forename: Mi-Ae
authors.initials: MA
authors.lastname: Park
authors.affiliation: From the Division of Nuclear Medicine and Molecular Imaging, Department of Radiology (M.-A.P., A.B., S.D., V.V., M.F.D., S.D.), Noninvasive Cardiovascular Imaging Program, Department of Medicine (Cardiology) and Radiology (V.V., M.F.D., S.D.), Cardiac Amyloidosis Program, Department of Medicine (R.F.P., R.H.F., S.D.), and Department of Pathology (R.F.P., D.H.H.), Brigham and Women's Hospital, Boston, MA.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Padera
authors.affiliation: From the Division of Nuclear Medicine and Molecular Imaging, Department of Radiology (M.-A.P., A.B., S.D., V.V., M.F.D., S.D.), Noninvasive Cardiovascular Imaging Program, Department of Medicine (Cardiology) and Radiology (V.V., M.F.D., S.D.), Cardiac Amyloidosis Program, Department of Medicine (R.F.P., R.H.F., S.D.), and Department of Pathology (R.F.P., D.H.H.), Brigham and Women's Hospital, Boston, MA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Belanger
authors.affiliation: From the Division of Nuclear Medicine and Molecular Imaging, Department of Radiology (M.-A.P., A.B., S.D., V.V., M.F.D., S.D.), Noninvasive Cardiovascular Imaging Program, Department of Medicine (Cardiology) and Radiology (V.V., M.F.D., S.D.), Cardiac Amyloidosis Program, Department of Medicine (R.F.P., R.H.F., S.D.), and Department of Pathology (R.F.P., D.H.H.), Brigham and Women's Hospital, Boston, MA.
authors.forename: Shipra
authors.initials: S
authors.lastname: Dubey
authors.affiliation: From the Division of Nuclear Medicine and Molecular Imaging, Department of Radiology (M.-A.P., A.B., S.D., V.V., M.F.D., S.D.), Noninvasive Cardiovascular Imaging Program, Department of Medicine (Cardiology) and Radiology (V.V., M.F.D., S.D.), Cardiac Amyloidosis Program, Department of Medicine (R.F.P., R.H.F., S.D.), and Department of Pathology (R.F.P., D.H.H.), Brigham and Women's Hospital, Boston, MA.
authors.forename: David H
authors.initials: DH
authors.lastname: Hwang
authors.affiliation: From the Division of Nuclear Medicine and Molecular Imaging, Department of Radiology (M.-A.P., A.B., S.D., V.V., M.F.D., S.D.), Noninvasive Cardiovascular Imaging Program, Department of Medicine (Cardiology) and Radiology (V.V., M.F.D., S.D.), Cardiac Amyloidosis Program, Department of Medicine (R.F.P., R.H.F., S.D.), and Department of Pathology (R.F.P., D.H.H.), Brigham and Women's Hospital, Boston, MA.
authors.forename: Vikas
authors.initials: V
authors.lastname: Veeranna
authors.affiliation: From the Division of Nuclear Medicine and Molecular Imaging, Department of Radiology (M.-A.P., A.B., S.D., V.V., M.F.D., S.D.), Noninvasive Cardiovascular Imaging Program, Department of Medicine (Cardiology) and Radiology (V.V., M.F.D., S.D.), Cardiac Amyloidosis Program, Department of Medicine (R.F.P., R.H.F., S.D.), and Department of Pathology (R.F.P., D.H.H.), Brigham and Women's Hospital, Boston, MA.
authors.forename: Rodney H
authors.initials: RH
authors.lastname: Falk
authors.affiliation: From the Division of Nuclear Medicine and Molecular Imaging, Department of Radiology (M.-A.P., A.B., S.D., V.V., M.F.D., S.D.), Noninvasive Cardiovascular Imaging Program, Department of Medicine (Cardiology) and Radiology (V.V., M.F.D., S.D.), Cardiac Amyloidosis Program, Department of Medicine (R.F.P., R.H.F., S.D.), and Department of Pathology (R.F.P., D.H.H.), Brigham and Women's Hospital, Boston, MA.
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Di Carli
authors.affiliation: From the Division of Nuclear Medicine and Molecular Imaging, Department of Radiology (M.-A.P., A.B., S.D., V.V., M.F.D., S.D.), Noninvasive Cardiovascular Imaging Program, Department of Medicine (Cardiology) and Radiology (V.V., M.F.D., S.D.), Cardiac Amyloidosis Program, Department of Medicine (R.F.P., R.H.F., S.D.), and Department of Pathology (R.F.P., D.H.H.), Brigham and Women's Hospital, Boston, MA. sdorbala@partners.org.
authors.forename: Sharmila
authors.initials: S
authors.lastname: Dorbala
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D028227:Amyloid Neuropathies, Familial / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D058227:Amyloidogenic Proteins / Q000378:metabolism*; D000814:Aniline Compounds / Q000378:metabolism; D001344:Autopsy; D001345:Autoradiography; D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005026:Ethylene Glycols / Q000378:metabolism; D005260:Female; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D049268:Positron-Emission Tomography; D011228:Prealbumin / Q000378:metabolism*; D011237:Predictive Value of Tests; D011485:Protein Binding; D019275:Radiopharmaceuticals / Q000378:metabolism; D014463:Ultrasonography
chemical_list: D058227:Amyloidogenic Proteins; D000814:Aniline Compounds; D005026:Ethylene Glycols; D007147:Immunoglobulin Light Chains; D011228:Prealbumin; D019275:Radiopharmaceuticals; C545186:florbetapir
keywords: amyloid; autoradiography; echocardiography; florbetapir; pathology; positron-emission tomography; radioisotopes