title: A practical approach to the diagnosis of systemic amyloidoses.
abstract: Accurate diagnosis of systemic amyloidosis is necessary both for assessing the prognosis and for delineating the appropriate treatment. It is based on histologic evidence of amyloid deposits and characterization of the amyloidogenic protein. We prospectively evaluated the diagnostic performance of immunoelectron microscopy (IEM) of abdominal fat aspirates from 745 consecutive patients with suspected systemic amyloidoses. All cases were extensively investigated with clinical and laboratory data, with a follow-up of at least 18 months. The 423 (56.8%) cases with confirmed systemic forms were used to estimate the diagnostic performance of IEM. Compared with Congo-red-based light microscopy, IEM was equally sensitive (75% to 80%) but significantly more specific (100% vs 80%; P < .001). In amyloid light-chain (AL) amyloidosis, κ cases were more difficult to diagnose (sensitivity 71%), whereas the analysis of abdominal aspirate was informative in only 40% of patients with transthyretin amyloidosis. We found a high prevalence (20%) of a monoclonal component in patients with non-AL amyloidosis, highlighting the risk of misdiagnosis and the need for unequivocal amyloid typing. Notably, IEM identified correctly the specific form of amyloidosis in >99% of the cases. IEM of abdominal fat aspirates is an effective tool in the routine diagnosis of systemic amyloidoses.
authors: Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo and University of Pavia, Pavia, Italy; Amyloidosis and Myeloma Unit, Department of Hematology, Hospital Clínic and Institut d'Investigacions Biomèdiques August Pi I Sunyer, Barcelona, Spain;
authors: Carlos
authors: C
authors: Fernández de Larrea
authors: Pathology Unit, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo and University of Pavia, Pavia, Italy; and.
authors: Laura
authors: L
authors: Verga
authors: Pathology Unit, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo and University of Pavia, Pavia, Italy; and.
authors: Patrizia
authors: P
authors: Morbini
authors: Scientific Direction, Biometry and Statistics, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy.
authors: Catherine
authors: C
authors: Klersy
authors: Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo and University of Pavia, Pavia, Italy;
authors: Francesca
authors: F
authors: Lavatelli
authors: Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo and University of Pavia, Pavia, Italy;
authors: Andrea
authors: A
authors: Foli
authors: Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo and University of Pavia, Pavia, Italy;
authors: Laura
authors: L
authors: Obici
authors: Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo and University of Pavia, Pavia, Italy;
authors: Paolo
authors: P
authors: Milani
authors: Pathology Unit, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo and University of Pavia, Pavia, Italy; and.
authors: Gian Luca
authors: GL
authors: Capello
authors: Pathology Unit, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo and University of Pavia, Pavia, Italy; and.
authors: Marco
authors: M
authors: Paulli
authors: Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo and University of Pavia, Pavia, Italy;
authors: Giovanni
authors: G
authors: Palladini
authors: Amyloidosis Research and Treatment Center, Department of Molecular Medicine, Fondazione Istituto Di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo and University of Pavia, Pavia, Italy;
authors: Giampaolo
authors: G
authors: Merlini
mesh_terms: D050153:Abdominal Fat / Q000737:chemistry*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000682:Amyloid / Q000032:analysis*; D000686:Amyloidosis / Q000145:classification / Q000175:diagnosis* / Q000378:metabolism*; D044963:Biopsy, Fine-Needle; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016253:Microscopy, Immunoelectron / Q000379:methods*; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D000682:Amyloid