AL amyloidosis associated with IgM monoclonal protein: a distinct clinical entity.
IgM-associated AL amyloidosis is rare and may represent a distinct entity. Sixty (7%) of 868 consecutive AL patients referred to our center had an IgM monoclonal protein. They were significantly older than non-IgM patients (median, 67 years vs. 62 years), had a higher frequency of lymph-node involvement (25% vs. 2%) and significantly lower median proteinuria (1.2 g/24h vs. 3.4 g/24h), N-terminal pro-natriuretic peptide type-B (1177 ng/L vs. 2135 ng/L) and troponin I (0.02 ng/mL vs. 0.05 ng/mL). In IgM patients, kappa light-chains were more frequent (42% vs. 23%) and the involved free light-chain concentration was lower (median 63 mg/L vs. 182 mg/L). Serum albumin and NT-proBNP were independent prognostic determinants. Response to treatment improved survival. The 14 patients who received melphalan/dexamethasone showed a 64% hematologic (complete remissions, 29%) and a 43% organ response rate. IgM-associated AL amyloidosis is a distinct entity, with less advanced organ dysfunction. Treatment with melphalan/ dexamethasone might be effective in these patients.
Center for Amyloidosis, Biotechnology Research Laboratories and Department of Biochemistry, Fondazione Instituto di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo and University of Pavia, Italy.
Giovanni
G
Palladini
Paola
P
Russo
Tiziana
T
Bosoni
Gabriele
G
Sarais
Francesca
F
Lavatelli
Andrea
A
Foli
Letizia Zenone
LZ
Bragotti
Vittorio
V
Perfetti
Laura
L
Obici
Franco
F
Bergesio
Riccardo
R
Albertini
Remigio
R
Moratti
Giampaolo
G
Merlini
D000328:Adult; D000368:Aged; D000686:Amyloidosis / Q000097:blood* / Q000188:drug therapy; D005260:Female; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood*; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
D007147:Immunoglobulin Light Chains; D007075:Immunoglobulin M