Light Chain Amyloidosis and Non-Hodgkin's Lymphomas: A Peculiar Association with Distinct Clinical Features and Outcome
Authors: Basset Marco , Defrancesco Irene , Milani Paolo , Rattotti Sara , Foli Andrea , Varettoni Marzia , Corso Alessandro , Paulli Marco , Merlini Giampaolo , Arcaini Luca , Palladini Giovanni 
Published: October 2019

Abstract
Bakground. The association of light chain (AL) amyloidosis with lymphoplasmacytic lymphoma/Waldenström's Macroglobulinemia is well established. However, both localized and systemic AL amyloidosis have been also reported in other types of lymphoma, but a detailed description of these cases is still lacking.
Methods. We systematically searched the database of 1,415 newly diagnosed consecutive patients (pts) with AL amyloidosis of the Pavia Amyloidosis Research and Treatment Center for pts with non-lymphoplasmacytic lymphoma and AL amyloidosis, and identified 34 pts diagnosed between 2004 and 2018.
Results. Seventeen pts (50%) had a diagnosis of marginal zone lymphoma (MZL), mainly extranodal MZL (EMZL). Median age at the time of lymphoma diagnosis was 65 years (45-81) and 23 pts (68%) were males. An autoimmune disease was documented in 8 pts (24%), with Sjögren Syndrome as the commonest type. Clinical characteristics of pts according to type of lymphoma (MZL vs non-MZL) and type of AL (systemic vs localized) are presented in Tables 1 and 2. The amyloid deposits were characterized as AL-type by immunoelectron microscopy or mass spectrometry in all cases.
Twelve pts (35%) had a concomitant diagnosis of AL (within 12 months before or after the diagnosis of lymphoma). In 2 cases the diagnosis of lymphoma occurred after 16 and 45 months from diagnosis of AL, respectively. In 20 pts (10 MZLs), the lymphoma was diagnosed a median time of 58.6 months (range: 13.6-320.8 months) before AL diagnosis: all but 1 of these cases were treated for the underlying lymphoma and 16 of them had a complete remission at the time of AL diagnosis.
Twenty-nine pts (85%) had positive serum and/or urine immunofixation and/or an abnormal free light chains ratio (FLCR), while 5 pts had no detectable monoclonal component (MC) and normal FLCR: these pts developed only localized AL amyloidosis. Localized AL was documented in 10 pts (29%), 7 of them had a MZL. Involved organs were represented by MALT sites (6 nodular pulmonary, 1 tracheobronchial, 2 skin, 1 bladder).
Eleven pts with systemic AL amyloidosis died for progression of amyloidosis and 1 because of gastric cancer, while no patient with localized AL died during follow-up. The median overall survival (OS) from the diagnosis of AL amyloidosis was 42.5 months (Fig.1).
Conclusions. In our series collected in a referral center, MZL is the most common non-lymphoplasmacytic lymphoma that associates with AL amyloidosis. Hematologists should be aware that MZL is associated not only with localized light chain deposition at the lymphoma site, but also with systemic AL amyloidosis. Systemic AL amyloidosis could be itself an indication to start a specific treatment for the lymphoproliferative disease, even in otherwise asymptomatic lymphomas. The presence of a MC and elevated FLC are clues for systemic AL amyloidosis.
Figure 1. Figure 1.

Disclosures
Merlini: Prothena: Consultancy; Janssen: Consultancy; Ionis: Consultancy; Millenium: Consultancy; Akcea: Consultancy; Pfizer: Consultancy. Palladini:Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Other: Travel support; Prothena: Honoraria.