Immunoparesis Recovery as Predictor Marker of Progression After Autologous Stem Cell Transplantation in Multiple Myeloma

Context: Localized light chain amyloidosis (LAL) is a rare disease. Systematic data regarding its presentation, management and patient outcomes are limited to small case series. Objective: To systematically describe the Mayo clinic experience of patients with LAL. Design and Setting: We retrospectively reviewed clinical records of 403 patients with biopsy proven LAL seen at the Mayo Clinic between 1969-2014. Results: OF XXXX patients, 403 (XX%) had LAL. Median age at diagnosis was 60 years (range, 13-93) and 51% of them were male. Sites involved included: urothelial (bladder, ureter, renal pelvis) 75 (19%), larynx 51 (13%), lung parenchyma 42 (11%), skin 44 (11%), synovial tissue (9%), tracheobronchial 31 (8%), gastrointestinal tract 30 (8%), seminal vesicles 22 (6%), eyes 23 (6%), pharynx 22 (6%) and other 24 (6%). Typing was performed in 178 (45%) cases. A monoclonal protein was detected in 23 of 351 evaluated (7%) cases, 5 of which had different light restriction from that of LAL. Thirty one (8%) patients had a co-existent autoimmune disease. During a median follow-up of 39 months, no patients progressed to systemic AL. Of 403, 109 (27%) were observed or received supportive care only and 241 (60%) underwent local excision of the amyloid deposits. Sixtyfour (16%) patients required repeated interventions (median 1, range 1-4, upper decile requiring 4 interventions) for progressive disease. Ten year overall survival (OS) and progression free survival were 79% and 61%, respectively and there was no difference according to site of involvement, although patients diagnosed before 2003 fared worse (5 yr. OS 85% vs 95%, p¼0.001). Of the 70 patients that died during the follow-up period, cause of death was known for 29 and death was attributed to LAL in only 2 cases. Conclusions: In the largest series of patients with LAL reported so far we demonstrated that LAL has an excellent prognosis. Treatment is usually local excision for symptom control but 10% of cases carry significant morbidity and require repeated interventions for relapse/ progression. Keywords: Localized, immunoglobulin light chain, amyloidosis.