Light chain amiloydosis: Clinical, laboratory characteristics and treatment approach

Abstract

Introduction: Light chain amyloidosis (AL) is a plasma cell neoplasia characterized by deposition of a pathological insoluble fibrillary protein, i.e. light chain immunoglobulin. Aim: To show clinical and laboratory characteristics of patients, course, treatment modalities, prognosis etc. Material and methods: A number of 30 newly diagnosed patients with AL amyloidosis were analyzed. Histopathological diagnosis was made by identifying Congo red positive deposits in the affected organs. Results: A number of 30 patients(pts) was analyzed, 21 male / 9 female, with average age of 59 years. Paraprotein was found in 26 (86.7%). The most frequent monoclonal protein was immunoglobulin light chain (14pts, 46.7%), Lambda isotope was more common (21pts, 70%). Organ involvement: heart (21pts, 70%), kidney (21pts, 70%), sub cutis (18pts, 60%), bone marrow (12pts, 40%), liver (7pts, 23.3%) and 9pts(30%) had unusual localization (lung, skin, uterus); 18pts (60%) had more than one parenchymal organ involved. Biomarkers of cardiac involvement: BNP in 8pts (26.7%), NTproBNP in 13pts (43.3%), and troponin 7pts (23.3). Elevation of LDH was found in 7pts (23.3%). Anemia was observed in 3 (10%) and thrombocytopenia in 1 pts (3.3%). With conventional chemotherapy 21pts(70%) were treated, bortezomib was applied in 9pts (30%). With ASCT was performed on 2pts (6.7%). Overall treatment response (ORR, ≥PR) was achieved in 21pts (70%). All pts treated with bortezomib based HT had treatment response (≥PR). In transplant ineligible patients, treatment modality did not affect PFS (Log Rank = 1.675, p = 0.196), but showed statistically significant effect on OS (Log Rank = 3.834, p = 0.05). Number of parenchymal organ involvement (1 vs. ≥ 2) did not show influence neither of PFS or OS (PFS: Log Rank = 0.017, p = 0.895; OS: Log Rank = 0.739, p = 0.390). Although the most important negative prognostic factor, cardiac involvement had no effect on OS (Log Rank = 2.480, p = 1.410). Conclusion: Heart involvement indicated a worse prognosis for patients. Bortezomib based protocols and HDT with ASCT are essential for maintaining long-term remission and improving OS.