Clinical impact and prognostic implications of concurrent light-chain amyloidosis in patients with POEMS syndrome: A single-center retrospective study

Abstract Background POEMS syndrome is an uncommon multisystem plasma cell disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes. In rare instances, patients may develop concurrent light chain amyloidosis (AL) , further complicating the clinical course. However, the clinical features and prognostic implications of concurrent AL in POEMS syndrome remain poorly defined. Methods We conducted a retrospective analysis of 78 patients diagnosed with POEMS syndrome at a single center from January 2018 to April 2025. Among them, 7 patients were identified as having concurrent AL amyloidosis. Clinical characteristics, laboratory parameters, organ involvement, treatment response, and survival outcomes were systematically compared between patients with and without AL. Statistical analyses included t-tests or Mann-Whitney U tests for continuous variables, chi-square tests for categorical data, Kaplan-Meier survival analysis, and Cox proportional hazards modeling for prognostic factor identification. A two-sided p-value of less than 0.05 was considered statistically significant. Results Patients with concurrent AL were older at diagnosis (median age 62 vs. 53 years, p=0.037), and demonstrated higher serum IgA (5.5 vs. 3.2 g/L, p=0.032), markedly elevated free lambda light chains (808.6 vs. 69.5 μmol/L, p=0.001), and increased bone marrow monoclonal plasma cell infiltration (1.3% vs. 0.3%, p=0.018). Multisystem organ involvement was notably more frequent in the AL group, with pronounced renal dysfunction (median eGFR 71.5 vs. 89.5 mL/min/1.73m², p=0.049) and substantially elevated cardiac biomarkers (NT-proBNP: 4264.1 vs. 668.9 pg/mL, p=0.011; cTnI: 692.8 vs. 4.2 pg/mL, p=0.002). Echocardiographic evaluation revealed both a higher incidence and severity of myocardial hypertrophy and left ventricular systolic dysfunction in patients with AL. Both cohorts received comparable therapeutic regimens, including lenalidomide, bortezomib, and dexamethasone. Despite similar treatments, the complete remission rate was significantly lower in the AL group (25.0% vs. 68.1%). Five-year overall survival was markedly inferior among patients with AL (28.6%) compared to those without (84.3%, p<0.001). Multivariate Cox regression identified age >60 years and serum albumin <33 g/L as independent adverse prognostic factors (both p<0.05), while the presence of concurrent AL was not an independent predictor of survival after adjusting for these variables. Conclusion POEMS syndrome patients with concurrent AL exhibit a more aggressive clinical phenotype, characterized by increased organ damage and inferior long-term survival. However, age and hypoalbuminemia, rather than the presence of AL alone, independently predict poor prognosis. These findings underscore the importance of vigilant risk stratification and early intervention in high-risk subgroups, particularly elderly patients and those with low albumin levels. Tailored therapeutic strategies are warranted to optimize outcomes in this complex and heterogeneous patient population.