High Serum Lactate Dehydrogenase adds Prognostic Value to Cardiac Biomarker Staging System for Light Chain Amyloidosis

Objective: To evaluate the impact of elevated serum lactate dehydrogenase (LDH) on prognosis of immunoglobulin light chain (AL) amyloidosis, and to investigate its prognostic value for the cardiac biomarker staging system. Patients and Methods: We analyzed 83 consecutive patients with newly diagnosed immunoglobulin light chain amyloidosis who were treated with bortezomib or thalidomide based therapies between August 2010 and May 2017. Results: Elevated serum LDH was identified to be associated with cardiac involvement, BNP and TNT (p=0.017, p=0.007, and p=0.026, respectively). The prognosis of patients with elevated serum LDH was inferior to that of patients with normal serum LDH. The two-year PFS rates of patients with elevated serum LDH and patients with normal serum LDH were 47.8% and 68.8% respectively (p=0.009), and the corresponding two-year OS rates were 51.5% and 73.9% respectively (p=0.007). We then incorporated serum LDH into the cardiac biomarker staging system involving cTNT and NT-proBNP. Patients were assigned a score of 1 of cTNT≥0.025ng/ml, NT-proBNP≥332ng/L, and LDH≥259U/L, creating a stage I to IV with scores 0 to 3 points, respectively. The proportion of patients with stage I, II, III, and IV were 31.6%, 32.9%, 21.1%, and 14.4%. The two-year PFS rates for patients in stage I, II, III and IV were 72.6%, 53.6%, 33.7% and 20%(p<0.001), respectively. The two-year OS rates of patients were 90.9%, 66.7%, 42.9%, and 20% (p<0.001), respectively. Conclusion: Elevated LDH had adverse influence on prognosis of AL amyloidosis, which added prognostic value to the cardiac biomarker staging system.