Circulating amyloidogenic free light chains and serum N-terminal natriuretic peptide type B decrease simultaneously...

Area of Science:

• Cardiology
• Hematology
• Oncology

Background:

• N-terminal natriuretic peptide type B (NT-proBNP) is a key indicator of cardiac dysfunction and prognosis in light chain amyloidosis (AL).
• Circulating free light chains (FLCs) are the underlying cause of AL, driving cardiac damage.

Purpose of the Study:

• To investigate the relationship between changes in FLC levels and NT-proBNP concentrations following chemotherapy in patients with cardiac AL.
• To assess the prognostic significance of FLC reduction on cardiac function and survival in AL.

Main Methods:

• Serum NT-proBNP and FLCs were measured in 51 cardiac AL patients at baseline and after 3 chemotherapy cycles.
• Hematologic response (FLC decrease >50%) and complete FLC disappearance were assessed.
• Changes in NT-proBNP, left ventricular wall thickness, and survival were correlated with FLC levels.

Main Results:

• A significant decrease in NT-proBNP (median 48%) was observed in patients with hematologic response (n=22), while NT-proBNP increased in others (47%, P=.01).
• NT-proBNP reduction was more pronounced with complete FLC disappearance (median 53%) compared to partial response (median 31%, P=.04).
• Fifteen patients died; 13 (in whom NT-proBNP and FLCs did not improve) died within 1.8 months, indicating poor prognosis.

Conclusions:

• Reduction in FLCs leads to a simultaneous decrease in NT-proBNP, improved cardiac function, and enhanced survival in AL patients.
• Failure of chemotherapy to reduce FLCs signifies a high risk of early mortality.
• Cardiac function can improve rapidly with precursor reduction, even if amyloid deposits appear unchanged on echocardiography.