The alternative complement pathway is dysregulated in patients with chronic heart failure

Area of Science:

• Immunology
• Cardiology
• Biochemistry

Background:

• The complement system is a key part of innate immunity and is activated in heart failure (HF).
• An imbalance in alternative amplification loop components may characterize HF patients.

Purpose of the Study:

• To investigate the balance of alternative pathway components and their relation to disease severity in HF patients.
• To explore the association between complement factors and clinical markers of HF.

Main Methods:

• Plasma levels of properdin, complement factor D, factor H, and terminal complement complex (TCC) were measured using enzyme immunoassay.
• 188 HF patients and 67 healthy controls were analyzed.

Main Results:

• HF patients had higher levels of factor D and TCC, and lower levels of properdin compared to controls.
• Factor D and properdin levels correlated with systemic inflammation (C-reactive protein), neurohormonal markers (Nt-proBNP), and cardiac function.
• Low levels of factor H and properdin were associated with adverse outcomes in HF patients.

Conclusions:

• Dysregulation of circulating alternative pathway components contributes to increased complement activation in HF.
• This complement system dysregulation is linked to HF disease severity and adverse outcomes.