Osteoprotegerin (OPG) and TNF-related apoptosis-inducing ligand (TRAIL) levels in malignant and benign pericardial effusions.

Objectives: Osteoprotegerin (OPG) is a regulator of bone and vascular homeostasis and acts as a decoy receptor for proapoptotic TNF-related apoptosis-inducing ligand (TRAIL).
Design and Methods: We assessed pericardial and serum levels of OPG and TRAIL in pericardial effusions (PE) of malignant (mPE, n=24) or non-malignant (nPE, n=34) origin, and in pericardial fluid (PF, n=25) of coronary artery disease (CAD) patients by ELISA.
Results: OPG was at least 5 fold higher in PE or PF compared to serum, with a significantly higher ratio of pericardial to serum OPG in patients with mPE or nPE compared to PF (mPE vs. PF, p=0.011; nPE vs. PF, p<0.001). TRAIL was only detectable in mPE and PF. Logistic regression analysis revealed that a high ratio of pericardial to serum OPG and high TRAIL in PE were the best variable combination to predict malignancy of PE.
Conclusions: Pericardial and systemic OPG or TRAIL are potential diagnostic tools to discriminate between malignant or benign PE.
(Copyright © 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)