Background: We studied whether the presence of cardiomyocyte apoptosis (CA) in explanted failing hearts is related to previous exposure to the proinflammatory cytokine tumor necrosis factor alpha (TNF-alpha).
Methods: Serum levels of TNF-alpha and its soluble type two receptors (sTNFRII) were measured with ELISAs in 15 cardiac transplant recipients. CA was quantified with TUNEL assay in the explanted failing hearts and autopsy samples from six normal hearts.
Results: The number of CA was significantly higher in explanted failing hearts than in normal hearts (0.041% vs. 0.007%, p<0.01). In heart failure patients, serum TNF-alpha was highly variable and did not correlate with CA. In contrast, serum sTNFRII showed a significant correlation (Pearson's r=0.74, p=0.002) with the amount of CA in explanted hearts. sTNFRII level >4500 pg/ml identified seven patients with 2.7 times higher percentage of CA than the other heart failure patients.
Conclusion: Increased levels of sTNFRII identify a heart failure patient subgroup with high CA activity.