Plasma levels of soluble glycoprotein 130 in acute myocardial infarction

OBJECTIVES: Soluble glycoprotein 130 (sgp130), a circulating form of receptor subunit for the interleukin (IL) -6 cytokine family, modulates the biological actions of its ligands as an inhibitory regulator. The role of sgpl30 in cardiovascular diseases such as acute coronary syndrome remains unknown. METHODS: Plasma levels of sgp130 were examined by enzyme-linked immunosorbent assay in 33 patients with acute myocardial infarction (AMI; mean age 67 +/- 2 years, 21 males and 12 females), who were admitted to our hospital within 24 hr of onset of AMI and survived for 4 weeks. RESULTS: Plasma sgp130 levels were significantly higher at admission (260.5 +/- 7.3 ng/ml), and were significantly lower from day 2 to day 5 (202.4 +/- 5.1 ng/ml at day 3) as compared with normal control subjects (n = 38, 227.1 +/- 5.6 ng/ml). The lowest sgp130 levels inversely correlated with white blood cell count at admission (r = -0.42, p < 0.05) and with peak C-reactive protein levels (r = -0.43, p < 0.05). Additional in vitro study revealed that incubation of AMI plasma with exogenous IL-6 plus soluble IL-6 receptor resulted in a decrease in plasma sgp130 levels, suggesting the possible reason for reduced plasma sgp130 levels in AMI. CONCLUSIONS: The present study indicates that plasma sgp130 levels were modulated during the time course of AMI and inversely associated with inflammation in AMI.