Interleukin-21--a biomarker of importance in predicting myocardial function following acute infarction?

INTRODUCTION

Following acute myocardial infarction (AMI), the acute inflammatory response contributes to wound healing but also to progressive myocardial injury. Interleukin-21 (IL-21) plays a key role in immunoregulation; whether IL-21 is associated with left ventricular (LV) remodelling after AMI is unknown.

METHODS

Plasma IL-21 concentrations were measured in 100 patients (age 58.9 ± 12.0 years, 77% male) admitted with AMI and LV dysfunction, at baseline (mean 46 h) and again at 24 weeks; cardiac magnetic resonance and measurement of B-type natriuretic peptide, monocyte chemoattractant protein-1, matrix metalloproteinase (MMP)-2, -3, -9, and tissue inhibitor of metalloproteinase (TIMP)-1, -2, -4 occurred at both time-points. Remodelling was defined as change in LV end-systolic volume index (ΔLVESVI).

RESULTS

Plasma IL-21 concentration was unchanged over time (48.1 [SD 35.4]pg/mL at baseline vs. 48.8 [61.3]pg/mL at 24 weeks, p=0.92). Baseline IL-21 correlated significantly with ΔLVESVI (r=0.30, p=0.005) and change in LV end-diastolic volume index (r=0.33, p=0.003). On multivariate analysis, plasma IL-21 was an independent predictor of remodelling. IL-21 was also significantly associated with higher TIMP-4 concentrations and lower MMP-9 concentrations at baseline.

CONCLUSIONS

IL-21 predicts adverse remodelling following AMI in patients with LV dysfunction. Whether it plays a direct pathophysiological role in remodelling merits further study.