Abstract
During end-stage heart failure, plasma levels of interleukin-6 (IL6) are elevated.
This cytokine exerts a negative inotropic influence on the myocardium. The production
site of IL6 is unclear. We examined the hypothesis that IL6 in end-stage heartfailure
patients is produced in the myocardium itself and is differentially regulated according
to etiology. Cardiac tissue was obtained from 27 patients (idiopathic dilated cardiomyopathy,
(DCM) 9/6 m/f, age 46 ± 14 y; ischemic cardiomyopathy (ICM), 11/1 m/f, age 55 ± 8
y) at the timeof transplantation. The tissue was subjected to IL6 Northern-blot analysis.
Signals were quantified by densitometric scanning after normalization to G3 PDH mRNA.
Data were compared by Mann-Whitney test between DCM and ICM patients, divided by chamber
origin. IL6 transcripts were found in all patients. In DCM, left-ventricular IL6 mRNA
expression was higher than in ICM (p = 0.006). Median right-ventricular as well as
left- and right-atrial IL6 mRNA expression was not significantly different in both
groups. In summary, in endstage heart failure, IL6mRNA is consistently expressed in
the myocardium. Left-ventricular expression is higher in DCM than in ICM. These data
support the concept of a potentially reversible inflammatory component in the etiology
of DCM which is more pronounced than in patients with ICM of comparable clinical severity.
Key words
lnterleukin-6 mRNA - Northern analysis - Explant cardiac tissue - Ischemic cardiomyopathy
- Idiopathic dilated cardiomyopathy
