Detection of interleukin and interleukin-receptor mRNA in human heart by polymerase chain reaction.

Diminished cardiac contractility associated with inflammatory infiltration may be mediated by the release of interleukins. To test this hypothesis, we assessed the presence of interleukin and interleukin-receptor mRNAs in non-failing human heart and in endomyocardial biopsies from patients with dilated cardiomyopathy or inflammatory myocarditis. Only those interleukins expressed by non-circulating cells (interleukin-1 beta, -4, and -8) were detected in samples of human heart while interleukins specific for activated leukocytes (interleukins-1 alpha and -2) were not detected in any samples. While interleukin-1-receptor mRNA was present in samples from non-failing hearts and those with idiopathic myopathy, it was absent from patients with inflammatory myocarditis, suggesting receptor mRNA down-regulation.