COAGULATION OF WHOLE-BLOOD STIMULATES INTERLEUKIN-1-BETA GENE-EXPRESSION

To study interleukin (IL)-1 beta gene expression, reverse transcriptio n-polymerase chain reaction was used on 25-mu L whole blood samples fr om 11 healthy subjects. Coagulated and unclotted whole blood was compa red. There was no evidence of IL-1 beta gene expression in any time ze ro samples (i.e., whole blood from which mRNA was immediately extracte d) from 11 subjects, whereas a 388-bp band representing IL-1 beta mRNA was detected in all coagulated samples. No mRNA for IL-1 beta was det ected in EDTA-anticoagulated whole blood, although in these samples th e addition of lipopolysaccharide as a positive control induced the exp ression of IL-1 beta. In time course studies on samples allowed to clo t, mRNA for IL-1 beta was detectable after 30 min. These findings demo nstrate that IL-1 beta gene expression is not present in circulating c ells of healthy subjects and that coagulation is a stimulus for IL-1 b eta gene expression. This may be a mechanism by which thrombosis produ ces inflammation and fever.