In vitro cytokine production by mononuclear cells exposed to bone cement extracts

The authors evaluated the ability of bone cement to modify the profile of pro-inflammatory cytokines secreted by the immune cells. Peripheral blood mononuclear cells (PBMC) collected from healthy individuals were cultured with cement extracts and tested to assess the release of IL-1β, TNFα, GM-CSF and IL-6 in both unstimulated and PHA-stimulated PBMC. The cytokine release of unstimulated PBMC was very poor, and in particular the IL-1β was undetectable: the addition of cement extract increased both TNFα and GM-CSF release and decreased IL-6, sometimes significantly. The most recurrent observation in PHA-stimulated PBMCs exposed to bone cement extract was the increase in both IL-1β and IL-6 release, while both the mean concentration and the index of release of TNFα and GM-CSF were changeable. In conclusion our results showed that leachable components of some bone cements can induce in vitro the release of pro-inflammatory cytokines which are known to be involved in the bone resorption associated with aseptic loosening of hip prostheses. These findings allowed us to identify materials endowed with the highest inflammatory power.