The effect of age on the inflammatory response to arthritis-associated crystals.

The effect of age on the inflammatory response to urate and hydroxyapatite crystals was examined using both in vivo (intradermal skin testing) and in vitro (neutrophil death following incubation with urate crystals) methods. No significant difference in crystal-induced inflammation was found between young (< 25 years) and elderly (> 75 years) subjects and there was no correlation between the in vivo and in vitro tests. There was good correlation (0.63, p < 0.001) between the intradermal responses to urate and hydroxyapatite, suggesting that subjects, regardless of their age, are consistent in their response to these two types of arthritis-associated crystal. Advanced age does not lead to a major alteration in the inflammatory response to arthritis-associated crystals.