Quantitative and qualitative alterations of acute-phase protein in healthy elderly persons

To assess acute-phase proteins in relation to ageing, we measured serum concentrations of C-reactive protein (CRP), serum amyloid-A protein (SAA), alpha-1 acid glycoprotein (AGP) and glycosylation microheterogeneity. of AGP in 131 healthy elderly individuals (aged greater than or equal to 65 years) living independently in the community, and 47 healthy younger individuals. Concentrations of CRP in the older persons (median = 3.0 mu g/ml) were significantly greater than in the younger group (median = 0.9 mu g/ml, p = 0.0003). Concentrations of SAA and AGP were similar in the two groups, but AGP glycosylation forms with reduced binding affinity for concanavalin-A (changes that have been observed in chronic inflammatory states) were increased in the elderly sample (p < 0.0001). These findings suggest that both quantitative and qualitative alterations of acute-phase proteins occur with physiological ageing in humans.