Assessing inflammageing

Immunosenescence has been scrutinized in detail, and evidence that inflammation and ageing are interrelated is consistent. Still, a gold standard for assessing the biological age of the immune function in an individual patient is lacking, so that immunosenescence is still not a quantifiable criterion in clinical decision-making processes.

This review highlights recent (partly ongoing) studies into biomarkers of inflammation to assess immunosenescence, including large-scale studies, and quotes expert opinion statements. Markers of basal inflammation frequently used include interleukin-6, tumor necrosis factor-α and receptors p55 and p75, C-reactive protein and cytomegalovirus antibody levels. Some cellular markers are particularly advocated to reflect age-related decay of specific immunity, namely the decrease of naive T cells, especially CD8cells, and accumulations of memory T cells, especially late-stage differentiated CD8 cells; the loss of CD28 on lymphocytes is also taken as a biomarker of immunosenescence.

Substantial progress has been made in both understanding and phenotyping immunosenescence and inflammageing. The diagnosis of the degree of immunosenescence in the individual patient, however, has not yet been standardized.