Inverted CD4:CD8 ratio is not associated with three-year mortality in a sample of community-dwelling oldest old: the OCTABAIX immune study.

BACKGROUND

The presence of an immune risk phenotype (IRP) has been correlated with survival rates in elderly people.

OBJECTIVE

To determine whether an inverted CD4:CD8 ratio might be a marker of IRP in a sample of oldest old by assessing its relationship with mortality.

DESIGN

Prospective cohort study.

SETTING

Community-based survey study of seven primary healthcare centres.

PARTICIPANTS

328 people born in 1924 and registered with primary healthcare centres.

MEASUREMENTS

Chronic drug prescription, functional status (Barthel and Lawton indexes) and cognitive status (Spanish version of the Mini-Mental State Examination) were recorded. CD4:CD8 ratios were determined, with a ratio of 1.00 or less being used to define IRP.

RESULTS

The CD4:CD8 ratio was 1.00 or less in 47 subjects (15.6%). After three years, 51 subjects had died (16.3%); 9 were from among the 47 (19.1%) with an inverted CD4:CD8 ratio and 42 (15.8%) from the remainder (P=0.52). Multivariate analysis identified two significant clinical variables (Lawton Index scores and the number of chronic drugs prescribed) as being independent predictors of three-year mortality risk in this cohort of octogenarians. This risk profile did not change when introducing the CD4:CD8 ratio into the calculation.

CONCLUSION

In this community-dwelling population of oldest old (85 years old at baseline) an inverted CD4:CD8 ratio was not associated with three-year mortality.