Seropositivity for pathogens associated with chronic infections is a risk factor for all-cause mortality in the elderly: findings from the Memory and Morbidity in Augsburg Elderly (MEMO) Study.

Abstract

Immunostimulation by chronic infection has been linked to an increased risk for different non-communicable diseases, which in turn are leading causes of death in high- and middle-income countries. Thus, we investigated if a positive serostatus for pathogens responsible for common chronic infections is individually or synergistically related to reduced overall survival in community dwelling elderly. We used data of 365 individuals from the German MEMO (Memory and Morbidity in Augsburg Elderly) cohort study with a median age of 73 years at baseline and a median follow-up of 14 years. We examined the effect of a positive serostatus at baseline for selected pathogens associated with chronic infections (Helicobacter pylori, Borrelia burgdorferi sensu lato, Toxoplasma gondii, cytomegalovirus, Epstein-Barr virus, herpes simplex virus 1/2, and human herpesvirus 6) on all-cause mortality with multivariable parametric survival models. We found a reduced survival time in individuals with a positive serostatus for Helicobacter pylori (accelerated failure time (AFT) - 15.92, 95% CI - 29.96; - 1.88), cytomegalovirus (AFT - 22.81, 95% CI - 36.41; - 9.22) and Borrelia burgdorferi sensu lato (AFT - 25.25, 95% CI - 43.40; - 7.10), after adjusting for potential confounders. The number of infectious agents an individual was seropositive for had a linear effect on all-cause mortality (AFT per additional infection - 12.42 95% CI - 18.55; - 6.30). Our results suggest an effect of seropositivity for Helicobacter pylori, cytomegalovirus, and Borrelia burgdorferi sensu lato on all-cause mortality in older community dwelling individuals. Further research with larger cohorts and additional biomarkers is required, to assess mediators and molecular pathways of this effect.