1 6508 121 TRAJECTORIES OF INFLAMMATORY BIOMARKERS OVER THE EIGHTH DECADE AND THEIR ASSOCIATIONS WITH IMMUNE CELL PROFILES AND EPIGENETIC AGEING. BACKGROUND: EPIGENETIC AGE ACCELERATION (AN OLDER METHYLATION AGE COMPARED TO CHRONOLOGICAL AGE) CORRELATES STRONGLY WITH VARIOUS AGE-RELATED MORBIDITIES AND MORTALITY. CHRONIC SYSTEMIC INFLAMMATION IS THOUGHT TO BE A HALLMARK OF AGEING, BUT THE RELATIONSHIP BETWEEN AN INCREASED EPIGENETIC AGE AND THIS LIKELY KEY PHENOTYPE OF AGEING HAS NOT YET BEEN EXTENSIVELY INVESTIGATED. METHODS: WE MODELLED THE TRAJECTORIES OF THE INFLAMMATORY BIOMARKERS C-REACTIVE PROTEIN (CRP; MEASURED USING BOTH A HIGH- AND LOW-SENSITIVITY ASSAY) AND INTERLEUKIN-6 (IL-6) OVER THE EIGHTH DECADE IN THE LOTHIAN BIRTH COHORT 1936. USING LINEAR MIXED MODELS, WE INVESTIGATED THE ASSOCIATION BETWEEN CRP AND IMMUNE CELL PROFILES IMPUTED FROM THE METHYLATION DATA AND EXAMINED THE CROSS-SECTIONAL AND LONGITUDINAL ASSOCIATION BETWEEN THE INFLAMMATORY BIOMARKERS AND TWO MEASURES OF EPIGENETIC AGE ACCELERATION, DERIVED FROM THE HORVATH AND HANNUM EPIGENETIC CLOCKS. RESULTS: WE FOUND THAT LOW-SENSITIVITY CRP DECLINED, HIGH-SENSITIVITY CRP DID NOT CHANGE, AND IL-6 INCREASED OVER TIME WITHIN THE COHORT. CRP LEVELS INVERSELY ASSOCIATED WITH CD8+T CELLS AND CD4+T CELLS AND POSITIVELY ASSOCIATED WITH SENESCENT CD8+T CELLS, PLASMABLASTS AND GRANULOCYTES. CROSS-SECTIONALLY, THE HANNUM, BUT NOT THE HORVATH, MEASURE OF AGE ACCELERATION WAS POSITIVELY ASSOCIATED WITH EACH OF THE INFLAMMATORY BIOMARKERS, INCLUDING A RESTRICTED MEASURE OF CRP (80,000 CPGS AND SPECIFIC HYPOMETHYLATION OF THE REGION ENCODING THE HUMAN LEUKOCYTE ANTIGEN LOCUS (HLA). WE FIND THAT DECREASED HLA METHYLATION IS PREDICTIVE OF LOWER CD4 / CD8 T CELL RATIO, LINKING MOLECULAR AGING, EPIGENETIC REGULATION, AND DISEASE PROGRESSION. 2016 20 3936 32 LIVING IN ENDEMIC AREA FOR INFECTIOUS DISEASES ACCELERATES EPIGENETIC AGE. INFLAMMAGING IS A LOW-GRADE INFLAMMATORY STATE GENERATED BY THE AGING PROCESS THAT CAN CONTRIBUTE TO FRAILTY AND AGE-RELATED DISEASES IN THE ELDERLY. HOWEVER, IT CAN HAVE DISTINCT EFFECTS IN THE ELDERLY LIVING IN ENDEMIC AREAS FOR INFECTIOUS DISEASES. AN INCREASED INFLAMMATORY RESPONSE MAY CONFER PROTECTION AGAINST INFECTIOUS AGENTS IN THESE AREAS, ALTHOUGH THIS ADVANTAGE CAN CAUSE ACCELERATING EPIGENETIC AGING. IN THIS STUDY, WE EVALUATED THE INFLAMMATORY PROFILE AND THE EPIGENETIC AGE OF INFECTED AND NONINFECTED INDIVIDUALS FROM AN ENDEMIC AREA IN BRAZIL. THE PROFILE OF CYTOKINES, CHEMOKINES AND GROWTH FACTORS ANALYZED IN THE SERA OF THE TWO GROUPS OF INDIVIDUALS SHOWED SIMILARITIES, ALTHOUGH INFECTED INDIVIDUALS HAD A HIGHER CONCENTRATION OF THESE MEDIATORS. A SIGNIFICANT INCREASE IN IL-1RA, CXCL8, CCL2, CCL3 AND CCL4 PRODUCTION WAS ASSOCIATED WITH LEPROSY INFECTION. NOTABLY, ELDERLY INDIVIDUALS DISPLAYED DISTINCT IMMUNE RESPONSES ASSOCIATED WITH THEIR INFECTION STATUS WHEN COMPARED TO ADULTS SUGGESTING AN ADAPTIVE REMODELLING OF THEIR IMMUNE RESPONSES. EPIGENETIC ANALYSIS ALSO SHOWED THAT THERE WAS NO DIFFERENCE IN EPIGENETIC AGE BETWEEN THE TWO GROUPS OF INDIVIDUALS. HOWEVER, INDIVIDUALS FROM THE ENDEMIC AREA HAD A SIGNIFICANT ACCELERATED AGING WHEN COMPARED TO INDIVIDUALS FROM SAO PAULO, A NON-ENDEMIC AREA IN BRAZIL. MOREOVER, THE LATTER COHORT WAS ALSO EPIGENETICALLY AGED IN RELATION TO AN ITALIAN COHORT. OUR DATA SHOWS THAT LIVING IN ENDEMIC AREAS FOR CHRONIC INFECTIOUS DISEASES RESULTS IN REMODELLING OF INFLAMMAGING AND ACCELERATION OF EPIGENETIC AGING IN INDIVIDUALS REGARDLESS OF THEIR INFECTIOUS STATUS. IT ALSO HIGHLIGHTS THAT GEOGRAPHICAL, GENETIC AND ENVIRONMENTAL FACTORS INFLUENCE AGING AND IMMUNOSENESCENCE IN THEIR PACE AND PROFILE. 2022