Life Course Socioeconomic Status and Immune Response to Persistent Infection in Mexican Americans.

Abstract

Immune response to persistent infections, such as cytomegalovirus (CMV), herpes simplex virus-1 (HSV-1), Toxoplasma gondii (T. gondii), and Helicobacter pylori (H. pylori), are patterned by socioeconomic status (SES) in the U.S. Though persistent infections are often acquired early in life, studies of social exposures and these pathogens in adults are often limited to concurrent measures of SES. Further, significant disparities in persistent infections exist by race/ethnicity, indicating that Mexican Americans are more likely to experience the detrimental effects of life course socioeconomic disadvantage on immune response, however, early life cultural exposures are rarely examined. Using data from the Sacramento Area Latino Study on Aging (SALSA), a longitudinal cohort study of community-dwelling Mexican Americans, this dissertation examines the life course mechanisms by which early life SES may influence immune response to persistent pathogens and pathogen burden later in life. Additionally, nativity and acculturation, important components of social and racial/ethnic disparities in health, are investigated as independent predictors and modifiers of the life course social patterning of immune response to persistent infections later in life.

The main findings indicate that 1) early life SES indirectly influences later life immune response and pathogen burden by a chain of risk mechanism, 2) nativity is independently associated with CMV, but not HSV-1, T. gondii, H. pylori immune response or pathogen burden, 3) acculturation is not independently associated with immune response or pathogen burden, and 4) nativity and acculturation modify the association between life course SES and immune response to CMV and T. gondii. This work contributes new knowledge and understanding of the life course mechanisms by which early life social conditions act to influence later life immune response to persistent infections and the early life cultural factors that impact these exposures. The results from these studies provide insight on points of intervention during the life course where addressing social disadvantage may improve immunological response to persistent infections later in life. Given the link between persistent infections examined in these studies and adverse health outcomes, this work may have broad implications for disrupting the development of social disparities in chronic health conditions and mortality.