Associations between perceived discrimination and immune cell composition in the Jackson Heart Study

Area of Science:

• Immunology
• Public Health
• Social Determinants of Health

Background:

• African American adults experience disproportionate disease burdens.
• Perceived discrimination is a stressor linked to health risks, with incompletely understood biological pathways.
• Previous research suggests stress impacts innate and adaptive immunity, but the link with discrimination is unclear.

Purpose of the Study:

• To investigate the association between perceived discrimination and immune cell counts (neutrophils, monocytes, lymphocytes) and the neutrophil-to-lymphocyte ratio (NLR) in African American adults.
• To explore if perceived discrimination is associated with shifts in both innate and adaptive immunity.
• To examine the relationship between perceived everyday and lifetime discrimination, and perceived burden from lifetime discrimination, with immune markers.

Main Methods:

• Analysis of data from 3,319 African American adults in the Jackson Heart Study (JHS).
• Measurement of white blood cell counts to determine neutrophil, monocyte, and lymphocyte counts, and NLR.
• DNA methylation analysis in a sub-sample (n=1,023) to estimate CD4T, CD8T, and B lymphocyte proportions.

Main Results:

• High lifetime discrimination was unexpectedly associated with lower neutrophils and NLR.
• High perceived burden from lifetime discrimination was associated with higher neutrophils and NLR.
• High perceived burden was linked to lower lymphocytes in older men, potentially due to CD4T cell differences.

Conclusions:

• Perceived discrimination is associated with significant alterations in innate and adaptive immune markers in African American adults.
• Immune function may serve as a crucial biological pathway connecting perceived discrimination to adverse health outcomes.
• Findings underscore the need to address discrimination as a factor influencing health disparities through immune mechanisms.