Differential Distribution of Allelic Variants in Cytokine Genes among African Americans and White Americans

• Published in: American journal of epidemiology 2004-12, Vol.160 (11), p.1033-1038
• Main Authors: Ness, Roberta B., Haggerty, Catherine L., Harger, Gail, Ferrell, Robert
• Format: Article
• Language: English
• Subjects: Adult; African Americans; Alleles; Analysis. Health state; Biological and medical sciences; Black or African American; Black People - genetics; confidence interval; Confidence Intervals; continental population groups; Cytokines; Cytokines - genetics; Epidemiology; Female; Fundamental and applied biological sciences. Psychology; General aspects; Genetics of eukaryotes. Biological and molecular evolution; Genotype & phenotype; Human; Humans; IL10; IL18; IL1A; IL1B; IL6; interleukin; interleukin-10; interleukin-18; interleukin-1α; interleukin-1β; interleukin-6; Medical sciences; Mortality; odds ratio; Pennsylvania; polymorphism (genetics); Polymorphism, Genetic; Population genetics, reproduction patterns; Pregnancy; Public health. Hygiene; Public health. Hygiene-occupational medicine; T-helper type 1; Th-1; TNFA; tumor necrosis factor-α; White people; White People - genetics
• ISSN: 0002-9262; 1476-6256; 0002-9262
• DOI: 10.1093/aje/kwh325

Racial disparities in health are largely unexplained. Because many diseases causing premature mortality among African Americans are mediated by the immune system, the authors explored the race-specific distribution of allelic variants in cytokine genes known to stimulate inflammation. The authors studied women seeking prenatal care and delivering singletons in uncomplicated first births at a US hospital in 1997–2001. A total of 179 African-American women and 396 White women were evaluated for functionally relevant allelic variants in cytokine genes. African-American women were significantly more likely to carry allelic variants known to up-regulate proinflammatory cytokines; odds ratios increased with allele dose. Odds ratios for African Americans versus Whites in genotypes up-regulating proinflammatory interleukin (IL) 1 (IL1A-4845G/G, IL1A-889T/T, IL1B-3957C/C, and IL1B-511A/A) ranged from 2.1 to 4.9. The proinflammatory cytokine interleukin-6 IL6-174 G/G genotype was 36.5 times (95% confidence interval (CI): 8.8, 151.9) more common among African Americans. Genotypes known to down-regulate the antiinflammatory interleukin-10 (IL10-819 T/T and IL10-1082 A/A) were elevated 3.5-fold (95% CI: 1.8, 6.6) and 2.8-fold (95% CI: 1.6, 4.9) in African Americans. Cytokine genotypes found to be more common in African-American women were consistently those that up-regulate inflammation.