Arthritis & Rheumatism, Volume 60,
October 2009 Abstract Supplement

The 2009 ACR/ARHP Annual Scientific Meeting
Philadelphia October 16-21, 2009.


Genetic Ancestry, Socioeconomic Status, and Disease Characteristics Among Hispanics with Systemic Lupus Erythematosus

Richman1,  I. B., Barton1,  J., Trupin1,  L., Petri2,  M. A., Yelin1,  E. H., Seldin3,  M.F., Criswell4,  L. A.

UCSF, San Francisco, CA
JHU, Baltimore, MD
Univ. of California, Davis
Univ. of California, San Francisco, CA

Purpose:

Systemic lupus erythematosus (SLE) is more severe among Hispanics than among Caucasians in the U.S. The extent to which genetic and environmental factors contribute to these disparities is incompletely understood. The objective of this study was to determine whether genetic ancestry and socioeconomic status (SES) are associated with disease characteristics including renal involvement, age at diagnosis, and disease activity among Hispanic adults with SLE.

Method:

This was a cross-sectional study of Hispanic adults with SLE enrolled in an ongoing study of the genetics of SLE. We confirmed SLE diagnosis and clinical characteristics by chart review. A subset of participants was enrolled in a prospective cohort study of SLE through which SES data and the Systemic Lupus Activity Questionnaire (SLAQ), a measure of disease activity, were collected. All participants were genotyped for a set of 112 single nucleotide polymorphisms informative for continental ancestry. Continental ancestry was estimated for each participant using the program STRUCTURE. We assessed the relationship between SLE characteristics and genetic ancestry using linear and logistic regression models adjusted for sex, disease duration, educational attainment, language, insurance status and type, and access to a rheumatologist.

Results:

Genetic ancestry estimation for 222 Hispanic SLE cases demonstrated that participants had on average 48% European ancestry, 39% Amerindian ancestry, 8% east Asian ancestry and 5% African ancestry. Forty percent of participants (n=89) had a history of renal involvement. The mean age at diagnosis was 31 (SD 12) and the mean SLAQ score was 13 (SD 8). In multivariable analysis, participants with a larger European ancestry contribution had a lower odds of renal involvement than those with a smaller European ancestry contribution. A 25% increase in European ancestry contribution was associated with a 65% reduction in the odds of having renal disease (OR 0.35, 95% CI 0.17–0.72, p=0.004) after adjustment for covariates. European ancestry was also associated with age at diagnosis. A 25% increase in European ancestry contribution was associated with a 4.8 year increase in age at diagnosis (95% CI 1.2–8.5, p=0.009) in multivariable analysis. European ancestry was not associated with SLAQ score, but health insurance type was. Compared to those with private health insurance, those with public insurance had on average a 4.4 point (95% CI 1.0–7.8, p=0.011) higher SLAQ score after adjusting for covariates.

Conclusion:

Both genetic ancestry and SES are associated with disease characteristics among Hispanic adults with SLE. Different facets of SLE may be differentially affected by genetic and environmental influences. Understanding the factors that contribute to SLE disease characteristics can help identify at-risk individuals and aid in devising targeted interventions to reduce health disparities in SLE.

To cite this abstract, please use the following information:
Richman, I. B., Barton, J., Trupin, L., Petri, M. A., Yelin, E. H., Seldin, M.F., et al; Genetic Ancestry, Socioeconomic Status, and Disease Characteristics Among Hispanics with Systemic Lupus Erythematosus [abstract]. Arthritis Rheum 2009;60 Suppl 10 :126
DOI: 10.1002/art.25209

Abstract Supplement

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