MedicalResearch.com Interview with:
Dr. Changfu Kuo MD PhD
Division of Rheumatology, Orthopaedics, and Dermatology
School of Medicine, University of Nottingham, Nottingham, England
Division of Rheumatology, Allergy, and Immunology
Chang Gung Memorial Hospital, Taoyuan, Taiwan
Medical Research: What is the background for this study? What are the main findings?
Dr. Kuo: Systemic lupus erythematosus (SLE) is a prototype of autoimmune disease with features like autoantibody production and multiple target organ damage. SLE can affect any part of the body and the course of the disease is highly diverse and unpredictable. SLE can occur at any age and affect both females and males with a sex ratio of 9 to 1.
Familial predisposition has been recognised as a risk factor previously and heritability of SLE has been estimated to be 66%. However, previous reports are often based on less robust sampling strategies and case ascertainment which generally depend on hospital records, self-reported diagnosis and disease registries, therefore limiting generalisability. The previous estimates of heritability are overestimated, due to a lack of consideration of shared environmental contribution.
This study utilised a unique health insurance database that provides information on the whole population of Taiwan and permits determination of spouse and first-degree relatives. Over 23 million people were included in this study. Furthermore, through inclusion of SLE status of the spouse in our analyses the study is also able to examine how much of familial clustering results from genetic versus shared environmental factors. Overall the familial relative risk is 16.92. The genetic contribution to SLE susceptibility is estimated to be 44%. In addition to SLE, other autoimmune diseases are also more prevalent in individuals with a family history of SLE.
Medical Research: What should clinicians and patients take away from your report?
Dr. Kuo: Family history for SLE is a strong predictive risk factor for SLE and other related autoimmune diseases. The heritability is high, but seems to be lower than previously thought. Despite high familial relative risk, the absolute risk is not high considering low background prevalence of SLE.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Kuo: This study is purely based on a Asian population. Estimation of familial relative risks and heritability should be undertaken in other population with different ethnic background.
Dr. Changfu Kuo (2015). Family History of Lupus Is Strong Risk Factor For Lupus and Other Autoimmune Diseases