Specifically, NIEHS is seeking volunteer families in which one twin or one of a pair of close brothers or pair of close sisters has rheumatoid arthritis, polyarticular juvenile rheumatoid arthritis, lupus, systemic sclerosis or idiopathic inflammatory myopathy, an autoimmune muscle disease.
The other same-gender twin or sibling must be free of these and other autoimmune diseases.
Even in the case of identical twins, the likelihood that one twin will have the disease and the other won't is generally greater than 50 percent.
That is one reason many scientists suspect that both genetic variations and environmental exposures may be involved in the diseases, according to Frederick Miller, M.D., who is leading the study. "Some of the environmental factors we'll look for," Dr. Miller said, "are exposures to a large number of drugs and vaccines, to bacteria and viruses, to foods such as dietary supplements, to occupational exposures, stress and ultraviolet light."
The twins or siblings may be children or adults and the researchers expect that the triggers may be different for each. Their parents are also eligible for enrollment to study the genetic risk factors for these diseases.
Blood and urine samples will be taken to test both for environmental exposures and for minor variations in their genes that might make the volunteer more susceptible - or less - to a disease trigger. The volunteers will be followed for five years but will remain under the care of their own local doctors. Washington-area volunteers may enroll at the Clinical Center on the National Institutes of Health campus in Bethesda, Md. Volunteers in other parts of the country can enroll at their local doctors' offices and have their samples sent to Bethesda for evaluation.
To qualify for the study, brother pairs and sister pairs must be within 47 months of age each other. Other investigators assisting Dr. Miller in this study are Lisa Rider, M.D. and Mark Gourley, M.D. also in the NIEHS Environmental Autoimmunity Group.
For information on the study, visit http://dir.niehs.nih.gov/direag or call the NIH patient recruiting office toll free at 1-800-411-1222 (For TTY: 1-866-411-1010).
NIEHS PR #03-05