Safe and effective contraception is an issue that many women of childbearing age face. But for women with lupus, doctors have often been hesitant to prescribe one of the most effective forms of contraception - oral contraceptives, or the "pill" - for fear that it might increase disease activity.
In the 15-center study of 183 women with inactive or stable lupus, those taking oral contraceptives (triphasic 35 μg.ethinylestradiol/0.5-1 mg norethindrone for twelve 28-day cycles) had no statistically significant difference in the occurrence of flares than those taking a placebo. Severe flares occurred in about 7 percent of the women, regardless of whether they received oral contraceptives or placebo. A severe flare was defined by several criteria, including the presence of new or worsening central nervous system involvement; inflammation of the blood vessels (vasculitis), kidneys (nephritis) and/or muscles (myositis); and/or blood problems, including low platelet count (thrombocytopenia) and destruction of the red blood cells (hemolytic anemia).
Mild-to-moderate flares and disease complications were similar between the two groups over the 12-month follow-up as well. Mild-to-moderate flares included fevers and inflammation of the skin, joints, the sac of fibrous tissue that surrounds the heart (pericarditis), and mucous membranes lining the nose and mouth.
Reluctance to prescribe oral contraceptives and other hormones for women with lupus arose in part from the fact that lupus is far more common in women (women with the disease outnumber men 10 to 1), and that it typically begins during the childbearing years (after the onset and before the cessation of menstruation) when female hormone levels are at their peak. In mouse models of lupus, giving estrogen makes lupus worse and, depending on the genetic background, influences the activity of white blood cells called B cells that are believed to play a key role in the disease process.
But for most women with moderate lupus that is inactive or stable, taking estrogen - whether as part of an oral contraceptive or hormone replacement therapy - appears to have no detrimental effect on disease activity, say co-authors Jill Buyon, M.D., of New York's Hospital for Joint Diseases, and Michelle Petri, M.D., M.P.H., of the Johns Hopkins University, who jointly led the study. However, they note that oral contraceptives still are not advised for women who have a history of, or are at high risk for, blood clots, because estrogens have been associated with dangerous blood clots.
The recently published study on oral contraceptives is one of two separate randomized, placebo-controlled studies that comprise the Safety of Estrogens in Lupus Erythematosus, National Assessment (SELENA) Trial. The other study, which showed no increased risk of severe flares in postmenopausal women on hormone replacement therapy, was published earlier this year (Buyon JP, et. al. The effect of combined estrogen and progesterone hormone replacement therapy on disease activity in systemic lupus erythematosus: a randomized trial," Ann Intern Med 2005;142:953-962).
"There are settings in which estrogens might provide benefit," say the authors. Among women with lupus, they say, there is a high elective abortion rate - approaching 23 percent of pregnancies - which may reflect a failure of the birth control method used or the absence of an adequate birth control program.
"Estrogen, as used in this study, appears to be safe in the majority of women with stable disease," says NIAMS Director Stephen I. Katz, M.D., Ph.D. "This research brings us another step forward in improving quality of life for people with rheumatic disease."
In addition to NIAMS, other funders of the study included NIH's Office of Research on Women's Health, National Center on Minority Health and Health Disparities, National Center for Research Resources and National Institute of Allergy and Infectious Diseases.
The mission of the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a part of the Department of Health and Human Services' National Institutes of Health, is to support research into the causes, treatment, and prevention of arthritis and musculoskeletal and skin diseases; the training of basic and clinical scientists to carry out this research; and the dissemination of information on research progress in these diseases. For additional information, call NIAMS's Clearinghouse toll free at 1-877-22-NIAMS, or visit the NIAMS Web site at www.niams.nih.gov.
Petri M, et al. Combined oral contraceptives in women with systemic lupus erythematosus. N Engl J Med 2005;353:2550-2558.