In a major study funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a part of the National Institutes of Health (NIH), women with either inactive or stable systemic lupus erythematosus (lupus) - a disease in which the body's immune system mistakenly attacks and damages healthy tissues of the skin, joints and internal organs, were able to take oral contraceptives without increased risk of flares, or periods of increased disease activity, that characterise the disease.

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.

According to a NIH release, in the 15-center study of 183 women with inactive or stable lupus, those taking oral contraceptives had no statistically significant difference in the occurrence of flares than those taking a placebo. Severe flares occurred in about 7 per cent 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 blood problems, including low platelet count (thrombocytopenia) and destruction of the red blood cells (haemolytic anaemia).

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," said co-authors Jill Buyon, New York's Hospital for Joint Diseases, and Michelle Petri, Johns Hopkins University, who jointly led the study. However, they noted 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 randomised, placebo-controlled studies that comprise the Safety of Estrogens in Lupus Erythematosus, National Assessment (SELENA) Trial.

"There are settings in which estrogens might provide benefit," said the authors. Among women with lupus, there is a high elective abortion rate, approaching 23 per cent of pregnancies, which may reflect a failure of the birth control method used or the absence of an adequate birth control programme.

"Estrogen, as used in this study, appears to be safe in the majority of women with stable disease. This research brings us another step forward in improving quality of life for people with rheumatic disease," said NIAMS director Stephen I. Katz.