ORLANDO – Progression from cutaneous to systemic lupus happens far more quickly than is commonly reported in the literature, according to an investigation from Brigham and Women’s Hospital, Boston.
Most studies have emphasized mean time to progression, which is generally said to be about 8 years. The problem is that the range is broad, anywhere from a few months to 30 or more years, so “the outliers influence the mean, and therefore, may not provide a fully accurate representation of the interval in which [most] patients progress” from discoid lupus erythematosus (DLE) to systemic lupus erythematosus (SLE), lead investigator Scott Elman, MD, said at the International Conference on Cutaneous Lupus Erythematosus.
He and his team thought it would be more useful to instead look at median time to progression, the point at which half of patients develop systemic disease. They found that , with the first quartile progressing by 303 days. The mean time to progression, meanwhile, was over 4 years, because of outliers who progressed at anywhere from 27 days to 30 years.
“The median progression of DLE to SLE occurs much sooner than previously reported” with mean progression times, said Dr. Elman, an internal medicine and dermatology resident at Brigham and Women’s. “We believe the use of median [time] is [more] clinically useful for both providers and patients in their understanding of what a diagnosis of DLE means for the risk of developing systemic disease.
“As clinicians seeing DLE patients, the primary question we are asking ourselves is how frequently we should be monitoring for signs and symptoms of systemic lupus,” he said. Relying on mean time instead of median time might give a false sense of security – and even delay checking for arthritis, nephritis, and other manifestations. There’s no current standard of practice about when monitoring should occur, but “I certainly think that closer monitoring of new patients with a diagnosis of DLE, especially in their first couple of years,” is a good idea, he noted, adding that for most patients, “it seems that if it’s going to happen, it’s going to happen sooner” rather than later. At Brigham and Women’s, newly diagnosed patients are generally brought back every 3-6 months for lab tests and a thorough review of symptoms, Dr. Elman said.
The next step is to identify risk factors for early progression. The study did not find any significant differences in lab values, medication exposures, or disease manifestations between early and late progressors, perhaps because of the small sample size. The work continues.
There was no external funding for the work. Dr. Elman had no disclosures.