Abstract
In a prospective longitudinal study 130 patients with systemic lupus erythematosus (SLE) were studied at least monthly for a relationship between the anti-dsDNA levels and disease activity. We observed 13 patients who developed 15 periods of exacerbations of their disease. All 15 exacerbations were preceded by a continuous increase of the anti-dsDNA levels. In 13 of the 15 exacerbations studied the exacerbation was preceded by an increase of anti-dsDNA with a doubling time (T2) of less than 6 weeks; in 4 of the 5 other exacerbations the T2 was less than 10 weeks. Four other patients with an increase of the anti-dsDNA levels showed no exacerbation. In these 4 patients the T2 was larger than 10 weeks. The other 113 patients did not show an increase of anti-dsDNA over the 2 years of monitoring and showed no signs of serious disease activity (no major symptoms). These observations suggest that an SLE patient who is followed up frequently and who shows a continuous increase of anti-dsDNA witha T2 shorter than 10 weeks is bound to develop an exacerbation.