Systemic lupus erythematosus. II. Observations on the occurrence of exacerbations in the disease course: Dutch experience with 110 patients studied prospectively.

The incidence of exacerbations in the disease course was investigated in 110 patients with systemic lupus erythematosus (SLE) who were studied prospectively at our institute for lupus research. At the time of disease onset and diagnosis the male patients were much older than the female patients (about 10 years); exacerbation frequency during follow up was increased in the male patients. The follow up data showed that if a patient with SLE was prone to develop an exacerbation this mostly took place within the first five years of follow up. It could be calculated that after fulfilling the American Rheumatism Association criteria only 56% (62/110) of the patients developed a subsequent exacerbation. Features at the time of diagnosis, distinguishing those patients who developed a subsequent exacerbation from those who did not, were haemolytic anaemia, the presence of anti-Sm antibodies, and a falsely positive serological test for syphilis. At the time of diagnosis, however, the prevalences of these features were low; for haemolytic anaemia, anti-Sm antibodies, and a falsely positive serological test for syphilis they amounted to 40%, 5%, and 12% respectively.