Systemic lupus erythematosus. Differences between patients who do, and who do not, fulfill classification criteria at the time of diagnosis.

We compared 31 patients who did, and 31 patients who did not, fulfill 4 or more criteria for the classification of systemic lupus erythematosus (SLE) at the time of diagnosis. Twenty-one of the latter 31 patients eventually developed enough manifestations to fulfill classification criteria. Ten never did despite average follow-up of 41 months. Patients who did not fulfill criteria at the time of diagnosis frequently had more thrombocytopenia and/or hemolytic anemia and continued to have fewer manifestations during the course of their disease than those who did. Failure to include this subject of SLE in studies with series of SLE patients may give a distorted picture of the disease.