Systemic lupus erythematosus activity and IgE.

Patients with active systemic lupus erythematosus (SLE) had a higher mean serum level of IgE than patients with SLE in remission. All five patients who had serum obtained during active disease had a drop in their total IgE levels when the disease process was quiescent. Further investigations are needed to settle the question of whether the elevated IgE found during active disease is primary or secondary, a pathogenic factor or an epiphenomenon.