Acetylator phenotype in spontaneous SLE and rheumatoid arthritis

Acetylator phenotype was determined in 22 patients with spontaneous systemic lupus erythematosus and the proportion of 'slow' acetylators compared with that obtained in a group of patients with rheumatoid arthritis and a group of healthy controls. 73% of the SLE group were designated 'slow' compared with 72% of the rheumatoid group and 64% of the control group. These differences were not significant.