Characteristics of azathioprine use and cessation in a longitudinal lupus cohort

OBJECTIVE: Guidelines for azathioprine (AZA) use in systemic lupus erythematosus (SLE), including indications for initiation and cessation, are lacking. Clinical decision-making could be improved if reasons for cessation of AZA treatment were standardised. METHODS: We determined the characteristics of AZA use in a cohort of patients with SLE and evaluated reasons for AZA cessation. Patients with SLE in a single centre had longitudinal recording of disease activity (Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI)-2k), laboratory investigations and treatment from 2007 to 2012. RESULTS: Of 183 patients studied, 67 used AZA on at least one occasion. There was no significant difference between AZA users and non-users in age or American College of Rheumatology criteria. Compared with those not treated with AZA, patients treated with AZA had higher disease activity (time-adjusted mean SLEDAI 5.2+/-0.3 vs 3.8+/-0.3, p=0.0028) and damage (Systemic Lupus International Collaborating Clinics (SLICC)-SDI 1.6+/-0.3 vs 1.2+/-0.1, p=0.0445), and were more likely to have a positive dsDNA (p=0.0130) and receive glucocorticoids (p