P160 Investigating clinical parameters associated with outcomes in treatment of discoid lupus erythematosus with methotrexate

Abstract

The factors influencing the response of discoid lupus erythematosus (DLE) to methotrexate are poorly described in the literature, despite this being a commonly prescribed treatment for the condition. The aim of this study was therefore to investigate the factors that are associated with clinical response and tolerance to methotrexate in patients with DLE. Patients with a histologically confirmed diagnosis of DLE were identified by searching electronic health records within our tertiary referral centre. Only patients who had been treated with methotrexate for ≥ 3 months were included in this retrospective study. Baseline demographic and clinical parameters were recorded for this cohort and univariate analysis was performed. Clinical responses were documented as complete remission (CR), defined as resolution of all DLE lesions; partial remission (PR), defined as improvement but with ongoing lesions; and no remission (NR), defined as no improvement. Tolerance and reasons for cessation of methotrexate were also recorded. In total 32 patients with DLE who received treatment with methotrexate were identified. The mean dose of methotrexate was 15.2 mg and there was no significant difference in dose between patients achieving CR, PR or NR. Those with CR or PR had a greater baseline age at diagnosis of DLE (mean 44.3 years, SD 14.3) than those with NR (mean 30.3 years, SD 11.4) (P = 0.02). Overall, 13% of patients tested positive for double-stranded DNA antibodies, of whom none achieved CR. In total, 64% of patients discontinuing methotrexate had positive extractable nuclear antigen antibodies, compared with 29% of patients who tolerated sustained treatment (P = 0.07). There were no statistically significant differences in patients achieving CR, PR or NR in terms of ethnicity, the presence of concomitant systemic lupus erythematosus or smoking status. These results therefore add to our understanding of positive prognostic factors for the treatment of DLE with methotrexate.