Impact of systemic lupus erythematosus disease activity, hydroxychloroquine and NSAID on the risk of subsequent organ system damage and death: analysis in a single US medical centre.

OBJECTIVE: To assess the impact of mild-moderate systemic lupus erythematosus (SLE) disease activity during a 12-month period on the risk of death or subsequent organ system damage. METHODS: 1168 patients with ≥24 months of follow-up from the Hopkins Lupus Cohort were included. Disease activity in a 12-month observation period was calculated using adjusted mean Safety of Estrogens in Lupus Erythematosus National Assessment (SELENA) version of the SLE Disease Activity Index (SLEDAI), defined as the area under the curve divided by the time interval. Damage accrual in the follow-up period was defined as change in Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) score ≥1 among patients without prior damage. Patients visited the clinic quarterly and had SELENA-SLEDAI and SDI assessed at every visit. RESULTS: During follow-up (median 7 years), 39% of patients accrued new damage in any organ system (7% cardiovascular and 3% renal) and 8% died. In adjusted models, an increased SELENA-SLEDAI score increased the risk of death (HR=1.22, 95% CI 1.13 to 1.32, p<0.001), renal damage (HR=1.24, 95% CI 1.08 to 1.42, p=0.003) and cardiovascular damage (HR=1.17, 95% CI 1.07 to 1.29, p<0.001). Hydroxychloroquine use reduced the risk of death (HR=0.46, 95% CI 0.29 to 0.72, p<0.05) and renal damage (HR=0.30, 95% CI 0.13 to 0.68, p<0.05). Non-steroidal anti-inflammatory drug use increased the risk of cardiovascular damage (HR=1.66, 95% CI 1.04 to 2.63, p<0.05). Without prior damage, an increased adjusted mean SELENA-SLEDAI score increased the risk of overall damage accrual (HR=1.09, 95% CI 1.04 to 1.15, p<0.001). CONCLUSIONS: Each one-unit increase in adjusted mean SELENA-SLEDAI during a 12-month observation period was associated with an increased risk of death and developing cardiovascular and renal damage.

Lupus disease activity and the risk of subsequent organ damage and mortality in a large lupus cohort.

OBJECTIVES: To estimate the effect of SLE disease activity, observed over a 12-month period, on the risk of irreversible organ damage and mortality, adjusted for potential confounding factors. METHODS: Patients were enrolled into a prospective cohort study and followed up from 1991. This study retrospectively analyses the data captured in the prospective cohort study. The study population consisted of 350 patients with SLE (meeting four or more of the revised ACR criteria) enrolled at University College Hospital, London lupus clinic. Disease activity was assessed during the observation year using the classic BILAG system and a mean total BILAG score was calculated for that time period. Organ damage outcomes, assessed over a subsequent follow-up period, were based on SLICC/ACR damage index scores and included new damage overall and by specific organ systems (renal, CNS or cardiovascular/musculoskeletal/pulmonary systems) or reaching a serious level of damage (SDI ≥ 3). Adjusted hazard ratios (HRs) for the association between disease activity and subsequent organ damage or mortality were calculated using Cox proportional hazards regression. RESULTS: Disease activity as measured by mean total BILAG score was associated with mortality (HR = 1.15, P = 0.008), new organ damage (HR = 1.08, P = 0.009) and CV/pulmonary or musculoskeletal damage (HR = 1.11, P = 0.007) after adjustment for age, sex, ethnicity, SLE duration, steroid exposure level, NSAID, anti-malarial or immunosuppressant use, renal activity and complement C3 or anti-dsDNA levels. Of these adjustment factors, age, renal activity, immunosuppressant use and pre-existing organ damage were additional independent predictors. CONCLUSIONS: Disease activity as measured by global BILAG score during a 12-month observation period predicts the risk of subsequent organ damage and mortality after adjustment for key covariates.