Investigators behind a longitudinal study at a single center identified several risk factors for organ damage in patients with systemic lupus erythematosus (SLE), and demonstrated that organ damage compromises health-related quality of life (HR-QOL) in these patients. Factors such as preexisting damage at baseline, age, immunosuppressive drug use, cigarette smoking, and higher mean erythrocyte sedimentation and C-reactive protein (CRP) levels were associated with earlier organ damage; some of these risk factors are modifiable.
“The negative effect [of organ damage progression] on HR-QOL underlines the need to address modifiable risk factors and develop effective prevention and treatment strategies to reduce the risk of organ damage over time,” Alexandra Legge, MD, Department of Medicine, Nova Scotia Health Authority, Dalhousie University, Halifax, and colleagues explained.
The study included 273 patients with SLE who were followed up for ≤14 years (mean follow-up, 7.3 years). Patients with newly diagnosed and long-standing SLE were included, and may be a limitation of this study. During follow-up, 126 (46.2%) patients had evidence of organ damage progression, as reflected by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (ACR) Damage Index (SDI).
The researchers evaluated the effect of key disease-related factors, medical therapies, demographic variables, and serologic biomarkers on the rate of damage accrual to identify predictors of damage progression.
As has been shown by other studies, patients with preexisting organ damage at baseline were twice as likely to have earlier organ damage progression. They also examined the relationship between cumulative organ damage and HR-QOL.
At baseline, patients were predominantly women (87.2%) and white (92%), with a mean age of 44.1 years. The mean duration of SLE was 7.5 years. Approximately 40% of patients were enrolled ≤1 year of SLE diagnosis. Approximately 70% had no organ damage at baseline, whereas almost 30% had preexisting damage, as reflected by an SDI score of >1. There were 27 deaths during follow-up, and 37 (13.6%) additional patients were lost to follow-up.
In a multivariate analysis, older age at baseline, fulfilling ≥8 ACR criteria for SLE at baseline, immunosuppressive medication use up to time of first SDI change, mean serum CRP level up to time of first SDI change, and current or past cigarette smoking remained significantly statistically associated with progressive organ damage.
Over time, changes in SDI score were associated with initial declines in the Short Form (SF)-36 medical outcomes study at the time damage occurred; SF-36 scores then became comparable to those of SLE patients without damage progression.
The fact that >8 ACR criteria at baseline were identified as a risk factor suggests that having multisystem disease increases the likelihood of accumulating organ damage, either because of the disease itself, related to corticosteroid use, or more aggressive immunosuppressive therapy leading to drug-related damage.
Cigarette smoking is a modifiable risk factor, and the strong association between cigarette smoking and damage accrual should provide further encouragement to step up smoking cessation efforts in patients with SLE.
The relationship between cumulative organ damage and HR-QOL is complex, but it is important to note that organ damage seems to compromise QOL, according to the authors.
Limitations of the study include the fact that it was conducted at a single site, and among mostly white patients who were followed annually by a single assessment. The study did not evaluate mental health and psychological factors, and included a relatively small sample of patients, so meaningful subgroup analysis was not possible.
- Legge A, Doucette S, Hanly JG. Predictors of organ damage progression and effect on health-related quality of life in systemic lupus erythematosus. J Rheumatol. 2016 Apr 15. Epub ahead of print.