Background Adequate assessment of disease activity in patients with systemic lupus erythematosus (SLE) using disease activity index, evaluating the extent of organ damage and quality of life, contributes to better monitoring, treatment, and improved prognosis in SLE patients. Organ damage element of the index in SLE patients predicts further organ damage and is associated with increased risk of mortality.
Objectives Our aim was to examine the correlation between organ damage and disease activity, quality of life, and severity of fatigue. Risk factors for organ damage in SLE patients were established.
Methods The study enrolled 83 SLE patients with disease duration of over 6 months, hospitalized at the Institute “Niška Banja” in 2012, out of which 6 men (7.2%) and 77 women (92.8%), aged 45.8±9.2 years on the average, with average disease duration of 10.6±7.9 years. Disease activity was assessed using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and physician's global assessment, and degree of damage was assessed using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index for SLE (SLICC/ACR Damage Index - SDI). Quality of life was assessed based on the standardized Medical Outcome Survey Short Form 36 (SF-36), and severity of fatigue using the Fatigue Severity Scale.
Results Average SDI value was 1.8±1.9 (median 1, min. 0, max. 9), and average SLEDAI was 10.9±7.4. Our results demonstrated that SDI was positively correlated with SLEDAI, global physician's assessment, and severity of fatigue (r=0.359, p=0.001; r=0.357, p=0.001; r=0.296, p=0.007, respectively), being associated as well with poorer quality of life. Univariant analysis demonstrated that age, disease duration (especially if over 10 years- OR 3.368, CI95% 1.01-11.34, p=0.045), high disease activity at global physician's assessment, as well as the use of Azathioprine, were all independent risk factors for organ damage. Use of Chloroquine was an important protective factor regarding organ damage (OR 0.378, CI95% 0.14-0.99, p=0.048). Our results demonstrated that the levels of anti-dsDNA antibodies, anti-nucleosome, anti-C1q antibodies, as well as the level of monocyte chemoattractant protein-1 in the serum and urin, were not predictors of organ damage. Multivariant logistic regression showed that high disease activity at global physician's assessment (OR 31.839, 95CI% 2.33-435.58, p=0.01) and use of Azathioprine (OR 7.256, 95CI% 1.37-5.63, p=0.005) were the strongest predictors of organ damage.
Conclusions Organ damage in SLE patients increases with advancing age and disease duration. The strongest predictors of organ damage are high disease activity at global physician's assessment and use of cytostatic agents. Use of Chloroquine can afford some protection against organ damage.
Disclosure of Interest None declared