LAUSR

Background Systemic lupus erythematosus (SLE) is a multifactorial, autoimmune inflammatory disease with pleomorphic clinical manifestations involving different organs and tissues. Vitamin D (VITD) deficiency is highly prevalent and evidence is mounting that it contributes to the morbidity and mortality in SLE. VITD is an essential steroid hormone with well-established effects on mineral metabolism, skeletal health, and more recently established profound effects on immune system health. Objectives To evaluate the development of SLE after VITD supplementation in pristane-induced lupus model. Methods Female BALB/c mice divided into 3 groups: healthy animals (CO), SLE animals (PIL) and SLE animals + vitamin D supplementation (PIL+VITD). PIL+VITD group received a subcutaneous injection of Calcijex® [2 ug/kg] in PBS-Tween 20 buffer every second day during 180 days. Animals were monitored every 2 months for body weight, free exploratory locomotion, grip strength, endurance exercise performance and edema size. Interleukin 2 (IL-2), IL-4, IL-6, IFN-γ and TNF-α were measured by Luminex technology. The histological and immunofluorescence parameters (IgG, IgM and C3) of the kidney and the joints are under analysis. Data was analyzed with ANOVA Two-Way followed by Bonferroni and independent sample t-test. p<0.05 was considered significant. All data are represented as Mean±SEM. Results When compared with CO group (5.12±1.23 g), both PIL (7.53±1.09 g) and PIL+VIT D (8.08±2.28 g) groups exhibited a greater body weight gain by day 180 of the experiment (p<0.05). There was no statistically significant difference in free exploratory locomotion and grip strength between the groups, but both the PIL (29.39±6.75 min) and the PIL+VITD (25.75±12.48 min) groups showed increased fatigue compared to the CO group (42.08±3.47 min). Still, VITD supplementation reduced mean paw swelling to compared PIL group (0.207±0.29 vs 0.24±0.051, p<0.05) Conclusions The supplementation of VITD improves the clinical severity of PIL-manifestations, such as the reduction of hind paw edema. Further analysis of the histology of the joints and the kidney will complement the evaluation of the vitamin D modulating effects on the immune system. Disclosure of Interest None declared