Background Conflicting results concerning the role of soluble apoptosis molecules in rheumatic diseases still remains. In adulthood, sFas, sFasL, sBcl-2 and sTRAIL levels in lupus patients have been described as normal, decreased or elevated, varying among studies and according to disease activity and to organ damage. In dermatomyositis, overexpressions of Fas and Bcl-2 were observed in myofibers suggesting apoptosis mediated injury, while sFasL levels are higher in both sera and synovial fluid from patients with rheumatoid arthritis.
Objectives To evaluate sFas, sFasL, sTRAIL and sBcl-2 in sera from JSLE patients compared to JDM, JIA and healthy controls, and to evaluate associations with nephritis and disease activity.
Methods sFas, sFasL, sTRAIL and sBcl-2 were measured in sera from 43 patients with JSLE (36F:7M, mean age=14.3, range 8.2-20.8 yrs, revised ACR criteria) and gender and age machted 26 JIA (ILAR criteria), 13 JDM patients (Bohan & Peter criteria) and 35 healthy individuals. Lupus activity parameters included SLEDAI score, ESR, serum anti-dsDNA (by quantitative ELISA), C3 and C4 (by standard methods). Thirty JSLE patients had active disease (SLEDAI ≥4) and 32 had nephritis. Commercial solid phase ELISA kits were used following the manufacturer’s instructions. Statistical analysis used Kruskal-Wallis test and Spearman’s rank, with P value <0.05.
Results JSLE patients had increased sFas and sTRAIL, decreased FasL and similar sBcl-2 levels compared to healthy controls, which were all related to active but not inactive disease (Table). SLEDAI score correlated positively with sFas (r=0.52; p=0.001), while anti-dsDNA, C3, C4, ESR and renal involvement had no association with soluble proteins. Interestingly, JDM patients presented 2-fold higher sBcl-2 level compared with all control groups. JIA patients had soluble apoptosis levels similar to controls (Table).
Conclusions JSLE and JDM patients present distinct profile of soluble apoptosis molecules, indicating a pro-apoptotic profile in active JSLE patients. Additionally, increased sBcl-2 in JDM patients may suggest an apoptosis role in its pathogenesis, therefore further studies are necessary to determine the relevance of this anti-apoptotic protein in this myopathy.
Financial support: FAPESP grant 08/58238
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Disclosure of Interest None Declared