Increased sMer, but not sAxl, sTyro3, and Gas6 relate with active disease in juvenile systemic lupus erythematosus

Author(s)

Liphaus, Bernadete L. ; Lima, Laila ; Palmeira, Patricia ; Silva, Clovis A. ; Goldenstein-Schainberg, Claudia ; Carneiro-Sampaio, Magda

• Document type: Journal article
• Source: CLINICAL RHEUMATOLOGY; v. 39, n. 2, p. 6-pg., 2019-10-26.

Abstract

Introduction/objectives Tyro3, Axl, and Mer (TAM) receptors and ligands mediate apoptotic bodies engulfment which alteration has been related with juvenile systemic lupus erythematosus (JSLE) pathogenesis. Thus, the aim was to determine their soluble levels. Methods Serum sTyro3, sAxl, sMer, and Gas6 levels were measured using ELISA in 67 JSLE patients, 12 juvenile idiopathic arthritis (JIA) inflammatory and 20 healthy controls and related with SLEDAI-2K score, anti-dsDNA antibody, ESR, CRP, C3, C4 levels, and nephritis. Results JSLE patients with active disease (SLEDAI-2K> 4) had significantly increased sMer levels compared with healthy controls (median 8.4 vs. 6.0 ng/mL, p = 0.009) and inactive disease patients (5.2 ng/mL, p = 0.0003). sMer levels correlated with SLEDAI-2K (r = 0.44; p = 0.0004) and ESR (r = 0.24; p = 0.04), while sAxl correlated with SLEDAI-2K (r = 0.33; p = 0.008) and C4 levels (r = - 0.24; p = 0.04). JSLE patients taking glucocorticoid had increased sAxl and sMer levels. Moreover, sAxl correlated with sMer and sTyro3 levels. Patients with nephritis and those with focal or diffuse proliferative glomerulonephritis had these protein levels similar to healthy controls and patients without renal involvement. sTyro3 levels of JSLE patients taking glucocorticoid were decreased, and correlated with Gas6 and sAxl, while Gas6 levels correlated with age upon enrollment. JIA controls had protein levels similar to healthy controls and JSLE patients. Conclusions This study reinforces that sMer is increased in active JSLE patients, yet sMer and sAxl correlates with disease activity parameters, and their alterations are disease-specific. However, further studies are needed to determine exact roles of sTyro3 and Gas6 in disease pathogenesis. (AU)

• FAPESP's process: 12/22997-4 - Evaluation of apoptosis related proteins in lymphocytes, monocytes and NK cells from patients with juvenile systemic lupus erythematosus
• Grantee: Bernadete de Lourdes Liphaus
• Support Opportunities: Regular Research Grants
• FAPESP's process: 08/58238-4 - Autoimmunity in children: investigation of the molecular and cellular bases of early onset of autoimmunity
• Grantee: Magda Maria Sales Carneiro-Sampaio
• Support Opportunities: Research Projects - Thematic Grants