Role of syndecan-1 (CD138) in Egyptian systemic lupus erythematosus patients with lupus nephritis: Relation to disease activity

Abstract

BackgroundSyndecan-1, a transmemebrane heparan-sulfate glycoprotein, is predominantly expressed by plasma cells and is readily shed and released under certain pathologic conditions and remains biologically active to plasma cells behaviour. Aim of the workTo assess the level of syndecan-1 in relation to lupus nephritis (LN) and systemic lupus erythematosus (SLE) activity. Patients and methodsThe study included 60 SLE patients subgrouped according to the presence of LN and activity. SLE disease activity index (SLEDAI) was assessed. Serum syndecan-1 level was measured. ResultsThe patients mean age was 25.9 ± 8.6 years, they were 54 females and 6 males with a disease duration of 3.8 ± 3.4 years. There was a significant difference in the level of syndecan-1 between healthy control (46.3 ± 12.2 ng/ml) and SLE patients whether they were with active LN (150.2 ± 31.1 ng/ml) (p < 0.001), extrarenal flare (86.9 ± 16.7 ng/ml) (p < 0.001) or inactive (79.1 ± 19.8 ng/ml) (p < 0.003). Syndecan-1 was significantly higher in patients with active LN compared to those with extrarenal flare and inactive disease (p < 0.001 and p < 0.001 respectively). Serum syndecan-1 level was significantly higher in patients with arthralgia, arthritis, pleurisy and pericarditis) (all p < 0.001). There was a significant correlation between syndecan-1 level and 24 h urinary proteins (r = 0.8, p < 0.0001), and inversely with the complement (C3: r = −0.54, p < 0.0001 and C4: r = −0.48, p < 0.0001). There was a significant correlation between syndecan-1 and SLEDAI (r = 0.68, p < 0.001). ConclusionSerum syndecan-1 is significantly high in active LN patients and can be a useful tool for diagnosis of active nephritis. It correlates with disease activity, consumed complement and proteinuria. It was significantly related to the presence of musculoskeletal manifestations and serositis.