No association was observed between sRAGE levels and age or duration of disease. Available report indicates that serum sRAGE may increase in patients with impaired renal function [37]. Tan et al. [38] demonstrate that serum sRAGE associate with the severity of nephropathy in patients with type 2 diabetes. In the present study, the difference of plasma sRAGE between patients with normal and lower eGFR

was not statistical significant in lupus nephritis. The associations between sRAGE and clinical features of SLE need to be further elucidated with large size of patients. Several studies have shown that sRAGE levels can be modulated by different Idasanutlin concentration therapeutic treatment [39–41]. Pullerits et al. also reported that a significantly higher sRAGE level was found in synovial fluid of RA patients treated with methotrexate as compared with patients without disease-modifying or antirheumatic treatment.

However, the difference in the blood sRAGE level was not statistically different [31]. In the present study, patients with SLE receiving antilupus treatment showed comparable plasma sRAGE levels Protein Tyrosine Kinase inhibitor with untreated patients, whereas patients receiving short-term treatment showed an immediate decrease in plasma sRAGE levels. We compared the plasma sRAGE levels before and after 5 days treatment in five patients and found that sRAGE levels were decreased in all these patients after treatment. Notably, we found that patients with SLE receiving treatment

for short period (<1 month) had even lower plasma levels of sRAGE compared with untreated patients. In contrast, in patients treated for longer period (>1 month), sRAGE levels were increased in comparison to those with short-period Staurosporine treatment. Therefore, the immediate and long-term therapeutic treatment had different effect on the plasma level of sRAGE in patients with SLE, suggesting that sRAGE may play different roles in the initiation and progression stage of the disease. Alternatively, a compensating mechanism related to sRAGE production and regulation may evolve during the process of antilupus treatment. Autoantibody production is an important characteristic of SLE. However, the relationship between autoantibodies and sRAGE levels in SLE has not been reported. We demonstrated that SLE patients with negative ANA had comparable sRAGE level with ANA-positive patients. Moreover, in patients positive for anti-dsDNA, AnuA, anti-Sm, plasma sRAGE levels were not statistically different to their negative counterparts. These results indicated that sRAGE level was not correlated with the production of autoantibodies. RAGE has been implicated in leucocyte migration. Chavakis et al. [42] reported that cell-bound RAGE functioned as a counter-receptor for leucocyte integrin Mac-1 and was directly involved in leucocyte recruitment. In this context, sRAGE has been suggested to function as a potential inhibitor of leucocyte recruitment.