The S100 proteins expression in newly diagnosed systemic lupus erythematosus patients: Can they be potential diagnostic biomarkers?

Abstract

BackgroundThe S100 proteins are a unique class of calcium-binding proteins that play an essential role in promoting the inflammatory and anti-inflammatory responses under normal and pathological conditions such as systemic lupus erythematosus (SLE). Therefore, the present research aimed to measure mRNA expression of S100A4, S100A8, S100A9, and S100A12 as target genes of the study and evaluation of their diagnostic potentiality in the SLE patients. MethodsTwenty-three newly diagnosed SLE patients diagnosed and selected by an expert rheumatologist were enrolled based on American College of Rheumatology (ACR) criteria as well as 30 healthy age and sex-matched subjects. Following peripheral blood collection from the subjects, the mRNA level of target genes was measured in isolated leukocytes by the real-time polymerase chain reaction (RT-PCR). ResultsThe findings of this study showed that the mRNA level of target genes was higher in SLE patients compared to healthy subjects; however, only gene expression of S100A12 raised significantly. Moreover, the results of the receiver operating characteristics (ROC) curve showed that among the studied genes, S100A12 was highly sensitive to the diagnosis of patients with SLE from the healthy subjects (specificity: 0.80, sensitivity; 0.75, area under the curve (AUC): 0.79). On the other hand, we observe that there was no significant correlation between the expression of target genes and disease activity. ConclusionRegarding the findings of this study, it can be concluded that S100A12 might be involved in SLE pathogenesis. Also, this molecule may be considered as a potential biomarker candidate for the early detection of SLE. However, further studies are needed to confirm this claim.