Background. Serum concentrations of soluble interleukin-7 receptor (sIL-7R) and anti-C1q antibody have recently been identified as unique serological markers for lupus nephritis (LN) in patients with systemic lupus erythematosus (SLE). In this study, we evaluated the correlation of serum sIL-7R and anti-C1q in SLE patients. Methods. Sera from 134 patients with SLE and 84 healthy cohorts were tested for levels of sIL-7R and anti-C1q antibodies in terms of ELISA. Correlations of the sIL-7R and anti-C1q autoantibodies were evaluated. Results. The serum concentrations of sIL-7R and anti-C1q antibodies were significantly higher in SLE patients and LN patients in comparison with healthy individuals/controls and SLE patients with non-LN, respectively. In addition, both sIL-7R and anti-C1q concentrations were found to significantly correlate with the SLE disease activity as evaluated by SLEDAI scores. Interestingly, the serum sIL-7R concentration was strongly correlated with the level of anti-C1q antibodies (r = 0.2871, p = 0.0008) but not statistically correlated with other serological markers, including the anti-dsDNA and complements C3 and C4 concentrations in SLE patients. Conclusion. Both serum sIL-7R and anti-C1q antibodies were strongly associated with disease activity and LN in SLE patients, suggesting that they may be reliable serological markers for identification of SLE patients with active diseases and LN.

An early diagnosis of lupus nephritis (LN) has an important clinical implication in guiding treatments of systemic lupus erythematosus (SLE) in clinical settings. In this study, the concentrations of Wnt-3A, Frizzled-8 (FZD-8), and Dickkopf-1 (DKK-1) of Wnt signaling, as well as their diagnostic values for accessing LN, were evaluated by ELISA in sera and urine of 111 SLE patients (31 with LN and 80 without LN) and 70 healthy cohorts. Significantly more abundances of DKK-1 protein were determined in both of sera and urine of SLE patients compared to healthy cohorts (p < 0.0001); in particular the serum DKK-1 concentration was even higher in LN-SLE patients relative to non-LN SLE subjects (p < 0.0001). Intriguingly, concentrations of above examined proteins in SLE patients showed no correlation between serum and urine. Moreover, a combination of DKK-1 with anti-dsDNA and/or levels of complement C3 and C4 could not increase the specificity and/or sensitivity for identification of patients with LN diseases, but both ROC curve and multiple-factor nonconditional logistic regression analysis showed that serum DKK-1 was considered better positive biomarker for identification of LN in SLE patients. These results imply that serum and/or urine DKK-1 may be a valuable and independent biomarker for identification of SLE patients with LN.

Objective. To investigate microRNA (miRNA) expression profiles in individuals with systemic lupus erythematosus (SLE) and identify the valuable miRNA biomarkers in diagnosing and monitoring SLE. Methods. Next-generation sequencing (NGS) was performed to assess miRNA amounts in peripheral blood mononuclear cells (PBMCs) from four SLE cases and four healthy controls. Quantitative polymerase chain reaction (qPCR) was carried out for validating candidate miRNAs in 32 SLE cases and 32 healthy controls. In addition, receiver operating characteristic (ROC) curve analysis was completed to evaluate diagnostic performance. Finally, the associations of candidate miRNAs with various characteristics of SLE were analyzed. Results. A total of 157 miRNAs were upregulated, and 110 miRNAs were downregulated in PBMCs from SLE cases in comparison to healthy controls, of which the increase of miR-183-5p and decrease of miR-374b-3p were validated by qPCR and both showed good diagnostic performance for SLE diagnosis. Besides, miR-183-5p expression levels displayed a positive association with SLE disease activity index (SLEDAI) and anti-dsDNA antibody amounts. Conclusion. Our data indicated that miR-183-5p is a promising biomarker of SLE.

The C allele at the rs631090 locus of C1q, the G allele at 1525A/G site of TRAIL, and the G allele of Tim-1 at -1454G/A site are susceptibility variants associated with SLE.

No abstract