Study On The Association Between Tumor Necrosis Factor (TNF)-like Weak Inducer Of Apoptosis And Systemic Lupus Erythematosus

Objective The aim of this study was to compare the mRNA and serum expression of Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) in patients with systemic lupus erythematosus (SLE) and healthy controls.Methods SLE patients were in- and out-patients of the Rheumatology Department in the Anhui Provincial Hospital. Age and sex-matched healthy controls were recruited at the second Affiliated Hospital, Anhui Medical University. Diagnosis of SLE was established according to the 1997 revised criteria of American College Rheumatology (ACR). Disease activity was evaluated using the SLE Disease Activity Index (SLEDAI) score. 62 patients and 15 healthy controls were recruited in the study. TWEAK messenger RNA (mRNA) expression in PBMC from 33 of 62 patients was detected by relative quantitation FQ-PCR. TWEAK concentrations in serum of all 62 patients were measured by Enzyme linked immunosorbent assay (ELISA).The data were analyzed by the SPSS 10.01 software. Quantitative variables were described using mean±SD. Data in which variables demonstrated nonparametric distributions were expressed as median with interquartile range (IQR), and analyzed by Mann-Whitney U test for unpaired samples. Other data were analyzed with Student's t test for unpaired values to compare differences between different control cultures. Pearson correlation or Spearman correlation were used to analyze the correlation between two continuous variables. A p value < 0.05 was considered statistically significant.Results TWEAK mRNA expressions in PBMC were decreased in SLE patients compared with healthy controls (P=0.001). Lower TWEAK mRNA expression was also found in the active SLE patients when compared to inactive counterparties (P=0.025). However, there is no significant difference between LN patients and non-LN SLE patients (P=0.614). The serum level of TWEAK (sTWEAK) in SLE patients was increased when compared to healthy controls (P<0.001). In addition, the sTWEAK level was higher in SLE patients with vasculitis than that in SLE patients without vasculitis (P=0.002), the same was true in comparison between patients with and without headache (P=0.024). Nevertheless, no significant differences were found between active SLE patients and inactive patients (P=0.961), as well as between LN patients and non-LN SLE patients (P=0.989).Conclusions In our study, SLE patients express reduced TWEAK mRNA but elevated level of sTWEAK, in addition, sTWEAK level was associated with several clinical manifestations of SLE, indicating that TWEAK may play a complex role in SLE.