Neutrophil extracellular traps-associated markers are elevated in patients with systemic lupus erythematosus.

Neutrophil extracellular traps (NETs) are the main source of autoantigens in systemic lupus erythematosus (SLE). The aim of this study was to evaluate the clinical importance of NETs-associated markers in SLE. We compared NETs-associated markers in SLE patients (n = 111) with healthy controls (n = 50). Moreover, in 35 patients with drug-naïve SLE (n = 35), we investigated correlation between NETs-associated markers [DNase I concentration, myeloperoxidase (MPO) activity, anti-MPO antibodies, cell-free DNA (cfDNA), NETolytic activity] with serological parameters [anti-dsDNA antibodies, C3, C4 and B-cell activating factor (BAFF) levels] and disease activity measured by modified SLE Disease Activity Index (M-SLEDAI-2K). In comparison with healthy controls, SLE patients had higher cfDNA, MPO activity, anti-MPO antibodies (p < 0.001), BAFF and DNase I concentration (p < 0.01). Contrary, NETolytic activity was lower in SLE patients (p < 0.05), despite higher concentration of DNase I. MPO activity and cfDNA levels showed correlation with DNase I concentration (p < 0.001, p < 0.01, respectively). BAFF levels correlated with cfDNA, DNase I concentration and MPO activity (p < 0.05). Anti-dsDNA antibodies showed correlation with MPO activity (p < 0.01), cfDNA and BAFF levels (p < 0.001). Anti-dsDNA and C3 levels were independent predictors of M-SLEDAI-2K in multivariate analysis (p < 0.01). We demonstrated that sera of SLE patients have decreased NETolytic activity, leading to increased levels of various NETs-associated markers, which correlate with anti-dsDNA antibodies in drug-naïve SLE. We showed that BAFF participates in a complex relationship between NETosis and anti-dsDNA antibodies production. These findings have important implications for a better understanding of SLE pathogenesis and development of therapy that inhibits NETs persistence and disease progression.

Cell-free DNA as biomarker and source for mutation detection in primary colorectal cancer.

PURPOSE: To analyze if cell-free (cf)DNA levels and the presence of KRAS and BRAF mutations in serum could be used as diagnostic biomarkers in patients with primary colorectal cancer (CRC). METHODS: This study included 92 individuals who were operated due to primary CRC (N=52;study group) and to hemorrhoids (N=40;control group). Serum cfDNA levels were measured with real-time PCR (RT-PCR) using PicoGreen dsDNA quantitation reagent. Colorectal tissue and related blood and serum samples taken at the time of surgery were subjected to DNA extraction and analysis of KRAS and BRAF mutations based on multiplex SNaPshot assay and DNA sequencing. RESULTS: The average cfDNA concentration was lower in patients of the study group (20±7 ng/µL) in comparison to controls (34±9 ng/µL) and this difference was statistically significant (p<0.001). The SNaPshot analysis detected KRAS c35 mutations in colorectal tumor tissue in 14 cases, but the presence of the mutation was not confirmed in cfDNA extracted from blood samples of these patients. CONCLUSIONS: The level of serum cfDNA in CRC is decreased in comparison to patients with hemorrhoids, which questions the usefulness of cfDNA as cancer biomarker. Also, cfDNA does not appear to be suitable as a source for mutation detection in this disease.