Elevated Serum Levels of the Antiapoptotic Protein Decoy-Receptor 3 Are Associated with Advanced Liver Disease.

Background. Decoy-receptor 3 (DcR3) exerts antiapoptotic and immunomodulatory function and is overexpressed in neoplastic and inflammatory conditions. Serum DcR3 (sDcR3) levels during the chronic hepatitis/cirrhosis/hepatocellular carcinoma (HCC) sequence have not been explored. Objective. To assess the levels and significance of sDcR3 protein in various stages of chronic liver disease. Methods. We compared sDcR3 levels between healthy controls and patients with chronic viral hepatitis (CVH), decompensated cirrhosis (DC), and HCC. Correlations between sDcR3 levels and various patient- and disease-related factors were analyzed. Results. sDcR3 levels were significantly higher in patients with CVH than in controls (P < 0.01). sDcR3 levels were elevated in DC and HCC, being significantly higher compared not only to controls (P < 0.001 for both) but to CVH patients as well (P < 0.001 for both). In addition, DcR3 protein was detected in large quantities in the ascitic fluid of cirrhotics. In patients with CVH, sDcR3 significantly correlated to fibrosis severity, as estimated by Ishak score (P = 0.019) or by liver stiffness measured with elastography (Spearman r = 0.698, P < 0.001). In cirrhotic patients, significant positive correlations were observed between sDcR3 levels and markers of severity of hepatic impairment, including MELD score (r = 0.653, P < 0.001). Conclusions. Circulating levels of DcR3 are elevated during chronic liver disease and correlate with severity of liver damage. sDcR3 may serve as marker for liver fibrosis severity and progression to end-stage liver disease.

Comparative study of candidate housekeeping genes for quantification of target gene messenger RNA expression by real-time PCR in patients with inflammatory bowel disease.

BACKGROUND: Mucosal expression of immunological mediators is modified in inflammatory bowel disease (IBD). Quantification of target gene messenger RNA (mRNA) transcripts depends on the normalization to a housekeeping or reference gene. Stability of housekeeping gene expression is critical for the accurate measurement of transcripts of the target gene. No studies have addressed the optimization of reference gene performance for mRNA studies in healthy intestinal mucosa and during mucosal inflammation. METHODS: RNA was extracted from endoscopically obtained intestinal biopsies from healthy control subjects and patients with active IBD or non-IBD inflammatory diseases. Comparative analysis of 10 candidate housekeeping genes for quantitative real-time PCR was carried out according to predefined criteria, including use of the Web-based RefFinder platform. RESULTS: We demonstrate that intestinal inflammation may significantly affect the stability of mucosal expression of housekeeping genes. Commonly used controls, such as glyceraldehyde-3-phosphate dehydrogenase, ß-actin, or ß2-microglobulin displayed high variability within the control group and/or between the healthy and inflamed mucosae. In contrast, we have identified novel genes with optimal stability, which may be used as appropriate housekeeping controls. The ribosomal proteins encoding genes (RPLPO and RPS9) were the most stable because their expression was not affected by interindividual differences, the presence of inflammation, or intestinal location. Normalization ofthe mRNA expression of mucosal tumor necrosis factor-α was highly dependent on the specific reference gene and varied significantly when normalized to genes with high or low stability. CONCLUSIONS: Validation for optimal performance of the housekeeping gene is required for target mRNA quantification in healthy intestine and IBD-associated lesions. Suboptimal reference gene expression may explain conflicting results from published studies on IBD gene expression.