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Background: Is the patient really suffering from acute appendicitis? Right lower quadrant pain is the most common sign of acute appendicitis. However, many other bowels pathologies might mimic acute appendicitis. Due to fear of the consequences of delayed or missed diagnosis, the indication for emergency appendectomy is liberally made. This has been shown to be associated with high rates of negative appendectomy with risk of potentially serious or lethal complications. Thus there is need for a better preoperative screening of patients with suspected appendicitis. Methods: This prospective single center single-blinded pilot study was conducted in the Department of surgery at the HELIOS Universitätsklinikum Wuppertal, Germany. Calprotectin was measured in pre-therapeutic stool samples of patients presenting in the emergency department with pain to the right lower quadrant. Fecal calprotectin (FC) values were analyzed using commercially available ELISA kits. Cut-off values for FC were studied using the receiver-operator characteristic (ROC) curve. The Area under the curve (AUC) was reported for each ROC curve. Results: The mean FC value was 51.4 ± 118.8 μg/g in patients with AA, 320.9 ± 416.6 μg/g in patients with infectious enteritis and 24.8 ± 27.4 μg/g in the control group. ROC curve showed a close to 80% specificity and sensitivity of FC for AA at a cut-off value of 51 μg/g, AUC = 0.7. The sensitivity of FC at this cut-off value is zero for enteritis with a specificity of 35%. Conclusion: Fecal calprotectin could be helpful in screening patients with pain to the right lower quadrant for the presence of acute appendicitis or infectious enteritis with the aim of facilitating clinical decision-making and reducing the rate of negative appendectomy. [ABSTRACT FROM AUTHOR]

Background: Epigenetic signatures are highly cell type specific. Separation of distinct cell populations is therefore desirable for all epigenetic studies. However, to date little information is available on whether separation protocols might influence epigenetic and/or gene expression signatures and hence might be less beneficial. We investigated the influence of two frequently used protocols to isolate intestinal epithelium cells (IECs) from 6 healthy individuals. Materials and Methods: Epithelial cells were isolated from small bowel (i.e. terminal ileum) biopsies using EDTA/DTT and enzymatic release followed by magnetic bead sorting via EPCAM labeled microbeads. Effects on gene/mRNA expression were analyzed using a real time PCR based expression array. DNA methylation was assessed by pyrosequencing of bisulfite converted DNA and methylated DNA immunoprecipitation (MeDIP). Results: While cell purity was >95% using both cell separation approaches, gene expression analysis revealed significantly higher mRNA levels of several inflammatory genes in EDTA/DTT when compared to enzymatically released cells. In contrast, DNA methylation of selected genes was less variable and only revealed subtle differences. Comparison of DNA methylation of the epithelial cell marker EPCAM in unseparated whole biopsy samples with separated epithelium (i.e. EPCAM positive and negative fraction) demonstrated significant differences in DNA methylation between all three tissue fractions indicating cell type specific methylation patterns can be masked in unseparated tissue samples. Conclusions: Taken together, our data highlight the importance of considering the potential effect of cell separation on gene expression as well as DNA methylation signatures. The decision to separate tissue samples will therefore depend on study design and specific separation protocols. [ABSTRACT FROM AUTHOR]