Human and murine studies showed that GM-CSF exerts beneficial effects in intestinal inflammation. To explore whether GM-CSF mediates its effects via monocytes, we analyzed effects of GM-CSF on monocytes in vitro and assessed the immunomodulatory potential of GM-CSF–activated monocytes (GMaMs) in vivo. We used microarray technology and functional assays to characterize GMaMs in vitro and used a mouse model of colitis to study GMaM functions in vivo. GM-CSF activates monocytes to increase adherence, migration, chemotaxis, and oxidative burst in vitro, and primes monocyte response to secondary microbial stimuli. In addition, GMaMs accelerate epithelial healing in vitro. Most important, in a mouse model of experimental T cell–induced colitis, GMaMs show therapeutic activity and protect mice from colitis. This is accompanied by increased production of IL-4, IL-10, and IL-13, and decreased production of IFN-γ in lamina propria mononuclear cells in vivo. Confirming this finding, GMaMs attract T cells and shape their differentiation toward Th2 by upregulating IL-4, IL-10, and IL-13 in T cells in vitro. Beneficial effects of GM-CSF in Crohn’s disease may possibly be mediated through reprogramming of monocytes to simultaneously improved bacterial clearance and induction of wound healing, as well as regulation of adaptive immunity to limit excessive inflammation.

In the present study, we combined the PCR-clamping approach with melting curve analysis using mutant specific hybridisation probes and wild-type specific peptide nucleic acids (PNAs) to determine the genotypes of the most frequent point mutation in codon 12 of the proto-oncogene Ki-ras in tissue and plasma samples of patients with pancreatic cancer. The sensitivity of our assay was 1–5 × 10⁻⁵. The melting curve analysis of tissue samples of four patients revealed two valine mutations, one none-valine mutation and one wild-type sequence. Ki-ras alterations were found in 28% of DNAs (18 out of 64) of nonrelated plasma samples of 10 patients with ductal adenocarcinoma of the pancreas. The valine mutation was the predominantly detected gene alteration (83%). Out of ten patients investigated, four patients (40%) became positive during clinical observation with respect to Ki-ras mutation. All four patients exhibited progressive disease and high levels of tumour marker CA 19-9. In conclusion, the one-step procedure discribed may be a useful clinical tool for analysing Ki-ras point mutations in tissue and plasmas samples. In addition, this method can be adapted for simultanous detection of multiple mutations and quantitation.

Prediction of inflammatory bowel disease relapse has important implications for therapeutic strategies. Fecal S100A12 has been reported as a novel marker of intestinal inflammation. The objective was to investigate the utility of S100A12 as a marker for the confirmation of stable remission and prediction of relapses. We consecutively included 147 adults and 34 children with Crohn's disease (n = 61) or ulcerative colitis (n = 120). Over a 3-year period, we collected 686 stool samples and 861 serum samples during regular follow-up visits. S100A12 and calprotectin levels were measured by an enzyme-linked immunoassay. Fecal S100A12 correlated with S100A12 serum levels, other laboratory markers, as well as disease activity, location, and behavior. Fecal S100A12 levels in the relapse group differed significantly from those of the nonrelapse group. A baseline fecal S100A12 level of >0.5 mg/kg was significantly associated with disease relapse within 18 months. Time course analysis of fecal S100A12 before and after relapse showed a clear increase of S100A12 concentrations up to 6 months before clinical relapse. At 0.43 mg/kg, the sensitivity and specificity of S100A12 for predicting relapse already 8 to 12 weeks earlier were 70% and 83%, respectively. Regular measurements of fecal S100A12 levels reliably detect inflammatory bowel disease relapse at an early stage, which makes the test a promising noninvasive tool for monitoring and optimizing therapy, and may reduce the need for invasive investigations during disease follow-up.

Irritable bowel syndrome (IBS) is a common functional gastrointestinal (GI) disorder characterized by unspecific symptoms. In clinical practice it is crucial to distinguish between non-inflammatory functional problems and inflammatory, malignant or infectious diseases of the GI tract. Differentiation between these involves the use of clinical, radiological, endoscopic, histological and serological techniques, which are invasive, expensive, time-consuming and/or hindered by inaccuracies arising from subjective components. A range of faecal markers now appears to have the potential to greatly assist in the differentiation of inflammatory bowel disease (IBD) and IBS. Faecal markers of neutrophil influx into the mucosa are reliable indicators of intestinal inflammation and their role has been mainly studied in discriminating IBD from non-IBD conditions (including IBS) rather than organic from non-organic diseases. Phagocyte-specific proteins of the S100 family (S100A12, calprotectin) are amongst the most promising faecal biomarkers of inflammation. Faecal leukocyte degranulation markers (lactoferrin, polymorphonuclear elastase and myeloperoxidase) have also been suggested as diagnostic tools for the differentiation of IBD and IBS. More recently, additional proteins, including granins, defensins and matrix-metalloproteases, have been discussed as differential diagnostic markers in IBD and IBS. In this review, some of the most promising faecal markers, which have the potential to differentiate IBD and IBS and to advance diagnostic practices, will be discussed.

Objective: We followed up the presence of Kirsten rat sarcoma (K-ras) mutations in plasma DNA and assessed its clinical value in patients with pancreatic cancer. Methods: Plasma samples (N = 430) of 56 patients with pancreatic cancer and 13 patients with pancreatitis were analyzed by real-time polymerase chain reaction using peptide nucleic acid-mediated polymerase chain reaction clamping. Results: K-ras mutations could be detected in the plasma DNA of 20 patients with cancer (36%). No K-ras mutation was found in the plasma of patients with pancreatitis. In 7 (35%) of 20 patients with lowly or moderately elevated carbohydrate antigen 19.9 (CA 19-9) levels lower than 100 U/mL, the result of the assay was positive for K-ras mutation. The combination of K-ras and CA 19-9 level determination gave a sensitivity for the diagnosis of pancreatic cancer of 91% (40/44) of the patients. Thirteen of 35 patients with pancreatic cancer (102 plasma samples) with elevated CA 19-9 levels (>35 U/mL) and altered K-ras gene showed significant correlation with elevated CA 19-9 levels (P=0.048). Conclusions: The summary of our approach of noninvasive, convenient, extremely high-sensitive K-ras mutation analysis in plasma might provide diagnostic and prognostic information to clinicians but will not be sufficient in a standardized early diagnosis of pancreatic carcinoma. The combination with CA 19-9 assay is useful for detection and prognostic evaluation of pancreatic carcinoma.