Differences in P-glycoprotein-170 expression and activity between Crohn's disease and ulcerative colitis

The clinical benefit of Cyclosporine A (CsA) in IBD is controversial. Drugs including CsA are substrates of the P-glycoprotein-170 (Pgp-170) cell surface pump. Although the mechanism of action of CsA is complex, we determined that Pgp-170 might be expressed differentially between these two diseases. Intra-epithelial, lamina propria and peripheral blood lymphocytes were stained with the antibody MRK-16, which recognizes the surface antigen Pgp-170. Functional activity was assayed using a Rhodamine dye efflux assay (Rh123). RT-PCR was used to detect Pgp-170 mRNA. Overall, less P-gp-170 surface expression was found on UC CD3+ intestinal lymphocytes compared to controls and Crohn's disease. A decrease in Pgp-170 activity was also measured using the Rh123 functional assay. Fewer CD8+ intraepithelial lymphocytes (IEL) (which intrinsically have more Pgp-170 function) were also found in UC. Furthermore, UC IEL P-gp expression was under the limit of detection by RT-PCR. Overall, greater and differential expression, function and mRNA for Pgp-170 was found in Crohn's disease compared to the UC and normal tissues analyzed.

The clinical experience of antisense therapy to ICAM-1 in Crohn's disease

ISIS-2302 is a 6781.24 amu molecular weight antisense molecule. Its sequence is 5'-GCCCAAGCTGGCATCCGTCA-3'. This 20 base phosphorothioate hybridizes to a sequence in the 3' untranslated region of human ICAM-1 mRNA. This substrate is cleaved by RNase H, resulting in specific message and protein reduction 11,21.

Clinical validation of the Helikit: a 13C urea breath test used for the diagnosis of Helicobacter pylori infection

OBJECTIVE

To assess the clinical performance of the Helikit, a 13C urea breath test, in the diagnosis of Helicobacter pylori infection.

METHODS

A total of 205 participants were assessed in Canada and Korea for H. pylori infection status by endoscopy, or a combination of IgG ELISA and CLO test, as well as by the Helikit. The Helikit contains 75 mg of 13C urea as well as citric acid, flavor enhancers and stabilizers in a single plastic cup. The powder is dissolved in 75 mL of water for oral administration. No extra mixing or dilution steps are required.

RESULTS

Using the biopsy-derived data as the gold standard the Helikit displayed a clinical sensitivity of 93.5% (95% confidence interval 88.5 to 98.5%) and a clinical specificity of 97.3% (94.3 to 100%). An overall diagnostic efficiency of 95.6% (92.8 to 98.4%) was obtained. No statistically significant difference in the performance characteristics was found between Korea and Canada. No significant adverse events were noted.

CONCLUSIONS

The Helikit offers an easy, safe and accurate approach to the diagnosis of H. pylori infection.

Multiple sclerosis patients have peripheral blood CD45RO+ B cells and increased intestinal permeability

Increased intestinal permeability and the CD45RO isoform expression of the leukocyte common antigen on peripheral blood CD20+ B cells are found in Crohn's disease. Others have observed that multiple sclerosis (MS) patients may have an increased risk of coacquisition of Crohn's disease. The aim of this study was to identify an association between these diseases using peripheral blood CD45 isoform expression and intestinal permeability in MS. Lactulose/mannitol permeability and peripheral blood CD20+ B cell CD45RO expression were defined in healthy controls, MS patients, and patients coincidentally affected by MS and Crohn's or MS and ulcerative colitis (UC). Five of 20 MS patients had increased intestinal permeability, a finding not previously reported. High levels of CD45RO were found on circulating CD20+ B cells from patients with MS. This has not been reported previously in MS and is found in very few other conditions. Eight patients with coincident MS and Crohn's disease or MS and UC were studied. Coincident MS and UC patients expressed CD45RO on CD20+ B cells, a finding not identified in UC patients alone. A subgroup of MS patients has increased intestinal permeability. These patients express CD45RO CD20+ B cells, also found in Crohn's disease.