Magnetic resonance enterography is feasible and reliable in multicenter clinical trials in patients with Crohn's disease, and may help select subjects with active inflammation

BACKGROUND

Reliable tools for patient selection are critical for clinical drug trials.

AIM

To evaluate a consensus-based, standardised magnetic resonance enterography (MRE) protocol for selecting patients for inclusion in Crohn's disease (CD) multicenter clinical trials.

METHODS

This study recruited 20 patients [Crohn's Disease Activity Index (CDAI) scores: <150 (n = 8); 150-220 (n = 4); 220-450 (n = 8)], to undergo ileocolonoscopy and two MREs (with and without colonic contrast) within a 14-day period. Procedures were scored centrally using, Magnetic Resonance Index of Activity (MaRIA), and both Crohn's Disease Endoscopic Index of Severity (CDEIS) and Simplified Endoscopic Score (SES-CD).

RESULTS

37 MREs were acquired. Both MREs were evaluable in 16 patients for calculation of test-retest and inter-reader reliability scores. The MaRIA scores for the terminal ileum had excellent test-retest and inter-reader reliability, with correlations >0.9. The proximal ileum showed strong within-reader agreement (0.90-0.96), and fair between-reader agreement (0.59-0.72). MRE procedures were tolerable. MaRIA scores correlated with CDEIS and SES-CD (0.63 and 0.71), but not with CDAI (0.34). MRE identified 3 patients with intra-abdominal complications, who would otherwise have been included in clinical trials. Furthermore, both MRE and ileocolonoscopy identified active bowel wall inflammation in 2 patients with CDAI <150, and none in 1 patient with CDAI > 220. Data quality was good/excellent in 85% of scans, and fair or better in 96%.

CONCLUSIONS

Magnetic resonance enterography of high-quality and reproducibility was feasible in a global multi- centre setting, with evidence for improved selectivity over CDAI and ileocolonoscopy in identifying appropriate CD patients for inclusion in therapeutic intervention trials.

Prominent vascular endothelial proliferation in clinically aggressive neuroblastoma

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Background: Tumor blood vessels are disorganized and vascular endothelial cell proliferation (VEP) has been identified as a poor prognosticator in many adult cancers. To determine the clinical significance of VEP in neuroblastoma (NB), we evaluated blood vessel architecture in tumor sections from 51 children diagnosed at Children's Memorial Hospital, Chicago (CMH) and in 154 NB tumors on a Tissue Microarray (TMA) constructed at Children's Hospital of Philadelphia (CHOP). Methods: H&E-stained tumor sections were examined for the presence of structurally abnormal vessels and further characterized by immunostaining with anti-CD31 and von Willebrand factor (vWF) antibody to highlight endothelial cells. Tumors that contained vessels with disorganized walls and more than one endothelial cell layer were classified as VEP positive. Tumor sections that contained only thin walled vessels with no more than one layer of endothelial cells were classified as VEP negative. Associations between VEP and established clinico-pathologic features and outcome were assessed. Results: In the CHOP series, VEP was associated with high-risk group classification and MYCN amplification (p<0.001 and p=0.006). In the CMH series only 5 of the 10 children with MYCN amplification had VEP but 4 of these 5 patients have died, while there were no deaths in the subset of patients with MYCN amplified tumors that lacked VEP (n=5). In both study groups, VEP was significantly associated with Schwannian stroma-poor histology (CMH series: p=0.008; CHOP series: p<0.001) and decreased survival probability (CMH series: p=0.017; CHOP series: p= 0.014). Conclusions: The association between structurally abnormal vessels and poor outcome provides further support for the concept that angiogenesis plays an important role in determining the biologic behavior of NB tumors. Our results also indicate that angiogenesis is regulated differently in Schwannian stroma-rich versus stroma-poor NB tumors. Further studies investigating the activity of angiogenic inhibitors in children with clinically aggressive stroma-poor NB are warranted.

No significant financial relationships to disclose.

In vivo and in vitro cytogenetic damage induced by sodium nitrite

The mutagenicity of sodium nitrite was assayed by in vivo and in vitro experiments. The in vivo experiments were carried out in male rats and mice intragastrically treated twice, with an interval of 24 h, with nitrite in doses of 1.72, 5.18, 15.55 and 46.66 mg/kg body weight and in male rabbits treated with the same doses of nitrite administered daily in drinking water for 3 months. Chromosomal aberration analysis was conducted in all 3 species of animals and micronucleus induction was only evaluated in mice. Nitrite induced increases in aberrant metaphases in all 3 species of animals. Likewise, in mice it induced increases of the numbers of micronucleated polychromatic erythrocytes and a light bone marrow depression. Neither in the increases of the numbers of chromosomal aberrations nor in that of micronuclei, were dose-related responses observed. The in vitro experiments were carried out on BSC-1 and HeLa cells grown in cultures with nitrite in doses of 0.265 and 0.530 mg/ml for 24 h. Both doses produced significant increases of the percentage of chromosomal aberrations but also without demonstration of positive dose-effect relationships.

Genetic damage induced by an occupational complex and prolonged chemical exposure

Some results of a study on the clastogenicity of chemicals in vivo are reported. The chromosomes in lymphocytes from whole blood cultures were studied in 60 subjects permanently exposed for about 6 years to several occupational chemicals acting concomitantly, and in 5 controls. The exposed subjects showed an increase in the rate of chromosomal aberrations as compared to controls.

In vivo cytogenetic screening for determination of the mutagenic potential of cyclophosphamide

Among the in vivo cytogenetic tests employed for chemically induced mutagenicity, a recent screening method was selected - the micronucleus test. The micronuclei were investigated, comparatively with chromosome breaks, on the bone marrow of Wistar rats after intraperitoneal administration of different doses of Cyclophosphamide (CY) applied in one or two injections at 24 hrs interval. The good relationship between these two tests was proved in evaluation of cytogenetic risk.