Based on the limited number of patients the clinical efficacy of SLIT was not statistically different from SCIT, and both treatments are clinically effective compared with placebo in the treatment of birch pollen rhinoconjunctivitis. The lack of significant difference between the two treatments does not indicate equivalent efficacy, but to detect minor differences necessitates investigation of larger groups. Due to the advantageous safety profile SLIT may be favored.

Background: Fistulae are a troublesome complication of Crohn's disease but little is known of the final effector molecules responsible for matrix degradation. Although matrix metalloproteinases (MMPs) have been strongly implicated in tissue injury in Crohn's disease, their role in fistula formation is unknown. Aim: To determine the expression pattern of MMPs and tissue inhibitors of metalloproteinases (TIMPs) in fistulae of patients with Crohn's disease. Patients and methods: Resected fistula specimens were obtained from patients with Crohn's disease (n = 11) and classified according to the predominant histological features-that is, acute versus chronic inflammation. Patients with fistulae due to other diseases (n = 9) and normal colon (n = 5) served as controls. MMP and TIMP protein expression was measured by single or double labelled immunohistochemistry, and mRNA expression by in situ hybridisation. MMP activity was measured by gelatin zymography. Results: Compared with normal colon, strong MMP-3 expression was consistently observed in fistulae in Crohn's disease, irrespective of the stage of inflammatory activity. MMP-3 transcripts and protein were localised in large mononuclear cells and fibroblasts. MMP-9 transcripts and protein were expressed in granulocytes and only in fistulae with acute inflammation. Staining for MMP-1 and MMP-7 was weak and negative for MMP-10, whereas MMP-2 was equally expressed in normal colon and fistulae. TIMP-1, TIMP-2, and TIMP-3 expression was low in all samples. Similar expression patterns were found in fistulae of the disease control group. Fistulae also expressed active MMP-2 and MMP-9, as measured by gelatin zymography. Conclusion: MMP-3 and MMP-9 are markedly upregulated in intestinal fistulae and may contribute to fistula formation through degradation of the extracellular matrix, irrespective of the underlying disease process.

Background and aims: Expression of inducible nitric oxide synthase (iNOS) is greatly upregulated in the colonic mucosa of patients with collagenous and ulcerative colitis. As the transcription factor nuclear factor kB (NFkB) is a major inducer of iNOS gene expression, we compared activation and transcriptional activity of NFkB in colonic mucosal biopsies from these patients. Patients: Eight patients with collagenous colitis, six with relapsing ulcerative colitis, and eight with uninflamed bowel were studied. Methods: NFkB DNA binding activity was assessed by electrophoretic mobility shift assay and inhibitor of NFkB (IkB) kinase (IKK) activity by immunocomplex kinase assay. In vivo recruitment of NFkB to the iNOS promoter was determined by chromatin immunoprecipitation analysis and transcriptional activity by NFkB gene expression profiling arrays. Cells showing NFkB activation were identified by immunohistochemistry. Results: In collagenous and ulcerative colitis, as opposed to uninflamed bowel, IKKb activity and strong NFkB DNA binding gave rise to activation of identical NFkB subunits and recruitment of transcriptionally active p65 to the iNOS promoter. In collagenous colitis, activated NFkB was observed only in epithelial cells while up to 10% of lamina propria macrophages showed activation in ulcerative colitis. Conclusions: In collagenous and ulcerative colitis, colonic mucosal NFkB is activated and recruited to the iNOS promoter in vivo via an IKKb mediated pathway. As collagenous colitis is not associated with tissue injury, these data challenge the prevailing view that activation of NFkB per se mediates tissue injury. Our results suggest that downstream inflammatory reactions leading to tissue damage originate in lamina propria immune cells, as increased NFkB activity in collagenous colitis was localised solely in epithelial cells, but present also in macrophages in ulcerative colitis.

Recent studies have characterized the ABC half-transporter associated with mitoxantrone resistance in human cancer cell lines. Encoded by the ABCG2 gene, overexpression confers resistance to camptothecins, as well as to mitoxantrone. We developed four polyclonal antibodies against peptides corresponding to four different epitopes on the mitoxantrone resistance-associated protein, ABCG2. Three epitopes localized on the cytoplasmic region of ABCG2 gave rise to high-affinity antibodies, which were demonstrated to be specific for ABCG2. Western blot analysis of cells with high levels of ABCG2 showed a single major band of the expected 72-kDa molecular size of ABCG2 under denaturing conditions. Immunoblot analysis performed under non-reducing conditions and after treatment with cross-linking reagents demonstrated a molecular weight shift from 72 kDa to several bands of 180 kDa and higher molecular weight, suggesting detection of dimerization products of ABCG2. Evidence of N-linked glycosylation was also obtained using tunicamycin and N-glycosidase F. Finally, both by light, fluorescence and electron microscopic immunohistochemical staining, we demonstrate cytoplasmic and predominantly plasma membrane localization of ABCG2 in cell lines with high levels of expression. Plasma membrane staining was observed on the surface of the chorionic villi in placenta. These results support the hypothesis that ABCG2 is an ABC half-transporter that forms dimers in the plasma membrane, functioning as an ATP-dependent outward pump for substrate transport.