Paolo Fociani

Small bowel stenosis in Crohn's disease: clinical, biochemical and ultrasonographic evaluation of histological features

Aim : To establish whether intestinal ultrasound, clinical or biochemical indices of activity can assess histological features of ileal stenosis in Crohns disease.

Creutzfeldt-Jakob disease: Carnoy's fixative improves the immunohistochemistry of the proteinase K-resistant prion protein.

The neuropathological diagnosis of Creutzfeldt‐Jakob disease relies on the immunohistochemical demonstration of the proteinase‐K resistant form of the prion protein (PrPres) in the brain tissue. The antigenicity of PrPres is strongly reduced by the formalin solution widely used to fix the tissue, thus the PrPres immunoreactivity is inconsistently detectable in formalin‐fixed tissue. A better PrPres immunostaining can be obtained by using Carnoys fixing solution, which is composed of ethanol, chloroform and acetic acid (6:3:1). PrPres can easily be extracted from Carnoys‐fixed, paraplast‐embedded tissue. Accordingly, Carnoys‐fixed tissue can prior to immunolabeling be subjected to proteinase K and guanidine thio‐cyanate, which respectively eliminate the normal cellular form of prion protein and promote protein denaturation. In comparison with the best protocols for formalin‐fixed tissue (i.e. ‐ hydrolytic autoclaving or autoclaving in distilled water followed by formic acid and guanidine thiocyanate), PrPres immunostaining carried out on sections cut from Carnoys‐fixed, paraplast‐embedded tissue blocks and subjected to proteinase K and guanidine thiocyanate, proved more successful to detect and map both diffuse and focal PrPres immunoreactivity, and to correlate the immunoreactivity pattern with MV polymorphism at PRNP codon 129 and PrPres banding and glycosyla‐tion pattern revealed by Western blot.

MM2-thalamic Creutzfeldt-Jakob disease: neuropathological, biochemical and transmission studies identify a distinctive prion strain

In Creutzfeldt–Jakob disease (CJD), molecular typing based on the size of the protease resistant core of the disease‐associated prion protein (PrPSc) and the M/V polymorphism at codon 129 of the PRNP gene correlates with the clinico‐pathologic subtypes. Approximately 95% of the sporadic 129MM CJD patients are characterized by cerebral deposition of type 1 PrPSc and correspond to the classic clinical CJD phenotype. The rare 129MM CJD patients with type 2 PrPSc are further subdivided in a cortical and a thalamic form also indicated as sporadic fatal insomnia.

Immunomodulatory effects of unselected haematopoietic stem cells autotransplantation in refractory Crohn's disease

BACKGROUND Autologous haematopoietic stem cells transplantation (HSCT) has been shown to be effective in refractory Crohns disease. AIM We analysed the effects of HSCT on the immune response of patients treated for moderate-severe Crohns disease, refractory or intolerant to multiple drugs. METHODS Unselected peripheral blood stem cells were collected after mobilisation with cyclophosphamide (CTX) and G-CSF. The conditioning regimen included CTX and rabbit antithymocyte globulin. Blood samples for immunological analyses were collected at baseline, after mobilisation, and 3, 6 and 12 months after transplantation. Immunological analyses evaluated: (1) CD4(+)/CD25(high+)/FoxP3(+) regulatory T cells (T-regs); (2) Toll-like receptor 2-(TLR2) and TRL4-expressing monocytes (CD14(+) cells); (3) IL-12, IL-10, TNF-alpha-production by mitogen-stimulated CD14(+) cells and IFN-gamma production by CD4(+) T cells. Immunological results were compared with healthy donors and associated with clinical and endoscopic response during 12 months of follow-up. RESULTS Overall, T-regs increased, whilst TLR4-expressing cells, as well as TNF-alpha and IL-10, all higher than healthy donors at baseline, significantly decreased after transplantation. Full responders at T(3) had higher T-regs and lower IFN-gamma and IL12. T-regs decreased and IL12 and TLR2 increased in the only relapsed patient. CONCLUSIONS HSCT can induce and maintain clinical and endoscopic remission in refractory Crohns disease, which is associated with immunomodulation.

Sporadic Creutzfeldt-Jakob disease: the extent of microglia activation is dependent on the biochemical type of PrPSc.

In prion-related encephalopathies, microglial activation occurs early and is dependent on accumulation of disease-specific forms of the prion protein (PrPSc) and may play a role in nerve cell death. Previously, we found that different types of PrPSc (i.e. type 1 and type 2) coexisted in approximately 25% of patients with sporadic Creutzfeldt-Jakob disease (CJD); and a close relationship was detected between PrPSc type, the pattern of PrP immunoreactivity, and extent of spongiform degeneration. To investigate whether microglial reaction is related to the biochemical type and deposition pattern of PrPSc, we carried out a neuropathologic and biochemical study on 26 patients with sporadic CJD, including all possible genotypes at codon 129 of the prion protein gene. By quantitative analysis, we demonstrated that strong microglial activation was associated with type 1 PrPSc and diffuse PrP immunoreactivity, whereas type 2 PrPSc and focal PrP deposits were accompanied by mild microglia reaction. These findings support the view that the phenotypic heterogeneity of sporadic CJD is largely determined by the physicochemical properties of distinct PrPSc conformers.

Small Bowel Adenocarcinomas Complicating Crohn's Disease Are Associated With Dysplasia: A Pathological and Molecular Study.

Background:Crohns disease (CD) is associated with an increased risk of small bowel adenocarcinoma (SBA). However, there are no guidelines for the screening and early diagnosis of SBA. Colorectal cancer associated with chronic colitis arises from dysplasia. High-risk patients benefit from surveillance colonoscopies aimed to detect dysplasia. The dysplasia–carcinoma sequence remains poorly documented in CD-associated SBA. Moreover, molecular data about SBA complicating CD and associated dysplasia are very limited. We therefore assessed dysplasia and several key molecular markers of carcinogenesis in SBA and dysplasia developed in patients with CD. Methods:Forty-five SBA complicating CD and 4 specimens with dysplasia without SBA were screened. In SBA, we looked for dysplasia and determined their pathological characteristics (type, grade, distribution). We also stained for mismatch repair proteins (MLH1, MSH2, MSH6, PMS2), p53, &bgr;-catenin, and p16 and looked for KRAS, BRAF and PIK3CA mutations. Results:All neoplastic lesions, except 1 lesion, were found in inflamed mucosal areas. Dysplasia was found in 20 of 41 patients with SBA (49%). Dysplasia was flat or raised, low grade or high grade, and adjacent or distant to concomitant SBA. Molecular markers of SBA carcinogenesis complicating CD were similar to those observed in chronic colitis-related colorectal cancer (KRAS, BRAF, p53, MSI), although differences were observed for &bgr;-catenin and p16. No PIK3CA mutations were observed. Conclusions:These results suggest that there is an inflammation–dysplasia–adenocarcinoma sequence in at least half of CD-related SBA, similar to what is observed in chronic colitis-related colorectal cancer and may have implications for the prevention and treatment of this cancer.

IBD care in Europe: A comparative audit of the inpatient management of Crohn's disease and ulcerative colitis using the national UK IBD audit tool

BACKGROUND AND AIMS The National UK IBD audit tool is an electronic database created to improve the quality and safety of care for IBD patients by auditing individual patient care, service resources and organisation against national standards. We used the National UK IBD audit tool to compare the organisation and process of IBD care between services in Oxford (UK) and Milan (Italy), as a pilot study to evaluate its application outside national boundaries. METHODS Clinical and demographic data of patients with CD and UC, consecutively admitted during a 2month period, were collected and compared between the centres, to each other and to the UK IBD standards obtained by previous audit analyses performed in Oxford in 2006. RESULTS 20 and 26 patients with UC were admitted in Oxford and Milan, as well as 21 and 20 patients with CD, respectively. Most admissions in Milan were planned admissions for moderately active treatment-refractory disease. No patient died. Oxford had a higher surgery rate. Endoscopy for UC consisted mainly of colonoscopy in Milan (92%) and flexible sigmoidoscopy in Oxford (64%). In CD, Oxford data revealed a higher use of immununomodulators and CT scan, compared with higher use of bowel ultrasound in Milan. CRP was the preferred biomarker of disease activity. The following areas did not reach the standards set for the 2006 UK IBD Audit: the lack in Milan of IBD specialist nurses and few dietitian visits, as well as little attention to heparin prophylaxis and abdominal radiography in UC. Both sites paid little attention to stool cultures and revealed a high rate of active smokers in CD and little attention to bone protection in steroids users. Since the 2006 audit in Oxford, improvements include IBD specialist nurse visits, dietitian visits, number of active smokers, stool samples, prophylactic heparin, bone protection and nutritional assessment. CONCLUSIONS Consistent procedural differences between Oxford and Milan identified by audits of both UC and CD could be resolved by organisational change, with an improvement in the service. The UK IBD audit tool is an easy instrument to assess the processes and outcomes of care delivery in IBD and can be applied also outside UK.

A novel phenotype of sporadic Creutzfeldt-Jakob disease

An atypical case of sporadic Creutzfeldt–Jakob disease (CJD) is described in a 78-year-old woman homozygous for methionine at codon 129 of the prion protein (PrP) gene. The neuropathological signature was the presence of PrP immunoreactive plaque-like deposits in the cerebral cortex, striatum and thalamus. Western blot analysis showed a profile of the pathological form of PrP (PrPSc) previously unrecognised in sporadic CJD, marked by the absence of diglycosylated protease resistant species. These features define a novel neuropathological and molecular CJD phenotype.

Role of the advanced glycation end products receptor in Crohn's disease inflammation.

AIM To investigate the level of mucosal expression and the involvement of the receptor for the advanced glycation end products (RAGE) in delayed apoptosis and tumor necrosis factor (TNF)-α production in Crohns disease (CD). METHODS Surgical and endoscopic specimens from both inflamed and non-inflamed areas of the ileum and/or colon were collected from 20 and 14 adult CD patients, respectively, and used for the assessment of RAGE expression by means of immunohistochemistry and western blotting analysis. Normal tissues from 21 control subjects were used for comparison. The same polyclonal anti-human RAGE antibody (R and D System) was used in all experimental conditions. RAGE staining was quantized by a score including both the amount of positive cells and intensity of immunoreactivity; cellular pattern was also described. The effects of RAGE blocking on apoptotic rate and TNF-α production were investigated on immune cells freshly isolated from CD mucosa and incubated both with and without the muramyl dipeptide used as antigenic stimulus. Statistical analysis was performed via the test for trend, with regression models to account for intra-patient correlations. A 2-sided P < 0.05 was considered significant. RESULTS In inflamed areas, RAGE expression in both the epithelial and lamina propria compartments was higher than control tissues (P = 0.001 and 0.021, respectively), and a cluster of positive cells were usually found in proximity of ulcerative lesions. Similar results were obtained in the lamina propria compartment of non-inflamed areas (P = 0.025). The pattern of staining was membranous and granular cytosolic at the epithelial level, while in the lamina propria it was diffuse cytosolic. When evaluating the amount of protein expression by immunoblotting, a significant increase of both surface area and band intensity (P < 0.0001 for both) was observed in CD inflamed areas compared to control tissue, while in non-inflamed areas a significant increase was found only for band intensity (P < 0.005). Moreover, a significantly lower expression in non-inflamed areas in comparison with inflamed areas was found for both surface area and band intensity (P < 0.0006 for both). Finally, RAGE blocking largely affects both the apoptotic rate of mucosal cells (towards an increase in both non-inflamed and inflamed areas of P < 0.001 and < 0.0001, respectively) and TNF-α secretion (towards a decrease in both non-inflamed and inflamed areas of P < 0.05 and < 0.01, respectively), mainly in the presence of antigenic stimulation. CONCLUSION RAGE is up-regulated in CD, especially in inflamed areas, and it appears to play a role in the mechanisms involved in chronic inflammation.

Panencephalopathic Creutzfeldt-Jakob Disease with Distinct Pattern of Prion Protein Deposition in a Patient with D178N Mutation and Homozygosity for Valine at Codon 129 of the Prion Protein Gene

Prion diseases include sporadic, acquired and genetic forms linked to mutations of the prion protein (PrP) gene (PRNP). In subjects carrying the D178N PRNP mutation, distinct phenotypes can be observed, depending on the methionine/valine codon 129 polymorphism. We present here a 53‐year‐old woman with D178N mutation in the PRNP gene and homozygosity for valine at codon 129. The disease started at age 47 with memory deficits, progressive cognitive impairment and ataxia. The clinical picture slowly worsened to a state of akinetic mutism in about 2 years and the disease course was 6 years. The neuropathologic examination demonstrated severe diffuse cerebral atrophy with neuronal loss, spongiosis and marked myelin loss and tissue rarefaction in the hemispheric white matter, configuring panencephalopathic Creutzfeldt‐Jakob disease. PrP deposition was present in the cerebral cortex, basal ganglia and cerebellum with diffuse synaptic‐type pattern of immunoreactivity and clusters of countless, small PrP deposits, particularly evident in the lower cortical layers, in the striatum and in the molecular layer of the cerebellum. Western blot analysis showed the presence of type 1 PrPSc (Parchi classification). These findings underline the clear‐cut distinction between the neuropathological features of Creutzfeldt‐Jakob disease associated with D178N PRNP mutation and those of fatal familial insomnia.