Ralf Keller

Oral budesonide therapy for steroid-dependent ulcerative colitis: a pilot trial

Budesonide, a corticosteroid with high topical anti‐inflammatory activity and low systemic activity, has been shown to prolong time to relapse in Crohns disease. In the present study, the efficacy of budesonide in an oral pH‐modified‐release formulation was evaluated for maintenance treatment in patients with steroid‐dependent ulcerative colitis.

Diagnostic Value of DNA Image Cytometry in Ulcerative Colitis

The increased risk of colorectal cancer in patients with extensive, long-standing ulcerative colitis is well established. The interpretation of dysplasia as the common precursor lesion of colorectal cancer in ulcerative colitis is, however, subject to inter- and intraobserver variation. The histologic diagnosis is particularly difficult in the presence of acute inflammation. Therefore, the analysis of ploidy patterns might be a more objective diagnostic tool. In the present study, the correlation of ploidy and dysplasia of the colonic mucosa was evaluated in the absence and presence of inflammation. Image cytometry was performed on 561 fixed, paraffin-embedded tissue specimens from 67 patients with ulcerative colitis. Twenty patients had long-standing and extensive disease, including eight patients in whom the colitis was associated with colorectal cancer. Dysplasia was only found in patients with long-standing colitis or with colorectal cancer and was significantly more often diagnosed in the case of concomitant inflammation. On the other hand, aneuploid patterns were shown to occur independent of inflammatory activity. Aneuploidy was present in all colorectal carcinomas associated with ulcerative colitis and in 46.2% of specimens with dysplasia. Moreover, aneuploidy was detectable in four of 12 samples with low-grade dysplasia as well as in one case devoid of any dysplastic alteration. Ulcerative colitis patients with low-grade dysplasia plus aneuploidy probably represent a subgroup that might be at higher risk of developing colorectal cancer than patients with low-grade dysplasia alone. All in all, image cytometry analysis might be instrumental in identifying neoplastic lesions even in cases of increased inflammatory activity or regenerative change.

Density gradient centrifugation of colonic fluid after segmental lavage: a method of purification of exfoliative epithelial colonic cells for cytological interpretation and image cytometry in patients with long-standing ulcerative colitis

Objectives:Patients with extensive, long-standing ulcerative colitis (UC) have an increased risk for developing colorectal cancer. In this study, we wanted to establish a method for retrieving cytological material after segmental colonic lavage for further cytopathological investigations and for performing DNA image cytometry.Methods:Ten patients with long-standing and extensive ulcerative colitis and 10 patients without macroscopic abnormalities were investigated. After segmental colonic lavage during routine colonoscopy a three-layer (1.146, 1.075, and 1.046 g/ml, respectively) density gradient centrifugation of the retrieved colonic fluid was performed for isolation and purification of the epithelial cells. For identification of the epithelial cells flow cytometry with monoclonal antibody against cytokeratin and counterstaining with propidium iodine was performed. The smears obtained were stained for routine cytopathological interpretation and for DNA image cytometry.Results:In eight of 10 UC patients and in nine of 10 control group patients adequate cytological material could be obtained. The band on top of the density gradient at 1.046 g/ml could be identified as the epithelial cells. Atypical cells were found in smears of three UC patients. In these patients and in one additional patient aneuploid stemlines could be detected. In smears of control group patients neither atypical cells nor aneuploidy were present.Conclusions:Isolation and purification of epithelial cells after segmental colonic lavage by using density gradient centrifugation was performed. This cytological material is adequate for cytopathological interpretation and for DNA image cytometry. Information about atypical cells and DNA aneuploidy as an additional marker of malignant transformation in UC patients was obtained. The combination of cytological examination and DNA image cytometry might improve the detection of UC patients with high risk for colorectal cancer.

Cytology and image cytometry after colonic lavage: a complementary diagnostic tool in patients with ulcerative colitis

BACKGROUND Patients with extensive, long-standing ulcerative colitis have increased risk of colorectal cancer. AIMS To improve the detection of high-risk patients, using a combination of colonic cytology, histology, and DNA image cytometry after segmental colonic lavage. PATIENTS A series of 16 patients (8 high-risk patients) with ulcerative colitis were investigated. METHODS After segmental lavage step, biopsies were obtained. Gradient centrifugation of the colonic fluid was performed for isolation and purification of epithelial cells. The smears and biopsy specimens obtained were stained for routine interpretation and for DNA image cytometry. RESULTS Segmental lavage could be performed in all patients. Specimens from two high-risk patients showed low grade dysplasia and atypia by means of histology and cytology, respectively. In one patient, without increased colorectal cancer risk, atypia was detected. Three patients in the high-risk group, two of those diagnosed as positive for dysplasia and atypia, showed aneuploidy histologically and cytologically. DNA aneuploidy, in cytological material, was found exclusively in three low-risk patients, one of those had atypia cytologically. CONCLUSIONS Isolation and purification of epithelial cells after segmental colonic lavage using density gradient centrifugation can be performed as part of routine endoscopy. It provides information about atypical cells and DNA aneuploidy as additional markers of malignant transformation. The combination of cytologic examination and DNA image cytometry might improve the detection of high-risk ulcerative colitis patients.