Digital pathology implementation in a private laboratory: The CEDAP experience.

Introduction: The transition to digital pathology has been carried out by several laboratories across the globe, with some cases described in Portugal. In this article, we describe the transition to digital pathology in a high-volume private laboratory, considering the main challenges and opportunities. Material and methods: Our process started in 2020, with laboratory workflow adaptation and we are currently using a high-capacity scanner (Aperio GT450DX) to digitize slides at 20×. The visualization system, Aperio eSlide Manager WebViewer, is integrated into the Laboratory System. The validation process followed the Royal College of Pathologists Guidelines. Results: Regarding validation, the first phase detected an error rate of 6.8%, mostly due to digitization errors. Phase optimization and collaboration with technical services led to improvements in this process. In the second validation phase, most of the slides had the desired quality for evaluation, with only an error rate of 0.6%, corrected with a new scan. The interpathologist correlation had a total agreement rate of 96.87% and 3.13% partial agreement. Conclusion: The implementation and validation of digital pathology was a success, being ready for prime time. The total integration of all laboratory systems and the acquisition of new equipment will maximize their use, especially with the application of artificial intelligence algorithms.

Preventive but not curative efficacy of celecoxib on bladder carcinogenesis in a rat model.

To evaluate the effect of a cyclooxygenase 2 inhibitor, celecoxib (CEL), on bladder cancer inhibition in a rat model, when used as preventive versus as curative treatment. The study comprised 52 male Wistar rats, divided in 5 groups, during a 20-week protocol: control: vehicle, carcinogen: 0.05% of N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN), CEL: 10 mg/kg/day of the selective COX-2 inhibitor Celebrex, preventive CEL (CEL+BBN-P), and curative CEL (BBN+CEL-C) groups. Although tumor growth was markedly inhibited by the preventive application of CEL, it was even aggravated by the curative treatment. The incidence of gross bladder carcinoma was: control 0/8(0%), BBN 13/20(65%), CEL 0/8(0%), CEL+BBN-P 1/8(12.5%), and BBN+CEL-C 6/8(75%). The number and volume of carcinomas were significantly lower in the CEL+BBN-P versus BBN, accompanied by an ample reduction in hyperplasia, dysplasia, and papillary tumors as well as COX-2 immunostaining. In spite of the reduction of tumor volumes in the curative BBN+CEL-C group, tumor malignancy was augmented. An anti-inflammatory and antioxidant profile was encountered only in the group under preventive treatment. In conclusion, preventive, but not curative, celecoxib treatment promoted a striking inhibitory effect on bladder cancer development, reinforcing the potential role of chemopreventive strategies based on cyclooxygenase 2 inhibition.

Cytokine expression in pediatric Helicobacter pylori infection.

Helicobacter pylori infection is one of the most common gastrointestinal infections worldwide and almost invariably causes chronic gastritis in the infected host. A predominant Th1 profile has been demonstrated in H. pylori-infected mucosa from adults, but no previous study has evaluated in situ cytokine expression in children. We therefore examined expression of proinflammatory, anti-inflammatory, and regulatory cytokines by immunohistochemistry in cryopreserved antral biopsy specimens from 10 H. pylori-infected and 10 uninfected children and correlated expression of cytokines with histology scores. Concomitant expression of interleukin-8 (IL-8), gamma interferon (IFN-gamma), IL-4, transforming growth factor beta, and tumor necrosis factor alpha was seen in 8/10 H. pylori-infected cases and in 5/10 noninfected cases; all H. pylori-infected subjects showed staining for at least two of the cytokines. The proportion of epithelial cytokine-specific staining did not differ significantly between the groups, either in surface or glandular epithelium. Furthermore, no significant differences were noticed between intraepithelial or lamina propria lymphocyte staining in the groups. There was, however, a tendency of higher numbers of IFN-gamma- and IL-8-positive cells in the H. pylori-infected group. IFN-gamma and IL-8 lamina propria lymphocyte expression correlated significantly with antrum chronic inflammation, but there was no correlation between histology scores and epithelial cytokine expression. When the same techniques were used, the cytokine response appeared to be smaller in H. pylori-infected children than in adults, and there was no clear Th1 dominance. These results therefore suggest a different mucosal immunopathology in children. It remains to be determined whether the gastric immune response is downregulated in children with H. pylori infection and whether this is relevant to the outcome of infection.