Target UroVysion FISH for Urinary Specimens Using the Duet Imaging System
GD Smith, JS Bentz, BT Collins. ARUP Laboratories, Salt Lake City, UT; University of Utah, Salt Lake City, UT; Laboratory Medicine Consultants, Ltd., Las Vegas, NV
Background: Cytology has a poor sensitivity for urothelial carcinoma, and molecular tests such as UroVysion FISH may aid in interpretation. Target (or Location Guided) FISH is an ideal tool for combining morphology (stained or immunolabeled cells) with FISH. Studies by Daniely et al, provide clinical evidence that the combined analysis of morphology and FISH has high sensitivity and negative predictive value for the detection of bladder cancer.
Design: The BioView Duet ™ imaging system was used to identify abnormal-appearing cells by cytology followed by UroVysion FISH. A preliminary study using Pap-stained slides followed by UroVysion FISH showed problems with cell recovery and stain interference with subsequent FISH. To reduce cell loss and stain interference, this study included 19 slides that were stained with May-Grünwald/Giemsa and not coverslipped. Target cells were identified by brightfield microscopy, followed by slide de-staining and UroVysion FISH, to detect amplifications of chromosomes 3, 7, and 17, and deletions of 9p21. Target cells were then re-located using Duet software and fluorescence microscopy, and probe signals were scored for cell recovery, target cell re-location accuracy, FISH signal strength, reproducibility, and correlation with cytology results.
Results: Brightfield, DAPI, and signal quality scored 2.95, 2.95, and 3.0 (possible 3.0), and reproducibility was 100%. Target cell re-location was highly accurate with target cells re-located to the microscope field center in all but one case, for which 86% of the target cells re-located to the field center. Average target cell recovery was 78%, with >85% recovery for slides showing no scrape marks by fluorescence microscopy. Other slides with visible scrape marks had a 63% cell recovery, with damage presumed to occur during coverslip removal after FISH hybridization. Correlation with urine cytology was 92.8%. One of three atypical cytology cases was FISH positive, which may provide support for clinical correlation and further patient follow-up.
Conclusions: The tools provided by the Duet system for Target FISH have potential for reflex testing, combined immunocytochemistry/FISH, and research applications. In our experience, setting up a limited fluorescence scan with targets selected interactively rather than by automated scan, appears to be the best approach for Target FISH.
Tuesday, March 23, 2010 9:30 AM
Poster Session III # 100, Tuesday Morning