Argon laser induced autofluorescence may distinguish between normal and tumor human urothelial cells: A microspectrofluorimetric study

Purpose: To assess the ability of argon laser-induced autofluorescence spectroscopy (LIAFS) to discriminate normal from tumor human urothelial cells. Materials and Methods: Emission spectra of single living cells excited at 488 nm. have been studied with a confocal microspectrofluorimeter. Results: Cellular autofluorescence appeared as a broad band with a maximum in the same ''green'' spectral range, 550 to 560 nm., probably corresponding to oxidized flavoprotein emission. However, the maximum autofluorescence intensity of normal urothelial cells was much higher, 10 times (p < 0.0001) that of any of the tumor cell types tested. Conclusion: These results, suggesting a significantly reduced oxidized flavoprotein concentration in tumor urothelial cells, should prompt us to evaluate argon LIAFS as a potential tool to detect occult urothelial severe dysplasia and carcinoma in situ.