Detection of transplant vasculopathy in a rat aortic allograft model by fluorescence spectroscopic optical analysis

Background and Objective: Transplant vasculopathy is a leading cause of lat e cardiac graft loss. We have examined laser-induced fluorescence (LIF) spe ctroscopy as an optical diagnostic tool for detection of intimal plaque dev elopment and inflammatory cellular invasion in a rat model of aortic allogr aft transplant, Study Design/Materials and Methods: Infrarenal aortic segments were transpl anted from Lewis to Sprague Dawley rats. A range of vasculopathy developmen t was produced by treatment with a viral anti-inflammatory protein. LIF spe ctra were recorded from the intima of aortic implants at 28 days. Fluoresce nce intensity was analyzed for correlation with vasculopathy development. Results: Significant differences in LIF intensity at 400-450 nm (P less tha n or equal to 0.05 by ANOVA) were detected. LIF emission was correlated wit h plaque growth (R-2 = 0.980), vessel narrowing (R-2 = 0.964), and cellular invasion (R2 = 0.971) by regression analysis. Conclusion: LIF optical anal ysis provides a nontraumatic diagnostic approach for detection of atheroscl erosis prior to cardiac transplant or during development of vasculopathy af ter transplant. Lasers Surg, Med. 24:346-359, 1999, (C) 1999 Wiley-Liss, In c.