Digital image analysis of lung transplant rejection in the rat: Quantitative differences between ischemic reperfusion injury in syngeneic grafts vs untreated allogeneic grafts

Objective: To investigate computerized digital image analysis (Mocha, Jandel) quantifying differences between ischemic/reperfusion injury in syngeneic grafts as opposed to alloimune graft rejection. Methods: Conventional bright field and novel high definition/SD microscopy with multiple oblique illumination (Edge, Inc.) was performed on various H&E and elastin stained specimens LEW to LEW syngeneic and UN to LEW (Rtl->Rtl') allogeneic single lung block grafts were performed. Nine images were captured and processed from each recipient (n=54). All recipients were examined at greater than two months post transplant. Results: Total alveolar air space in the syngeneic group was significantly (p<0.001) greater than the aliogeneic recipients (48.2 ±13.4% vs. 6.1±5.5%). Total interstitial tissue area was significantly less (pO.OOl) in the syngeneic group vs. the allogeneic group (51.9±13.4% vs. 93.9+ 5.5%). Analysis of arterioles demonstrated significant increases in vessel wall thickness when measured as a function of total vessel-diameter for the allografts compared to syngeneic grafts (0.288±0.028 vs. 0.140±0.021; p<0 002). The ratio of nuclear number to total tissue area as a measure of cellularity was significantly greater in the syngeneic group (0.009±0.001 vs. 0.006±0.003; p<0014) Conclusion: Significant differences were established for total alveolar air space, arteriolar wall thickness, and cellularity by computerized digital image.