THE PROGNOSTIC-SIGNIFICANCE OF SPECIFIC ARTERIAL LESIONS IN ACUTE RENAL-ALLOGRAFT REJECTION

Diagnosis of allograft dysfunction relies on the assessment of arteria l lesions. This study was designed to evaluate the prognostic signific ance of common specific vascular lesions in acute allograft rejection. Renal allograft biopsies (n = 111) with acute cellular rejection were scored for endarteritis, mononuclear cell adherence to endothelial ce lls, endothelial activation, fibrinoid necrosis, foam cells, and intim al fibrosis. These vascular lesions and other classic histologic featu res were correlated with outcome. Rejection with endarteritis (found i n 54% of biopsies) was less responsive to steroid treatment than rejec tion without endarteritis, as judged by recovery of creatinine in 3 wk (P = 0.03). Larger numbers of sampled arteries improved the predictiv e accuracy. Sticking of mononuclear cells to endothelial cells also co rrelated with steroid resistance (P < 0.05). Rejection with or without endarteritis responded to OKT3/antithymocyte globulin treatment equal ly well (61% versus 65%, respectively). Rejection with fibrinoid arter ial necrosis (4% of biopsies) did not respond to either steroids or an tibodies (0%). One-year graft failure was 21% without endarteritis, 28 % with endarteritis, and 100% with fibrinoid necrosis. Activated endot helial cells and interstitial hemorrhage were associated with endarter itis and graft failure tall P < 0.05). None of the other scored featur es had any statistically significant correlation with outcome. Thus, s pecific arterial lesions (endarteritis, fibrinoid necrosis, activated endothelial cells, mononuclear cell margination) and interstitial hemo rrhage, but not the extent of the interstitial infiltrate or tubulitis , are correlated with response to antirejection therapy and/or 1-yr cl inical outcome. Grading systems for therapeutic trials and clinical ma nagement should emphasize scoring of specific vascular lesions.