CHRONIC RENAL-ALLOGRAFT REJECTION IN THE FIRST 6 MONTHS POSTTRANSPLANT

Between May 1, 1986 and May 31, 1992 at the University of Minnesota, w e interpreted 129 renal allograft biopsy specimens (done in 48 grafts during the first 6 months posttransplant) as showing changes consisten t with chronic rejection, For this retrospective analysis, we reexamin ed these biopsies together with clinical information to determine: (a) whether a diagnosis other than chronic rejection would have been more appropriate, (b) how early posttransplant any chronic rejection chang es occurred, and (c) if the diagnosis correlated with outcome. We foun d that (1) chronic rejection is uncommon in the first 6 months posttra nsplant; it was documented in only 27 (2.4%) of 1117 renal allografts and was preceded by acute rejection in all but 3 recipients (for these 3, the first biopsy specimen showed both acute and chronic rejection) , (2) Chronic vascular rejection was seen in 1 recipient as early as 1 month posttransplant; the incidence increased over time and was assoc iated with an actual graft survival rate of only 35%, (3) The most fre quent cause of arterial intimal fibrosis in the first 6 months posttra nsplant was arteriosclerotic nephrosclerosis (ASNS) of donor origin, L ongterm graft function for recipients with ASNS was 67%, (4) Early-ons et ischemia or thrombosis was seen in 14 recipients and predicted poor outcome: only 35.7% of these recipients had long-term graft function, (5) Cyclosporine (CsA) toxicity was implicated in only 3 recipients, who had mild diffuse interstitial fibrosis in association with elevate d CsA levels. Other variables (including systemic hypertension, urinar y tract infection, obstructive uropathy, neurogenic bladder, cobalt th erapy, and recurrent disease) were not significantly associated with c hronic renal lesions in the first 6 months posttransplant. A significa nt number of biopsies were originally interpreted as showing chronic r ejection, but the diagnosis was changed upon reevaluation in conjuncti on with clinical data,We conclude that many factors coexist to produce chronic lesions in biopsies during the first 6 months posttransplant, so clinical correlation is needed before establishing a diagnosis of chronic rejection.