Gonwa, Thomas

AbstractHistologic findings on 1‐year biopsies such as inflammation with fibrosis and transplant glomerulopathy predict renal allograft loss by 5 years. However, almost half of the patients with graft loss have a 1‐year biopsy that is either normal or has only interstitial fibrosis. The goal of this study was to determine if there was a gene expression profile in these relatively normal 1‐year biopsies that predicted subsequent decline in renal function. Using transcriptome microarrays we measured intragraft mRNA levels in a retrospective Discovery cohort (170 patients with a normal/minimal fibrosis 1‐year biopsy, 54 with progressive decline in function/graft loss and 116 with stable function) and developed a nested 10‐fold cross‐validated gene classifier that predicted progressive decline in renal function (positive predictive value = 38 ± 34%%; negative predictive value = 73 ± 30%, c‐statistic = .59). In a prospective, multicenter Validation cohort (270 patients with Normal/Interstitial Fibrosis [IF]), the classifier had a 20% positive predictive value, 85% negative predictive value and .58 c‐statistic. Importantly, the majority of patients with graft loss in the prospective study had 1‐year biopsies scored as Normal or IF. We conclude predicting graft loss in many renal allograft recipients (i.e., those with a relatively normal 1‐year biopsy and eGFR > 40) remains difficult.

AbstractKidney transplant (KT) programs have extended recipient eligibility to those who were previously excluded due to advanced age. We aimed to determine the outcomes of the patients ≥70 years undergoing KT and investigate factors predicting survival. Two thousand six hundred and twenty‐four KT patients between 2003 and 2013 at two institutions were divided into two groups; those ≥70 years (n=300) and those <70 years (n=2324) at the time of KT. Patient survival at 1, 3, and 5 years was 95%, 86%, and 77% in ≥70 years of age group and 98%, 95%, and 90% in the <70 years group (P<.001). When graft loss due to death was censored, graft survival was not significantly different between the two groups (P=.18). On multivariable analysis, the significant predictors of inferior survival in patients ≥70 years included: body mass index (BMI)>30 kg/m2 (hazard ratio [HR] 1.07; P=.01), panel reactive antibody (PRA)>20% (HR 2.38; P=.01), previous coronary artery bypass grafting (CABG; HR 1.95; P=.03) and peripheral vascular disease (PVD; HR 2.60; P=.04). Acceptable outcomes can be achieved in KT recipients ≥70 years. Caution should be used when listing these patients if they have BMI>30 kg/m2, PRA>20%, CABG or PVD.