1Hepatopatías Infecciosas, Hospital Francisco J. Muñiz, Buenos Aires, Argentina.
2University of California, San Francisco, CA.
3University of Colorado, Aurora, CO.
Donor age has become the dominant donor factor used to predict graft failure (GF) after liver transplantation (LT) in HCV recipients.
To develop and validate a model of Corrected Donor Age (CDA) for HCV LT recipients that transforms the risk of other donor factors into the scale of donor age.
We analyzed all first LT recipients with HCV in the UNOS registry from 1/1998-12/2007 (development cohort, n=14,538) and 1/2008-12/2011 (validation cohort, n=7,502) using Cox regression, excluding early GF (<90 days from LT). Accuracy in predicting 1yr GF (death or Re-LT) was assessed with the net reclassification index (NRI).
In the development cohort, controlling for pre-LT recipient factors and geo-temporal trends (UNOS region, LT year), the following donor factors were independent predictors of GF (Hazard Ratio); all p<0.05; donor age (1.02/yr), circulatory death (DCD) (1.31), diabetes (1.23), height<160cm (1.13), AST>120 U/L (1.10), female (0.94), cold ischemia time (CIT) (1.02/hr), donor non-AA: recipient AA (1.65). Transforming these risk factors into the donor age scale yielded the following: DCD=+16yrs, diabetes=+12yrs, height<160cm=+7yrs, AST >120 U/L=+5yrs, female=-4yrs, CIT=+1yr/hr>8hrs and -1yr/hr<8 hrs. There was a large effect of donor-recipient race combinations; +29yrs for donor non-AA: recipient AA but only +5yrs for donor AA: recipient AA, and -2yrs for donor AA: recipient non-AA. In a validation cohort, CDA better classified risk of 1yr GF versus actual age (NRI 4.9%, p=0.009) and versus the donor risk index (9.0%, p<0.001).
The CDA, compared to actual donor age, provides an intuitive and superior estimation of graft quality for HCV-positive LT recipients since it incorporates additional factors that impact LT GF rates.