Donor hepatitis C antibody positivity misclassifies kidney donor profile index in non-hepatitis C-infected donors: time to revise the kidney donor profile index - a retrospective cohort study.

The kidney donor profile index (KDPI) defines an hepatitis C (HCV) positive donor based on HCV antibody (Ab) and/or nucleic acid amplification test (NAT) positivity, with donors who are not actively infected (Ab+/NAT-) also classified as HCV positive. From Scientific Registry of Transplant Recipients dataset, we identified HCV-negative recipients, who received a kidney transplant from HCV Ab+/NAT- (n = 116) and HCV Ab-/NAT- (n = 25 574) donor kidneys. We then compared recipients' estimated glomerular filtration rate (eGFR) at 6 months in matched cohorts, using combined exact matching (based on KDPI) and propensity score matching. We created two separate matched cohorts: for the first cohort, we used the allocation KDPI, while for the second cohort we used an optimal KDPI, where the HCV component of KDPI was considered negative in Ab+/NAT- patients. The mean ± SD age of the allocation KDPI-matched cohort at baseline was 59 ± 10 years, 69% were male, 61% were white. Recipients' eGFR at 6 months after transplantation was significantly higher in the HCV Ab+/NAT- group compared to the HCV Ab-/NAT- group (61.1 ± 17.9 vs. 55.6 ± 18.8 ml/min/1.73 m2 , P = 0.011) in the allocation KDPI-matched cohort, while it was similar (61.8 ± 19.5 vs. 62.1 ± 20.1 ml/min/1.73 m2 , P = 0.9) in the optimal KDPI-matched cohort. Recipients who received HCV Ab positive, but NAT-negative donor kidneys did not experience worse 6-month eGFR than correctly matched HCV Ab-/NAT- recipients.