GDF15 and chronic kidney disease: Therefore, our results, which show a strong association between elevated GDF15 levels and impaired allograft function one year after KTx, and the observation that GDF15 was able to predict graft function one year later, are consistent with Nair et al. who showed an increased risk for CKD progression with higher GDF15 levels in two separate, independent CKD patient cohorts (Nair et al. 2017).