Changes in High Resolution peripheral Quantitative Computed Tomography in adolescents undergoing a first kidney transplantation.

Abstract

Purpose Mineral bone disorders associated to chronic kidney disease (CKD-MBD) frequently persist after kidney transplantation (Tx), being due to pre-existing CKD-MBD, immunosuppressive therapies and post-Tx hypophosphatemia. We aimed to evaluate bone biomarkers and microarchitecture at the time of and 6 months after Tx. Methods Here we present the single-center sub-group of patients included between 10 and 18 years of age from the prospective TRANSOS study (NCT02729142). Patients undergoing a first Tx were matched on a 1:2 basis on sex, puberty and age with healthy controls (HC) from the VITADOS cohort. Results are presented as median (Q1-Q3). Non-parametric tests were performed. Results At a median age of 15 (13-16) years, 19 patients (6 girls, 7 pre-emptive Tx, 7 steroid-sparing immunosuppressive strategies) underwent a first Tx, with PTH levels of 1.9 (1.4-2.9) the upper limit of normal (ULN). When comparing HC and patients at the time of Tx, we found significantly higher total and trabecular densities with High Resolution peripheral Quantitative Computed Tomography (HR-pQCT). Six months after Tx, patients displayed significantly impaired trabecular parameters at radius compared to baseline; results were not different at the weight-bearing tibia, neither cortical parameters at both sites. Six months after Tx, 6 (31%) patients displayed acidosis, 10 (53%) persistent hyperparathyroidism (always < 2 ULN) and 5 (26%) increased FGF23 levels; 11 (58%) received phosphate supplementation. Conclusion Data on bone health in adolescent receiving a first Tx seem reassuring, but radial trabecular bone microarchitecture impairment observed 6 months post-Tx may reflect subtle albeit present post-Tx CKD-MBD. NCT02729142- March 25 2016