Two-year retrospective study of the effect of preemptive kidney transplantation and pretransplant mineral bone factors on calcium in post-kidney transplant recipients.

ABSTRACT

BACKGROUND: Preemptive kidney transplantation (PEKT) incidence has recently increased in Japan. The effect of PEKT and mineral bone factors before kidney transplantation (KTx) on long-term calcium (Ca) levels remains unknown. METHODS: Eighty-one consecutive patients at Nagoya Daini Red Cross Hospital were included in this study (PEKT group with 41 patients and non PEKT group with 40 patients). Ca metabolism, including intact fibroblast growth factor 23 (iFGF23), were measured before KTx and intact parathyroid hormone (iPTH), and corrected Ca (cCa) were measured before KTx and 6 months (M), 12 M, and 24 M after KTx. RESULTS: In PEKT group, cCa levels at 24 M were higher from the baseline level. At baseline, cCa levels had a positive correlation with iFGF23 levels (r = 0.51; p < 0.001) and a negative correlation with iPTH levels (r = 0.51; p < 0.001). The cCa difference between baseline and 24 M was 0.8 ± 0.6 mg/dL in PEKT group and 0.3 ± 0.7 mg/dL in non-PEKT group (p = 0.001). A multivariate linear regression analysis showed iFGF23 and iPTH at baseline in entire groups were useful markers on calcium levels at 24 M. However, in PEKT group, both markers were found to be not associated with Ca at 24 M, whereas in non PEKT group, iPTH was the only effective marker. CONCLUSIONS: This study suggested that iFGF23 and iPTH may be useful markers of the calcium status after KTx. However, no correlation was noted in PEKT group.