The incidence of hypophosphatemia in the early posttransplant period in renal transplant recipients and its association with graft function

Abstract

Objectives: To investigate the prevalence of posttransplant hypophosphatemia in the early posttransplant period among renal transplant recipients in relation to its impact on renal graft function.

Methods: A total of 78 renal transplant recipients who were transplanted between January 2016 and March 2020 were included in this retrospective single center study. Data on laboratory findings (phosphate, creatinine, estimated glomerular filtration rate [eGFR], albumin, serum corrected calcium and parathyroid hormone [PTH] levels) at pre- and posttransplant 3 month follow up period were recorded.

Results: Hypophosphatemia was detected in 16 (20.8%), 13 (16.7%) and 7 (9.1%) patients at the posttransplant day 10, month 1 and month 3, respectively. Posttransplant day 10 and day 30 measurements revealed significantly lower serum creatinine values (p < 0.001 and p < 0.07, respectively) and significantly higher eGFR values (p = 0.009 and p = 0.036, respectively) in the hypophosphatemic group compared to the normophosphatemic group. Serum phosphate displayed linear relationship with creatinine at day 10 (r=0.687, p < 0.001), day 30 (r=0.301, p = 0.007), while not correlated with PTH levels at posttransplant day 10, day 30 and day 90.

Conclusions: Our findings suggest that hypophosphatemia is common in the early posttransplant period, particularly first month after kidney transplantation, being associated with better renal graft function.

Keywords

• Hypophosphatemia
• kidney transplantation
• graft function

References

1. 1. Huber L, Naik M, Budde K. Frequency and long-term outcomes of post-transplant hypophosphatemia after kidney transplantation. Transpl Int 2013;26:94-6.
2. 2. Sirilak S, Chatsrisak K, Ingsathit A, Kantachuvesiri S, Sumethkul V, Stitchanrtakul W, et al. Renal phosphate loss in long-term kidney transplantation. Clin J Am Soc Nephrol 2012;7:323-31.
3. 3. Nakai K, Mitsuiki K, Kuroki Y, Nishiki T, Motoyama K, Nakano T, et al. Relative hypophosphatemia early after transplantation is a predictor of good kidney graft function. Clin Exp Nephrol 2019;23:1161-8.
4. 4. Kawarazaki H, Shibagaki Y, Fukumoto S, Kido R, Ando K, Nakajima I, et al. Natural history of mineral and bone disorders after living-donor kidney transplantation: a one-year prospective observational study. Ther Apher Dial 2011;15:481-7.
5. 5. Ghorbani M, Ossareh S. Early postkidney transplantation hypophosphatemia. J Res Med Sci 2020;25:36.
6. 6. Evenepoel P, Meijers BK, de Jonge H, Naesens M, Bammens B, Claes K, et al. Recovery of hyperphosphatoninism and renal phosphorus wasting one year after successful renal transplantation. Clin J Am Soc Nephrol 2008;3:1829-36.
7. 7. Benavente D, Chue CD, Moore J, Addison C, Borrows R, Ferro CJ. Serum phosphate measured at 6 and 12 months after successful kidney transplant is independently associated with subsequent graft loss. Exp Clin Transplant 2012;10:119-24.
8. 8. Ketteler M, Block GA, Evenepoel P, Fukagawa M, Herzog CA, McCann L, et al. Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder: Synopsis of the Kidney Disease: Improving Global Outcomes 2017 Clinical Practice Guideline Update. Ann Intern Med 2018;168:422-30.

9. 9. Levey AS, Stevens LA, Schmid CH, Zhang YL, Castro AF, Feldman H, et al. A new equation to estimate glomerular filtration rate. Ann Intern Med 2009;150:604-12.
10. 10. Solez K, Colvin RB, Racusen LC, Haas M, Sis B, Mengel M, et al. Banff 07 classification of renal allograft pathology: updates and future directions. Am J Transplant 2008;8:753-60.
11. 11. van Londen M, Aarts BM, Deetman PE, van der Weijden J, Eisenga MF, Navis G, et al. Post-transplant hypophosphatemia and the risk of death-censored graft failure and mortality after kidney transplantation. Clin J Am Soc Nephrol 2017;12:1301-10.
12. 12. Seifi S, Pezeshki ML, Khatami MR, Mazdeh MM, Ahmadi F, Maziar S. Post-renal transplantation hypophosphatemia. Transplant Proc 2003;35:2645-6.
13. 13. Taweesedt PT, Disthabanchong S. Mineral and bone disorder after kidney transplantation. World J Transplant 2015;5:231-42.
14. 14. Prasad N, Jaiswal A, Agarwal V, Kumar S, Chaturvedi S, Yadav S, et al. FGF23 is associated with early post-transplant hypophosphataemia and normalizes faster than iPTH in living donor renal transplant recipients: a longitudinal follow-up study. Clin Kidney J 2016;9:669-76.
15. 15. Bhan I, Shah A, Holmes J, Isakova T, Gutierrez O, Burnett SM, et al. Post-transplant hypophosphatemia: Tertiary 'Hyper-Phosphatoninism'? Kidney Int 2006;70:1486-94.
16. 16. Falkiewicz K, Nahaczewska W, Boratynska M, Owczarek H, Klinger M, Kaminska D, et al. Tacrolimus decreases tubular phosphate wasting in renal allograft recipients. Transplant Proc 2003;35:2213-5.
17. 17. Ninkovic M, Skingle SJ, Bearcroft PW, Bishop N, Alexander GJ, Compston JE. Incidence of vertebral fractures in the first three months after orthotopic liver transplantation. Eur J Gastroenterol Hepatol 2000;12:931-5.