The effect of hypercalcemia on allograft calcification after kidney transplantation

Abstract

Hypercalcemia and persistent hyperparathyroidism are not rare after KTx. Tubulointerstitial calcification is more common and progressive among patients with persistent hypercalcemia. Normalization of calcium levels may contribute to regression of calcification in some patients.

Clinical outcomes of parathyroidectomy <i>versus</i> cinacalcet in the clinical management of secondary hyperparathyroidism

“…Regardless of attempts to normalize parathyroid function, it has been well established that vascular calcification is irreversible. Therefore, efforts should be made to minimize vascular calcification in preparation for effective kidney transplantation [29].…”

Timing of parathyroidectomy for kidney transplant patients with secondary hyperparathyroidism: A practical overview

“…With the restoration of a more normal eGFR, SHPT might resolve in mild cases or remain stable until the end of the first year post-transplant (11,14). Even with adequate allograft function, PHPT is still observed in 30-60% of kidney transplant recipients 1 year after KT and in 20% of patients even at 5 years (4,14,15). The direct and most prominent impact of PHPT is on the serum calcium level (12,14).…”

“…Although the serum calcium level normalizes a few days after KT, hypercalcemia may develop as soon as 1 week after transplantation (7,14). Hypercalcemia is closely associated with PHPT in the majority of cases and is usually considered to be an indicator of PHPT, with a incidence between 10% and 30% (9,14,15). This variability in incidence may be attributable to various factors such as the use of different serum calcium levels for diagnosis, evaluation of the ionized or total calcium level, regardless of whether the calcium levels are corrected based on albumin, and the timing of diagnosis (15).…”

“…Hypercalcemia is closely associated with PHPT in the majority of cases and is usually considered to be an indicator of PHPT, with a incidence between 10% and 30% (9,14,15). This variability in incidence may be attributable to various factors such as the use of different serum calcium levels for diagnosis, evaluation of the ionized or total calcium level, regardless of whether the calcium levels are corrected based on albumin, and the timing of diagnosis (15). A point worth noting is that the prevalence of hypercalcemia may decrease over time, but 5-10% of patients continue to have persistently high serum calcium levels over the long term (7).…”

“…PHPT and hypercalcemia have a close causal relationship and both affect three aspects of allograft function: (i) PHPT and hypercalcemia promote nephrocalcinosis, which is characterized by tubular and interstitial deposits of calcium in the form of calcium oxalate or calcium phosphate. As the duration and severity of hypercalcemia increases, the extent of tubulointerstitial calcification increases, which may contribute to allograft dysfunction over the long term, and especially when the calcium level rises rapidly (14,15). (ii) Hypercalcemia promotes vascular calcification.…”