Safety and Efficacy of a 3-Year Therapy With Cinacalcet in Persistent Hyperparathyroidism After Renal Transplant

Evaluation of alterations in length and calcification of the styloid process in patients with end-stage renal failure

OBJECTIVE

This study compared alterations in length and types of elongation and calcification of the styloid process (SP) between patients with end-stage renal failure (ESRF) who received renal transplantation, patients with ESRF undergoing dialysis, and a healthy control group.

STUDY DESIGN

The SPs of 58 patients who had undergone renal transplants, 58 patients who received dialysis treatment, and 58 healthy individuals were examined with panoramic radiographs. Length measurements were made from the apex to the base of the SP. Elongation types were classified into 5 groups: normal, non-segmented, pseudo-segmented, segmented, and non-continuous. Calcification types were classified into 4 groups: external, partial, nodular, and complete.

RESULTS

SP length was significantly greater in the renal transplantation and dialysis groups than in the control group (P < .001) and significantly longer in the renal transplantation group than in the dialysis group (P < .001). There was a significant difference between the groups regarding elongation types (P < .001), with the non-segmented type more frequent in the dialysis and renal transplant groups than in the control group. There was no significant difference in calcification types between groups (P = .225). Elongation and calcification types differed between sexes (P ≤ .008) CONCLUSIONS: Orofacial pain complaints in patients with ESRF should raise the suspicion of abnormal elongation and calcification of the SP, perhaps a manifestation of Eagle syndrome. It would be useful to evaluate the SPs of these patients clinically and radiographically.

Current Status of Mineral and Bone Disorders in Transplant Recipients

Most patients with end-stage kidney disease undergoing kidney transplantation are affected by the chronic kidney disease-mineral and bone disorder. This entity encompasses laboratory abnormalities, calcification of soft tissues, and the bone abnormalities of renal osteodystrophy that together result in an increased risk of fracture, cardiovascular events, and mortality. Although many biochemical disturbances associated with end-stage kidney disease improve in the first year after transplantation, hyperparathyroidism commonly persists, and residual changes of renal osteodystrophy are slow to resolve. When superimposed on common, traditional risk factors, post-transplant glucocorticoid treatment, the possibility of tubular disturbances and post-transplant chronic kidney disease, rates of incident fracture remain high. This review examines hormonal and biochemical changes before and after kidney transplantation, fracture risk assessment tools and imaging modalities, a staged approach to management and concerns associated with antiresorptive and anabolic therapies. A multidisciplinary approach is proposed as the best means to improve patient-level outcomes.

Effects of Cinacalcet on Post-transplantation Hypercalcemia and Hyperparathyroidism in Adult Kidney Transplant Patients: A Single-Center Experience

OBJECTIVE

Secondary hyperparathyroidism may manifest as hypercalcemia in the post-transplant period. The classical treatment method is parathyroidectomy and the alternative is oral cinacalcet, a calcimimetic agent therapy. We retrospectively investigated the effect of cinacalcet therapy on kidney and patient survival in these patients.

MATERIALS AND METHODS

In our single-center, retrospective, observational study, files of 934 patients who underwent renal transplantation in our unit between 2008 and 2022 were reviewed. A total of 23 patients were started on cinacalcet for the treatment of hypercalcemia (calcium > 10.3 mg/dl) and parathyroid hormone (PTH) elevation (>65 pg/ml). Patients with calcium < 10.3 mg/dl and PTH > 700 pg/ml at any time in the follow-up after renal transplantation were included in the study. In addition, the demographic data of the patients, baseline creatine, calcium, phosphorus, and PTH levels at the time of hypercalcemia, parathyroid ultrasonography, parathyroid scintigraphy, creatinine, calcium, phosphorus, and PTH levels in the last controls, and survival status were evaluated.

RESULTS

 The mean age of 23 patients included in the study was 52.7 ± 11 years (minimum: 32; maximum: 66). Of the patients, 16 (69.6%) were male, and 15 (65.2%) were transplanted from a living donor. Parathyroid scintigraphic revealed adenoma in three (13%) patients, hyperplasia in five patients (21.7%), and no involvement in 15 patients (65.2%). Cinacalcet treatment was initiated at a median of 33 months (interquartile range (IQR) = 13-96) after the kidney transplant operation. There was no graft loss in the patients during the follow-up period. Twenty-two patients (95.7%) were alive, and one patient died. The calcium level of the patients decreased from 11.3 ± 0.64 mg/dl to 9.98 ± 0.78 mg/dl (p = 0.001) after cinacalcet treatment. Phosphorus values increased from 2.7 ± 0.65 mg/dl to 3.10 ± 0.65 mg/dl (p = 0.004). On the other hand, there was no significant difference in PTH levels between the initial and final controls (285 (IQR = 150-573) vs. 260 pg/ml (IQR = 175-411), p = 0.650). Also, creatinine levels were similar (1.2 ± 0.38 vs. 1.24 ± 0.48 mg/dl, p = 0.43). Despite cinacalcet treatment, calcium levels did not decrease in eight patients. Complications such as renal dysfunction and pathological fracture did not develop in these patients.

CONCLUSIONS

It seems that cinacalcet treatment is a suitable option for patients with hypercalcemia and/or hyperparathyroidism with low drug interactions and good biochemical control after renal transplantation.