Incidence, risk factors and survival outcomes of post-transplant tertiary hyperparathyroidism in kidney recipients

Figure 1 Flow diagram of the study cohort selection. A total of 963 kidney transplant recipients transplanted between 2000 and 2020 were screened. Of these, 76 patients were excluded due to early graft loss or missing data (n = 54), primary hyperparathyroidism (HPT) (n = 2), calciphylaxis treated with cinacalcet (n = 1), or pre-transplant tertiary HPT (tHPT) (n = 19). The final analysis included 887 patients, of whom 125 developed post-transplant tHPT and 762 did not. HPT: Hyperparathyroidism; KTR: Kidney transplant recipient; tHPT: Tertiary hyperparathyroidism.

Figure 2 Receiver operating characteristic curve for the logistic regression model predicting post-transplant tertiary hyperparathyroidism. The X-axis represents the false positive rate (specificity), and the Y-axis represents the true positive rate (sensitivity). The diagonal line (dashed) represents random guessing, while the solid line represents the model's performance. The model demonstrates good discriminatory ability with an area under the curve of 0.834, indicating high accuracy in distinguishing between patients who developed post-transplant tertiary hyperparathyroidism and those who did not. AUC: Area under the curve; ROC: Receiver operating characteristic.

Figure 3 Adjusted survival analysis comparing outcomes in kidney transplant recipients with post-transplant tertiary hyperparathyroidism vs those without tertiary hyperparathyroidism. A: Death-censored graft survival was significantly lower in patients with tertiary hyperparathyroidism (tHPT) [adjusted hazard ratio (aHR) = 3.41, 95%CI: 2.09-5.59, P < 0.001], adjusted for age, donor type, acute rejection, and baseline estimated glomerular filtration rate (eGFR); B: All-cause graft survival was significantly reduced in the tHPT group (aHR = 2.51, 95%CI: 1.78-3.53, P < 0.001), adjusted for age, acute rejection, baseline eGFR, and post-transplant smoking; C: Recipient survival was also significantly lower in the tHPT group (aHR = 1.94, 95%CI: 1.25-3.01, P = 0.003), adjusted for age, pre-transplant diabetes, dialysis duration, history of acute rejection, baseline eGFR, and post-transplant smoking. aHR: Adjusted hazard ratio; eGFR: Estimated glomerular filtration rate; tHPT: Tertiary hyperparathyroidism.

Figure 4 Survival probability (adjusted for pre-transplant parathyroid hormone). A: Recipient survival by treatment modality; B: Graft survival by treatment modality; C: All-cause survival by treatment modality. Adjusted hazard ratio and P values are shown in the legend for each treatment group, using conservative management as the reference category. There was no statistically significant difference in recipient survival in those who received active treatment compared to those managed conservatively. Cox regression survival curves were adjusted for baseline pre-transplant parathyroid hormone levels using multivariable Cox proportional hazards models. aHR: Adjusted hazard ratio; PTH: Parathyroid hormone.