New Therapies for Uremic Secondary Hyperparathyroidism

Ultrasound-guided microwave ablation for secondary hyperparathyroidism: a systematic review and meta-analysis

OBJECTIVES

Microwave ablation (MWA) is used for the treatment of severe secondary hyperparathyroidism (SHPT), but its efficacy and safety still remained unclear. This study aimed to investigate the efficacy and safety of ultrasound (US)-guided MWA in patients with SHPT.

METHODS

The PubMed, Cochrane library, Embase, China national knowledge infrastructure (CNKI) and Wanfang databases were searched to identify published studies that evaluated the efficacy and safety of US-guided MWA in patients with SHPT. The primary outcomes were parathyroid hormone (PTH), serum calcium and phosphorus levels.

RESULTS

A total of 26 studies with 932 patients were identified. The PTH levels showed significant reduction at 1 month [weighted mean difference (WMD) = 945.33, 95% CI: 797.15∼1093.52] and 6 months (WMD = 1,151.91, 95% CI: 990.93∼1312.89) after MWA of SHPT patients. The serum calcium (WMD = 0.39, 95% CI: 0.30 ∼ 0.48) and phosphorus levels (WMD = 0.64, 95% CI: 0.43 ∼ 0.85) showed significant reduction at 6 months after MWA of SHPT patients. The most common complications observed were hypocalcemia (35.2%) and transient hoarseness (9.2%). No other major complications or death occurred in our study patients.

CONCLUSION

These findings suggest MWA as a safe and effective minimally invasive technique for the management of SHPT. PTH, calcium, and phosphorus levels were significantly reduced at 1 and 6 months after MWA.

Efficacy of Ultrasound-guided Radiofrequency Ablation of Parathyroid Hyperplasia: Single Session vs. Two-Session for Effect on Hypocalcemia

To evaluate safety and efficacy of one- vs. two-session radiofrequency ablation (RFA) of parathyroid hyperplasia for patients with secondary hyperparathyroidism (SHPT) and to compare the outcome of both methods on hypocalcemia. Patients with secondary hyperparathyroidism underwent ultrasound guided RFA of parathyroid hyperplasia. Patients were alternately assigned to either group 1 (n = 28) with RFA of all 4 glands in one session or group 2 (n = 28) with RFA of 2 glands in a first session and other 2 glands in a second session. Serum parathyroid hormone (PTH), calcium, phosphorus and alkaline phosphatase (ALP) values were measured at a series of time points after RFA. RFA parameters, including operation duration and ablation time and hospitalization length and cost, were compared between the two groups. Mean PTH decreased in group 1 from 1865.18 ± 828.93 pg/ml to 145.72 ± 119.27 pg/ml at 1 day after RFA and in group 2 from 2256.64 ± 1021.72 pg/ml to 1388.13 ± 890.15 pg/ml at 1 day after first RFA and to 137.26 ± 107.12 pg/ml at 1 day after second RFA. Group 1's calcium level decreased to 1.79 ± 0.31 mmol/L at day 1 after RFA and group 2 decreased to 1.89 ± 0.26 mmol/L at day 1 after second session RFA (P < 0.05). Multivariate analysis showed that hypocalcemia was related to serum ALP. Patients with ALP ≥ 566 U/L had lower calcium compared to patients with ALP < 566 U/L up to a month after RFA (P < 0.05). Group 1's RFA time and hospitalization were shorter and had lower cost compared with Group 2. US-guided RFA of parathyroid hyperplasia is a safe and effective method for treating secondary hyperparathyroidism. Single-session RFA was more cost-effective and resulted in a shorter hospital stay compared to two sessions. However, patients with two-session RFA had less hypocalcemia, especially those with high ALP.

Deficiency in the secreted protein Semaphorin3d causes abnormal parathyroid development in mice

Primary hyperparathyroidism (PHPT) is a common endocrinopathy characterized by hypercalcemia and elevated levels of parathyroid hormone. The primary cause of PHPT is a benign overgrowth of parathyroid tissue causing excessive secretion of parathyroid hormone. However, the molecular etiology of PHPT is incompletely defined. Here, we demonstrate that semaphorin3d (Sema3d), a secreted glycoprotein, is expressed in the developing parathyroid gland in mice. We also observed that genetic deletion of Sema3d leads to parathyroid hyperplasia, causing PHPT. In vivo and in vitro experiments using histology, immunohistochemistry, biochemical, RT-qPCR, and immunoblotting assays revealed that Sema3d inhibits parathyroid cell proliferation by decreasing the epidermal growth factor receptor (EGFR)/Erb-B2 receptor tyrosine kinase (ERBB) signaling pathway. We further demonstrate that EGFR signaling is elevated in Sema3d ^-/- parathyroid glands and that pharmacological inhibition of EGFR signaling can partially rescue the parathyroid hyperplasia phenotype. We propose that because Sema3d is a secreted protein, it may be possible to use recombinant Sema3d or derived peptides to inhibit parathyroid cell proliferation causing hyperplasia and hyperparathyroidism. Collectively, these findings identify Sema3d as a negative regulator of parathyroid growth.

Factors associated with parathyroid hormone control in haemodialysis patients with secondary hyperparathyroidism treated with cinacalcet in real-world clinical practice: Mimosa study

Background

Secondary hyperparathyroidism (SHPT) is frequent in haemodialysis (HD) patients. Oral cinacalcet-hydrochloride (HCl) decreases parathyroid hormone (PTH); however, real-life PTH data, according to Kidney Disease: Improving Global Outcomes (KDIGO) guidelines, are still lacking. Our goal is to assess the percentage of cinacalcet-HCl-treated HD patients with controlled SHPT (PTH <9× upper limit of the normal range) after 12 months (M12) of treatment.

Methods

This is a retrospective observational study in HD patients with SHPT treated by cinacalcet-HCl between 2005 and 2015 and dialysed in seven French HD centres using the same database (Hemodial™).

Results

The study included 1268 patients with a mean (standard deviation) follow-up of 21 ± 12 months. Their mean dialysis vintage was 4.3 ± 5.6 years. PTH values were available and exploitable at M12 in 50% of them (645 patients). Among these patients, 58.9% had controlled (mean PTH of 304 ± 158 pg/mL) and 41.1% uncontrolled SHPT (mean PTH of 1084 ± 543) at M12. At the baseline, patients with controlled SHPT were older (66 ± 15 versus 61 ± 17 years), and had lower PTH (831 ± 346 versus 1057 ± 480 pg/mL) and calcaemia (2.18 ± 0.2 versus 2.22 ± 0.19 mmol/L) than uncontrolled patients. In multivariate analysis, these three factors still remained significantly associated with controlled SHPT.

Conclusion

In this real-life study, 41.1% of HD patients with SHPT treated with cinacalcet-HCl remained with a PTH above the KDIGO recommended target after 12 months of treatment. Apart from the possibility of non-compliance, the severity of SHPT appears to be a major factor determining the response to cinacalcet-HCl treatment, reinforcing the importance of treating SHPT at earlier stages.

US-guided microwave ablation for secondary hyperparathyroidism in patients after renal transplantation: a pilot study

OBJECTIVE

To assess the safety and efficacy of ultrasound-guided microwave ablation (MWA) in the treatment of patients who develop secondary hyperparathyroidism (SHPT) after renal transplantation (RT).

METHODS

In total, nine patients, each with symptomatic SHPT caused by RT and at least one enlarged parathyroid gland, underwent MWA via hydrodissection. Intact parathyroid hormone (i-PTH), serum calcium, serum phosphorus, creatinine and blood urea nitrogen concentrations, before and after MWA, were assessed and compared.

RESULTS

Complete ablation was achieved in all patients for a total of 14 ablated parathyroid glands. The mean follow-up time was 17.2 ± 1.7 months post-operation. The mean maximum diameter of the parathyroid glands was 1.3 ± 0.4 cm (range: 0.4-2.0 cm). The ablation power implemented was 30 W and the mean time for each parathyroid gland to achieve complete ablation was 287.5 ± 83.4 s. The mean i-PTH, serum calcium and phosphorus concentrations at one day post-MWA (69.6 pg/mL, 2.23 ± 0.29 mmol/L, 1.2 2 ± 0.48 mmol/L, respectively) were significantly lower than those before MWA (780.0 pg/mL, 2.62 ± 0.32 mmol/L, 1.39 ± 0.61 mmol/L, respectively; p < .01), whereas the creatinine and blood urea nitrogen concentrations before and after MWA did not differ significantly from each other (p > .05). No significant differences were found between the biomarker concentrations observed at one day post-MWA and at the follow-ups (p > .05). No major operation-related complications occurred.

CONCLUSION

Ultrasound-guided MWA is a safe and effective technique for destroying parathyroid gland tissue in patients who develop SHPT after RT and its clinical effects are long-lasting.

Lesion based diagnostic performance of dual phase 99mTc-MIBI SPECT/CT imaging and ultrasonography in patients with secondary hyperparathyroidism

Background

We aimed to evaluate the diagnostic performance of ^99mTc-MIBI SPECT/CT and ultrasonography in patients with secondary hyperparathyroidism (SHPT), and explored the factors that affect the diagnostic performance.

Methods

^99mTc-MIBI SPECT/CT and ultrasonography were performed in 50 patients with SHPT within 1 month before they underwent surgery. Imaging results were confirmed by the pathology. Pearson correlation analysis was used to determine the correlation of PTH level with clinical data. The optimal cutoff value for predicting positive ^99mTc-MIBI results was evaluated by ROC analysis in lesions diameter.

Results

Forty-nine patients had a positive ^99mTc-MIBI imaging results and 39 patients had positive ultrasonography results. The sensitivities of ^99mTc-MIBI and ultrasonography were 98.00% and 78.00%, respectively. A total of 199 lesions were resected in 50 patients. Among them, 183 lesions were proved to be parathyroid hyperplasia. On per-lesion basis analysis, the sensitivity and specificity of ^99mTc-MIBI and ultrasonography were 59.34% and 75.00% vs 46.24% and 80.00%, respectively. The Pearson correlation analysis showed that the serum AKP and PTH level had a significant linear association (r = 0.699, P < 0.001). The lesion diameter was a statistically significant predictive factor in predicting positive ^99mTc-MIBI SPECT/CT. The optimal cutoff value for predicting positive ^99mTc-MIBI results evaluated by ROC analysis in lesions diameter was 8.05 mm.

Conclusion

Dual phase ^99mTc-MIBI SPECT/CT imaging had a higher sensitivity in patients with SHPT than ultrasonography. Therefore, using ^99mTc-MIBI positioning the lesion could be an effective method pre-surgical in patients with SHPT.

Parathormone et maladie rénale chronique

The serum parathyroid hormone (PTH) rises in chronic kidney disease (CKD) and induces renal bone disease as well as other organ damage. The bone disease guidelines were released by the K-DOQI in 2003 in order to help physicians to improve bone management at all different CKD stages. However, many different PTH commercial assays are available today and some questions are raised concerning the interpretation, the validity and the practical choice of these different measurements. After reviewing PTH biosynthesis and metabolism, we will describe the regulation of different PTH fragments (particularly 1-84 and 7-84) and the various types of PTH assays. In compromised clinical situations, bone biopsy still remains the golden standard assessment of bone disease, and it will be helpful to clarify the interest of new 3rd generation PTH measurements. At present, we do not dispose of valid therapeutic recommendations using 3rd generation tests, as well as the relevance of the ratio PTH 1-84/7-84.