Autotrasplante de paratiroides

Improving management of severe hypoparathyroidism: a case series

INTRODUCTION

Hypoparathyroidism is considered a rare endocrine disease. Despite being a deficiency of parathyroid hormone, the standard therapy is based on oral calcium and active vitamin D supplementation. This approach provides satisfactory management in most cases but may be inadequate for patients in the most complex spectrum of the disease. Other therapies are being explored, and among them, the use of recombinant human parathyroid hormone (PTH) has proved to decrease the requirements of calcium and active vitamin D to reach adequate therapeutic goals.

OBJECTIVE

We aimed to provide information on the effectiveness of the current recombinant parathyroid hormone analogs in the clinical management of difficult to control cases of hypoparathyroidism.

METHOD AND MATERIALS

We report our experience using teriparatide and PTH (1-84) through five complex cases of hypoparathyroidism of diverse etiologies. We describe each case and report the effectiveness of treatment in clinical practice.

RESULTS

Four patients with postsurgical hypoparathyroidism and one patient with autoimmune hypoparathyroidism, all of them with suboptimal control under the standard treatment with calcium and calcitriol supplements or calcium gluconate infusion, are presented. They were all started on teriparatide or PTH (1-84), and all of them showed a diminishment of symptoms and were able to maintain normocalcemia without parenteral calcium despite a reduction of oral treatment.

CONCLUSION

This article highlights the effectiveness and safety of hormonal replacement treatment in difficult to manage hypoparathyroidism and provides evidence which justifies its off-label prescription in the case of teriparatide. We consider that this treatment should be considered in cases in which standard treatment fails to reach adequate therapeutic goals.

Co-transplantation with adipose-derived cells to improve parathyroid transplantation in a mice model

Background

Accidentally removed parathyroid glands are still challenging in neck surgery, leading to hypoparathyroidism characterized with abnormally low levels of parathyroid hormone. Parathyroid auto-transplantation is usually applied in compensation. To improve the efficiency of parathyroid transplantation, we introduced a method by co-transplanting with adipose-derived cells, including stromal vascular fractions (SVFs) and adipose-derived stem cells (ADSCs), and investigated the underlying molecular mechanisms involved in parathyroid transplantation survival.

Methods

Rat and human parathyroid tissues were transplanted into nude mice as parathyroid transplantation model to examine the effects of SVFs and ADSCs on grafts angiogenesis and survival rates, including blood vessel assembly and parathyroid hormone levels. Several angiogenic factors, such as vascular endothelial growth factor (VEGF)-A and fibroblast growth factor (FGF) 2, were assessed in parathyroid grafts. The effects of hypoxia were investigated on ADSCs. The modulatory roles of the eyes absent homolog 1 (EYA1), which is vital in parathyroid development, was also investigated on angiogenic factor production and secretion by ADSCs. All experimental data were statistically processed. Student’s t test was used to assess significant differences between 2 groups. For multiple comparisons with additional interventions, two-way ANOVA followed by Tukey’s post hoc test was performed. P < 0.05 was considered as significant.

Results

SVFs improve rat parathyroid transplantation survival and blood vessel assembly, as well as FGF2 and VEGF-A expression levels in parathyroid transplantation mice. Functional human parathyroid grafts have higher microvessel density and increased VEGF-A expression. The supernatant of ADSCs induced tubule formation and migration of human endothelial cells in vitro. Hypoxia had no effect on proliferation and apoptosis of human ADSCs but induced higher angiogenic factor levels of VEGF-A and FGF2, modulated by EYA1, which was confirmed by parathyroid glands transplantation in mice.

Conclusions

Adipose-derived cells, including ADSCs and SVFs, improve parathyroid transplantation survival via promoting angiogenesis through EYA1-regulating angiogenetic factors in vitro and in vivo. Our studies proved an effective method to improve the parathyroid autotransplantation, which is promising for clinical patients with hypoparathyroidism when parathyroid glands were accidentally injured, removed, or devascularized.

Xenotransplantation of human cryopreserved parathyroid tissue isolated from parathyroid adenomas to normocalcemic rabbits

OBJECTIVE

Parathyroid allotransplantation is a new method for the treatment of permanent hypoparathyrodism. Adenoma cells are not used for transplantation because of the potential for functional or histopathologic transformation. In this study, we transplanted human adenomatous parathyroid cells to rabbits.

MATERIAL AND METHODS

Parathyroid adenoma tissue taken from a male patient was cryopreserved and transplanted into seven New Zealand white rabbits (mean weight, 3700±220 g; mean age, 4.5 months) under immunosuppression. The levels of parathormone, calcium and phosphorus were measured before and after transplantation, and the parathyroid cells were observed histopathologically.

RESULTS

Mean parathyroid hormone level was 0.5 pg/dL before transplantation and 6.6 pg/dL after transplantation (p<0.05). Preoperative mean calciumlevel was 14.1 mg/dL, and mean phosporus level was 3.5 mg/dL before transplantation while these values were 14.4 mg/dL and 3.3 mg/dL, respectively, after transplantation (p>0.05). Morphologic transformation was not observed in parathyroid cells after transplantation.

CONCLUSION

In short-term observation, adenomatous parathyroid cells can function without malignant transformation. In the future, the preliminary methodology in this study may serve as a safe alternative for allotransplantation into patients with permanent hypoparathyroidism.

Clinical Pathway for Thyroidectomy

Clinical pathways are care plans applicable to patient care procedures that present variations in practice and a predictable clinical course. They are designed not as a substitute for clinical judgment, but rather as a means to improve the effectiveness and efficiency of the procedures. This clinical pathway is the result of a collaborative work of the Sections of Endocrine Surgery and Quality Management of the Spanish Association of Surgeons. It attempts to provide a framework for standardizing the performance of thyroidectomy, the most frequently performed operation in endocrine surgery. Along with the usual documents of clinical pathways (temporary matrix, variance tracking and information sheets, assessment indicators and a satisfaction questionnaire) it includes a review of the scientific evidence around different aspects of pre, intra and postoperative management. Among others, antibiotic and antithrombotic prophylaxis, preoperative preparation in hyperthyroidism, intraoperative neuromonitoring and systems for obtaining hemostasis are included, along with management of postoperative hypocalcemia.