Recombinant PTH therapy for severe hypoparathyroidism after kidney transplantation in pre-transplant parathyroidectomized patients: review of the literature and a case report

Surgical outcomes of parathyroidectomy for pre-kidney transplantation versus post-kidney transplantation patients

BACKGROUND

Hyperparathyroidism (HPT) is common in end-stage kidney disease and resolves in less than half of kidney transplant (KT) recipients. The ideal timing of parathyroidectomy (PTX), before or after KT, remains unclear. We sought to understand differences in morbidity and mortality after PTX pre-KT and post-KT.

METHODS

We identified adult patients who underwent PTX pre-KT or post-KT between 2012 and 2021 utilizing the National Surgical Quality Improvement Program database. Demographics, clinical characteristics, morbidity, and mortality were compared. Adjusted logistic regression with propensity score weighting assessed odds of 30-day composite morbidity, major adverse cardiovascular events (MACE), readmission, and mortality.

RESULTS

We identified 1972 patients who underwent PTX pre-KT and 541 patients who underwent PTX post-KT. Post-KT HPT patients were older (mean age 53.9 v 48.2 and p < 0.01) and more commonly White (45.3% v 32.3% and p < 0.01) and diabetic (30.0% v 18.5% and p < 0.01). In comparison, pre-KT HPT patients were more commonly Black (53.2% v 30.1%), had American Society of Anesthesiologists (ASA) class 3-4 (98.0% v 89.6% and p < 0.01), chronic obstructive pulmonary disease (4.2% v 1.5% and p < 0.01), and congestive heart failure (4.4% v 1.1% and p < 0.01). After adjusting for confounders, patients pre-KT had 1.72-fold increased odds of morbidity (95% confidence interval [CI]: 1.13-2.61), 8.39-fold increased odds of MACE (95% CI: 1.13-62.18), and 2.07-fold increased odds of readmission (95% CI: 1.38-3.10). There was no difference in mortality or risk of infections.

CONCLUSIONS

Patients who underwent PTX prior to KT were at significantly increased risk for 30-day morbidity and MACE, but no different odds of mortality compared to PTX after KT. This can help inform decision-making regarding timing of PTX in patients with HPT.

New Human Leukocyte Antigen (HLA) Antibody Formation and Creatinine Elevation With Abaloparatide in Kidney Transplant Recipient

A 39-year-old female with a history of kidney transplant presented to the endocrinology clinic for osteoporosis evaluation after sustaining an ankle fracture from a fall. Her kidney transplant regimen (mycophenolate mofetil 360 mg twice a day, tacrolimus 0.5 mg every morning and 0.5-1 mg every evening, prednisone 5 mg/day) and baseline creatinine (1.0-1.2 mg/dL) had been stable for several years. After an appropriate secondary workup, she was started on abaloparatide 80 μg subcutaneous daily injections for osteoporosis. She had a good initial biochemical response to therapy. However, 5 months after abaloparatide initiation she was found to have a new elevation in serum creatinine (1.17 to 1.69 mg/dL) despite stable serum tacrolimus trough levels, and two new human leukocyte antigen (HLA) antibodies (anti-HLA antibodies detected to Cw7 and DP28). Abaloparatide was stopped due to concern for immunogenicity. There was no evidence of rejection on kidney biopsy and she was restabilized on her transplant regimen with a new baseline creatinine of 1.3-1.6 mg/dL. The patient was subsequently started on teriparatide 20 μg daily subcutaneous injections for 2 years with good biochemical response, significant improvement in bone mineral density, and stable transplant regimen without additional signs of immunogenicity or rejection. This is the first case report to raise concern about immunogenicity with abaloparatide in solid organ transplant recipients. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

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

Kidney transplantation remains the best treatment for patients with end-stage kidney disease, and it could partially mitigate systemic disorders of mineral and bone metabolism caused by secondary hyperparathyroidism. However, persistent hyperparathyroidism is still observed in 30-60% of patients 1 year after kidney transplantation, leading to impairment of allograft function and a disturbance of mineral metabolism. The timing of parathyroidectomy varies among transplant centers because the possible negative effects of parathyroidectomy on allograft outcomes are still unclear. This review provides a comprehensive and detailed overview of the natural course of hyperparathyroidism following kidney transplantation and the effects of the timing and extent of parathyroidectomy on allograft function. It aims to provide useful information for surgeons to propose an appropriate intervention strategy to break the vicious cycle of post-kidney transplantation hyperparathyroidism and deterioration of allograft function.

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.

KDIGO Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation

The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, and immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The goal is to assist the clinical team to assimilate all data relevant to an individual, consider this within their local health context, and make an overall judgment on candidacy for transplantation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Guideline recommendations are primarily based on systematic reviews of relevant studies and our assessment of the quality of that evidence, and the strengths of recommendations are provided. Limitations of the evidence are discussed with differences from previous guidelines noted and suggestions for future research are also provided.

Long-term outcomes and management considerations after parathyroidectomy in the dialysis patient

Parathyroidectomy (PTX) remains an important intervention for dialysis patients with poorly controlled secondary hyperparathyroidism (SHPT), though there are only retrospective and observational data that show a mortality benefit to this procedure. Potential consequences that we seek to avoid after PTX include persistent or recurrent hyperparathyroidism, and parathyroid insufficiency. There is considerable subjectivity in defining and diagnosing these conditions, given that we poorly understand the optimal PTH targets (particularly post PTX) needed to maintain bone and vascular health. While lowering PTH after PTX decreases bone turnover, long-term changes in bone activity have been poorly explored. High turnover bone disease, usually present at the time a PTX is considered, often swings to a state of low turnover in the setting of sufficiently low PTH levels. It remains unclear if all low bone turnover equate with disease. However, such changes in bone turnover appear to predispose to vascular calcification, with positive calcium balance after PTX being a potential contributor. We know little of how the post-PTX state resets calcium balance, how calcium and VDRA requirements change or what kind of adjustments are needed to avoid calcium loading. The current consensus cautions against excessive reduction of PTH although there is insufficient evidence-based guidance regarding the management of chronic kidney disease - mineral bone disease (CKD-MBD) parameters in the post-PTX state. This article aims to compile existing research, provide an overview of current practice with regard to PTX and post-PTX chronic management. It highlights gaps and controversies and aims to re-orient the focus to clinically relevant contemporary priorities in CKD-MBD management after PTX.

Mineral and Bone Disease in Kidney Transplant Recipients

PURPOSE OF REVIEW

Despite metabolic improvements following kidney transplantation, transplant recipients still often suffer from complex mineral and bone disease after transplantation.

RECENT FINDINGS

The pathophysiology of post-transplant disease is unique, secondary to underlying pre-transplant mineral and bone disease, immunosuppression, and changing kidney function. Changes in modern immunosuppression regimens continue to alter the clinical picture. Modern management includes reducing cumulative steroid exposure and correcting the biochemical abnormalities in mineral metabolism. While bone mineral density screening appears to help predict fracture risk and anti-osteoporotic therapy appears to have a positive effect on bone mineral density, more data regarding specific treatment is necessary. Patients with mineral and bone disease after kidney transplantation require special care in order to properly manage and mitigate their mineral and bone disease. Recent changes in clinical management of transplant patients may also be changing the implications on patients' mineral and bone disease.